w 'o ^^ /, -^^ ^■- '■>, ,-0 A' CO i^' ^^, r.\ V- \ '"^^ ^' \" "O. *• .'"1 »St-,, ■ ,^ '^. ^ . . , j^ J' cS -^ : ^$i;iii^' : a^' ^ oO '' ^ » .i s ^ , \ ^ d- %"^^%^^^ -^^ ,^' -r. ^ 0- o 'o. . ..-* '"o 0^ \# >^^ -^^ ^^. » .oq. ^ .■ '■ " /? ^N' ■-oo^ ..-X" -'>;,. o. Digitized by tine Internet Arciiive in 2011 witii funding from Tine Library of Congress Iittp://www.arcliive.org/details/newessaysconcern01leib .1 NEW ESSAYS CONCERNING HUMAN UNDERSTANDING NEW ESSAYS CONCERNING HUMAN UNDERSTANDING GOTTFRIED WILHELM LEIBNltz TOGETHER WITH AN APPENDIX CONSISTING OF SOME OF HIS SHORTER PIECES TRANSLATED FROM THE ORIGINAL LATIN, FRENCH AND GERMAN, WITH NOTES ALFRED GIDEON LANGLEY A.M. (Brown)' L2ND EDITION] CHICAGO LONDON THE OPEN COURT PUBLISHLNG COMPANY 11916 A// righ/s reserved 325^1 COPYRIGHT THE OPEX COURT PUBLISHING CO. Gift NOV 13 HMt LC Control Number tmp96 026017 Printed in the United States of America CC; -6 1916 ;<^ Ca mg iWotfier anli Sister SOMETIME GONE WHERE WE SHALL KNOW AS WE ARE KNOWN lull to mg iFatf)£r STILL WHERE WE SEE AS IN A MIRROR OBSCURELY IN DEEPEST LOVE AND GRATITUDE I DEDICATE THIS BOOK CONTENTS I'AGE Translator's Preface xi Gerhardt's Introduction to his edition of Leibnitz's Nouveaux Essais y LEIBNITZ'S CRITIQUE OF LOCKE On Locke's Essay on Human Understanding, 1696 . . . .13 Specimen of Thoughts upon the First Book of the Essay on Human Understanding, 1698 . ■ 20 Specimen of Thoughts upon the Second Book, 1698 .... 23 On Coste's Translation of Locke's Essay concerning Human Under- standing ; fi'om the " Monatliche Auszug," September, 1700, pp. 611-686 26 Addition thereto. " Monatliche Auszug," 1701, pp. 7.3-75 . . 37 New Essays on The Understanding, by the Author of the System of Pre-established Harmony Preface ^ 41 B(wl: I. — Innate Ideas CHAPTEa I. Are there innate principl*s in the mind of man ? . . .64 II. No innate practical principles 85 III. Other considerations touching innate principles, both spec- ulative and practical . . . - 100 Bouk II. — Ideas. I. Which treats of ideas in general, and examines by the way whether the mind of man always thinks . II. Simple ideas ' III. Of ideas which come to us by one sense t)nly . IV. Of solidity 6-1 V. Of simple ideas which come by different senses VI. Of simple ideas which come by reflection vli 109 120 121 122 129 130 CONTENTS s; ideas CHAPTER ^: VII. Of ideas wliich come by sensation and reflection VIII. Other considerations upon simple ideas IX. Of perception . . . . X. Of retention XI. Of discernment, or the faculty of distinguishin XII. Of complex ideas XIII. Of simple modes, and first of those of space XIV. Of duration and its simple modes XV. Of duration and expansion considered together XVI. Of number .... XVII. Of infinity .... XVIII. Of other simple modes XIX. Of the modes of thinking . XX. Of modes of pleasure and pain XXI. Of power and freedom XXII. Of mixed modes . XXIII. Of our complex ideas of substances . XXIV. Of collective ideas of substances XXV. Of relation XXVI. Of cause and effect and some other relations XXVII. What identity or diversity is . . . XXVIII. Of some other relations, and especially of moral relations XXIX. Of clear and obscure, distinct and confused ideas XXX. Of real and fantastical ideas .... XXXI. Of adequate and inadequate ideas XXXII. Of true and false ideas XXXIII. Of the association of ideas . . . Book III. — Words. I. Of words or language in general II. Of the signification of words III. Of general terms IV. Of the names of simple ideas V. Of the names of mixed modes and relations VI. Of the names of substances VII. Of particles VIII. Of abstract and concrete terms . IX. Of the imperfections of words . X. Of the abuse of words .... XI. Of the remedies which may be applied to the iniperfec tions and abuses just spoken of . 390 CONTENTS ix Book I V. — Of Knowledge CHAPTER PAGK I. Of knowledge in general ...... . 397 II. Of the degrees of our knowledge . 404 III. Of the extent of human knowledge 423 IV. Of the reality of our knowledge . . . 444 V. Of truth in general ...... . 449 VI. Of universal propositions, their truth and certitude . 452 VII, Of propositions called maxims or axioms . . 462 VIII. Of trifling propositions . 490 IX. Of our knowledge of our existence . 497 X. Of our knowledge of the existence of God . . 449 XI. Of our knowledge of the existence of other things . 511 XII. Of the improvement of our knowledge . 517 XIII. Other considerations concerning our knowledge . 528 XIV. Of judgment . 528 XV. Of probability . ... , . . . ■ . . 529 XVI. Of the degrees of assent . 532 XVII. Of reason . 555 XVIII. Of faith and reason and their distinct limits . 588 XIX. Of enthusiasm . 596 XX. Of error . 607 XXI. Of the division of the sciences .... . 621 APPENDIX I. II. III. IV. V. VI. VII. Leibnitz to Jacob Thomasius. April 20-30, 1669 . Fragment, (c. 1671) ... . Demonstration against atoms taken from the contact of atoms. (October, 1690) Essay on Dynamics on the laws of motion, in which it is shown that not the same quantity of motion is preserved, but the same absolute force, or rather the same quantity oi vaowmg action {V action motrice') . (c. 1691) Essay on Dynamics in defence of the wonderful laws of nature in respect to the forces of bodies, disclosing their mutual actions aiid referring them to their causes. Part I. 1695 Ih. Part II. 1695 On the radical origin of things. 1697 . . Appendix to a letter to Honoratus Fabri. 1702 . 631 651 652 657 670 684 692 699 CONTENTS PAGK VIII. Letter of Leibnitz to Basnage de Beauval, editor of tlie " Histoire des Ouvrages des Savants," printed in that journal, July, 1698, pp. 329 sq 706 IX. Fragment of a letter to an unknown person. 1707 . . 712 X. That the most perfect Being exists 714 XL What is idea 716 XIL On the metliod of distinguishing real from imaginary phe- nomena .......... 717 Additions and Corrections ..... ^. . . 721 Index A. To the Critique of Locke 777 Index B. To the Appendix ... ^ ... . 823 Index C. To the Notes, Additions, and Corrections . . . 831 TRANSLATOR'S PREFACE \^ The work herewith given to the public consists of a transla- tion of the entire fifth volume of Gerhardt's Die jjhilosophischen Schrifien von G. W. Leibniz, sub-entitled " Leibniz und Locke," consisting of an Introduction by Gerhardt, several short pieces on Locke's Essay and the New Essays on Human Under- standing ; and of an Appendix containing a translation of other short pieces of Leibnitz bearing on the subjects dis- cussed in the New Essays or referred to therein. I The Intro- duction on The Philosophy of Leibnitz by the translator suggested and urged by Professors Palmer and Royce of Har- vard University, and for some time contemplated, is deferred, and reserved, if at all, for another time and occa.sion, owing to the size of the present volume, as well as for other good and sufficient reasons which it is not necessary here to mention. The translation of Leibnitz's Noiiveaux Essais sio- VEntende- ment Huniain was first suggested by the following sentence of the late Professor George S. Morris, of the University of Michigan, in a note to his Philosophy and Christianity, page 292: "It suggests no favorable comment on the philosophic interest of the countrymen of Locke that the above-mentioned reply of Leibnitz to Locke has never (so far as I can ascertain) been translated into English." Pour instalments, consisting of Book I. and Book II., chapters 1-11 inclusive, were pub- lished in as many numbers of the "Journal of Speculative Philosophy. " * Professor Morris very kindly sent me a care- ful criticism of about one-third of the first instalment, with valuable suggestions regarding the further work of transla- tion. His corrections and suggestions received careful con- 1 Vol. 19, No. 3, .Tuly, 1885; Vol. 21, No. 3, .July, 1887; Vol. 21, No. 4, Octo- ber, 1887 ; Vol. 22, No. 2, April, 1888. xi TRANSLATOR'S PREFACE sideration and were embodied in subsequent revisions of the translation in preparing it for the present issue. The portion of the Neio Essays thus published being favorably received by professors and students of philosophy in this country and in Europe, and being encouraged to go on and translate the entire piece, the work begun in 1885 was continued in leisure hours until in June, 1891, the translation was' completed. Revision, annotation, and the labor of get- ting it through the press have occupied the greater part of my fre^e time since then. The annotation, which was not a part of the original plan, but which Avas found to be desirable, if not even necessary, as the sheets began to appear in type, has been the chief cause of the delay in the appearance of the book, the labor involved therein proving far greater and una- voidably more protracted than was expected, the annotation also, as is frequent in such cases, growing with the progress of the book. The text-basis of the translation is that of C. I. Gerhardt, in his Die philosophischen Schriften von G. W. Leibniz, 7 vols., Berlin, 1875-1890, except for the Dynamical Pieces in the Appendix, JSTos. IV., V., the text-basis of which is C. I. Ger- hardt's Leihnizens viathematische Schriften, Berlin and Halle, 1849-1863, and Appendix Ko. VII., for which both these editions are used; for Appendix No. IX., the text is that given by Guhrauer, G. W. Freiherr v. Leibnitz. Eine Biographie, Breslau, 1846. The other editions used in the comparison of the text and the preparation of the notes are: J. E. Erd- mann, Leibnitvi Opera Philosopliica, Berlin, 1839-1840; M. A. Jacques, CEuvres de Leibniz, Paris, 1842; P. Janet, (Eiivres PJnlosophiques de Leibniz, Paris, 1866; Dutens, Leibnitii Opera Om/u'a, Geneva, 1768; Toucher de Careil, Lettres et Opuscules inedits de Leibniz, Paris, 1854, Nouvelles Jjettres et Opuscules de Leibniz inedits, Paris, 1857, and CEuvres de Leibniz, Paris, 1859 sq., 2d ed., Paris, 1867 sq. R. E. Raspe, CEuvres PJnloso- phiques de feu Mr. Leibnitz, Amsterdam and Leipzig, 1765, was received too late to be of service, but as his text is the original printed text of the Neio Essays, and has been used by all sub- sequent editors, it is not probable that any important variation of reading has been overlooked; and Raspe's text has no notes. Besides these editions of Leibnitz's Works, the German trans- TRANSLATOR'S PREFACE lations of the Theodicee and of the smaller philosophically important works entitled Die Meineren lyhilosophisch wichtigeren Schriften by J. H. von Kirchmann, in his Philosophische Bibliothek, Berlin, 1879, and the English translation of his important philosophical opuscules by Professor George M. Duncan of Yale University, entitled The Philosophical Works of Leibnitz, New Haven, 1890, have been consulted. From the last-named work, so as to include in one book all of Leib- nitz's discussions of Locke, it was at first intended to reprint in the Appendix all the pieces bearing upon the subject dis- cussed in the New Essays, or especially referred to therein. It finally seemed best to both Professor Duncan and myself to change the plan and translate new material, rather than duplicate that already translated, so that with the exception of Appendix No. VL, Professor Duncan's translation of which was either forgotten or unnoticed till after mine was in type, nothing appears in both books save such portions of the Neiv Essays as he has included, and the piece entitled On Lockers Essay on Human Understanding, 1696. This statement will explain the references in certain notes, for example, page 101, note 1, page 154, note 1 (c/. infra, pages 737 and 749 respec- tively), to certain pieces of Leibnitz in the Appendix, which references are corrected in the Additions and Corrections by being changed to the proper pages of Professor Duncan's book. Of great value in the revision of the translation, and of the greatest service in the preparation of the notes, has been the German translation of the Nouvea\ix Essais, with notes, by Professor Carl Schaarschmidt of the University of Bonn. His material has been freely used, either by direct translation and quotation, or in substance, in the notes of the present edi- tion, though always, so far as possible, only after verification and further independent study. His notes, I regret to say, contain many numerical errors, occasioned presumably by in- sufficient care and accuracy in proof-reading; otherwise they are, for the most part, accurate. The fact that Professor Schaarschmidt's book was not received till after a portion of mine was in type accounts in part for the appearance of so much of his note-material in the Additions and Corrections, rather than in its proper place in the foot-notes to the text. TRANSLATOR'S PREFACE Professor A. C. Frazer's splendid edition of Lockers Essay, Oxford, 1894, did not appear until after most of the New Essays were in type; and P. Coste, Essai j^hilosojihique con- cernant V Entendement humain — j)'^'^^' M. Locke, Amsterdam, 1742, 1 vol., 4to, 1774, 4 vols., 12mo, could not be obtained until all the New Essays and most of the Appendix were in type. Both of these works, therefore, could be used only in the supplementary notes in the Additions and Corrections. With regard to the text itself, particularly of the Neiv Essays, a few words may not be out of place. The variations are slight and chiefly verbal, and scarcely ever essentially modify the thought. They are ultimately due either to the manuscript of Leibnitz — which Erdmann (Preface, p. xxii) says is " written in such small characters often, and so full of corrections, that it is very difficult to read it" ("tam parvis saspe Uteris con- scriptum et correctionibus adeo abundans ut perdifficile lectu ") — or to certain changes made for the purpose of improving the literary style of the author, and of thus making his work more , acceptable to his French readers. The chief difference between the text as given by Gerhardt, who has compared his impres- sion "with the original, so far as it is still extant," and that of the other editors consists in a transposition of the text in Book I., chap. I., a transposition Avhich is fully indicated in the note at the point in the text of the translation where it occurs, and which is, I suppose, due to Gerhardt's fidelity to Leibnitz's original text. All the important textual variations are listed in the notes. Gerhardt's text, having been compared with the original, seems the most trustworthy, and accordingly has been followed in this translation, excepting in a few instances mentioned in the notes, where it is manifestly erroneous from inaccurate proof-reading or other cause, and where the text' of some other editor seemed more consistent or correct. Gerhardt has intro- duced into his text the brackets, [ ], in which, " in the original,. Leibnitz has enclosed the words of Philalethes, who states the views of Locke, " " perhaps as an indication that they are not his own ; " and I have introduced them into the translation precisely as they stand in the text of Gerhardt, in order that the translation may conform to and represent as perfectly as possible Leibnitz's original text in its integrity. There seems TRANSLATOR'S PREFACE xy to be, however, little regularity or consistency in the employ- ment of these brackets, so far, at least, as I can discover upon comparison with Locke's treatise. Besides the editions and translations already named, the various separate editions of single works of Leibnitz, as also the various discussions of his philosophy, theology, etc., and the monographs on different parts of the same, were occasion- ally consulted or referred to, so far as these were accessible or could be procured. Among the monographs, especial men- tion should be made of Professor John Dewey's most excellent Leibniz's New Essays concerning the Human Understanding . A Critical Exposition, 1888, in the series of German Philo- sophical Classics edited by Professor George S. Morris, and published by S. C. Griggs & Co., Chicago; and of the earlier monograph of G. Hartenstein, Locke's Lehre von der mensch- liclien Erheyintniss in Vergleichung mit Leibniz's Kritik derselben, Leipzig, 1861. The translation has purposely been made close rather than free, a philosophical treatise seeming properly to require a closer adherence on the part of the translator to the author's form of thought and expression than a history, novel, or poem. Whatever view may be taken on this point, — and I frankly admit that at least two views are possible and that each method of translation has its advantages and its disadvantages, its perils and its successes, — the form and style of the JSIeiv Essays make an elegant and forceful translation well-nigh impossible. Such a translation would necessitate the entire re-writing of Leibnitz's work, would, in fact, be a reproduction rather than a translation, a task I have not attempted nor felt it incumbent on me to attempt. My aim has been simply to represent as faithfully and as accurately as jDOSsible, and in as good English as its form and expression admitted, Leibnitz's exact thought. The style of Leibnitz in the JSletv Essays, especially in . the abbreviations or abstracts of Locke's Essay put into the mouth of Philalethes, is often abrupt and obscure and sometimes even ungrammatical (c/., for example, Neiv Essays, Book III., chap. II., § 18, page 392, lines 6 and 7, and the note thereto, infra, page 768 ad Jin.). This condition of things is due partly to the form of the work, but chiefly to the method of its com- position (c/. Gerhardt's introduction, infra, j)age 8, and notes. TRANSLATOR'S PREFACE and the letters of Leibnitz cited by Raspe in his Preface, page 12, note 6, and which he says, " I found with the manuscript of the New Essays" and "give as I found them "). A work so written, in spite of more or less revision, could not possibly be a finished treatise or a work of literary art like the Dia- logues of Plato, and the character of the work must of neces- sity be reflected in the translation. The notes aim to give the desirable or necessary biographical and bibliographical information regarding the persons and books referred to in the course of the work, so far as such information could be obtained; references to other pieces of Leibnitz, and occasionally to other authors, where the same topic is discussed; and explanations of a few terms thought to be obscure and the explanations of which are not generally known or easily accessible. The notes do not pretend to be a commentary on the text. Except in a few cases, the reader or student has purposely been left to gain his knowledge of Leibnitz's views from Leibnitz himself. Extended com- mentary was impossible within the necessary limits of the volume, and accordingly was not included in the plan. The philosophical notes, therefore, confine themselves to a brief statement of Leibnitz's views and to brief criticism or indica- tion of criticism. The aim was to bring Leibnitz's great work within the reach of English students and to render it more easily accessible, with such annotation, literary and other, as would make it more acceptable to the student. All material taken from other authors has, so far as pos- sible, been verified and made the subject of such independent study as the case seemed to demand. All references to authorities have been verified when possible, and very great pains have been taken to secure perfect accuracy in all refer- ences. The citations have uaiformly been taken and the references made to the best editions, and usually to the latest, when these editions were accessible. Occasionally other works or editions are referred to because of their accessibility or for other evident reasons. For the convenience of those possess- ing diiferent editions of Leibnitz's works, as well as for those who may have access to only one of them, reference is usually made, especially in the earlier notes, to all of the editions. Later this procedure seemed to encumber the notes with an TRANSLATOR'S PREFACE unnecessary amount of numerical reference, and it was for the most part discontinued. Attention is called to the Additions and Corrections as containing matter of importance, most of which was not obtained till after the portion of the book to which it refers was already in type, and which, therefore, could not be inserted in its proper place in the book, but had to be reserved to the end. The Indexes are intentionally full and complete and have been made with great care by Rev. Robert Kerr Eccles, M.D. There is no adequate index to Leibnitz's works, and none whatever exclusively devoted to the Neio Essays. The refer- ences thereto in the meagre index in Raspe's edition of the Philosophical Works, not generally accessible, and in the general index, full as it is, in Erdmann's edition, are by no means sufficient. It is hoped that the Indexes here furnished may prove adequate for the works of Leibnitz included in tliis volume, and that thus a beginning at least of an adequate index to Leibnitz's complete works shall have been made. In Appendix No. IV., infra, page 663, and No. V., infra, pages 674, 682, and 686, the numbering of the cuts is changed from that of the original text to conform to their proper numerical order in this book. The fact is here noted to pre- vent confusion in referring to the original. I gratefully acknowledge my obligations and express my thanks to all who have aided me in my long and arduous work. Especially to President E. B. Andrews of Brown University, for aid in the note on the term ^^ quarto moclo,'' page 455, and for the verification of references; to Professor Albert G. Harkness of Brown University, for aid in locating some of the Latin quotations in the Neio Essays; to Professor J. F. Jameson of Brown University, for the note, page 757, ex- plaining the term "Promoter," page 227; to Professor John M. Manly of Brown University, for information and aid in the notes to the Neiv Essays, Book III., chap. 2, page 294, notes 2, 3, page 295, notes 2, 3; to Professor E. B. Delabarre of Brown University, for aid in the note to page 122, lines 1, 2, i7ifra, pages 739-740; to Professor H. P. Manning of Brown University, for aid in the note on the " perles " of De Sluse, page 768; to Rev. R. H. Ferguson, for aid in the THANSLA'IOR'S PREFACE same note, and in the revision of a portion of the Appendix; to Mr. Frank E. Thompson, A.M., Head-master of the Rogers High School, N^nvport, R. I., for aid in connection with a part of the subject-matter of the Dynamical Pieces in the Ap- pendix; to Professor Benjamin 0. True of Rochester Theo- logical Seminary, for information and verification of references in connection with the notes to the New Essays, Book IV., chap. 19, page 599, note 2, 601, note 1, 602, note 1; to Pro- fessor F. A. March of Lafayette University, for the location of the Latin poetical quotation on page 603 ; to Professor Carl Schaarschmidt of Bonn University, for consulting books inac- cessible in this country, and for information kindly furnished by letter, and for his cordial interest in my work, as well as for the very valuable notes to his translation of the Neiv Essays, without which mine never would have been written in their present form ; to the various libraries whose resources have in one way or another been placed at my disposal, among which should be mentioned the Boston Public Library, the Boston Athenaeum, the libraries of Andover Theological Semi- nary, Newton Theological Institution, Rochester Theological Seminary, Brown University, Harvard University, Yale L^niversity through Professor Duncan, the Library of the Surgeon General's Office, Washington, D.C., and the Red- wood Library, Newport, R.I. ; to the libraries particularly of Newton Theological Institution, Brown University, and Harvard University, for the long-continued loan of needed books ; to Professor Charles R. Brown of Newton Theological Institution for information and the verification of references; to my friend and former pupil Mr. Alfred R. Wightman, of the Morgan Park Academy of the University of Chicago, for the verification of references and aid in the revision of a portion of the Appendix; to Mr. Thomas J. Kiernan of the Harvard University Library, for special favors in the consul- tation of the library, for the loan of books from the same, and for information cordially furnished by mail; to Benjamin Rand, Ph.D., of the Department of Philosophy at Harvard University, for frequent consultation of authorities, verifica- tion of references and information furnished; to my friend Mr. Richard Bliss, Librarian of the Redwood Library, with- out whose competent criticism and constant advice and aid, TRANSLATOR'S PREFACE added to his comprehensive and accurate knowledge in many fields, and especially in bibliography, my notes would have been far less full and accurate than, I trust, they now are; and last but not least, to my wife for literary criticism in the revision of the translation and notes, and aid in the laborious task of proof-reading. Had I always accepted and adopted her criticism and that of Mr. Bliss, my work would doubtless rank higher as a piece of literature than is now possible. My thanks are also due and most heartily tendered to my publishers, Messrs. Macmillan & Co., for their uniform courtesy and long-suffering patience in the repeated but un- avoidable delays which have characterized the a|3pe-arance of this book; and to J. S. Gushing & Co., of the Norwood Press, for the excellence of their work, and the pains they have taken to secure the greatest possible accuracy in the same, and for their luiiform courtesy and long-suffering patience amid the vexatious delays unavoidably incident to the preparation of the notes and the correction of the proof. In editing the work of a thinker and writer so comprehen- sive as Leibnitz, it is impossible to escape all errors of fact or judgment. I have done the best I could in the circumstances in which I have had to work, away from large libraries and from the advice and criticism of fellow-students in the same lines. Competent and truth-loving criticism, and the correc- tion of any and all real errors will be thankfully received. With one sentence from Leibnitz's letter to Coste, June 16, 1707, as significant of his character and illustrative of his spirit, more truth-loving than polemical, and as beautifully expressing the essence of true criticism, I close this Preface : " Mon but a este plustost d'eclaircir les choses, que de refuter les sentimens d'autruy," which, being interpreted, is: "My purpose has been to throw light upon things rather than to refute the opinions of another." Alfred G. Langley. Newport, E.I., April 11, 18%. LEIBNITZ'S CEITIQITE OF LOCKE ON HUMAN UNDERSTANDING GEKHARDT'S INTEODUCTION TO HIS EDITION OF LEIBNITZ'S NOUVEAUX ESSAIS IFfom the German] In the first philosophical treatise, Meditationes de Cognitione, Veritate, et Ideis,^ which Leibnitz published in the year 1684, he had firmly laid the foundations of human knowledge ; he de- clared adequate and at the same time intuitive knowledge as the most complete. At the end he adds : Quod ad controver- siam attinet, utrum omnia videamus in Deo , , . an vero proprias ideas habeamus, sciendum est, etsi omnia in Dko videremus, necesse tamen esse ut habeamus et ideas proprias, id est non quasi icunculas quasdam, sed affectiones sive modifi- cationes mentis nostrse, respondentes ad id ipsum quod in Deo perciperemus : utique enim aliis atque aliis cogitationibus sub- euntibus aliqua in mente nostra mutatio fit ; rerura vero actu a nobis non cogitataruni Idese sunt in mente nostra, ut figura Herculis in rudi marmore. The assumption of these ideas slumbering in the mind, these innate ideas (angebornen Ideen; idees innees), Leibnitz regards as necessary in order to understand the nature of the mind. (Habet anima in se perceptiones et appetitus, iisque natura ejus continetur, he writes to Bierling, Hanoverse 12. Augusti 1711.^ Et ut in corpore intelligimus avTLTVTTLav, et figui"am generatim, etsi nesciamus, quae sint figurse corporum insensibilium : ita in anima intelligimus perceptionem et appetitum, etsi non cognoscamus distincte insensibilia ingredientia perceptionum confusarum, quibus insensibilia corporum exprimuntur.) He could therefore only prove the necessary truths, i.e. 1 G. I. Gerhai'dt: Die philosopMschen Schriften von G. W. Leibniz. Vol. 4, pp. 422-426. J. E. Erdmann: G. G. Leibnitii Opera Philosophica, pp. 78- 81. Translated by George M. Duncan, The Philosophical Works of Leibnitz, pp. 27-.32, New Haven : Tuttle, Morehouse, & Taylor, 1890. — Tr. '^ The letter is found in Gerhardt's ed., Vol. 7, pp. 500-502. — Tr. LEIBNITZ'S CRITIQUE OF LOCKE those which are known by demonstration, inasmuch as the senses indeed teach what happens, but not what necessarily happens. Such ideas innate to the mind are, according to Leibnitz, the conceptions of substance, identity, the true and the good. The writing of the man who questioned and rejected these fundamental principles of the system of Leibnitz could not fail to lay claim to Leibnitz's entire attention. It was John Locke (born, 1632, at Wrington, near Bristol; died, 1704, at Gates, in the county of Essex, in the house of Sir Francis Masham, whose wife was a daughter of Cudworth), who in his celebrated work ("An Essay concerning Human Understand- ing " ; in four books, London, 1690 ^) sought to discover also the origin, the certainty, and the extent of human knowledge, but who denied the existence of innate ideas and principles, and affirmed that the mind is originally like an unwritten tablet {tabula rasa). In the first book of the Avork named, Locke seeks to set forth the view that there are no innate ideas, and therefore no innate principles and truths ; that the under- standing is by nature like an unwritten sheet of paper. The second book contains the proof whence the understanding gets its ideas. Since there are no innate concepts and principles, the origin of all ideas can be only in experience. Experience, however, has a double sphere, that of external and of internal perception : the first Locke calls Sensation; the second, Kefiec- tion. Sensation is the perception of external objects mediated through the senses ; reflection, the perception of the activities of the soul in relation to the ideas presented through the senses. Ideas are partly simple, partly complex. Simple ideas arise through the single senses, remoter ideas through more senses, as extension, form, motion, rest ; through reflection alone, for 1 This work was already completed in the year 1G87 ; au abstract made by Locke himself appeared in the following; year, 1688, translated into French in Leclerc's " Bibliotheque nniverselle," T. VIII., pp. 49-142. The contents of the work, after it was completely pnblished in the year IfiOO. was communi- cated in much detail by Leclerc in the " Biblioth. Univers.," T. XVII., p. .S99 sq. The new editions, which already in the shortest time followed each other in quick siiccession in the years 1694, 1697, 1699, 1705, prove what a mighty impression Locke's work made upon cultivated circles. 1700 appeared Coste's French translation of Locke's work : it was enriched by Locke himself with improvements' ^nd additions. Leibnitz followed this French translation in the composition of his Novveavx Essais. ON HUMAN UNDERSTANDING example, the idea of thought and will ; through union of sensa- tion and retiection, the ideas of power, existence, unity. The complex ideas are of three kinds : modes, substances, relations. The modes, i.e. the complex concepts, which contain nothing existing for itself, are either pure (simple modes), as space, time, or mixed (mixed modes), as thought, motion, power. By sub- stances Locke understands those combinations of simple ideas or groups of ideas, which are conceived upon the hypothesis that they correspond to definite, actually existing things, so that the substance (substratum) presupposed for and in them is considered as the point of union for the rest of the constitu- ent parts contained in the group of ideas. Of substance, man has no clear conception ; it is, according to Locke, worthless. According to him this conception is not limited to single things, but he extends it also to the collective ideas of many things ; thus an army, a herd of sheep, is just as much a substance as a single man or one sheep. Relations arise from the comparison of many things with one another, as the conceptions of cause and effect, time — and place — relations, identity and diversity. Ideas and their combinations are apprehended in language ; therefore Locke begins in the third book with an investigation upon language, in so far as our knowledge, although relating to things, is bound to words, and words are an indispensable middle-term between thoughts and things. The extent and the certainty of knowledge are on this account conditioned upon the constitution and significance of words. In the fourth book Locke pronounces the concluding judgment upon the extent and the different grades of certainty in human knowledge.^ Leibnitz's attention was already turned from his own work to that of the English philosopher by the above-mentioned edition published by Locke himself in the "Bibliotheque universelle." When later Locke's work reached his hands, he threw off, as was his custom while he skimmed through the book, some remarks ; ^ they follow here under the superscription : " Sur 1 For the foregoing are of value: Hartenstein, Locke's Lehre von der vienschlichen Erkenntniss in Verf/leichmicj mit Leibniz's Kriiik derselben- Leipzig, 1861. — Ueberweg, Griindi-iss der Geschirhte der Philosophie, 3 Theil. Berlin, 1880. " 2 They came into being after the year 1693, since mention is made in them of Locke's Tract upon Education: Thovghts on Education, London, 1693. They were first printed in Some Familinr Letters betiveen Mr. Locjce and Several of his Friends, London, 1708, pp. 19()-205. LEIBNITZ'S CRITIQUE OF LOCKE I'Essay de I'eutendeiiieut humaiii de Monsieur Lock."^ Leibnitz sent it in accord with his pleasant custom to Thomas Burnett, with whom he corresponded.^ Through him they came to the knowledge of Locke, who, however, upon vain pretexts, de- clined every reply thereto.^ When Leibnitz received among others the communication from Burnett (July 26, 1698), that Locke had so far expressed his opinion that he for his part did not sufficiently understand Leibnitz's remarks upon his book, he resolved upon a remodelling of the same. Two fragments of the year 1698 are thereupon at hand ; they are printed here for the first time, under the superscription : " Echantillon * de Reflexions sur le I. Livre de I'Essay de I'Entendement de I'homme. — Echantillon de Reflexions sur le 11. Livre." Leib- nitz again sent them to Burnett; through whom Locke re- ceived them ; but this attempt also on Leibnitz's side remained without result, as appears from Burnett's letter to Leibnitz October 23, 1700. 1 On Locke's Essay on Human Understanding. See infra, pp. 13-19. — Tr. 2 Leibnitz to Thomas Burnett, 7th-17th March, 1696: " I found, also, finally, a rough draught which I had had copied formerly, of some remarks I made when running through the excellent essay of Locke upon Human Understand- ing; I take the liberty of sending you a copy." —Leibnitz to Th. Burnett, 17th-27th July, 1697: " What I sent you of my reflections upon the important book of Locke is entirely at your disposal, and you can communicate it to whomever it seems good to you ; and if it falls into his hands, or those of his friends, so much the better ; for that will give him an opportunity to instruct us and to clear up the matter." 3 Highly characteristic is that which Burnett communicated to Leibnitz upon the 23d of July, 1697 : " I must tell you a joke of Locke's the other day, on this matter. We began to speak of the controversies of savants with those of this country. He said: 'It seems to me we live very peaceably as good neighbors of the gentlemen in Germany, for they do not know our books, and we do not read theirs, so that the tale (la [? le — Tr.] conte) (? le eompte, the account) was well adjusted on each side.'" — On the other hand, we find a very dissenting judgment of Locke's iipon Leibnitz and his remarks in his letter to Dr. Molyneux, of April 10, 1697: "I must confess to you that Mr. L 's great name had raised in me an expectation which the sight of his paper did not answer, nor that discourse of his in the ' Acta Eruditornm,' which he quotes, and I have since read, and had just the same thoughts of it, when I read it, as I find you have. From whence I only draw this infer- ence, That even great parts will not master any subject without great thinking, and even the largest minds have but narrow swallows." — Not less disparaging is Locke's judgment upon Leibnitz in the next letter to Molyneux, of May 3, H)97. — The correspondence betAveen Locke and Molyneux is contained in the already quoted book: Some Faini liar Letters betiueen Mr. Locke, etc. ■* Specimen of Reflections on Book I. of the Essay on Human Understand- in;/. Specimen of Reflections on Book II. See infra, pp. 20-25. — Tr. ON HUMAN UNDERSTANDING In the year 1700 appeared, the French translation of Locke's work published by Pierre Coste;^ it was prepared according to the fourth edition and contained accordingly the additions which Locke had made to the previous editions of his book. Leibnitz at once took occasion thereof to write a sketch for the '^ Monatliche Auszug ^ aus allerhand neu-herausgegebenen, niitz- lichen und artigen Biichern," for the year 1700 (September, pp. 611-636). This follows here under No. III.^ together with the supplement of the following year, 1701.* In this sketch Leib- nitz discusses two of the weightiest of Locke's additions, filling two separate chapters, viz. : chapter 33 of the second book, wherein Locke treats of the Association of Ideas, and then chapter 19 of the fourth book, in which he discourses of Enthusiasm. Through the French translation Leibnitz first gained real access to Locke's work.'' He recognized the importance of its contents in its fullest extent; at the same time the extremely large circulation and the universal recognition, which ex- pressed itself through the editions following each other in rapid succession, must have made upon hi m a deep impression. Evidently for these reasons Leibnitz conceived the plan of 1 Essai Philosophique concernant I'entendement liumain, ou I'on tnontre, quelle est I'entendue de nos Connoissances certaines et la maniere dont nous y paivenons, traduit de I'Anglais de Mr. Locke par Mr. Pierre Coste, sur la quatrieme edition, revue, corrigee et augmentee par I'Auteur. A Amsterd.. 1700. 4. Tliis first edition of Coste's translation was not accessible to me : 1 have been able to make use of the second : Essai Philosophique concernant, etc. Traduit de I'Anglois par M. Coste. Seconde edition, revue, corrigee, et augmentee de qvielques Additions importantes de I'Auteiir qui n'ont paru qa'apres sa mort, et de quelques Remarques du Tradueteur. A Amsterd., 1729. 4. 2 I.e. " ' Monatliche Auszug ' (Monthly Abstract) of the various newly pub-, lished, profitable, and pleasing books." — Tr. * See infra, pp. 2(5-38. — Tr. * This " Monatliche Auszug " appeared in three annual sets from 1700-1702. Guhrauer {Leibnitz's deutsche Svhriften, 2ter Band) has tried to prove in a very complete excursus that Leibnitz was the real editor of this Journal. Certainly the sketch of Locke's work originated with him. 5 Leibnitz to Thomas Burnett, 17th-27th July, 1606: "I could wish I had the same knowledge of the English language " (as of the French) ; " but, not having had the occasion for it, all I can do is to understand passably the books written in this language. And at the age at which I liave arrived, I doubt if I could ever make myself better acquainted with it." — Leibnitz to Coste, of June 16, 1701 : " I have followed your French version, because I thought it proper to write my remarks in French, since nowadays this kind of investiga- tion is but little in fashion in the Latin Quarter." LEIBNITZ'S CRITIQUE OF LOCKE answering Locke's work with a more extensive writing. It grew out of the often hastily -throwu-off remarks which he occasionally put on paper in the years following that of 1700, in which he was not permitted to undertake any continuous work.^ In order to obliterate the traces of this method of work, Leibnitz considered it advisable, before he published it, to submit his book, as to composition and style, to the judg- ment of a native Frenchman. This revision was protracted until the year 1705, as appears from a writing which has no signature.^ Another delay occurred by reason of the fact that Leibnitz in the following year, 1706, entered into correspond- ence with Pierre Coste, the translator of Locke's work ; Coste told him (April 20, 1707) that the translation of Locke itself would be examined and furnished with important improve- ments; he would urgently advise him (Leibnitz) to put off the publication of his work until he obtained a knowledge of these changes of Locke. This further consideration, that he learned of the dissenting opinions of Locke in his corre- spondence with Molyneux, as also Locke's death, which had 1 " I have made these remarks in the leisure hours when I was travelling or at Herrenhausen, where I could not apply myself to researches which required more care" (besoin^ in sense of soiii ? — Tr.).i 2 " The frequent diversions to which I have been exposed have }3revented me from pushing forward my remarks. Besides, I have been obliged to divide my time between the reading of your work and the commissions with which I have been entrusted by the Count de Schwerin, of which I must give account to him. You will find few remarks upon this paper; but I have taken the liberty of changing in the work itself a very large number of places in reference to which I did not at all hesitate when I saw' that I could do this without dis- arranging the rest of the writing. I have not touched what is properly called the style ; but the confidence with which you have honored me obliges me to say to you here that it greatly needs amendment, and that you seem too much to have neglected it. You know, sir, to what excess our French people have carried their well- or ill-founded delicacy. Too long periods are distasteful; an And (Et) or some other word too often repeated in the same period offends them ; unusual constructions embarrass them ; a trifle, so to speak, shocks them. It is proper, however, to accommodate yourself to their taste if you wish to write in their language; and, in case you should decide to print your work, I believe you will do well to retouch it with a little more severity. I am certain that you will not be displeased at the freedom with which I speak to you, since it comes from a person devoted to your service." — Feb. 2, 1705. 1 W. T. Harris, editor of the " .Journal of Speculative Philosophy," suggests that per- hajis the reading was beaogne (work) —instead of besoin. So that the passage read, " researches which required more worli (or labor)." — Tb. ON HUMAN UNDERSTANDING already followed in the year 1704, altered Leibnitz's original plan.^ In order to obtain an easier entrance for his own ideas, and at the same time to make his reader familiar with those of Locke, Leibnitz had composed his work in the form of a dia- logue. Two friends, Philalethes and Theophilus, converse together; the first states the views of Locke, the second joins thereto his own (Leibnitz's) remarks. This form of composi- tion Leibnitz thought of abandoning. He writes to Thomas Burnett, May 26, 1706: "The death of Locke has taken away my desire to publish my remarks upon his works. I prefer now to publish my thoughts independently of those of another." On the other hand, he remarks, wellnigh it seems in the opposite sense, to the same, three years later, May 12, 1709 : " My remarks upon the excellent work of Locke are almost finished ; although we are not of the same opinion, I do not cease to value it and to find it valuable." Leibnitz's work remained, in form at least, unfinished ; a magnificent torso, and unpublished.^ He turned to the compo- 1 Leibnitz to Coste, June 16, 1707 : " The great merit of Mr. Locke, and the general esteem which his work has with so much jiistice gained, united to some intercourse by letters which I have had the pleasure of having with my Lady Masham, caused me to employ some weeks in remarks upon tliis impor- tant work, in the hope of conferring ujion tliem witli Mr. Locke himself. But liis death sliocked me, and caused my reflections to be behindhand, although they are finished. My purpose has been to throw light upon things rather than to refute the opinions of anotlier. I shall be delighted, however, sir, to receive the additions and corrections of tliis excellent man, in order to profit from them." — Leibnitz to Remond, March 14, 1711: "He (Hugony) has also seen my somewhat extended reflections upon Locke's work, which treats of Human Understanding. But I dislike to publish refutations of dead authors, althougii they might appear during their lifetime and be communicated to the authors themselves. Some minor remarks escaped me, I know not how, and were carried to England by a relative of the late Mr. Burnett, bishop of Salis- bury. Locke having seen them, spoke of them slightingly in a letter to Molynenx, wliicli may be found among some posthumous letters of Locke. I learned his opinion of them only from this impression. I am not astonished at it: we differed a little too much in principles, and the views I advanced seemed to him paradoxical. However, a friend more biassed in my favor and less so in favor of Locke informs me that those of my reflections there inserted appear to him the best of the collection. I do not adopt this view, not having examined the collection." ■^ Over the Preface, which certainly was composed after the completion of the entire work, Leibnitz has written as the title of the work: Noureaiix Essois sicr I'entendpmoit par I'Aitteur dv systeme de V Harmonk preefttablie. In the Preface itself he leaves out the word "humain." The superscription of the 10 LEIBNITZ'S CRITIQUE OF LOCKE sition of the "Theodicy." For the first time, fifty years after his death, it was sent to the press in " (Euvres Philosophiques latines et franqoises de feu Mr. de Leibnitz. Tirees de ses manuscrits qui se conservent dans la bibliotheque Eoyale a Hanovre, et publiees par Mr. Rud. Eric. Raspe. Avec uue Preface de Mr. Kaestner, Professeur en Matheniatiques a Gottingen. A Amsterdam et a Leipzig, 1765." The present impression has been newly compared with the original, so far as it is still extant.^ The corrections in reference to the style proposed by the native Frenchman are not taken into consider- ation, in order not to obliterate Leibnitz's style of expression ; they relate, indeed, only to the first books. In the preface to his work, in which Leibnitz has put together the points of difference between his system and that of Locke, he remarks in the first place that Locke's Essay upon Human Understanding is one of the most beautiful and valua- ble works of its time ; that he has determined to make some remarks upon it, because he himself has considered the same subject for a long time, and deemed it a good opportunity to create a favorable entrance for his own ideas in this way. His own system differs, in truth, from Locke's considerably, in so far as Locke's is more closely related to Aristotle, his own, on the other hand, to Plato ; Locke's is more universall}'' com- prehensible, his own more abstract. Meanwhile, b}^ clothing his own remarks in the form of a dialogue between two per- sons, one of whom presents Locke's views, the other joins thereto his own, he hopes to avoid the dryness belonging to abstract remarks ; at the same time the reader is spared the labor of comparing the passages from Locke's essay under dis- cussion. — The first important point of difference, Avherein Leibnitz distinguishes himself from Locke, is in the ques- tion whether the soul is in itself empty like a tabula rasa, as Aristotle had already maintained, and that it receives every- thing through sense-perceptions and experience, or whether fourth book runs thus: N'ouveaiix E^ays svr V entendement ; in the case of the three first books we find the superscription: Noitveaux Essais stir Vcn- tendement humuine. 1 In the original, Leibnitz has enclosed the words of Philalethes, who states the views of Locke, in [], perhaps as an indication that they are not his own. Raspe has omitted them. — Gerhardt's Note. In this translation Gerhardt's use of [] has been strictly followed. — Tk. ON HUMAN UNDERSTANDING * 11 the soul originally has the principles of many conceptions and doctrines, as Leibnitz with Plato thinks. Hence arises another question, whether all truths depend upon experience, or whether there is still another principle. The senses are necessary for our actual knowledge, but they give us only examples, i.e. in- dividual truths, which are not adequate for grounding the uni- versal necessity of a truth. The necessary truths, which are found in pure mathematics, appear to rest upon other princi- ples, whose proof depends not upon experience and the testi- mony of the senses, — a point to be well considered. Logic, metaphysics, ethics, are full of such truths, which can arise only from such principles as are called innate. It is neverthe- less possible, continues Leibnitz, that my opponent is not wholly remote from my view. For after he has rejected innate ideas in the first book of his essay, he begins the second book with the statement that the ideas which have not their origin in sensation arise through reflection. What, however, is reflection but a regard for what is in us and born in us ? Such are the ideas of being, unity, substance, etc. If, thinks Leibnitz, an understanding with his opponent might easily, perhaps, be re-established in reference to the above, yet it might create more difficulty in reference to the affirmation that the soul does not always think, just as bodies do not always have motion. To this Leibnitz opposes the statement ■that bodies are always in motion and that a substance cannot exist without activity ; there are in the soul a multitude of impressions too small to be separately distinguished, but which, however, united produce an activity, although simply inarticu- late, like the noise of the waves. These little perceptions are of greater significance than we think. By means of these in- sensible perceptions the pre-established harmony between the soul and the body is explained. In the same manner they are of great importance for Physics, for thereupon rests the law of continuity. These minute insensible perceptions are also the reason why there are not two perfectly similar souls or things of the same kind. Another point of difference between Leibnitz and Locke is in reference to the conception of the nature of Matter. Locke considered the smallest particles of matter to be rigid bodies, and therefore assumed that space is empty, else were any mo- 12 • LEIBNITZ'S CRITIQUE OF LOCKE tion impossible. Leibnitz, on the other hand, supposes space to be tilled with a fluid matter which is divisible to infinity ; he calls especial attention to the fact that Locke, who at first professed the gravitation theory of Newton constantly contested by Leibnitz, viz. : that bodies work upon each other from any distance whatever without touching, at a later period freed himself from this assumption of Newton. In discussing the concepts of space, time, and number, Locke had remarked that only with these concepts may that of infinity be united. Leibnitz agrees with him in this, that there is neither an infinite space, nor an infinite time, nor an infinite number, that in general the infinite is not given in that which is put together out of parts. But the true infinite, Leibnitz adds, is in the Absolute, which is without parts. From this proceeds the concept of the finite through limitation. In the beginning of the third book Locke had undertaken a discussion of language as the expression of the forms of knowledge. He had made thereby a distinction between nom- inal and real being. Leibnitz rejects this distinction as a perplexing innovation. Things, Leibnitz affirms, have only one essence, but different definitions of them, nominal and real definitions, are possible. The contents of the fourth book, in which is treated the knowledge of the truth, gives Leibnitz no occasion to raise an important point of controversy. In reference to the axioms, whose indispensableness to scientific investigations Leibnitz affirms, Locke contests, the former enters into a more protracted explanation. In like manner he turns against Locke's notion that the use of Losfic is rather unfruitful. ON LOCKE'S ESSAY ON HUMAN UNDEKSTANDING,^ 1696 [From the Frencli] I FIND SO many marks of unusual penetration in what Mr. Locke has given us on the Human Understanding and on Education, and I consider the matter so important, that I have thought I should not employ the time to no purpose which I should give to such profitable reading ; so much the more as I have myself meditated deeply upon the subject of the foundations of our knowledge. This is my reason for putting upon this sheet some of the reflections which have occurred to me while reading his Essay on the Understanding. Of all researches, there is none of greater importance, since it is the key to all others. The first book considers chiefly the principles said to be born with us. Mr. Locke does not admit them, any more than he admits innate ideas. He has doubtless had good reasons for opposing himself on this point to ordinary prejudices, for the name of ideas and principles is greatly abused. Common philosophers manufacture for themselves principles according to their fancy ; and the Cartesians, who profess greater accuracy, do not cease to intrench themselves behind so-called ideas of extension, of matter, and of the soul, desiring to avoid thereby the necessity of proving what they advance, on the pretext that those who will meditate on these ideas will discover in them the same thing as they ; that is to say, that those who will accustom them- selves to their jargon and mode of thought will have the same prepossessions, which is very true. My view, then, is that nothing should be taken as first principles but experiences and the axiom of identity or (what 1 Erdmann, Leibnitii Opera Philosophica, pp. 136-139. — Tb. 13 14 LEIBNITZ'S CRITIQUE OF LOCKE [i is the same thing) contradiction, which is primitive, since otherwise there would be no difference between truth and falsehood; and all investigation would cease at once, if to say yes or no were a matter of indifference. We cannot, then, prevent ourselves from assuming this principle as soon as we wish to reason. All other truths are demonstrable, and I value very highly the method of Euclid, who, without stopping at what would be supposed to be sufficiently proved by the so- called ideas, has demonstrated (for instance) that in a triangle one side is always less than the sum of the other two. Yet Euclid was right in taking some axioms for granted, not as if they were truly primitive and indemonstrable, but because he would have come to a standstill if he had wished to reach his conclusions only after an exact discussion of principles. Thus he judged it proper to content himself with having pushed the proofs up to this small number of propositions, so that it may be said that if they are true, all that he says is also true. He has left to others the task of demonstrating further these principles themselves, which besides are already justified by experience; but with this we are not satisfied in these matters. This is why Apollonius, Proclus, and others, have taken the pains to demonstrate some of Euclid's axioms. -Philosophers should imitate this method of procedure in order finally to attain some fixed principles, even though they be only provisional, after the way I have just mentioned. As for ideas, I have given some explanation of them in a brief essay printed in the " Actes des Scavans " ^ of Leipzig for November, 1684 (p. 537), which is entitled Meditationes de Cognitione, VerUate, et Ideis;^ and I could have wished that Mr. Locke had seen and examined it; for I am one of the most docile of men, and nothing is better suited to advance our thought than the considerations and remarks of clever per- sons, when they are made with attention and sincerity. I ^hall only say here, that true or real ideas are those whose 1 The "Acta Eruditoram," Lipsiae, 1682-1731. — Tr. 2 Gerhardt, Vol. 4, pp. 422-42G : Erdmann, pp. 78-81. Translated in part by- Sir William Hamilton, Lectures on Logic, Lect. X., U XXX., pp. 127-129, Amer. ed. ; and complete by George M. Duncan, The Philosophical lVo7-ks of Leibnitz, pp. 27-32, New Haven: Tuttle, Morehouse, & Taylor, 1890; also by Professor Thomas Spencer Baynes, in tlie Ajipeudix to his edition of the Port Royal Logic. — Tn. I] ON HUMAN UNDERSTANDING 15 execution we are assured is possible ; the others are doubtful, or (in case of proved impossibility) chimerical. Now the possibility of ideas is proved as much a 'priori by demon- strations, by making use of the possibility of other more simple ideas, as a posteriori by experience ; for what exists cannot fail to be possible. But primitive ideas are those whose possibility is indemonstrable, and which are in truth nothing else than the attributes of God. I do not find it absolutely essential for the beginning or for the practice of the art of thinking to decide the question whether there are ideas and truths born with us ; whether they all come to us from without or from ourselves ; we will reason correctly provided we observe what I have said above, and proceed in an orderly way and without prejudice. The ques- tion of the origin of our ideas and of our maxims is not pre- liminary in Philosophy, and Ave must have made great progress in order to solve it successfully. I think, however, that I can say that our ideas, even those of sensible things, come from within our own soul,^ of which view you can the better judge by what I have published ^ upon the nature and connection of sub- stances and Avhat is called the union of the soul with the body. For I have found that these things had not been well under- stood. I am nowise in favor of Aristotle's tabula rasa; and there is something substantial in what Plato called reminis- cence. There is even something more ; for we not only have a reminiscence of all our past thoughts, but also a presentiment of all our future thoughts. It is true that this is confused, and fails to distinguish them, in much the same way as when I hear the noise of the sea I hear that of all the particular waves which make up the noise as a whole, though without discerning one wave from another. Thus it is true in a cer- tain sense, as I have explained, that not only our ideas, but also our sensations, spring from within our own soul, and that the soul is more independent than is thought, although it is always true that nothing takes place in it which is not deter- 1 The French is : " de nostre propre fonds." — Te. 2 In the "Journal des Savants," June, 1695. For the piece, of. Gerhardt, Vol. 4, pp. 477 sq. (first sketch 470 sq.) ; and the portion of his introduction and notes referring to the same. Vol. 4, pp. 414-417 ; Erdniann, pp. 124-128 ; c/. also pp. 129-136. For the translation, Appendix, pp. . — Tr. 16 LEIBNITZ'S CRITIQUE OF LOCKE [i mined, and nothing is found in creatures that God does not continually create. In Book II., which comes to the details of ideas, I admit that the reasons brought forward by Mr. Locke to prove that the soul sometimes exists without thinking of anything, do not ap- pear to me convincing, unless he gives the name of thoughts to those perceptions only which are sufficiently noticeable to be distinguished and retained. I hold that the soul (and even the body) is never without action, and that the soul is never with- out some perception : even in dreamless sleep we have a con- fused and dull sensation of the place where we are ; and of other things. But even if experience should not confirm the view, I believe that it may be demonstrated. It is much the same as we cannot prove absolutely by experience whether there is a vacuum in space, and whether there is rest in matter. Nevertheless, questions of this kind appear to me, as well as to Mr. Locke, to be decided demonstratively. I admit the difference which he puts with much reason be- tween matter and space ; but as for the vacuum, many clever people have believed in it., Mr. Locke is of this number. I was nearly persuaded of it myself ; but I gave it up long ago.. And the incomparable Mr. Huygens, who was also for the vacuum and the atoms, began at last to reflect upon my reasons, as his letters can testify. The proof of the vacuum derived from motion, of which Mr. Locke makes use, assumes that body is originally hard, and that it is composed of a cer- tain number of inflexible parts. For in this case it would be true, whatever finite number of atoms migiit be taken, that motion could not take place without a vacuum. But all the parts of matter are divisible and even pliable. There are also some other things in this second book which arrest my attention: for example, when it is said (chap. 17) that infinity should be attributed only to space, time, and num- bers. I believe, indeed, with Mr. Locke that, properly speak- ing, we may say that there is no space, time, nor number which is infinite, but that it is only true that however great ^ may be 1 Gephardt's text seems here, for some reason, to be defective. It reads thus : " Mais qu'il est seulement vi-ay que pour grand que luy sans fin," etc. Erdmann's seems the more correct, and is therefore followed in the translation. It reads thus: "Mais qu'il est seulement vrai que pour grand que soit un espace, un tems, ou un nombre, il y en a toujours un autre plus grand que lui I] ON HUMAN UNDERSTANDING 17 a space, a time, or a number, there is always another greater than it without end; and that thus the true infinite is not found in a whole composed of parts. It is none the less, how- ever, found elsewhere ; namely, in the absolute, which is with- out parts, and which has influence over compound things, because they result from the limitation of the absolute. The positive infinite, then, being nothing else than the absolute, it may be said that there is in this sense a positive idea of the infinite, and that it is anterior to that of the finite. For the rest, in rejecting a composite infinite, we do not deny the demonstrations of the geometers de Seriehus infinitis, and par- ticularly what the excellent Mr. Newton has given us, not to mention my own contributions to the subject. As for what is said (chap. 30) de ideis adcequatis, it is allowable to give to the terms the signification which one finds pertinent. Yet without finding fault with Mr. Locke's mean- ing, I put degrees in ideas, according to which I call those adequate in which there is nothing more to explain, much the same as in numbers. ISTow all ideas of sense-qualities, as of light, color, heat, not being of this nature, I do not reckon them among the adequate. So it is not through themselves, nor a priori, but through experience, that we know their reality or possibility. There are further many good things in Book III. in which he treats of words or terms. It is very true that everything cannot be defined, and that sense-qualities have no nominal definition : thus they may be called primitive in this sense ; but they can none the less receive a real definition. I have shown the difference between these two kinds of definition in the meditation ^ cited above. The nominal definition explains the name by the marks of the thing ; but the real definition makes known a priori the possibility of the thing defined. For the rest, I strongly commend Mr. Locke's doctrine of the demon- strability of moral truths. The fourth or last book, which treats of the knowledge of truth, shows the use of what has just been said. I find in it, as well as in the preceding books, an infinite number of beauti- sans fin." p. 138 a. Cf. also Leibniz's New Essays concerning the Human Understandinq. — A Critical Exposition, by John DeM'ey, Ph.D. pp. 190. Chicago: S. C. Griggs & Co., 1888. — Tr. 1 I.e. Meditationes de Cognitione, Veritate, et Ideis. — Tr. C 18 LEIBNITZ'S CRITIQUE- OF LOCKE [i fill reflections. To make suitable remarks upon them would be to make a book as large as the work itself. It seems to me that the axioms receive therein a little less consideration than they deserve. The apparent reason for this is that, excepting those of the mathematicians, we ordinarily find none which are important and solid : I have tried to remedy this defect. I do not despise identical propositions, and I have found that they are of great use even in analysis. It is very true that we know our own existence by an immediate intuition, and that of God by demonstration; and that a mass of matter, whose parts are without perception, cannot make a thinking whole. I do not despise the argument invented some centuries ago by Anselm, archbishop of Canterbury, which proves that the perfect being must exist; although I find that the argu- ment lacks something, because it assumes that the perfect being is possible. For if this single point were proved in addi- tion, the whole demonstration would be complete. As for the knowledge of other things, it is very well said, that experience alone does not suffice for a sufficient advance in Physics. A penetrating mind will draw more conclusions from some quite ordinary experiences, .than another could draw from the most choice ; besides, there is an art of experimenting upon and, so to speak, questioning nature. Yet it is always, true that we can make progress in the details of Physics only in proportion as we have experience. Our author shares with many able men the opinion that the forms of logic are of little use. I should be quite of another opinion, and I have often found that the paralogisms, even of mathematics, are the faults of form. Mr. Huygens has made the same observation. Much might be said upon this point, and many excellent things are despised because the use of which they are capable is not made of them. We are inclined to despise what we have learned in the schools. It is true we learn there many useless things ; but it is good to exercise the function delta Crusca,^ i.e. to separate the good from the bad. 1 "La Cnisca, a celebrated academy of Florence, founded in 1582, for the purpose of maintaining the purity of the Italian language, that is to say, of separating the bran (crusca) from the flour : hence the name." Duncan's note. Philos. Works of Leibnitz, p. 378. i] ON HUMAN UNDERSTANDING 19 Mr. Locke can do this as well as any one whatsoever ; and in addition he gives us important thoughts of his own invention ; his penetration and fairness appear everywhere.^ He is not only an assayer, but he is also a transmuter by the increase of good metal he gives. Should he continue to present it to the public, we should be greatly indebted to him. 1 Erdmann omits this clause. — Tr. II SPECIMEN OF THOUGHTS UPOIs^ THE FIEST BOOK OF THE ESSAY ON HUMAN UNDERSTANDING [From the French^ In order to prove that there are no ideas born with us, the excellent author of the Essay on Human Understanding ad- duces experience, which shows us that we need external occa- sions in order to think of these ideas. I agree with him, but it does not seem to me that it follows that the occasions which cause us to see them, cause them to spring into being. And this experience cannot determine whether it is through immis- sion of a species or by impression of outlines upon an empty tablet, or whether it is by the development of what is already in us that we perceive ourselves. It is not extraordinary that there be somewhat in our mind of which we are not always conscious. Reminiscence shows us that we often have diffi- culty in remembering what we know, and in seizing what is already in the enclosure and possession of our understanding. This proving to be the truth in acquired knowledge, nothing prevents its being also true in the case of that which is innate. And, indeed, there is still more difficulty in perceiving this last, since it has not yet been modified and detailed by ex- perience, as is the acquired, of which often the circumstances remind us. The author undertakes to show in particular that impossibil- ity and identity, whole and part, etc., are not innate ideas. But I do not understand the force of the proofs he brings. I ad- mit that it is difficult to make men perceive distinctly these metaphysical notions, for abstraction and thought cost them effort. But one may have in himself that which he has diffi- culty in distinguishing there. Something else, however, than 20 I] ON HUMAN UNDERSTANDING 21 the idea of identity is necessary to answer the question, which is here proposed, viz. : Whether Euphorbus and Pythagoras and the cock,^ in which the soul of Pythagoras dwelt for some time, were always the same individual, and it does not at all follow that those who cannot solve this question have no idea of identity. What is clearer than the ideas of geometry? Yet there are some questions which we have not yet been able to decide. But that one which considers the identity of Pytha- goras following the story of his metempsychosis is not one of the most impenetrable. Kegarding the idea of God, he brings forward examples of some nations who have had no such knowledge. M. Pabritius, a very distinguished theologian of the late Elector Palatine Charles Louis, has published the '' L'Apologie du genre humain centre I'accusation de I'Atheisme," in which he replies to such passages as are here cited. But I do not enter into this dis- cussion. Suppose there are men, and even peoples, who have never thought of God;, we may say that this fact proves only that there has not been an occasion sufficient to awaken in them the idea of the supreme substance. Before passing to the complex principles or primitive truths, I will say that I agree that the knowledge, or better, the actual consideration (envisagement) , of ideas and truths is not innate, and that it is not necessary that we have distinctly known them in a former state of being, according to Plato's doctrine of reminiscence. But the idea being taken for the immediate internal object of a notion, or of what the logicians call an incomplex term, there is nothing to prevent its always being in us, for these objects can subsist when they are not per- ceived. Ideas and truths may, furthermore, be divided into primitive and derivative : the knowledge of the primitives does not need to be formed ; they must be distinguished only ; that of the derivative is formed by the understanding and by the reason upon occasion. However, we may say in one sense, that the internal objects of this knowledge, that is to say, the ideas and truths themselves, primitive as well as derivative, are all in us, since all the derivative ideas and all the truths deduced from them result from the relations of primitive ideas which are in us. But usage makes it customary to call innate i Cf. Locke, Philos. Works (Bohn's ed.), Vol. 1, p. 181 sq., and note. — Tr. 22 LEIBNITZ'S CRITIQUE OF LOCKE [ii the truths to which credence is given as soon as they are heard, and the ideas whose reality (that is to say, tlie possibility of the thing which it represents) is of the number of these truths, and needs not to be proved by experience or by reason ; there is then considerable ambiguity in this question, and it suffices at the last to recognize that there is an internal light born with us, which comprises all the intelligible ideas and all the necessary truths which are only a result of these ideas and need not experience in order to be proved. To reduce, then, this discussion to something practical, I believe that the true end one should have is the determination of the grounds of truths and their origin. I admit that con- tingent truths, or truths of fact, come to us by observation and experience ; but I hold that necessary derivative truths de- pend upon demonstration, i.e. upon definitions or ideas, united with the primitive truths. And the primitive truths (such as the principle of contradiction) do not come at all from the senses or from experience, and cannot be perfectly proved, but froiu the natural internal light, and this is what I mean in saying that they are innate. The geometers also have very well understood this. They could prove passably their proposi- tions (at least, the most important of them) by experience, and I do not doubt that the ancient Egyptian and the Chinese had such an experimental geometry. But the true geometers, above all, the Greeks, have desired to show the force of rea- son, and the excellence of science, by showing that they can in these matters foresee ever3'thing, by the internal light in advance of experience. It must also be admitted that experi- ence never assures us of a perfect universality, and still less of necessity. Some of the ancients laughed at Euclid because he proved what a fool even is not ignorant of (as they say), viz. : that in a triangle two sides together are greater than the third. But those who know what genuine analysis is, are much obliged to Euclid for his proof. And it is much that the Greeks, if less exact in other things, have been so much so in geometry. I attribute it to providence; and I believe Avithout that we should hardly know what demonstration is. I also believe that it is principally in that respect that we are thus far superior to the Chinese. But it is needful further to look a little at what our clever II] ON HUMAN UNDEESTANDING 23 and celebrated author says in chapters 2 and 3, to sustain his point that there are no innate principles. He is opposed to the universal consent alleged in their favor, maintaining that many races doubt even this famous principle that two contra- dictories cannot be true or false at once, and that the greater part of the human race ignores it altogether. I admit that there are an infinite number of persons who have never made a statement of them. I have indeed seen authors who desired to refute them, apprehending them, Avithout doubt, wrongly. But where shall we find one who does not avail himself of them in practical life, and who is not offended with a liar who contradicts him ? Nevertheless, I do not ground myself wholly upon universal consent ; and as for propositions which are ap- proved as soon as they are proposed, I admit that it is not at all necessary for them to be primitive or proximate to them, for they may be very common facts. As for this statement which teaches us that one and one make two (which the aiithor brings forward as an example), it is not an axiom, but a defini- tion. And when he says that sweetness is a different thing from bitterness, he states only a fact of primitive experience, or of immediate perception. Or better, we have only to say that the perception of what is understood by the term sweet- ness is different from the perception of that which is under- stood by the term bitterness. I do not here distinguish at all the practical truths from the speculative ; they are always the same. And as we can say that it is one of the most manifest truths, that a substance whose knowledge and power are infinite should be honored, we can say that it emanates at once from the light which is born with us, provided one can give his attention to it. SPECIMEN OF THOUGHTS UPON THE SECOND BOOK [From the French'} It is very true that our perceptions of ideas come either from the external senses or from the internal sense, which may be called reflection ; but this reflection is not limited to the 24 LEIBNITZ'S CRITIQUE OF LOCKE [n operations alone of the mind, as is stated (chap. 1, § 4) ; it reaches even to the mind itself, and it is in the consciousness of self that we perceive substance. I admit that I am of the opinion of those who believe that the soul always thinks, although often its thoughts are too confused and too feeble for it to be able distinctly to remember them. I believe I have certain proofs of the continual activity of the soul, and I believe also that the body can never be without motion. The objections raised by the author (Book II., chap. 1, §§ 10 to 19) can be easily met by what I have just said or am about to say. They are based upon the experience of sleep, which is sometimes dreamless ; and in fact there are some persons who do not know what it is to dream. How- ever, it is not always safe to deny everything that is not per- ceived. It is much the same as when there are people who deny the corpuscles and insensible motions, and laugh at the particles because they cannot be proved. But some one will tell me that there are proofs which force us to admit them. I reply that there are in like manner proofs which compel us to admit perceptions which are not marked enough for us to remember them. Experience, furthermore, favors this view ; , for instance, those who have slept in a cold place notice that they have had while sleeping a confused and feeble sensation. I know a person who wakes up when the lamp which he always keeps lighted at night in his room goes out. But here is something more precise, and which shows that if we did not always have perceptions, Ave could never be waked up from sleep. Let a man who is sleeping be called by several persons at once, and let it be assumed that the voice of each by itself is not loud enough to awake him, but that the noise of all these voices together awakes him : let us take one of them ; it is very necessary that he be touched by this voice in particular, for the parts are in the whole, and if each one by itself does nothing at all, the whole will do nothing, either. Yet he would have continued to sleep, if the voice had been a single one, and that, too, without remembering that he had been called. Thus there are some perceptions too feeble to be noticed, although they are always retained, but among an infi- nite number of other small perceptions which we have con- tinually. For neither motions nor perceptions are ever lost; II] ON HUMAN UNDERSTANDING 25 both continue always, only becoming indistinguishable through composition with many others. One might reply to this reasoning, that each voice by itself effectively touches the body, but that a certain quantity of it is needed in order that the motion of the body may reach the soul. I reply, that the least impression reaches the entire body, and consequently to that part whose motions correspond to the actions of the soul. And accordingly no principle of limitation can be found, how- ever necessary a certain quantity may be. I do not Avish to insist upon the interest that the immortality of the soul has in this doctrine. For if the soul is passive, it is also without life, and it seems that it can be immortal only by grace and by miracle — a view which there is reason to disapprove. I admit, however, that our interest is not the measure of truth, and I do not wish to mix here theological reasons with those of philosophy. Ill [From the German'] Essai Philosophique concernant I'Entendement huniain, ou Ton montre, quelle est I'entendue de nos counoissances certaiues et la maniere dont nous y parvenons, traduit de I'Angiois de Mr. Locke par Mr. Pierre Coste, sur la quatrienie edition, revue, corrigee et augmentee par I'Auteur. A Amsterd. 1700 in 4to. Philosophischer Versuch, betreffend den Menschlichen Verstand, alwo gewiesen wird, wie weit sicli unsre gewisse Erkandtniisseu erstrecken, und aui: wass Weise wir darzu gelangen ; ausz den Eugiischen iibersetzet von Hrn. Peter Coste nach der vierten vera Autor selbst iibersehenen, verbesserten und vermehrten Edition. 5. Alpli. 12. Bog. It ^ is unnecessary for ns to give a complete abstract of this notable book, after the author himself has relieved us of this task, since in the year 1688 he prepared such an abstract for Mr. Clerc for insertion in his " Bibliotheque universelle," ^ T. VIII., p. 49 sqq., before he gave it to the press. In the year 1690 it appeared first in London in folio, and Mr. Clerc again published lengthy excerpts in the said " Bibliotheque univer- selle," T. XVII., p. 399. Soon afterwards a new English edition appeared, enlarged with many pieces, and in particular with an entire chapter ^ on Identity and Diversity, which he treats in an exceedingly clear and excellent manner. In the second edition mentioned, Locke acknowledges that he erred in the first edition wdien he assumed, in accordance with the common view, that what brings the will to any change of action in the course of arbitrary actions is the assurance of a much greater good. For when he coiisidered the matter more carefully, he found that a present unrest which consists in desire or is constantly accompanied by the same, places its limits upon the will. For the reasons for this view, see Book 1 From the "Monatliche Auszug," Sept. 1700, pp. 611-636.— Tb. 2 " Bibliotheque universelle et historique," Amsterdam, 1686-1693. — Tr. 3 lu the present edition this chapter is 27 in the second book. — Gerhardt's note. 26 Ill] ON HUMAN UNDERSTANDING 27 II., chap. 21. He will gladly, howevei', be informed of a bet- ter view. Some time after, a third, and in the year 1699, a fourth, edition appeared, in which last edition Locke either further explained his previous thoughts by many additions or supported them by wholly new grounds. Peter Coste made his translation on the basis of this edition, and when Locke sent him his manuscript, had worked upon the same for more than two years. Locke himself considered this translation a good one and presented his thanks accordingly, so that con- sequently it must be the more welcome by a great deal to us. To enumerate all the new additions would take too long; hence we will content ourselves with the mention of the two most important, which make two separate chapters, of which the first is Book II., chap. 33, and treats of the Association of Ideas. Locke says there is almost no one who does not find something in the opinions, conclusions, and actions of other people which seems to him fantastic and extravagant, and is so in fact. Every one may have eyes keen-sighted enough to mark the least fault of this kind in the case of another, if only it may be distinguished from his own, and he himself may have sufficient understanding to condemn the same, although he also may have in his own opinions and his own conduct the greatest errors of which he might be aware, and of which, where not impossible, he may yet with difficulty be convinced. This arises, he continues, not merely from self-love, although this passion has often a great part therein. For one daily sees such people lying sick with the same disease, who are otherwise skilful and whole enough to make nothing of their own merits. This defect of reason is customarily ascribed to education and to the force of prejudice, and this, according to the common opinion, not without cause, but according to Locke's statement, this explanation reaches not to the root of the disease, and does not show completely its origin and peculiarity. He himself explains it as follows : Some of our ideas [his own words] have among themselves an exact correspondence and connection. The obligation and highest perfection of our reason consists in the fact that it reveals such ideas and holds them together in the selfsame unity and correspondence as that which is grounded in their particular nature. There is 28 LEIBNITZ'S CRITIQUE OF LOCKE [in besides this another bond of ideas which depends upon chance or custom, so that the ideas which naturally are wholly unre- lated become so exactly united in the minds (esprit^) of some men, that they can with difficulty be separated from one another. They accompany one another constantly, and one can no sooner present itself to the understanding (intellectid) than ithe others or, indeed, more of them, so united are they, appear also, nor can they at all be separated from one another. This association of ideas, which the mind makes in itself either voluntarily or by chance, is the sole source of the defect of which we now speak. And as this strong union of ideas is not originally caused by nature, it is for this reason wholly dif- ferent in different persons, viz. : according to their different inclinations, education, and self-interests. That there are such associations of ideas, which custom begets in the minds of most men, no one, according to Locke's statement, can doubt, who with much earnestness considers himself and other people. And to this ca\ise can perhaps with convenience and reason be ascribed the greater part of those sympathies and antipathies which one finds among men, and which work as strongly and produce as regular effects, as if they were natural, which fact then makes them to be called so, although at first view they had no other origin than the chance connection of two ideas, which the strength of a first impres- sion, or of an excessively great compliance, so firmly united, that they always thereafter remain together in the mind of the man, as though only a single idea. Locke, however, in no respect denies that there are wholly natural antipathies which depend upon our original constitution and are born with us. He believes, however, that with proper consideration man would recognize the most of those which have been regarded as natural, as in the beginning caused by impressions which were not heeded, whether they were suggested sufficiently early or through a ridiculous fancy. Locke notices incidentally the difference which may be made between natural and ac- quired antipathies, so that those who have children or who 1 This word I have voluntarily retained here and for the most part in what follows, because it cannot be expressed quite clearly in German. — Leibnitz's note, Gerhardt, p. 27. Perhaps we should retain the word " esprit " in English. — Tr. Ill] ON HUMAN UNDERSTANDING 29 must educate them, may see how much heed they should take of this principle, and with what care this disorderly union of ideas in the mind of the youth should be prevented. He thereupon points out by some examples how such a union of ideas, which are not of themselves united, yet depend one upon another, is sufficient to impede our moral and natural action, yea more, our notions themselves. The ideas of goblins or of spirits agree as little with dark- ness as with light ; if, however, a foolish maid instils and awakens these different ideas in the mind of a child, as though they were connected with each other, the child during his entire life will perhaps not be able to separate them from each other; so that the darkness ever more will seem to him to be accom- panied with these horrible ideas. If any one has suffered a grievous wrong on account of another, he thinks very often of the persons and the deed, and while he thus strongly or for a long time thinks thereupon, he at the same time glues these two ideas together so firmly, that he makes them almost one, as it were, and never remembers the person but that the wrong received also enters his head. And while he can scarcely distinguish these two things, he has just as much aversion for the one as for the other. Thence it comes, Locke adds, that hatred arises from slight and worth- less reasons, and quarrels are taken up and continued in the world. One of Locke's friends was wholly cured of madness by a certain man through a very painful operation, for which service he acknowledged himself under great obligation to him through- out his life, as he was so circumstanced that he required from no one a greater service during his life. Eeason or gratitude might suggest to him what they would, yet he could never bear the sight of this surgeon. For as the sight of him always brought again to mind the idea of the very great pain which he had been obliged to endure at his hands, he could not endure this idea, so violent were the impressions it produced in his mind. Many children hold their books, which were the occasion hereto, accountable for most of the ill treatment they endured at school, and they unite these ideas so well that they regard a book with great disgust, and all their life study and books 30 LEIBNITZ'S CEITIQUE OF LOCKE [in cannot win their love, because to them reading, which might otherwise have greatly delighted them, became a genuine tor- ture. An example notable for its singularity is the following which an eminent man, who assured him he had himself seen it, re- lates to Locke : A young man had learned to dance very prettily and perfectly. There chanced to stand, however, in the hall where he first learned, an old trunk, the idea of which com- bined so imperceptibly with his turns and steps in the dance, that although he could dance incomparably well in this hall, he could do this only when the old trunk was there ; in other places, however, he could not dance at all, unless the old trunk itself or one like it stood in its accustomed place. The habitus intellectuales which are contracted through such association of ideas, are, as Locke further informs us, just as strong and numerous, even though very little heeded. Sup- posing the ideas of being and matter were very strongly united, either by education or by an excessively great application to these two ideas, according as they are combined in the mind, what notions and reasonings would they not produce concern- ing different spirits ? If a custom accepted from childhood up had united a form or figure with the idea of God, into what absurdities would such a thought in the contemplation of deity not plunge us ? We shall no doubt find, Locke adds, that it is nothing else than similar ill-grounded and unnatural combi- nations of ideas, which break the path for the many conflicting sects in philosophy and religion ; for it is not to be svipposed that each member of those different sects is willingly deceived, and against his better knowledge and conscience rejects the truth demonstrated to him by clear evidence. It is indeed certain that sometimes interest assists greatly in this sort of thing, yet no one could affirm that it could captivate and lead astray whole societies, so that they all, none excepted, should affirm plain and deliberate falsehoods. For it must be that some at least do what others pretend to do, viz. : seek truth sincerely. Therefore there must be something which blinds their un- derstanding and hinders them from recognizing the falsehood of what they consider as pure and refined truth. If now we ■investigate accurately what takes reason prisoner and darkens in] ON HUMAN UNDERSTANDING 31 the understanding of otherwise sincere people, v/e find that it is simply and solely some free ideas, which, properly speaking, really have no bond among themselves, but which, by educa- tion, custom, and uninterrupted action on their part, are so united in the mind that they can no more be separated and distinguished from one another than a single idea. Thence it comes, Locke continues, that often the crudest things are taken for worthy opinions, absurdities for demonstrations, and intolerable and absurd results for strong and fluent reason- ings. The other chapter we promised to present, treats of Enthu- siasm, and is the 19th in the 4th book. Locke's thoughts thereupon are as follows : — Whoever will earnestly seek for truth must first before all things acquire a love for it. Whoever does not love the truth, to him we must necessarily attribute the opposite. Hence we can rightly say, that among those who pretend to seek it, there are very few who really Ipve it. We may recognize a genuine seeker of the truth, since he does not assume for a statement any greater certainty than the proofs upon which he grounds it warrant. Whoever steps bej'ond this limit lays hold of the truth not out of love for it, but from another indi- rect purpose. For while the unquestionable clearness of a statement truly consists in the evidence for it (excepting those which are sufficiently clear of themselves), yet it is plain that so far as space is given to assent beyond the unques- tionable clearness of a proposition, the remaining portion of the assurance is not drawn from love for the truth, but from another passion. For as it is impossible that love for the truth can bring any one to give to any proposition an assent greater than that certified by the truth itself, just so is it also impossijble that any one out of love for the truth can assent to a statement in view of evidence of such a character that from it he cannot see whether the statement is true ; which would be actually equivalent to the assumption that the proposition is a truth because possibly, or, indeed, probably, it seems not to accord with the truth. Locke adds, it follows indisputably from this evil disposi- tion of the mind, that men assume the authority to dictate their own opinions to others. For how should one who has 32 LEIBNITZ'S CRITIQUE OF LOCKE [in imposed on his own belief, not be willing also to impose on the belief of others ? How is it to be expected that one will use valid arguments and proofs in dealing with others, who is not accustomed to use them in dealing with himself,, who does violence to his own powers, who tyrannizes over his own mind, and misuses the advantage which truth alone has, viz. : that it assents to nothing but what is indisputably true ? After Locke has laid this foundation, he proceeds to the in- vestigation of Enthusiasm, to which some people ascribe as much power as to faith and reason, and would establish revela- tion without the aid of reason, whereby, however, they would at once destroy both reason and revelation, and without any reason erect in 'their place the fancies forged in their own brain, which they choose as the plumb-line of their opinions and conduct. Eeason is nothing else than a natural revela- tion, whereby God bestows upon men that portion of truth which he has poured into the capacity of their natural powers. Eevelation is natural reason, enlarged by a new set of discov- eries flowing immediately from God, the ground (raison) of which is the truth by testimony and proof they offer that these discoveries actually come from God.^ Whoever, there- fore, destroys reason to make room for revelation, extin- guishes both these lights at the same time. As, however, men find that an immediate revelation is a much easier means of strengthening their opinions and of directing their conduct than the labor of arranging all according to strict reasoning, which is usually irksome, prejudiced, and for the most part without successful progress ; so it is not to be wondered at that they often pretend revelations and persuade themselves that God directs them in particular as regards their actions and opinions, and especially in those things which they cannot justify by the principles of reason. If their minds are once possessed with this thought, the most absurd opinions which are firmly impressed upon their fancy, must seem to be illu- minations coming from the Spirit of God and having divine authority. Every extraordinary thing to which they are led by a strong impulse, they consider as certainly a divine call 1 On this whole discussion, rf. an article by the translator entitled "Reve- lation, Inspiration and Authority," in "The Andover Review," April 1891. — Tr. Ill] ON HUMAN UNDERSTANDING 33 which they must follow, and as a command from on high in whose execution it is impossible to err. This is, properly speaking, what is meant by Enthusiasm, which is not adjusted to reason nor to divine revelation, but springs forth only from the imagination of a heated and con- ceited spirit, and which, as soon as it has taken a little root, plays much more strongly upon the opinion and actions of men than reason or revelation separately or together. Although now the extravagant actions and opinions, wherein enthusiasm has involved men, should spur them on to be more on their guard and to avoid the false principia, which lead astray both their belief and their conduct ; yet through its love for the extraordinary, through its ease and illumined by its glory, and through its extraordinary paths to knowledge it has come to pass that the laziness, ignorance, and vanity of many are so tickled, and they are brought to such a point, that after they are captivated by such ways of an immediate reve- lation, of an illumination without search, of a certainty with- out proof and investigation, it is very difficult to bring them out of it again. They are transported beyond reason, and reason in their case perishes. They see a light infused into their understand- ing and can no longer be deceived. This light visibly appears as the clearest sunbeam and requires no other proof than its own clearness. They feel, according to their statements, the hand of God moving them within ; they feel the impulses of the Spirit, and cannot be mistaken in their feeling. Thus they persuade themselves that reason has nothing to do with what they see and feel in themselves. The things which they clearly experience are beyond all doubt, and need no proof; and so of all the rest of their strange talk. They are sure of these things because they are sure of them, and their opinions are correct because they are firmly fixed in their mind. For this is the upshot of their words when stripped of the meta- phors of hearing smd feeling in which they are clothed. Locke investigates the ground of this inner light and feel- ing, upon which these people so firmly base themselves, and speaks thus : Is this seeing of the light a perception of the truth of a certain particular statement, or perhaps of this, that it is a revelation from God ? Is this feeling a perception of D 34 LEIBNITZ'S CRITIQUE OF LOCKE [iii an inclination, which, comes from a fancy to do something, or from the spirit of God, Avhich begets in it this inclination? These are two wholly different feelings, which must be care- fully distinguished from one another if we would not deceive ourselves. I can perceive the truth of a proposition; but I cannot thereby know as yet whether it is an immediate revela- tion from God. I can perceive the truth of a proposition in Euclid without its being or my knowing that it is a revelation, I may also know that I did not attain this knowledge through natural means, thence may indeed conclude that it is revealed to me, but I cannot thereby yet know it is a revelation from God; because there may be minds which without a divine commission for this work arouse these ideas in me and set them in such order in my mind that I may perceive their con- nection. So that the knowledge of a proposition, which enters my head, I know not how, is thus not an evidence that it comes from God. Still less is a firm persuasion that this fancy is true, a certain evidence that it comes from God, or that it is true. We itiay call such a fancy sight or light, yet it is nothing more than belief and confidence.^ For if the proposition under discussion be one which they have imagined, but do not know to be true, it cannot be seeing, but believing. One may also give to such, fancy any name he pleases. What I believe, I must put forth as true upon another's testimony, and must know certainly in the case that this testimony is given ; for without this my belief would be groundless. I must see whether God reveals this to me, or whether I see nothing. Thus the issue is, that I know how I am to know that God reveals something to me, that this impression in my soul occurs through the Holy Spirit, and that consequently I am bound to follow it. If I do not know this, my confidence, great as it may be, is without the least foundation, and all the light with which I perceive myself illumined, is but enthusi- asm. For whether the proposition supposed to be revealed, be evidently true in itself, or visibly probable, or whether it be difficult to vindicate it by the ordinary paths of knowledge, this must nevertheless before all things be clearly established and proved, that God has revealed this proposition, and that 1 The German is " Credulitat und Confldentz." — Tr. Ill] ON HUMAN UNDERSTANDING 35 what I take as a revelation certainly comes of itself into my mind, and is no illusion, which some one else has thrust in or my own fancy has awakened. Until one has come this far, all confidence that this revelation .comes from God is a mere conjecture, and all this light which dazzles one is nothing but an ignis fatuus, which will unceasingly lead us into this circle : Tills is a revelation because I firmly believe it; and I believe it because it is a revelation. It follows from this that those who imagine that they have such revelations of this or that truth must be assured that it is God who has revealed it to them. Eor to say, as they gen- erally do, that they know it by the light which it brings with it, which shines and flashes in their souls, and which they cannot resist, means only that it is a revelation because they believe it certainly is one ; since all the light of which they speak is nothing but a strong imagination which is firmly fixed in their mind, and yet has not the least ground that it is a truth. For they must consider that to assume accepted grounds as reasonable and as a proof that it is a truth, is a nec- essary acknowledgment that they have no such (grounds). ■■• Because, if they have such, they receive this truth no longer as a revelation, but as a truth established upon common grounds. And if they believe it to be true, because it is no revelation, and if they have no other reason to prove it a revelation than simply because they are completely persuaded of its truth, without any other ground and only on account of this fancy, then they believe it to be a revelation only be- cause they strongly believe it to be a revelation. Who does not see that if we build vipon such grounds, we make our own fancy the only rule of our opinions and conduct, and conse- quently subject ourselves to the strangest errors and vexa- tions. For once for all the strength of our opinions is no proof of their correctness. Meanwhile men can approve an error as a truth, as may be seen in the case of those zealous people who maintain in the sharpest manner two propositions contrary to one another. In reference to which Locke well says, that if the liglit, 1 The text is: "Denn dieses miissen sie vor raisonable und von einigem Beweise halten, der da zeige, dass es eine Warheit sey, genommene Griinde annehmen, dass sie erkermen miissen, wie sie dergleiclien nicht liaben." — Tk. 36 LEIBNITZ'S CRITIQUE OF LOCKE [m which every one thinks he has in himself, and which in this case is nothing but the strength of his own opinion, be a proof that his thought comes from God, then we must conclude that all contrary opinions have the right to pass as divine inspira- tions ; and God would be not only the father of light, but also of wholly opposite lights, which lead men in ways wholly contrary. Therefore Locke concludes that he who does not wish to fall into a mass of disorderly delusions and errors must first test thoroughly this inner light which offers itself as a guide. God, he says, does not destroy the man when he makes a prophet. He leaves all his faculties in their natural condi- tion, so that he may thereby judge whether the inspirations which he feels within have sprung from God or not. If God will have us acknowledge the truth of a proposition, he permits us to see this truth either through the ordinary paths of nat- ural reason, or he makes us know that it is a truth which we must receive upon his authority, while he convinces us by certain marks which reason cannot reject that it comes from him. I will not, however, Locke adds, say by this, that we are to examine by reason whether a proposition thus revealed to us by God may be proved by natural principles, and if not we may reject it; but I will say, that we must consult reason and by its aid see whether it be a revelation from God or no. For if reason finds it to be a divine revelation, it declares for it as such from that hour on as well as for any other truth, and makes it one of its rules, so that it cannot be rejected. If this inner light, or a proposition which presents itself in our mind as revealed, accords with the principles of reason or with the word of God which is an attested revelation, we have the warrant of reason for it, and may accept this light as true, and direct our faith and walk accordingly. If, however, this light has the witness or proof of neither of these rules, we cannot consider it as a revelation ; nay more, as a truth. For if we at the same time believe it to be a revelation, that does not, however, make it so ; it may, however, be shown by some other mark to be really a revelation. The old prophets, when they were to receive revelations from God, had other proof than the inner light which assured them that these revelations really came from God, They imagined not only that their Ill] ON HUMAN UNDERSTANDING 37 imaginations came from God, but they had also external signs which convinced them that God was the author of their reve- lation. And if they were to convince others of the same, they received beforehand a special power to set forth the truth of the commission given them of Heaven with visible signs. Thus Moses saw a burning bush which was yet not consumed and heard a voice out of the bush. This was something more than an inner feeling of an impulse to free the children of Israel from the hands of Pharaoh. Yet, Moses did not believe that this was enough to warrant him in going into Egypt with God's commission ; until God assured him by still another miracle, of the rod changed into a serpent, that such was his real will, and granted him the power to work precisely similar wonders in the sight of Pharaoh. Precisely similar was it in Gideon's case. These and other examples of the old prophets show suificiently that they did not believe that an inner vision or their own imagination attested by no other affirmation a suffi- cient evidence that their imagination came from God ; although the Scripture does not everywhere mention that they always asked for or received such proofs. These few passages from the clever work of Locke, under the guidance of the accurate translator Coste, we have brought forward as specimens. Perhaps we shall have further oppor- tunity to speak of it, when the Latin translation, with which some one ^ is now occupied in England, is published. In the " Monatliche Auszug " of the year 1701 is found (pp. 73-75) the following addition to the foregoing sketch : — What Locke says of the connection and accompaniment of ideas is not to be despised, and serves often to arouse the emo- tions; as for errors and false judgments, however, they spring from other contiguous and peculiar causes, viz.: that one assumes false principles, and imagines that he once had proof of them in his mind, within which now a lapse of memory occurs ; and then from incorrect conclusions which he produces from these principles assumed as known, because he gives not the time and labor to investigate all in a formal and orderly way. 1 Burridge of Dublin. The version appeared in 1701. — Tr. 38 ■ LEIBNITZ'S CRITIQUE OF LOCKE [in Meanwhile it is true that the emotions greatly assist this credu- lity concerning principles and carelessness in false deduction ; for one believes and easily draws the conclusion he would gladly have. It is besides noticeable in this book of Locke's, that in his last writings against the Rev. Lord Bishop Stillingfleet he has changed a large part of his opinions concerning the nature of the body contained in this Tentamen or Essay on Human Understanding; while in this Tentamen he held opinions, in common with modern philosophers, especially the followers of Descartes and Gassendi, that in the body nothing is to be met with but size, solidity or impenetrability, and motion or change ; noAV, however, he begins to hold the opinion that there is something to be found therein not revealed through these qualities. He repudiates, besides, in this essay innate ideas and the natural light, but appears not to distinguish suffi- ciently the necessary truths arising from possibility, from those others whose ground must be assumed from the experience of realities, and thus must be drawn from without. Thus he accepts the tabula rasa of Aristotle, rather than the implanted (ideas) of Plato. It is true that we do not come upon thoughts in these most abstract matters, without external sensations, but in the case of these necessary truths, such sensations serve more as a reminder than as a proof ; which (proof) must come simply and solely from internal grounds, as those do not sufficiently understand who deal little b> -demonstration proper. NEW ESSAYS ON THE UNDERSTANDING Bv THE Author of the System of Pke-Established Harmony PREFACE The Essay on the Understanding, by a distinguished English- man, being one of the most beautiful and esteemed works of this period, I have resolved to make some remarks upon it, because having sufficiently meditated for a long time upon the same subject and upon the greater part of the matters therein touched upon, I have thought that it would be a favorable opportunity to publish something under the title of " jSTew Essays on the Understanding," and to procure a favor- able reception to my thoughts, by putting them in so good company. I ^ have thought also that I could profit from the labor of another not only to lessen my own (since in fact it is less difficult to follow the thread of a good author than to work wholly independently), but further to add something to what he has given us, which is always easier than to start from the beginning ; for I think I have cleared up some difficulties which he had left in their entirety. Thus his reputation is aii advantage to me ; having for the rest a disposition to render justice, and very far from wishing to diminish the esteem in which this work is held, T would increase it, if my approval carried any weight. It is true I' often differ in my views (from 1 Gerliardt's text reads as follows: "J'ai cru encor pouvoir profiter du travail d'autruy non seulement pour diminuer le mien (puisqu'eii effect il y a moins de peine a suivre le fil d'un bon attteur qn'a travailler a nouveaux frais en tout), mais encor pour ad j outer quelque chose a ce qu'il nous a donne, ce qui est tousjours plus facile que de commencer; car je crois d'avoir leve quelques difficulte's qu'il avoit laisse'es en leur entier. Ainsi sa reputation m'est avantaguese; estant d'ailleurs d'liumeur a rendre justice et bieu loin de vouloir diminuer I'estime qu'on a pour cet ouvrage, je I'accroistrois, si mon approbation estoit de quelque poids. II est vray qne je suis souvent d'un autre avis, mais bien loin de disconvenir du merite des Ecrivains celebres, on leur rend temoignage, en faisant connoistre en quoy et pour quoy on s'eloigne de leur sentiment, quand on juge necessaire d'empecher que leur autorite ne prevaille a la raison en quelques points de conseqiience, outre qu'en satisfaisant a de si excellens hommes, on rend la verite' plus recevable, et il faut supposer que c'est principalement pour elle qu'ils travaillent." — Tk. 41 42 LEIBNITZ'S CRITIQUE OF LOCKE liim^), but very far from denying the merit of celebrated writers, we bear witness to it, by making known in what and why we differ from their views, when we judge it necessary to prevent their authority from prevailing over reason on some important points ; besides, by satisfying such excellent men, we render the truth more acceptable, and it must be supposed that it is principally for truth that they labor. In fact, although the author of the Essay says a thousand beautiful things which I commend, our systems are very dif- ferent. His has more relation to Aristotle, mine to Plato, although we both differ in many things from the doctrine of these two ancient philosophers. He is more popular, and I am compelled sometimes to be a little more acroamatic and more abstract, which is not an advantage to me, especially when writing in a living language. I think, nevertheless, that by making two persons speak, one of whom sets forth the views drawn from the Essay of this author, and the other joins thereto my observations, the parallel will be more to the liking of the reader than wholly dry remarks, the reading of which would be interrupted at every moment by the necessity of recurring to his book in order to understand mine. It will nevertheless be well still to compare sometimes our writings, and not to judge of his views except by his own work, although I have ordinarily preserved its expressions. It is true that the constraint, which another's discourse, whose thread must be followed, gives in making remarks, has prevented me from thinking to secure the charms of which the dialogue is sus- ceptible ; but I hope the matter will make amends for the defects of the style. Our differences are upon subjects ^ of some importance. The question is to know whether the soul in itself is entirely empty as the tablets iipon which as yet nothing has been written (tabula rasa) according to Aristotle, and the author of the Essay, and whether all that is traced thereon comes solely from the senses and from experience ; or whether the soul con- tains originally the principles of many ideas and doctrines which external objects merely call up on occasion, as I believe 1 Ei-dmann and Jacques read : " que lui," which does not occur in Gerhardt's text.— Tr. ^ Erdmann and Jacques read : " objects." —Tr. ON HUMAN UNDERSTANDING 43 with Plato, and even with the schoolmen, and with all those who interpret in this way the passage of St. Paul (Rom. 2: 15) where he states that the law of God is written in the heart. The Stoics call these principles ^ proZepses, i.e. fundamental assumptions, or what is taken for granted in advance. The Mathematicians call them general notions (Kocval ei/votat). Mod- ern philosophers give them other beautiful names, and Julius Scaliger in particular named them semina ceternitatis, also zopyra, i.e. living fires, luminous flashes, concealed within us, but which the encounter of the senses makes appear like the sparks which the blow makes spring from the steel. And the belief is not without reason, that these glitterings indicate something divine and eternal which appears especially in the necessary truths. Whence another question arises, whether all truths depend upon experience, i.e. upon induction and examples, or whether there are some which have still another foundation. For if some events can be foreseen prior to any proof which may have been made of them, it is manifest that we ourselves contribute something thereto. The senses, although necessary for all our actual knowledge, are not suffi- cient to give it all to us, since the senses never give us anything but examples, i.e. particular or individual truths. Now all the examples which confirm a general truth, whatever their num- ber, do not suffice to establish the universal necessity of that same truth, for it does not follow that what has happened will happen in the same way. Por example, the Greeks and the Eomans, and all the other peoples of the earth known to the ancients, have always observed that before the lapse of twenty- four hours day changes into night, and night into day. But we would be deceived, if we believed that the same law holds good everywhere else; for since then, the contrary has been experienced in the region of Nova Zembla. And he would still be in error who believed that, in our climates at least, this is a necessary and eternal truth, which will always endure, since we must think that the earth, and the sun even, do not necessarily exist, and that there will perhaps be a time when this beautiful star, together with its whole system, will not longer exist, at least in its present form. Whence it appears 1 For a very full nomenclature of these principles, see Hamilton's Reid, Note A., § v., Vol. II., pp. 755-770. 8th ed., Edinburgh and Loudon, 1880. — Tr. 44 LEIBNITZ'S CRITIQUE OF LOCKE that necessary truths such as are found in pure mathematics, and particularly in arithmetic and in geometry, must have principles whose proof does not depend upon examples, nor consequently upon the testimony of the senses, although with- out the senses it would never have occurred to us to think of them. This distinction must be carefully made, and was so well understood by Euclid, that he often proved by the reason, what is sufficiently seen through experience and by sensible images. Logic also, together with metaphysics and ethics, one of which shapes theology and the other jurisprudence, both natural (sciences), are full of such truths, and consequently their proof can come only from internal principles which are called innate. It is true that we must not imagine that these eternal laws of the reason can be read in the soul as in an open book, as the praetor's edict is read upon his album without diffi- culty and research; but it is sufficient that they can be discov- ered in us by dint of attention, for which the senses furnish occasions, and successful experience serves to confirm reason, in much the same way as proofs in arithmetic serve for the better avoidance of error in calculating when the reasoning is long. Herein, also, human knowledge differs from that of the brutes : the brutes are purely empirics and only guide themselves by examples; for, so far as we can judge of them, they never attain to the formation of necessary propositions ; while men are capable of demonstrative sciences. It is also for this reason that the faculty the brutes have for making consecutions is something inferior to the reason of man. The consecutions of the brutes are merely like those of simple empirics, who claim that what has sometimes happened will happen again in a case where something strikes them as similar, without being able to judge whether the same reasons hold good. This is why it is so easy for men to entrap the brutes, and so easy for simple empirics to make mistakes. This is why persons who have become skilful through age and experi- ence are not exempt (from error) when they depend too much upon their past experience, as has happened to many in civil and military affairs ; because they do not consider sufficiently that the world changes, and that men become more skilful by finding a thousand new dexterities, while the deer and hares of the present do not become more cunning than those of the ON HUMAN UNDERSTANDING 45 past. The consecutions of the brutes are only a shadow of reasoning, i.e. are only connections of the imagination and passages from one image to another, because in a new juncture which appears similar to the preceding they expect anew that connection which they formerly met with, as if things were united in fact because their images are united in the memory. It is true that reason also counsels us to expect ordinarily to see that happen in the future which is conformed to a long past experience, but it is not on this account a necessary and infalli- ble truth, and success may cease when least expected, when the reasons change which have sustained it. Therefore the wisest men do not so commit themselves to it as not to try to discover, if possible, something of the reason of this fact in order to judge when it is necessary to make exceptions. For reason is alone capable of establishing sure rules, and supply- ing Avhat is wanting to those which were not such by inserting their exceptions ; and of finding at length certain connections in the force of necessary consequences, which often furnish the means of foreseeing the result without the necessity of experiencing the sense-connections of images, to which the brutes are reduced, so that that which justifies the internal principles of necessary truths also distinguishes man from the brutes. Perhaps our clever author will not Avholly differ from my view. For after having employed the whole of his first book in rejecting innate intelligence, taken in a certain sense, he nevertheless, at the beginning of the second and in the sequel, admits that ideas, Avhicli do not originate in sensation, come from reflection. 'Now reflection is nothing else than attention to what is in us, and the senses do not give us what we already carry with us. That being so, can it be denied that there is much that is innate in our mind, since we are innate, so to speak, in ourselves ? and that there is in us : being, unity, substance, duration, change, action, perception, pleasure, and a thousand other objects of our intellectual ideas ? And these objects being immediate to our understanding and always pres- ent (although they cannot always be perceived by reason of our distractions and needs), what wonder that we say that these ideas with all depending upon them are innate in us ? I have made use also of the comparison of a block of marble which 46 LEIBNITZ'S CEITIQUE OF LOCKE has veins, rather than of a bh)ck of marble wholly even, or of blank tablets, i.e. of what is called among j)hilosophers a tabula rasa. For if the soul resembled these blank tablets, truths would be in us as the figure of Hercules is in the marble, when the marble is wholly indifferent to the reception of this figure or some other. But if there were veins in the block which should indicate the figure of Hercules rather than other fig- ures, this block would be more determined thereto, and Her- cules would be in it as in some sense innate, although it would be needful to labor to discover these veins, to clear them by polishing, and by cutting away what prevents them from ap- pearing. Thus it is that ideas and truths are for us innate, as inclinations, dispositions, habits, or natural potentialities, and not as actions ; although these potentialities are always accom- panied by some actions, often insensible, which correspond to them. It seems that our clever author claims that there is nothing virtual in us, and indeed nothing of which we are not always actually conscious ; but he cannot take this rigorously, other- wise his opinion would be too paradoxical ; since, moreover, acquired habits and the stores of our memory are not always perceived and do not even always come to our aid at need, although we often easily recall them to the mind upon some slight occasion which makes us remember them, just as we need only the beginning of a song to remember it.^ He limits his thesis also in other places, by saying that there is nothing in us of which we have not at least formerly been conscioiis. But besides the fact that no one can be assured by reason alone how far our past apperceptions, which we may have for- gotten, may have gone, especially according to the Platonic doctrine of reminiscence which, wholly fabulous as it is, is in no respect incompatible at least in part with reason wholly pure : besides this, I say, why must we acquire all through the perception of external things, and nothing be unearthed in ourselves ? Is our soul then by itself such a blank that besides the images borrowed from without, it is nothing ? This is not an opinion (I am sure) that our judicious author could approve. 1 Erdmann and Jacques read : " le commencement d'une chanson pour nous faire ressouvenir du reste," i.e. the heginning of a song to remind us of the rest. — Tr. ON HUMAN UNDERSTANDING 47 And where do we find tablets that have no variety in them- selves ? For we never see a plane perfectly even and uniform. Why, then, could we not furnish also ourselves with something of thought from our own depths if we should dig therein ? Thus I am led to believe that at bottom his opinion upon this point is not different from mine, or rather from the common view, inasmuch as he recognizes two sources of our knowledge, the Senses and Reflection. I do not know whether it will be so easy to harmonize him with us and with the Cartesians, when he maintains that the mind does not always think, and particularly that it is without perception when we sleep without dreaming; and he objects ^ that since bodies can exist without motion, souls can also exist without thought. But here I make a somewhat different reply than is customary, for I hold that naturally a substance cannot-exist without action, and that there is indeed never a body without movement. Experience already favors me, and you have only to consult the book of the 'distinguished Mr. Boyle against absolute rest, to be con- vinced of it; but I believe reason favors it also, and this is one of the proofs I have for doing away with atoms. (Moreover, there are a thousand indications which make us think that there are at every moment an infinite number of perceptwi s in us, but without apperception and reflection, i.e. chtoges in the soul itself of which we are not conscious, be- cause the impressions are either too slight and too great in number, or too even, so that they have nothing sufficiently distinguishing them from each other; but joined to others, they do not fail to produce their effect and to make themselves felt at least confusedly in the mass. Thus it is that habit makes us take no notice of the motion of a mill or a waterfall when we have lived quite near it for some time. It is not that the motion does not always strike our organs, and that something no longer enters into the soul corresponding thereto, in virtue of the harmony of the soul and the body, but these impressions which are in the soul and the body, be- ing destitute of the attractions of novelty, are not strong enough to attract our attention and our memory, attached to objects more engrossing. \ For all attention requires memory, 1 Erdmann and Jacques read: " II dit que," i.e. He says that. — Tr. 48 LEIBNITZ'S CRITIQUE OF LOCKE and often when we are not admonished, so to speak, and warned to take note of some of our own present perceptions, we allow them to pass without reflection, and even without being noticed; but if any one directs our attention to them immediately after, and makes us notice, for example, some noise which was just heard, we remember it, and are conscious of having had at the time some feeling of it. Thus there were perceptions of which we were not conscious at once, con- sciousness arising in this case only from the warning after some interval, however small it may be. And to judge still better of the minute perceptions which we cannot distinguish in the crowd, I am wont to make use of the example of the roar or noise of the sea which strikes one when on its shore. To understand this noise as it is made, it would be necessary to hear the parts which compose this whole, i.e. the noise of each wave, although each of these little noises makes itself known only in the confused collection of all the others, i.e. in the roar itself, and would not be noticed if the wave which makes it Avere alone. For it must be that we are affected a little by the motion of this wave, and that Ave have some per- ception of each one of these noises, small as they are ; other- wise we would not have that of a hundred thousand waves, since a hundred thousand nothings cannot make something. One never sleeps so soundly as not to have some feeble and confused sensation, and one would never be awakened by the greatest noise in the world if he did not have some perception of its small beginning; just as one would never break a rope by the greatest effort in the world if it were not stretched and lengthened a little by smaller efforts, although the slight extension they produce is not apparent. These minute perceptions are, then, of greater efficacy in their results than one supposes. They form I know not what, these tastes, these images of the sense-qualities, clear in the mass, but confused in the parts, these impressions which sur- rounding bodies make upon us, which involve the infinite, this connection Avhich each being has with all the rest of the uni- verse. We may even say that in consequence of these minute perceptions, the present is big with the future and laden with the past, that all things conspire (o-iJ/Airvota Travra, as Hip- pocrates said), and that in the least of substances eyes as ON HUMAN UNDERSTANDING 49 penetrating as those of God could read the whole course of the things in the universe. Quse sint, quse fuerint, quae mox futura trahantur.i These insensible perceptions indicate also and constitute the same individual who is characterized by the traces or expres- sions which they conserve of preceding states of this individual, in making the connection with his present state ; and they can be known by a superior mind, even if this individual himself should not be aware of them, i.e. when there would no longer be in him the express recollection of them. But they (these perceptions, 1 say) furnish, indeed, the means of finding again this recollec- tion at need by the periodic developments which may some day happen. It is for this reason that death can be only a sleep, and cannot, indeed, continue, the perceptions ceasing merely to be sufficiently distinguished, and being reduced in the animals to a state of confusion which suspends consciousness, but which can- not last always ; not to speak ^ here of man, who must have in this regard great privileges in order to preserve his X->ersonality. It is also by means of the insensible perceptions that this admirable pre-established harmony of the soul and the body, and indeed of all the monads or simple substances, is ex- plained;^ which supplies the place of the unmaintainable influence of one upon the others, and which in the judgment of the author of the most excellent of dictionaries exalts the grandeur of the divine perceptions beyond what has ever been conceived. After this I would add little if I should say that it is these minute perceptions which determine vis in many junctures without being thought of, and which deceive the vulgar by the appearance of an indifference of equilibrium, as if we were entirely indifferent whether we turned (for ex- ample) to the right or to the left. It is not needful also that I notice here, as I have done in the book itself, that they cause that uneasiness which I show to consist in something which differs from pain only as the small from the great, and which, however, often constitutes our desire and even our 1 Erdmann reads: qitas mox, etc.; Jacques: qiias mox venUira trahantur. Gerhardt's reading: " que " is evidently an error. — Tr. 2 Erdmann and Jacques omit: "pour ne parler icy de I'homme qui doit avoir en cela des grands privileges pour garder sa personalite." — Tr. 3 Erdmann and Jacques read " j'explique," I explain. — Tr. E 50 LEIBNITZ'S CRITIQUE OF LOCKE pleasure by giving to it au exciting flavor. It is also^ the insensible parts of our sensible perceptions, which jDroduce a relation between the perceptions of colors, heat, and other sensible qualities, and between the motions in bodies which correspond to them ; while the Cartesians together with our author, penetrating as he is, conceive the perceptions which Ave have of these qualities as arbitrary, i.e. as if God had given them to the soul according to his good pleasure, without any regard to any essential relation between these perceptions and their objects : a view which surprises me and which appears to me little worthy of the wisdom of the Author of things, who does nothing without harmony and without reason. In a word, the insensible perceptions are as eminently use- ful in Pneumatology ^ as are the insensible corpuscles in Physics, and it is equally unreasonable to reject the one or the other under the pretext that they are out of reach of our senses. Nothing is accomplished all at once, and it is one of my great maxims, and one of the most verified, that nature maTces no leaps : a maxim which I called the Laio of Contimdty, when I spoke of it in the first "Nouvelles de la Eepublique des Lettres," ^ and the use of this law is very considerable in Physics. This law declares that we pass always from the small to the great, and the reverse, through the medium, in degree as in parts, and that motion never springs immediately from rest, nor is reduced thereto save by a smaller motion, as one never completes the survey of any line or length until he has com- pleted a smaller line, although hitherto those who have set forth the laws of motion have not observed this law, believing that a body can receive in a moment a motion contrary to the preceding. And all this makes one indeed think that the 1 Erdmann and Jacques read : " Ce sont les memes parties insensibles, " etc., It is the same insensible parts, etc. — Tr. 2 I.e. Psycliolosy. Cf. Hamilton's Reid, 8th ed., Vol. I., p. 217 a, and note. — Tr. 3 A literary journal published by Pierre Bayle at Amsterdam, 168-i-lfi87 ; afterwards continued, at Bayle's request, by Basnage, under the title " Histoire de ouvrages des Savants," 1687-1709. Leibnitz published in this journal in July, 1698, his Eclaircissement deii difflculUs que M. Bayle a troiivees clans le sy.'iteme nouveau de I'vnion de I'dme et dti corps. Gerhardt, Vol. 4, pp. 517- 524; Erdmann, pp. 150-154; Jacques, Vol. 1, pp. 481-487. Translation, Appen- dix, pp. 706-712.— Tr. ON HUMAN UNDERSTANDING 51 noticeable perceptions also arise by degrees from those which are too minute to be observed. To think otherwise, is to have little knowledge of the immense subtilty of things which always and everywhere surrounds an actual infinite. I have also noticed that in virtue of these insensible varia- tions, two individual things cannot be perfectly alike, and that they must always differ more than ')imnero : a fact which destroys the blank tablets of the soul, a soul without thought, a substance without action, a vacuum in space, atoms and even particles not actually divided in matter, absolute rest, entire uniformity in one portion of time, place, or matter, perfect globes of the second element, born of cubes perfect and orig- inal, and a thousand other fictions of philosophers which arise from their incomplete notions, and which the nature of things does not allow, and which our ignorance and the little atten- tion we give to the insensible let pass, but which cannot be made tolerable unless they are limited to the abstractions of the mind which protests that it does not deny what it puts aside, and thinks should not enter into any present considera- tion. Otherwise if it were very well understood, viz. : that things of which we are not conscious are neither in the soul nor the body, we should be lacking in philosophy as in politics, in neglecting ro fxiKpov, the insensible progressions, while an abstraction is not an error, provided we know what it is that we feign therein. Just as the mathematicians employ it when they speak of the perfect lines which they propose to us, of uniform motions and of other regulated effects, although matter (i.e. the medley of the effects of the surrounding infinite) always makes some exception. It is for the sake of distinguishing the considerations and of reducing so far as we may do so the effects to reasons, and of foreseeing some of their consequences, that we proceed thus. For the more we are careful to neglect no consideration that we can regulate, the more practice corre- sponds to theory. But it belongs only to the supreme Reason, whom nothing escapes, distinctly to comprehend all the infinite and to see all the reasons and all the consequences. All that we can do in regard to infinites is to know them confusedly, and to know at least distinctly that they are such ; otherwise we judge very wrongly of the beauty and the grandeur of the universe ; so also we could.not have a sound Physics explaining 52 LEIBNITZ'S CRITIQUE OF LOCKE the nature of bodies in general, and still less a proper Pneuma- tology comprising the knowledge of God, of souls, and of simple substances in general. This knowledge of insensible perceptions serves also to explain why and how two souls, human or otherwise,^ of one and the same species never come forth perfectly alike from the hands of the Creator and have always each its original relation to the points of view which it will have in the uni- verse. But this it is vfhich already follows from the remarks I have made about two individuals, viz. : that their difference is always 7nore than numerical. There is, moreover, another point of importance, in respect to which I am obliged to devi- ate not only from the opinions of our author, but also from those of the majority of modern philosophers : I believe with the majority of the ancients that all genii,- all souls, all simple created siibstances, are always joined to a body, and that there are never souls entirely separated. I have a priori reasons for my view ; but the doctrine will be found to have this advan- tage, that it resolves all the philosophical difficulties as to the condition of souls, their perpetual conservation, their immor- tality, and their operation. The difference between one of their states and another, never being and never having been other than that of more sensible to less sensible, of more perfect to less perfect, or the reverse, this doctrine renders their past or future state as explicable as that of the present. One feels sufficiently, however little reflection he makes, that this is rational, and that a leap from one state to another infinitely different could not be natural. I am astonished that by leaving the natural without reason, the schoolmen have been willing purposely to plunge themselves into very great difficulties, and to supply matter for apparent triumphs of the strong-minded, all of whose reasons fall at once by this explanation of things, in which there is no more difficulty in conceiving the conservation of souls (or rather, according to my view, of the animal) than there is in conceiving the change of the caterpillar into the butterfly, and the conservation of thought in sleep, to wdiich Jesus Christ has divinely well com- pared death. I have already said also that sleep could not 1 Erdmann reads : " ou denx cliosos," or two things. — Tr. 2 /_e_ Aiio-els and archangels. — Tb. ON HUMAN UNDERSTANDING 53 last always, aiicL it will last least or almost not at all in the case of rational souls who are always destined to preserve the personality which has been given them in the City of God, and consequently remembrance : and this in order to be more susceptible of chastisements and recompenses. And I add further that in general no derangement of the visible organs is capable of throwing things into entire confusion in the animal or of destroying all the organs and depriving the soul of all its organic body and of the ineffaceable remains of all preceding traces. But the ease wdth which the ancient doc- trine of subtile bodies connected with the angels (which was confounded with the corporeality of the angels themselves) has been abandoned, and the introduction of pretended sepa- rate intelligences in creatures (to which those who make the heavens of Aristotle revolve have contributed much), and finally the poorly understood view into which we have fallen, that the souls of brutes could not be preserved without falling into metempsychosis, and-"- wdthont conducting them from body to body, and the perplexity into which men have fallen by their ignorance of what to do with them, have caused us, in my opinion, to neglect the natural explanation of the conserva- tion of the soul. This has done much harm to natural relig- ion, and has caused many to believe that our immortality was only a miraculous grace of God, of Avhicli also our cele- brated author speaks with some hesitation, as I shall presently remark. But it would be well had all those who are of this opinion spoken as wisely and in as good faith as he, for it is to be feared that many who speak of immortality as a grace do so only to keep up appearances, and resemble at bottom these Averroists and some bad Quietists who picture to themselves an absorption and the reunion of the soul with the ocean of divinity : a notion whose impossibility my system alone perhaps evinces. It seems also that we differ further in regard to matter, in that the author thinks that a vacuum is necessary to motion, because he thinks that the minute parts of matter are rigid. And I admit that if matter were composed of such parts, 1 Gephardt's text is : " et sans les promener de corps en corps, et I'embar- ras ou Ton a este en ne sachant ce qu'ou en devoit faire." Erdmann and Jacques omit the clause. — Tr. 54 LEIBNITZ'S CRITIQUE OF LOCKE motion in a pleimvi would be impossible, as if a room were full of a quantity of little pebbles without there being the least empty space. But this supposition, for which there appears also to be no reason, is not admissible, although this learned author goes as far as to believe that rigidity or cohe- sion of the minute parts makes the essence of the body. It is necessary rather to conceive space as full of a matter origi- nally fluid, susceptible of all the divisions, and even actually subject to divisions and subdivisions to infinity, but with this difference, however, that it is divisible and divided un- equally in different parts on account of the motions which more or less concur there. This it is which causes matter to' have everywhere a degree of rigidity as well as of fluidity, and no body to be hard or fluid in the highest degree, i.e. no atom to be found of an insurmountable hardness nor any mass entirely indifferent to division. The order, also, of nature, and particularly the law of continuity, destroy equally the one and the other. I have also shown that cohesion, which by itself would not be the effect of impulse or of motion, would cause a- traction, taken strictly. For if there were a body originally rigid, — for example, an Epicurean atom, — which should have a part pro- jecting like a hook (since we can imagine atoms of all sorts of shapes), this hook pushed would draw with it the rest of this atom ; i.e. the part which is not pushed, and which does not fall in the line of the impulsion. Our learned author, how- ever, is for himself opposed to these philosophic tractions, such as were formerly attributed to the abhorrence of a vacuum, and he reduces them to imjndsions, maintaining with the moderns that one part of matter works immediately upon another only by pushing it by contact, in which I think they are right, because otherwise there is nothing intelligible in the operation. I must not, however, conceal the fact that I have noticed a sort of retraction by our excellent author on this subject, whose modest sincerity I cannot forbear praising in this respect as much as I have admired on other occasions his penetrating genius. It is in his reply to the second letter of the late Bishop of Worcester,^ printed in 1699, p. 408, where, 1 Edward Stillingfleet, 1635-1699: Bishop of Worcester, lt;89-l(i99. — Tr. ON HUMAN UNDERSTANDING 55 in order to justify the view which he had maintained against this wise prelate, viz. : that matter might think, he says among otlier things : " / admit that I said (Essay on Understanding, Book II. chap. 8, § 11) that body acts by impidse and not otherwise. This also was my view token I wrote it, and even now I cannot conceive its action in any other way. But since then I haoe been convinced by the judicious Mr. Newton's incomxmrable book that there is too much presumption in loishing to limit the power of God by our limited conceptions. The gravitation of matter toivards matter in ivuys inconceivable to me, is not only a demonstration that God, when it seems to him good, can put into bodies powers and modes of acting ivhich are beyond what can be derived from our idea of body or explained by ivhat we know of matter; but it is .furthermore an incontestable instance that he has really done so. I shcdl therefore take care to correct this pidssage in the next edition of my book." ^ I find that in the French version of this book, made undoubtedly from the latest edi- tions, the matter has been put thus in this % 11 : It is evident, at least so far as we can conceive it, that it is by impulse and not otherwise thcd bodies act on each other ; for it is impossible for lis to understand how the body can act upon what it does not touch, ivhich is the same as to imagine that it can act ivhere it is not. I can only praise this modest piety of our celebrated author, who recognizes that God can do more than we can understand, and that thus there may be inconceivable mysteries in the articles of faith ; but I should not wish to be obliged to recur to the miracle in the ordinary course of nature and to admit powers and operations absolutely inexplicable. Otherwise too much license will be given poor philosophers, under cover of what God can do, and by admitting these centripetcd virtues or these immediate attractions from afar without being able to make them intelligible, I see nothing to hinder our Scholastics from saying that everything is done simply by their faculties and from maintaining their intentional species which proceed I I have retranslated the passage from the French version, as given by Ger- hardt. For the original, cf. Locke, Philos. Works (Bohn's ed.). Vol. II., p. 395. The entire letter is found in Locke's Works, Vol. I., pp. 578-774; this particu- lar passage, p. 754. Edition of 4 vols., 4to. 7th ed., 1768. Printed for H. Wood- fall, A. Millar, and others. — Tr. 5U LEIBNITZ'S CRITIQUE OE LOCKE from objects even to us and Unci means of entering even into our souls. If that is so, Omnia jam fieiit, fieri quse posse negabam. So that it seems to me that our author, quite judicious as he is, goes here a little too much from one extreme to the other. He makes a difficulty in regard to the operations of souls when the question is only of admitting what is not sensible, and behold he gives to bodies what is not even intelligible; granting them powers and actions which surpass in my view all that a created spirit can do and understand, since he grants them attraction, and that even at great distances without limiting them to any sphere of activity, and this in order to maintain a view which does not appear less inexj^licable, viz. : the possi- bility of the thought of matter in the natural order. The question which he discusses with the celebrated Prelate who attacked him, is, lohether matter can think, and as it is an important point even for the present work, I cannot refrain from entering upon it a little and from taking note of their controversy. I will give the substance of their discussion upon this subject, and take the liberty of saying what I think of it. The late Bishop of Worcester, fearing (but in my opinion without good reason) lest our author's doctrine of ideas might be liable to certain abuses prejudicial to the Christian faith, undertook to examine some points in it in his "Vindication of the Doctrine of the Trinity" ; ^ and having rendered justice to this excellent writer, by recognizing that he thinks the exist- ence of spirit as certain as that of body, although one of these substances is as little known as the other, he asks (p. 241 sq.) how reflection can assure us of the existence of spirit, if God can give to matter the power of thought according to the view of our author, Book IV., chap. 3, since thus the way of ideas which must serve to discern - what may suit the soul or tho body, would become useless ; while he had said in Book II. of the Essay on Understanding, chap. 23, §§ 15, 27, 28, that the operations of the soul furnish us the idea of mind and the 1 Published in tlie autumn of 1696. Cf. Alexander Campbell Fraser, Locke, pp. 24.5-246 (Philosophical Classics), Edinburgh: Wm. Blackwood and Sons,, 1890. — Tr. 2 Gerhardt reads: "discerner"; Erdmann and Jacques: " discuter," to discuss, debate, argue. — Tr. ON HUMAN UNDERSrANDING 57 understanding, and the will renders this idea as intelligible to us as the nature of body is rendered intelligible to us by solid- ity and impulse. This is how our author replies in his first letter (p. 65 sq.) : " I believe I have proved that there is a spirit- ual substance in us, for ive experience in ourselves thought. JSfoio this action or this mode cannot be the object of the idea of a thing subsisting by itself, and consequently this mode needs a supiport, a subject, in ivhich it may inhere, and the idea of this sxq')port forms ivhat ive ccdl substance. . . . For since the general idea of sub- stance is everywhere the same, it follows that the modification^ which is called thought or poiver of thinJcing, being joined to it, there residts a mind without the necessity of considering ivhat other modijication it has besides ; i.e. ivhether it has solidity or not. And, on the other hand, the substance which has the modiji- cation called solidity icill be matter, ivhether thought is joined to it or not. But if by a spiritual substance you mean an immatericd substance, I admit that I have not jjroved that there is one in us, and that it cannot be demonstrably proved on my princip)les. Al- though ichat I have said on the systems of matter (Book IV., chap. 10, § 16) in proving that God is immatericd, renders it in the highest degree probable, that the substance ivhich thinks in us is immaterial. . . . However, I have shoivn [the author adds, p. 68] that the great ends of religion and of morals are' assured by the immortcdity of the soul, tvithoiU the need of supposing its immatericdity .'^ ^ The learned Bishop in his reply to this letter, in order to make it evident that our author held another view, when he wrote the second book of the Essay, quotes, p. 51, this passage (taken from the same book, chap. 23, § 15), where it is said, that by the simjde ideas which ive have deduced from the operations of our mind, we can form the compilex idea of a mind. And that putting together the ideas of thought, of perception, of liberty, and of power to move our body, ive have as clear a notion of immcde- rial substances as of material. He quotes still other passages to show that the author opposes mind to body. And he says (p. 54) that the ends of religion and of morals are the better 1 1 have retranslated the passage from the French version as given by Ger- hardt. For the original, cf. Locke, Philos. Works (Bohn's ed.), Vol. II., p. 387. The entire letter is found in Locke's Works, Vol. I., pp. 458-.517 ; this particular passage, p. 477. Edition of 4 vols., 4to. 7th ed., 17()8. Printed for H. Woodfall, A.' Millar, and others. — Tr. 58 LEIBNITZ'S CRITIQUE OF LOCKE assured by proving that the soul is immortal by its nature, i.e. immaterial. He quotes also (p. 70) this passage, that the ideas we have of particular and distinct kinds of substances are nothing else than different combinations of simple ideas ;^ and that thus the author believed that the idea of thinking and of willing gave another substance different from that which the idea of solidity and of impulse gives, and that (§ 17) he remarks that these ideas constitute the body as opposed to mind. The Bishop of Worcester might add that from the fact that the general idea of substance is in the body and in the mind, it does not follow that their differences are modifications of one and the same thing, as our author has just said in the part of his first letter which I have quoted. It is necessary carefully to distinguish between modifications and attributes. The faculties of having perception and of acting, extension, solid- ity, are attributes or perpetual and principal predicates ; but thought, impetuosity, figures, movements, are modifications of these attributes. Furthermore, we must distinguish between physical (or, rather, real) genus and logical or ideal genus. Things which are of the same physical genus, or which are homogeneous, are of the same matter, so to sjDcak, and may often be changed the one into the other by the change of mod- ification, as circles and squares. But two heterogeneous things may have a common logical genus, and then their differences are not simple accidental modifications of one and the same subject, or of one and the same metaphj^sical or physical mat- ter. Thus time and space are yqvj heterogeneous things, and we should do wrong to imagine I know not what real common subject which had only the continuous quantity in general, and whose modifications should cause the rise of time and space. ^ Some one will perhaps laugh at these distinctions of the philosophers of two genera, the one merely logical, the other real ; and of two matters, the one physical, viz. : that of bodies, the other metaphysical only or general ; as if some one said that two parts of space are of one and the same matter, or that two hours are likewise among themselves of one and 1 Locke, Philos. Works (Boliu's ecL), Vol. 1, p. 426, chap. 23. § 6. — Tr. 2 Erdmanu and Jacques add : " Cepeudant leur genre logique commun est la quantite' continue," i.e. Nevertheless their common logical genus is the con- tinuous quantity. — Tr. ON HUMAN UNDERSTANDING 59 the same matter. Nevertheless, these distinctions are not dis- tinctions of terms merely, but of things themselves, and seem to come in here very opportunely, Avhere their confusion has given rise to a false conclusion. These two genera have a common notion, and that of the real genus is common to the two matters, so that their genealogy will be as follows : — f Logical merely, varied by simple differences. j r Metaphysical only, where TfJiMS-, ^g^;^ ^i^Qgg ^jjg,,g,jg^s are modi-] there is homogeneity. [ Jications, i.e. Matter. ] Physical, where there is a [ solid homogeneous mass. I have not seen the second letter of the author to the Bishop,- and the reply which this prelate makes to it scarcely touches the point relating to the thinking of matter. But the reply of our author to this second answer returns to it. God (says he, nearly in these words, p. 397) adds to the essence of matter the qualities and j^&i'f^ctions ivMch please him, simple movement in some 2>arts, hut in plants, vegetation, and in ani- mals, sentiency. Those ivho agree up to this point, cry out as soon as we go a step farther, and say that God can give to matter thought, reason, will, as if this destroyed the essence of matter. But to prove it, they allege that thought or reason is not included in the essence of matter, a 2'>oint of no consequence, since move- ment and life are not included therein either. They assert, cdso, that we cannot conceive of matter as thinJcing ; but our coyiception is not the measure of God's poicer.^ After this he cites the ex- ample of the attraction of matter (p. 99, but especially p. 408), where he speaks of the gravitation of matter towards matter, attributed to Mr. Newton (in the terms which I have quoted above), admitting that we can never conceive the manner of it. This is in reality to return to the occult, or, what is more, in- explicable qualities. He adds (p. 401) that nothing is more calculated to favor the sceptics than to deny what "We do not understand ; and (p. 402) that we do not conceive even how the soul thinks. He will have it (p. 403) that, since the two sub- 1 For the original, cf. Locke, Philos. Works (Bohn's eel.), Vol. 2, pp. 390, 391. The entire letter is found in Locke's Works, Vol. 1, pp. 578-774; this particu- lar passage, pp. 749, 750. Edition of 4 vols., 4to. 7th ed., 17G8. Printed for H. Woodfall, A. Miller, and others. — Te. 60 LEIBNITZ'S CRITIQUE OF LOCKE stances, material and immaterial, are capable of being conceived in their naked essence without any activity, it depends upon God to give to each the power of thought. And he wishes to take advantage of the admission of his opponent, who had granted sentiency to the brutes, but who would not grant them any immaterial substance. He claims that liberty, conscious- ness (p. 408), and the power of abstract thought (p. 409) can be bestowed upon matter, not as matter, but as enriched by a divine power. Finally, he quotes (p. 434) the remark of a traveller as eminent and judicious as M. de la Loubere,-^ that the pagans of the East acknowledge the immortality of the soul without being able to comprehend its immateriality. On all this I would remark, before coming to the explana- tion of m}'- view, that it is certain that matter is as little capa- ble of mechanically producing feeling, as of producing reason, as our author admits ; that in truth I acknowledge that it is not permissible to deny what we do not understand, but I add that we are right in denying (at least in the natural order) what is absolutely neither intelligible nor explicable. I main- tain, also, that substances (material or immaterial) cannot be conceived in their naked essence without any activity ; that activity belongs to the essence of substance in general ; that, finally, the conception of creatures is not the measure of God's power, but that their conceptivity, or power of conception, is the measure of nature's power; all this is in harmony with the natural order, being capable of being conceived or under- stood by some creature. Those who understand my system will think that I cannot wholly agree with the one or the other of these two excellent authors, whose discussion, however, is very instructive. But to explain myself distinctly, it is necessary before all things to consider that the modifications which may belong naturally or without miracle to a subject must come to it from the limi- tations or variations of a real genus, or of a constant and abso- lute original nature. Tor it is thus that Philosophers dis- 1 La Loubere, Simon de, 1642-1729. Sent by Louis XIV. in 1687 to Siam, to establish diplomatic and commercial relations between that kingdom and France. While there he collected a large amount of exact and interesting information concerning the country, its history, customs, religion, etc., which, on his return, he published in his Du royaitme de Siam, Paris, 1691; English translation, London, 1693. — Tr. ON HUMAN UNDERSTANDING 61 tinguish the modes of an absolute being from that being itself ; as it is known that size, figure, and movement are manifestly limitations and variations of corporeal nature. For it is clear how a limited extension gives figures, and that the change which is made in it is nothing but motion. And whenever we find any quality in a subject, we must believe that if we understood the nature of this subject and of this quality, we should conceive how this quality can result therefrom. Thus in the order of nature (miracles aside) it is not optional with God to give to substances indifferently such or such qualities, and he will never give to them any, save those which will be natural to them, i.e. which can be derived from their nature as explicable modifications. Thus it may be asserted that matter will not naturally possess the attraction mentioned above, and will not proceed of itself in a curved line, because it is impossi- ble to conceive how this takes place there, i.e. to explain it mechanically, while that which is natural must be capable of becoming distinctly conceivable if we were admitted into the secrets of things. This distinction between what is natural and explicable and what is inexplicable and miraculous removes all the difficulties, and by rejecting it, we should maintain something worse than the occult qualities ; and in so doing would renounce philosophy and reason, by opening retreats for ignorance and idleness, though a dead system, which admits not only that there are qualities which we do not understand, of which there are only too many, but also that there are some which the greatest mind, if God gave him every possible opening, could not comprehend, i.e. which would be either miraculous or without rhyme and reason ; and also that God should work miracles ordinarily would be without rhyme and reason, so that this hypothesis would destroy equally our philosophy which seeks reasons, and the divine wisdom which furnishes them. Now as to thought, it is certain, and the author admits it more than once, that it could not be an intelligible modifica- tion of nature or one which could be comprised therein and explained, i.e. that a being who feels and thinks is not a mech- anism like a watch or a mill, so that we might conceive sizes, figures, and movements, whose mechanical conjunction might produce something thinking, and even feeling in a mass in 62 LEIBNITZ'S CRITIQUE OF LOCKE which there was nothing of the kind, which would cease also in the same manner upon the derangement of this mechanism. It is not then a natural thing for matter to feel and think, and this can happen within it only in t^^^o ways, of which one will be that God should unite with it a substance to which thought is natural, and the other that God by a miracle should put thought therein. In this, then,. I am wholly of the opinion of the Cartesians, except that I extend it even to the brutes, and that I believe they have sentiency and (properly speak- ing) immaterial souls, and are as imperishable as the atoms of Democritus or Gassendi, while the Cartesians, perplexed with- out reason by the souls of brutes, and not knowing what they are to do with them if they are preserved (for want of having thought of the conservation of the same animal reduced to miniature), have been compelled to refuse even sentiency to the animals against all appearances and contrary to the judgment of the human race. But if any one should say that God at least may add the faculty of thinking to the prepared mechan- ism, I should reply that if this were done, and if God added this faculty to matter without putting therein at the same time a substance which was the subject of inhesion of this same faculty (as I conceive it), i.e. without adding thereto an immaterial soul, it Avould be necessary that matter should be miraculously exalted in order to receive a power of which it is naturally incapable ; as some scholastics ^ claim that God ex- alts fire even to the point of giving it the force to burn imme- diately spirits separated from matter, a thing which would be a miracle, pure and simple. And it is enough that it cannot be maintained that matter thinks without putting into it an imperishable soul, or a miracle, and that thus the immortality of our souls follows from what is natural, since their extinc- tion can be maintained only by a miracle, whether hy exalting matter or by annihilating the soul. For we know well that God's power can make our souls moi"tal, wholly immaterial (or immortal by nature alone) as they may be, since he can annihilate them. Now this truth of the immateriality of the soul is undoubt- 1 Erdmann and Jacques read : " Quelques scholastiques ont pretendu quelque chose d'approchant savoir," i.e. Some scholastics have clamied something like this : viz. — Tr. ON HUMAN UNDEESTANDING edly of importance. For it is infinitely more advantageous to religion and morality, especially in our times (when many people hardly respect revelation alone and miracles ^), to show that souls are immortal by nature, — and that it would be a mir- acle if they were not, — than to maintain that our souls ought naturally to die, but that it is in virtue of a miraculous grace grounded in the promise of God alone that they do not die. Also for a long time it has been known that those who have desired to destroy natural religion and to reduce all to revealed religion, as if reason taught us nothing regarding it, have been looked ujjon with suspicion ; and not always without reason. But our author does not belong to that number. He maintains the demonstration of the existence of God, and he attributes to the immateriality of the soul a probability in the highest de- gree, which could consequently pass for a moral certainty, so that I think that, having as much sincerity as penetration, he could easily accommodate himself to the doctrine which I have just set forth, and which is fundamental in every rational phi- losophy. For otherwise I do not see how one can prevent him- self from falling back into the fanatical philosophy,'^ such as the "Philosophia Mosaica" of Fludd,^ which saves all phenomena by attributing them to God immediately and by miracle ; or into the barbaric philosophy like that of certain philosophers and physicians of the past, which still manifested the barbarity of their age, and which to-day is with reason despised, who saved appearances by forging purposely occult qualities or facidties which they imagined to be like little demons or goblins capa- ble of producing without ceremony what is demanded, just as if watches marked the hours by a certain horodeictic faculty without needing wheels, or as if mills ground the grain by a fractive faculty without needing anything resembling mill- stones. As to the difficulty that many people have had in conceiving an immaterial substance, it will easily cease (at least in good part) if they will not demand substances sepa- rated from matter, as in fact I do not believe there ever are any naturally among creatures. 1 Ex-dmann and Jacques omit this clause. — Tr. 2 Erdmann and Jacques read : " la philosophie ou fanatique," i.e. philosophy or fanaticism. — Tr. 3 Robert Fludd (1574-1637), an Ensflish physician and mystical philosopher. The Philosophia Mosaica was published at Gouda in 1638. —Tr. NEW ESSAYS ON HUMAN UNDERSTANDING Book I. — I:n^nate Ideas CHAPTEE I^ ARE THERE IXNATE PRINCIPLES Ilf THE MIjSTD OF MAN ? Philalethes. Having recrossed the sea after finishing my business in England, I thought at once of paying you a visit, sir, in order to cultivate our former friendship, and to con- verse upon matters which lie close to our hearts, and upon which I believe I have acquired some new light during my long stay in London. When we were living formerly quite near each other at Amsterdam, we both took much pleasure in making researches into the principles and means of pene- trating into the heart of things. Although our opinions often differed, this diversity increased our satisfaction, when, in our conference together, notwithstanding the contrariety which sometimes existed, there mingled nothing disagreeable. You were for Descartes^ and for the opinions of the celebrated author^ of "The Search after Truth," and I found the opinions of Gassendi,^ cleared up by Bernier, easier and more natural. Now I feel myself greatly strengthened by the excellent work which an illustrious Englishman, with whom I have the honor of a particular acquaintance, has since published, and which has several times been reprinted in England, under the modest 1 Book I. of Locke's Essay has foiir chapters, of which chap. 1 is introduc- tory. Chap. 1 of Leibnitz corresi^onds to chap. 2 of Locke. — Tr. 2 Rene' Descartes, 1596-1650; Nicolas Malebranche, 1638-1715, his chief work, I)e la Recherche de la Verite, 1674; Pierre Gassendi, 1592-1655, Abrege de la Philosophie de Gassendi, 8 vols., 1678, 2d ed., 7 vols., 1684, by Fran9ois Bernier. — Tr. 64 CH. I] ON HUMAN UNDERSTANDING 65 title of "An Essay concerning Human Understanding." And I am delighted that it has appeared lately in Latin and in French, in order that it may be more generally useful. I have greatly profited by the reading of this work, and indeed from the conversation of the author, with whom I have talked often in London, and sometimes at Gates, at the house of my Lady Masham,^ worthy daughter of the celebrated Cudworth,^ a great English philosopher and theologian, author of the Intellectual System, from whom she has inherited the spirit of meditation and the love for good learning, which appeared particularly in the friendship which she kept up with the author of the Essay. And, as he had been attacked by some clever Doctors, I took pleasure in reading also the defence which a very wise and very intelligent young lady made for him, besides those which he made for himself. This author writes in the spirit of the system of Gassendi, which is at bottom that of Democritus ; ^ he is for the vacuum and for atoms ; he believes that matter might think ; that there are no innate ideas, that our mind is a tabula rasa, and that we do not always think; and he appears disposed to approve the most of the objections which Gassendi has made ^ to Descartes. He has enriched and strengthened this system by a thousand beautiful reflections ; and I do not at all doubt that now our party will triumph boldly over its adversaries, the Peripa- tetics and the Cartesians. This is why, if you have not yet read this book, I invite you to do so, and if you have read it, I ask you to give me your opinion of it. Tlieophiliis. I rejoice to see you, on your return after a long absence, happy in the conclusion of your important business, full of health, steadfast in your friendship for me, and always transported with an ardor equal to the search for the most 1 The correspondence between Leibnitz and Lady Masham is given in full by Gerhardt, Vol. 3, pi5. 331 sq. — Tr. 2 Ralph Cudworth, 1617-1688, his principal work, The True Intellectual System of the Universe, London, 1678; Democritus, born probably about the middle of the fifth century B.C., as he says (Diog. L., IX., 41) he was "still young when Anaxagoras," 500-428 B.C., "was already old (veo? Kara irpea-^vrriv 'Ava^ayopav)." . . . "The year of his death is unknown," Zeller, Outlines of the Historij of Greek Philosophy, pp. 76, 77, New York: H. Holt & Co., 1886. — Tb. 3 In Vol. 3 of his Opera, of which two editions were published: by Mont- mort, 1655, 6 vols, folio, Lyons ; by Averanius, 1727, also 8 vols, folio. — Tr. F 66 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i important truths. I no less have continued my meditations in the same spirit, and I believe I have profited as much as, and, not to flatter myself, perhaps more than yourself. In- deed, my need therein was greater than yours, for you were more advanced than I. You were more conversant with spec- ulative philosophers, and I was more inclined towards ethics. But I have learned more and more how ethics receives strength, from the solid principles of true philosophy ; therefore I have lately studied these principles more diligently, and have begun meditations quite new. So that we shall have the means of giving ourselves a reciprocal pleasure of long duration in com- municating the one to the other our solutions. But it is nec- essary for me to tell you, as a piece of news, that I am no longer a Cartesian, and that, nevertheless, I am farther re- moved than ever from your Gassendi, whose knowledge and merit I, for the rest, recognize. I have been impressed with. a new system, of which I have read something in the " Jour- naux des Savans " of Paris, Leipzig, and Holland, and in the marvellous Dictionary of Bayle, article " Rorarius " ^ ; and since then I believe I see a new aspect of the interior of things. This system appears to unite Plato ^ and Democritus, Aristotle^ and Descartes, the scholastics with the moderns, theology and ethics with the reason. It seems to take the best from all sides, and then it goes much farther than any has yet gone. I find in it an intelligible explanation of the union of soul and body, of which I had before this despaired. I find the true principles of things in the Unities of Substance, which this system introduces, and in their harmony pre-established by the primitive Substance. I find therein a wonderful sim- plicity and uniformity, so that it may be said that this sub- stance is everywhere and always the same thing, differing only in degrees of perfection. I see now what Plato meant when he assumed matter to be an existence imperfect and transitory ; what Aristotle meant by his Entelechy ; what that promise of another life is which Democritus himself made according to Pliny ; how far the Sceptics were right in de- claiming against the senses ; how animals are in fact automata 1 Cf. Gerhardt, Vol. 4, pp. 52i-554, the article "Rorarius " with Leibnitz's remarks. — Tr. 2 Plato, 427-347 B.C. ; Aristotle, 384-322 b.c. — Tr. CH. I] ON HUMAN UNDERSTANDING 67 according to Descartes, and how they have, nevertheless, souls and feeling according to the opinion of mankind; how it is necessary to explain rationally those who have lodged life and perception in all things, as Cardan,^ Campanella,^ and, better than they, the late Countess of Connaway, a Platonist, and our friend, the late M. Franq-ois Mercure van Helmont^ (although elsewhere bristling with unintelligible paradoxes), with his friend, the late Mr. Henry More.^ How the laws of nature (a good part of which were unknown before this system) have their origin in principles superior to matter, and how, never- theless, everything takes place mechanically in matter, in which respect the spiritualizing authors I just named have failed with their Archaei,^ and even the Cartesians, in believ- 1 Girolamo Cardano, 1501-1576 ; Tommaso Campanella, 1568-1639 ; cf. Erd- maun, Grundriss d. Gesch. d. Philos., 3d ed., Vol. 1, §§ 242, 246, Berlin: Wil- belin Hertz, 1878, and the English translation of the same, London: Swan Sonnenschein & Co., 1889; also the articles "Cardan" and "Campanella" in the Encyclopxdia Britannica, 9th ed. — Tk. 2 Van Helmont, 1618-1698 : Henry More, 1614-1687. — Tr. 3 Archasus, i. Modern Latin, from the Greek ipxato?, apxri, that which is at the beginning, source, origin, a first principle. Littre defines the term thus : " Arche'e. Terme de physiologie ancienne. Principe immaterial different de I'ame intelligent et qu'on su^jposait presider a tons les phenomeues de la ■vie materielle." I.e. "A term of ancient physiology. An immaterial princi- ple different from the intelligent soul, and which is supi^osed to preside over all the phenomena of the material life." The Century Dictionary gives the following exposition and illustration: "In the philosophy of Paracelsus and other spagyrics, mystics, and theosophists, a spirit or invisible man or animal of ethereal substance, the counterpart of the visible body, within which It resides, and to which it imparts life, strength, and the power of assimilating food. The word is said to have been used by Basil Valentine, a German chemist of the fifteenth century, to denote the solar heat as the source of the life of plants. Paracelsus uses it with the above meaning. It is frequent in the writings of Van Helmont, who explains it as a material pre-existence of the human or animal form in posse. He regards the archaeus as a fluid, i.e. as a semi-material substance like air, and seems to consider it a chemical constituent of the blood. Paracelsus has particularly made use of the hypothesis of the archaeus to explain the assimilation of food. This function of the archseus became prominent in medicine. Van Helmont calls it the doorkeeper of the stomach (Janitor stomachi). There are further divarications of meaning. Also spelled Archeus." " As for the many pretended intricacies in the instance of the efformation of Wasps out of the Carcase of a Horse, I say, the Archei that formed them are no parts of the Horse's Soul that is dead, but several distinct Archei that do as naturally joyn with the matter of his body, so putrified and prepared, as the Crowes come to eat his flesh." — Dr. H. More, Antidote against Atheism, app. xi. Cf. Leibnitz: Considerations sur le Principe de Vie et sur les Natures Plas- 68 LEIBXITZ'S CEITIQUE OF LOCKE [bk. i ing that immaterial substances altered if not the force, at least the direction or determination, of the motions of bodies, whereas the soul and the body retain perfectly each its own laws, according to the new system, and yet one obeys the other as much as is necessary. In fine, it is since I have med- itated upon this system that I have found out how the souls of beasts and their sensations are in no sense prejudicial to the immortality of human souls, or, rather, how nothing is more suited to establish our natural immortality than to con- ceive that all souls are imperishable (morte carent animce), without, however, the fear of metempsychoses, since not only the souls, but further, the animals endure and will endure liv- ing, feeling, acting ; it is everywhere as here, and always and everywhere as with us, according to what I have already said to you, except that the conditions of animals are more or less perfect and developed, without there ever being a need of souls wholly separate, while we nevertheless have always spirits as pure as possible, notwithstanding our (physical) organs, which cannot disturb by any influence the laws of our (spiritual) spontaneity. I find the vacuum and atoms excluded in quite another way than by the sophism of the Cartesians, grounded in the pretended coincidence of the idea of body and extension. I see all things determined and adorned beyond anything hitherto conceived; matter everywhere organic, no sterile, neglected vacuum, nothing too uniform, everything varied, but with order; and, what passes imagination, the entire universe in epitome, but with a different aspect in each of its parts, and likewise in each of its unities of substance. Besides this new analysis of things, I have a better compre- hension of that of notions or ideas, and of truths. I under- stand what a true, clear, distinct, adequate idea is, if I dare adopt this word. I understand what are primitive truths, and true axioms, the distinction between necessary truths and tiquespar VAuteur de VHurmonie Preetahlie, published in the "Histoire des Ou-sTages des Savaiis," May, 1705, Gerhardt, Vol. 6, pp. 539-546; Erdmanii, pp. 429-432; translation, Duncan, Philos. Works of Leihnitz, pp. 1(33-169. See also Erdmann, Grundriss d. Gesch. d. Philos. 3d ed.. Vol. 1, § 241, 7, Vol.2, § 290, 12, or the English translation of the same. Slight additional information may be foiand in the Enci/clopsBdia Britannica, 9th ed., 'under the article, "Medicine," in the part giving an account of Paracelsus and Van Hel- mont. — Tr. cj. I] ON HUMAN UNDERSTANDING 69 truths of fact, between the reasoning of men and the consecu- tions of animals, which are a shadow of the reasoning of men. In short, you will be surprised to hear all that I have to say to you, and, above all, to understand how much the knowledge of the grandeur and of the perfection of God is therein exa'lted. For I cannot conceal from you, from whom I have had nothing concealed, how I have been thrilled now with admiration and (if we may dare to make xise of the term) with love for this sovereign source of things and of beauty, having found that what this system discovers surpasses everything one has hith- erto conceived. You know that I had gone a little too far formerly, and that I began to lean toward the side of the Spinozists,^ who allow God only infinite power, without recog- nizing either perfection or wisdom in his case, and regarding with contempt the search for final causes, derive everything from brute necessity. But these new lights have cured me of this ; and since then I sometimes take the name of Theopliilus. I have read the book of this celebrated Englishman of whom you have just spoken. I value it highly, and I have found in it some good things. But it seems to me necessary to go much farther, and necessary even to turn aside from his views, since he has adopted some which limit us more than is neces- sary, and lower a little not only the condition of man, but, besides, that of the universe. Ph. You astonish me in fact with all the marvels which you have recited to me in a manner a little too favorable for an easy credence of them on my part. However, I will hope that there will be something solid among so many novelties with which you desire to regale me. In this case you Avill find me very docile. You know that it was always my disposition to surrender myself to reason, and that I sometimes took the name of Philalethes. This js why, if you please, we will now make use of these two names which are so congruous Avith our mental constitution and methods. There are means of pro- ceeding to the trial, for — since you have read the book of the 1 On the relation of Leibnitz to Spinoza, see Leibniz u. Spinoza. Ein Beitrag zur Entwieklungsgesehiehte der Leibnizischeu Philosopliie. Von Prof. Dr. LudWig Stein. Mit neunzehn Ineditis aus dem Naehlass von Leibniz. Berlin: G. Reimer, 1890. pp. xvii., 3(32. Also " Mind," No. 62, p. 298 ; No. 6.3, pp. 443 sq., the latter an extended note on Stein's book by Prof. George Groom Robertson, the late editor of " Mind." — Tr. 70 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i celebrated Englishman, which gives me so much satisfaction and which treats a good part of the subjects of which you were just speaking, and above all, the analysis of our ideas and knowledge — it will be the shortest way to follow the thread of this work, and to see what you will have to say. Th. I approve your proposition. Here is the book. § 1. Ph. [I have read this book so thoroughly that I have retained even its expressions, which I shall be careful to fol- low. Thus I shall not need to recur to the book, except at certain junctures where we shall jiidge it necessary. We shall speak first of the origin of ideas or notions (Book. I.), then of the different kinds of ideas (Book II.), and of the words that serve to express them (Book III.), lastly of the knowl- edge and truths which therefrom result (Book IV.) ; and it is this last part which will occupy us the most. As for the ori- gin of ideas, I believe, with this author and a multitude of clever persons, that there are no innate ideas nor innate prin- ciples.] And, in order to refute the error of those who admit them, it is sufficient to show, as it appears eventually, that there is no need of them, and that men can acquire all their knowledge without the aid of any innate impression. Th. [You know, Philalethes, that I have been for a long time of another opinion ; that I have always held, as I still hold, to the innate idea of God, which Descartes maintained, and as a consequence to the other innate ideas, which cannot come to us from the senses. Now, I go still farther in con- formity to the new system, and I believe even that all the thoughts and acts of our soul come from its own depths, Avith no possibility of their being given to it by the senses, as you shall see in the sequel. But at present I will put this investi- gation aside, and, accommodating myself to the received ex- pressions, since in fact they are good and tenable, and one can say in a certain sense that the external senses are in part causes of our thoughts, I shall consider how in my opinion one must say even in the common system (speaking of the action of bodies upon the soul, as the Copernicans speak with other men of the movement of the sun, and with cause), that there are some ideas and some principles which do not come to us from the senses, and which we find in ourselves without form- ing them, although the senses give us occasion to perceive them. CH. I] ON HUMxVN UNDERSTANDING 71 I imagine that your clever author has remarked that under the name of innate principles one often maintains his prejudices, and wishes to free himself from the trouble of discussion, and that this abuse doubtless has stirred up his zeal against this supposition. He desired, no doubt, to combat the indolence and the superficial manner of thinking of those who, under the specious pretext of innate ideas and of truths naturally en- graved upon the mind, to which we readily give our consent, care nothing about investigating or considering the sources, the relations, and the certainty of this knowledge. In that I am entirely agreed with him, and I go even farther. I would that our analysis should not be limited, that definitions should be given of all the terms which are capable of definition, and that .one should demonstrate, or give the means of demonstrat- ing, all the axioms which are not primitive, without distin- guishing the opinions which men have of them, and without caring whether they give their consent or not. There would be more profit in this than one thinks. But it seems that the author has been carried too far on the other side by his zeal, otherwise very praiseworthy. He has not sufficiently distin- guished, in my opinion, the origin of the necessary truths, whose source is in the understanding, from that of the truths of fact drawn from the experience of the senses, and even from those confused perceptions which are in us. You see, then, that I do not agree with what you lay down as fact — that we can acquire all our knowledge without the need of innate impressions. And the sequel will show which of us is right.] § 2, Ph, We shall see it indeed. I grant you, my dear The- ophilus, that there is no opinion more commonly received than that which establishes the existence of certain principles of truth in which men generally agree ; this is why they are called general notions, kowoL ewotat ; whence it is inferred that these principles must be so many impressions which our minds receive with their existence. § 3. But though it were certain that there are some principles in which the entire human race is agreed, this universal consent would not prove that they are innate if one can show, as I believe he can, an- other way through which men have been able to reach this aniformity of opinion. § 4. But, what is much worse, this 72 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i universal consent is nowhere found, not even with regard to these two celebrated speculative principles (for we shall speak about the practical ones later), that whatever is, is; and that it is impossible for a thing to be and not to be at the same time. For there is a large part of the human race to which these two propositions, which will pass doubtless for neces- sary truths and for axioms with you, are not even known. Th. [I do not ground the certainty of innate principles upon universal consent, for I have already told you, Philalethes, that my opinion is that we ought to labor to be able to demon- strate all the axioms which are not primitive. I grant you also that a consent very general, but which is not universal, may come from a tradition diffused throughout the human race, as the practice of smoking tobacco has been received by nearly all nations in less than a century, although some island- ers have been found who, not being acquainted with fire even, were unable to smoke. Thus some clever people, even among theologians, but of the party of Arminius,^ have believed that the knowledge of the Deity came from a very ancient and very general tradition ; and I believe indeed that instruction has confirmed and rectified this knowledge. It appears, however, that nature has contributed to its attainment without learning ; the marvels of the universe have made us think of a superior power. A child born deaf and dumb has been seen to show veneration for the full moon, and nations have been found, who seemed not to have learned anything of other peoples, fearing invisible powers. I grant you, my dear Philalethes, that this is not yet the idea of God that we have and ask for ; but this idea itself does not cease to be in the depths of our souls, without being put there, as we shall see, and the eternal laws of God are in part engraved thereon in a manner still more legible and by a species of instinct. But they are practical principles of which we shall also have occasion to speak. It must be admitted, however, that the inclination we have to recognize the idea of God is in human nature. And, even if the first instruction therein should be attributed to revelation, the readiness which men have always shown to receive this doctrine comes from the nature of their souls. ^ But we will 1 James Arminius, 1560-1609, a distinguished Dutch theologian. — Tr. 2 From this point on Gerhardt, whose edition, it will be remembered, is the CH. I] ON HUMAN UNDERSTANDING 73 supj)ose that these ideas which are innate comprehend incom- patible notions. § 19. Pli. Although you maintain that these particular and self-evident propositions, whose truth is recognized as soon as one hears them stated (as that green is not red), are received as consequences of these other more general propositions, which are regarded as so many innate principles, it seems that you do not at all consider that these particular propositions are received as indubitable truths by those who have no knowl- edge of these more general maxims. Th. I have already replied to that above. We biTild on these general maxims as we build upon the majors, which are sup- pressed when we reason by enthymemes ; for, although very often we do not think distinctly of what we do in reasoning any more than of what we do in walking and leaping, it is always true that the force of the conclusion consists in part in that which is suppressed and could not elsewhere arise, as you will find should you wish to prove it. § 20. Ph. But it seems that general and abstract ideas are more foreign to our mind [than notions and particular truths ; consequently particular truths will be more natural to the mind than the principle of contradiction, of which you admit they are only the application]. Th. It is true that we commence sooner to perceive particu- basis of the present translation, transposes the text as given by Erdmann and Jacques as follows : "Mais nous jugerons que ces idees qui sont innees, ren- ferment des notions incompatibles," the first three words of which will be found in Erdmann, p. 207, b., about two-thirds down the page, Jacques, Vol. 1, p. 29, about two-thirds down, the remainder in Erdmann, p. 211, a., at the middle of the page, Jacques, p. 36, first third, just preceding § 19 in each case, whence the three texts go on in agreement until § 26, G., p. 72, E., p. 212, b., J., p. 39. Here the Gerhardt text has the following : " S'il y a des verites innees, ne faut il pas qu'il y ait dans la suite, que la doctrine externe ne fait qu'exciter icy ce que est en nous " : taking up with the words " dans la suite," the text as given by E., p. 207, b., J., p. 29, where it previously left it, the three texts continuing again in agreement until the words " des qu'on s'appercjoit," G., p. 79, last third, E., 211, a., at the middle, J., 36, first third, whence G. completes his sentence with the last three words of the first sentence of § 26, as given by E., 212, b., J., 39, from which point again the three texts substantially agree to the end of Chap. 1. It may be added that the texts of Erdmann, Jacques, and Janet follow the order of Locke's Essay. Why Gerhardt has transposed the text in his edition, I do not know, as he has not alluded to the matter. From his statement that " the present impression has been newly compared with the original, so far as it is still extant" (Introduction, p. 10), I presume that the transposition is due to his fidelity to this original, — Tr. 74 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i lar truths when we commence with ideas more complex and gross ; but that does not prevent the order of nature from com- mencing with the most simple, and the proof of the more par- ticular truths from depending upon the more general, of which they are only examples. And when we wish to consider what is in us virtually and before all apperception, we are right in commencing with the most simple. For the general principles enter into our thoughts, of which they form the soul and the connection. They are as necessary thereto as the muscles and sinews are for walking, although we do not at all think of them. The mind leans upon these principles every moment, but it does not come so easily to distinguish them and to rep- resent them distinctly and separately, because that demands great attention to its acts, and the majority of people, little accustomed to think, has little of it. Have not the Chinese like ourselves articulate sounds ? and yet being attached to another manner of writing, they have not yet thought of making an alphabet of these sounds. Thus it is that one possesses many things without knowing it. § 21. Ph. If the mind acquiesces so promptly in certain truths, cannot that acquiescence come from the consideration itself of the nature of things, which does not allow it to judge of them otherwise, rather than from the consideration that these propositions are engraved by nature in the mind ? Til. Both are true. The nature of things and the nature of mind agree. And since you oppose the consideration of the thing to the apperception of that which is engraven in the mind, this objection itself shows, sir, that those whose side you take understand by innate truths only those which would be approved naturally as by instinct, and even without knowing it, unless confusedly. There are some of this nature, and we shall have occasion to speak of them. But what is called nat- ural light supposes a distinct knowledge, and very often the consideration of the nature of things is nothing else than the knowledge of the nature of our mind, and of these innate ideas which we have no need to seek outside. Thus I call innate the truths which need only this consideration for their verifi- cation. I have already replied (§ 5) to the objection (§ 22) which claimed that when it is said that innate notions are implicitly in the mind, the statement must mean simply that CH. i] ON HUMAN UNDERSTANDING 75 it has the faculty of knoAviug them ; for I have pointed out that besides this it has the faculty of finding them in itself, and the disposition to approve them when it thinks of them as it should. § 23. Ph. It seems, then, that you claim that those to whom these general maxims are proposed for the first time learn nothing which is entirely new to them. But it is clear that they learn first the names, then the truths, and even the ideas upon which these truths rest. Th. The question here is not of names, which are in some sense arbitrary, while ideas and truths are natural. But, with respect to these ideas and truths, you attribute to us, sir, a doctrine which we have strongly repudiated ; for I agree that we learn ideas and innate truths either in considering their source, or in verifying them through experience. Thus I do not make the supposition which you aver, as if, in the case of which you speak, we learned nothing new. And I cannot admit this proposition : all that one learns is not innate. The truths of numbers are in us, and we are not left to learn them, either by drawing them from their source when we learn them through demonstrative proof (which shows that they are in- nate), or by testing them in examples, as do ordinary arithme- ticians, who, in default of. a knowledge of the proofs, learn their rules only by tradition, and, at most, before teaching them, justify them by experience, which they continue as far as they think expedient. And sometimes even a very skilful mathematician, not knowing the source of another's discovery, is obliged to content himself with this method of induction in examining it ; as did a celebrated writer at Paris, when I was there, who continued a tolerably long time the examination of my arithmetical tetragonism, comparing it with the numbers of Ludolphe,^ believing he had found therein some error ; and he had reason to doubt until some one communicated to him the demonstration, which for us dispenses with these tests, which could always continue without ever being perfectly certain. And it is this very thing, namely, the imperfection of inductions, which may yet be verified by instances of expe- rience. For there are progressions in which one can go very 1 Jolni Joli Ludolphe, 16-19-1711: his Tetragonometria Tabidaria, Frank- fort, 1690.— Tr. 76 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i far before noticing the changes and the laws that are found there. Ph. But is it not possible that not only the terms or words which we use, but even the ideas, come to us from without ? Th. It would then be necessary that we should be ourselves outside of ourselves, for the intellectual or reflective ideas are derived from our mind; and I should much like to know how we could have the idea of being if we were not beings our- selves, and did not thus find being in ourselves. Ph. But what do you say, sir, to this challenge of one of my friends ? If any one, says he, can find a proposition whose ideas are innate, that he can name to me, he would do me a very great favor. Th. I would name the propositions of arithmetic and geome- try, which are all of this nature ; and, as regards necessary truths, no others could be found. § 25. Ph. That will appear strange to most people. Can it be said that the most difficult and the most profound sciences are innate ? Th. Their actual knowledge is not, but much that may be called virtual knowledge is innate, as the figure traced by the veins of the marble is in the marble, before one discovers them in working. Ph. But is it possible that children, while receiving notions that come to them from without, and giving them their con- sent, may have no knowledge of those which you suppose to be inborn with them, and to make, as it were, a part of their mind, in which they are, you say, imprinted in ineffaceable characters in order to serve as a foundation ? If that were so, nature would have taken trouble for nothing, or, at least, she would have badly engraved their characters, since they cannot be perceived by the eyes Avhich see very well other things. Th. The apperception of that which is in us depends upon attention and order. Now, not only is it possible, but it is also proper, that children give more attention to the ideas of the senses, because the attention is regulated by the need. The outcome, however, shows in the sequel that nature has not uselessly given herself the trouble of impressing upon us in- nate knowledge, since without it there would be no means of attaining actual knowledge of the truths necessary in the CH. I] ON HUMAN UNDERSTANDING 77 demonstrative sciences, and the reasons of facts ; and we should possess nothing above the beasts. § 26. Ph. If there are innate truths, does it not necessarily follow that the external doctrine only stirs up here what is in us ? I conclude that a consent sufficiently general among men is an indication, and not a demonstration, of an innate princi- ple ; but that the exact and decisive proof of these principles consists in showing that their certitude comes only from what is in us. To reply further to what you say against the general approbation which is given to the two great speculative prin- ciples, which are, nevertheless, the best established, I may say to you that even if they were not known they would not cease to be innate, because they are recognized as soon as heard ; but I will add further that at bottom everybody knows them, and makes use at every moment of the principle of contradic- tion (for example) without considering it distinctly ; and there is no barbarian who, in an affair of any moment, is not (i offended by the conduct of a liar who contradicts himself. ' Thus, these maxims are employed without an express consid- eration of them. And in nearly the same way we have virtu- ally in the mind the propositions suppressed in enthymemes, Avhich are set aside not only externally, but further in our thought. § 5. Ph. [What you say of this virtual knowledge and of these internal suppressions surprises me] ; for to say that there are truths imprinted upon the soul which it does not perceive is, it seems to me, a veritable contradiction. Th. [If 3^ou are thus prejudiced, I am not astonished that you reject innate knowledge. But I am astonished that the thought has not occurred to you that we have an infinite amount of knowledge of which we are not always conscious, not even when we need it. It is for the memory to preserve this, and for the reminiscence to represent it to us, as it often, but not always, does at need. That is very well called remembrance (st(bvenire), for reminiscence needs some aid. And it must certainly be that in this multiplicity of our knowledge we are determined by something to renew one part rather than another, since it is impossible to think distinctly and at once of every- thing we know.] Ph. In that I believe you are right ; and this too general 78 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i affirmation, that we always perceive all the truths which are in our soul, escaped me without my having given it sufficient attention. But you will have a little more trouble in reply- ing to what I am going to show you. That is, that if you can say of some particular proposition that it is innate, you could maintain by the same reasoning that all propositions which are reasonable, and which the mind could always regard as such, are already impressed upon the soul. Th. I agree with you in regard to pure ideas, which I oppose to the phantoms of the senses, and in regard to necessary truths, or those of the reason, which I oppose to truths of fact. In this sense it must be said that all arithmetic and all geometry are innate, and are in us virtually, so that we can find them there if we consider attentively and set in order what we already have in the mind, without making use of any truth learned through experience or through the tradition of another, as Plato has shown in a dialogue ^ in which he intro- duces Socrates leading a child to abstract truths by questions alone without giving him any information. We can then make for ourselves these sciences in our study, and even with closed eyes, without learning through sight or even through touch the truths which we need ; although it is true that we would not consider the ideas in question if we had never seen or touched anything. For through an admirable economy of nature we cannot have abstract thoughts which have no need whatever of anything sensible, when that would only be of such a character as are the forms of the letters and the sounds, although there is no necessary connection between such arbi- trary characters and such thoughts. And if the sensible out- lines were not requisite, the pre-established harmony between soul and body, of Avhich T shall have occasion to speak more fully, would have no place. But that does not prevent the mind from taking necessary ideas from itself. You see also sometimes how it can go far without any aid, b}^ a logic and arithmetic purely natural, as that Swedish youth who, in culti- vating his own (mind), went so far as to make great calcula- tions immediately in his head without having learned the common method of computation, or even to read and write, if I remember correctly what has been told me of him. It is il/ereo, 82 sg.—TR. CH. i] ON HUMAN UNDERSTANDING 79 true that he cannot work out intricate problems, such as those which demand the extraction of roots. But that does not at all prevent him from being able still to draw them from its depths by some new turn of mind. Thus that proves only that there are degrees in the difficulty of perceiving what is in us. There are innate principles which are common and very easy to all ; there are theorems which are discovered likewise at once, and which compose the natural sciences, which are more understood in one case than in another. Einally, in a larger sense, which it is well to employ in order to have notions more comprehensive and more determinate, all truths which can be drawn from primitive innate knowledge can still be called innate, because the mind can draw them from its own depths, although often it would not be an easy thing so to do. But, if any one gives another meaning to the terms, I do not wish to dispute about words. Ph. [I have agreed with you that we can have in the soul what we do not perceive there, for we do not always remem- ber at once all that we know, but it must be always what we have learned or have known in former times expressly. Thus] if we can say that a thing is in the soul, although the soul has not yet known it, this can only be because it has the capacity or faculty of knowing it. Th. [Why could not this have still another cause, such as the soul's being able to have this thing within it without its being perceived ? for since an acquired knowledge can be con- cealed therein by the memory, as you admit, why could not nature have also concealed therein some original knowledge ? Must everything that is natural to a substance which knowa itself be known by it actually at once ? Cannot and must not this substance (such as our soul) have many properties and[ affections which it is impossible to consider all at once and all together ? It was the opinion of the Platonists that all our knowledge was reminiscence, and that thus the truths Avhich the soul has brought with the birth of the man, and which are called innate, must be the remains of an express anterior knowledge. But this opinion has no foundation ; and it is easy to believe that the soul must already have innate knowl- edge in the precedent state (if there were any pre-existence), however remote it might be, entirely as here : it would then 80 LEIBNITZ'S CRITIQUE OE LOCKE [bk. i have to come also from another precedent state, or ^ it would be finally innate, or at least concreate ; or else it would be needful to go to infinity and to make souls eternal, in which case this knowledge would be innate in fact, because it would never have commenced in the soul; and if any one claimed that each anterior state has had something from another more anterior, which it has not left to the succeeding, the reply will be made that it is manifest that certain evident truths must have been in all these states ; and in whatever manner it may be taken, it is always clear in all states of the soul that neces- sary truths are innate, and are proved by what is within, it not being possible to establish them through experience, as we establish truths of fact. Why should it be necessary also that we could have no possession in the soul of which we had never made use ? And is it the same thing to have a thing without using it as to have only the faculty of acquiring it ? If that were so, we should never possess anything but the things which we enjoy ; instead of which, we know that, be- sides the faculty and the object, some disposition in the fac- ulty or in the object, or in both, is often necessary, that the faculty may exercise itself upon the object.] Ph. Taking it in that way, we could say that there are truths written in the soul which the soul has, however, never known, and which, indeed, it will never know. This appears to me strange. Th. [I see there no absurdity, although in that case you could not be assured that there are such truths. For things more exalted than those which we can know in this present course of life may be developed some time in our souls, when they are in another state.] Fh. But suppose there are truths which could be imprinted upon the understanding without its perceiving them ; I do not see how, in relation to their origin, they could differ from the truths which it is only capable of knowing. Til. The mind is not only capable of knowing them, but further of finding them in itself ; and, if it had only the sim- ple capacity of receiving knowledge, or the passive power there- for, as indeterminate as that which the wax has for receiving figures and the blank tablet for receiving letters, it would not 1 The reading of Gerhardt and Erdmann ; Jacques has " ou," where. — Tr. CH. ij OX HUMAN UNDERSTANDING 81 be the source of necessary truths, as I have just shown that it is ; for it is incontestable that the senses do not suffice to show their necessity, and tliat thus the mind has a disposition (active as well as passive) to draw them itself from its own depths; although the senses are necessary to give it the occa- sion and attention for this, and to carry it to some rather than to others. You see, then, sir, that these elsewhere very clever persons who are of another opinion appear not to have thought enough upon the consequences of the difference which there is between necessary or eternal truths and the truths of experi- ence, as I have already observed, and as all our discussion shows. The original proof of the necessary truths comes from the understanding alone, and the other truths come from experience or from the observation of the senses. Our mind is capable of knowing both; but it is the source of the former, and, whatever number of particular experiences we may have of a universal truth, we could not be assured of it forever by induction without knowing its necessity through the reason. Ph. But is it not true that if the words, to he in the under- standing, involve something positive, they signify to be per- ceived and comprehended by the understanding ? Th. They signify to us wholly another thing. It is enough that what is in the understanding can be found there, and that the sources or original proofs of the truths which are in ques- tion are only in the understanding; the senses can hint at, justify, and confirm these truths, but cannot demonstrate their infallible and perpetual certainty. § 11. Ph. Kevertheless, all those who will take the trouble to reflect with a little attention upon the operations of the understanding will find that this consent, which the miud gives xmthout difficulty to certain truths, depends upon the faculty of the human mind. Th. Very well. But it is this particular relation of the human mind to these truths which renders the exercise of the faculty easy and natural in respect to them, and which causes them to be called innate. It is not, then, a naked faculty which consists in the mere possibility of understanding them ; it is a disposition, an aptitude, a preformation, which determines our soul and which makes it possible for them to be derived from it. Just as there is the difference between the figures G 82 LEIBNITZ'S CEITIQUE OF LOCKE [bk. i which, are given to the stone or the marble indifferently, and between those which its veins already indicate, or are disposed to indicate, if the workman profits by them. Ph. But is it not true that the truths are subsequent to the ideas of which they are born ? jSTow, the ideas come from the senses. Th. The intellectual ideas, which are the source of neces- sary truths, do not come from the senses ; and you admit that there are some ideas which are due to the reflection of the mind upon itself. For the rest, it is true that the express knowledge of truths is subsequent (temjoore vel natura) to the express knowledge of ideas ; as the nature of truths dependb upon the nature of ideas, before we expressly form one or the other, and the truths, into which enter ideas which come from the senses, depend upon the senses, at least in part. But the ideas which come from the senses are confused, and the truths which depend upon them are likewise confused, at least in part; while the intellectual ideas, and the truths dependent upon them, are distinct, and neither the one nor the other have their origin in the senses, although it may be true that we would never think of them without the senses. Ph. But, in your view, numbers are intellectual ideas, and yet it is found that the difficulty therein depends upon the express formation of the ideas ; for example, a man knows that 18 and 19 equal 37 with the same evidence that he knows that 1 and 2 equal 3 ; but a child does not know the first propo- sition so soon as the second, a condition arising from the fact that he has not formed the ideas as soon as the words. Th. I can agree Avith you that often the difficulty in the express formation of truths depends upon that in the exjjress formation of ideas. Yet I believe that in your example the question concerns the use of ideas already formed. For those who have learned to count as far as 10, and the method of passing farther on by a certain repetition of tens, understand without difficulty what are 18, 19, 37 ; viz., 1, 2, or 3 times 10 with 8, or 9, or 7 ; but, in order to draw from it that 18 plus 19 make 37, more attention is necessary than to know that 2 plus 1 are 3, Avhich at bottom is only the definition of 3. § IS. Ph. Furnishing propositions in which you infallibly acquiesce as soon as you hear them is not a privilege attached CH. I] ON HUMAN UNDERSTANDING 83 to the numbers or to the ideas, which you call intellectual. You meet these in physics and in all the other sciences, and the senses even furnish them. For example, this proposition : two bodies cannot be in the same place at the satne time, is a truth of which you are not otherwise convinced than of the following maxims : It is impossible for a thing to be and not to be in the same time; white is not red; the square is not a circle; yellowness is not sweetness. Th. There is a difference between these propositions. The first, which declares the impenetrability of bodies, needs proof. All those who believe in true and strictly formed condensa- tion and rarefaction, as the Peripatetics and the late Chevalier Digby,^ reject it, in fact ; without speaking of the Christians who believe, for the most part, that the contrary view — namely, the penetration of space ---is possible to God. But the other propositions are identical, or very nearly so, and identi- cal or immediate propositions do not admit of proof. Those who look upon the senses as furnishing them, as that one who says that yellowness is not sweetness, have not applied the general identical maxim to particular cases. Ph. Every proposition composed of two different ideas, of which one is the denial of the other — for example, that the square is not a circle, that to be yellow is not to be sweet — will be as certainly received as indubitable, as soon as its terms are understood, as this general maxim : It is impossible for a thing to be and not to be in the same time. . Th. That is, the one (namely, the general maxim) is the principle, and the other (that is to say, the negation of one idea by another opposed to it) is its application. Ph. It seems to me rather that the maxim depends upon this negation, which is its ground; and that it is, besides, much easier to understand that lohat is the same thing is not different, than the maxim which rejects the contradictions. Now, according to this statement, it will be necessary for you to admit as innate truths an infinite number of propositions of this kind which deny one idea by another without speaking 1 Sir Kenelm Digby, 1603-1665, an eminent English physical philosopher, who lived for a time in France, wliere he enjoyed the friendsliij) of Descartes and other learned men, and wrote his Treatise on the Nature of Bodies and other works. — Tr. 84 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i of other truths. Add to this, that a proposition cannot be innate unless the ideas of Avhich it is composed are innate ; it will be necessary to suppose that all the ideas which we have of colors, sounds, tastes, figures, etc., are innate.- Th. I do not well see how this : icliat is the same thing is not different, is the origin of the principle of contradiction, and easier ; for it appears to me that you give yourself more freedom in advancing that A is not B than in saying that A is not non-A. And the reason that prevents A from being B is that B includes non-A. For the rest this proposition : the siveet is not the hitter, is not innate, according to the sense which Ave have given to the term innate truth. For the sen- sations of sweet and bitter come from the external senses. Thus it is a mixed conclusion (Jiyhrida conclusio), where the axiom is applied to a sensible truth. But as regards this proposition : the square is not a circle, you can affirm that it is innate, for, in considering it, you make a subsumption or application of the principle of contradiction to what the un- derstanding itself furnishes as soon as you are conscious of innate thoughts. Th. Not at all, for the thoughts are acts, and the knowledge or the truths, in so far as they are Avithin us, even when we do not think of them, are habitudes or dispositions ; and Ave are Avell acquainted with things of which Ave think but little. Ph. It is very difficult to conceive that a truth may be in the mind if the mind has ncA^er thought of that truth. Th.^ It is as if some one said it is difficult to conceive that there are veins in the marble before Ave have discovered them. This objection seems also to a^oproach a little too much the, hegging of the question.^ All those who admit innate truths, without grounding them in the Platonic reminiscence, admit some of Avhich they have not yet thought. Besides, this reasoning proves too much ; for, if truths are thoughts, we shall be deprived not only of the truths of Avhich Ave have never thought, but also of those of AAdiich Ave have thought, and of which Ave no longer actually think ; and if truths are not thoughts, but habits and aptitudes, natural or acquired, nothing prevents there being in us some of which we have never thought, nor Avill ever think. 1 Petit io 2)^'inci2)iL — Tr. CH. II] OX HUMAN UNDERSTANDING So § 27. Pli. If general inaxiins were innate, they would appear more vividly in the mind of certain persons where, however, we see no trace of them ; I may mention children, idiots, and savages,^ for of all men these are they who have the mind less altered and corrupted by custom and by the impress of extraneous opinions. Th. I believe we must reason here very differently. Innate maxims appear only through the attention which is given to them ; but these persons have little of it, or have it for entirely different things. Their thoughts are mostly confined to the needs of the bod}' ; and it is reasonable that pure and detached thoughts be the reward of cares more noble. It is true that children and savages have the mind less altered by customs, but they also have it exalted by the teaching which gives attention. It would not be very just that the brightest lights should shine better in minds which less deserve them, and which are enveloped in thicker clouds. I would not then have one give too much honor to ignorance and barbarism when one is as learned and as clever as you are, Philalethes. as well as your excellent author ; that would be lowering the gifts of God. Some one will say that the more ignorant we are, the more we approach the advantage of a block of marble ■or of a piece of wood, which are infallible and sinless. But, unfortunatel}', it is not by ignorance that we approach this advantage ; and, as far as Ave are capable of knowledge, we sin in neglecting to acquire it. and we shall fail so much the more easily as wei are less instructed. CHAPTER II NO IXXATE PRACTICAL PRINCIPLES § 1. Ph. Ethics is a demonstrative science, and yet it has no innate principles. And, indeed, it would-be very difficult to produce a rule of ethics of a nature to be settled by an assent as general and as prompt as this maxim : Wliatever is, is. 1 For an excellent exposition of the content of the term savarie, cf. Andrevr Lan^,'M>/th, Ritual, and Religion, Vol. 1, p. 31, and note; also chap. 3, pp. 4(! ><']., London: Longmans, Green, & Co., 1887. — Tr. 86 LEIBNITZ'S CRITIQUE OF LOCKE [bk. Th. It is absolutely impossible that there be truths of reason as evident as those which are identical or immediate. And, although you can truly say that ethics has principles which are not demonstrable, and that one of the first and most practical is, that we ought to pursue joy and avoid sorrow, it is needful to add that this is not a truth which is known purely by reason, since it is based upon internal experience, or upon confused knowledge, for we do not feel what joy or sadness is. Ph. It is only through processes of reasoning, through lan- guage, and through some mental application, that you can be assured of practical truths. Th. Though that were so, they would not be less innate. However, the maxim I just adduced appears of another na- ture ; it is not known by the reason, but, so to speak, by an instinct. It is an innate princixsle, but it does not form a part of the natural light, for it is not known luminously. But this principle admitted, you can draw from it scientific con- sequences, and I commend most heartily what you just said of ethics as a demonstrative science. Let us note also that it teaches truths so evident that thieves, pirates, and bandits are forced to observe them among themselves. § 2, Ph. But bandits keep the rules of justice among them- selves without considering them as innate principles. Til. What matters it ? Does the world concern itself about questions of theory ? Ph. They observe the maxims of justice only as convenient rules, the practice of which is absolutely necessary to the con- servation of their society. Th. [Very well. You could say nothing better in general in respect to all men. And thus it is that these laws are written in the soul, namely, as the consequences of our preservation and of our true welfare. Do you imagine that we suppose that truths are in the understanding as independent the one of the other as the edicts of the prator were on his placard or album ? I put aside here the instinct which prompts man to love man, of which I shall presently speak, for now I wish to speak only of truths in so far as they are known by the reason. I admit, also, that certain rules of justice cannot be demon- strated, in all their extent and perfection, without supposing CH. iij ON HUMAN UNDERSTANDING 87 the existence of God and the immortality of the soul, and these, where the instinct of humanity does not impel us, are Avritten in the soul only as other derivative truths.] Those, however, who base justice only upon the necessities of. this life and upon the need the^' have of it, rather than upon the pleas- ure they ought to take in it, which is the greatest when God is its ground, are liable to resemble a little the society of bandits. Sit spes fallendi, miscebunt sacra profanis.^ § 3. Ph. I agree with 3'ou that nature has put in all men the desire for happiness and a strong aversion to misery. These are the truly innate practical principles, and principles which, according to the purpose of every practical principle, have a continual iniiuence upon all our actions. But they are inclinations of the soul toward the good, and not impressions ^ of some truth which is written in our understanding. Til. [I am delighted, sir, to see that you admit in effect innate truths, as I shall presently say. This princijjle agrees sufficiently with that which I just indicated, which prompts as to seek joy and shun sorrow. For felicity is only a last- ing joy. Our inclination, however, does not tend to felicity proper, but to joy — that is to say, to the present; it is the reason which prompts to future and enduring welfare. Xow, the inclination, expressed by the understanding, passes into a precept or practical truth ; and if the inclination is innate, the truth is innate also, there being nothing in the soul which may not be expressed in the understanding, but not alwa3^s by a consideration actually distinct, as I have sufficiently shown. The instincts also are not always practical ; there are some which contain theoretical truths, and such are the internal principles of the sciences and of reasoning, when, without rec- ognizing the reason in them, we employ them by a natural instinct. And in this sense you cannot dispense with the recognition of innate principles, even though you might be willing to deny that derivative truths are innate. But this would be a question of name merely after the explanation I 1 Of. Hor. Epist., 1, 16, 54. Horace has " miscebis." ^Tr. - Errlmanu and .Tacqnes read, " des imperfections de quelque verite." Ger- hardt reads, "des impressions de q^ielqne ve'rite." Locke has, "impressions of truth." Book I., chap. 3, § 3. Vol. 1, p. 158, line 5. Bohn's edition.— Tk. 88 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i have given of what I call innate. And if any one desires to give this appellation only to the truths which are received at first by instinct, T shall not contest the point with him.] Ph. That is well. But if there were in our soul certain characters imprinted there by nature, like so many principles of knowledge, we could only perceive them acting in us, as we feel the influence of the two principles which are constantly active in us — namely, the desire of happiness and the fear of miser}". Th. [There are principles of knowledge which influence us as constantly in our reasoning processes as these practical prin- ciples influence us in our volitions ; for example, everybody employs the rules of deduction by a natural logic without being aware of it. § 4. Ph. The rules of Morality need to be proved ; they are then not innate, like that rule which is the source of the vir- tues which concern society : Do to another only lohat yoti loonld JioA'e him do to yourself. Th. You always make me the objection which I have al- ready refuted. I agree with you that there are moral rules which are not innate principles ; but that does not prevent them from being innate truths, for a derivative truth will be innate, supposing that we can draw it from our mind. But there are innate truths, which we find in us in two ways — by insight and by instinct. Those which I have just indicated, show by our ideas what natural insight accomplishes. But there are conclusions of natural light which are principles in relation to instinct. It is thus that we are prompted to acts of human- ity, by instinct because it j^leases us, and by reason because it is just. There are then in us truths of instinct, which are innate principles, which we feel and approve, although we have not the proof of them which we obtain, however, when we give a reason for this instinct. It is thus that we make use of the laws of deduction conformably to a confused knowledge, and as by instinct, but logicians show the reason of them, as mathematicians also give a reason for what they do without thinking in walking and leaping. As for the rule which states that we ought to do to others only what we would have them do to us, it needs not only proof, but also to be proclaimed. We should Avish too much for ourselves if we could have our own CH. ii] ON HUMAN UNDERSTANDING 89 Avay ; shall we say then that we also owe too much to others ? ^ You will tell me that the rule means only a just will. But thus this rule, very far from being adequate to serve as a measure, would itself need one. The true sense of the rule is, that the place of another is the true point of view for equi- table judgment when we attempt it.] § 9. Ph. Bad acts are often committed without any remorse of conscience ; for example, when cities are carried by storm, the soldiers commit, without scruple, the worst acts ; some civilized nations have exposed their children, some Caribbees castrate theirs in order to fatten and eat them. Garcilasso de la Yega^ reports that certain peoples of Peru took prisoners in order to make concubines of them, and supported the children up to the age of thirteen, after which they ate them, and treated in the same manner the mothers so soon as they no longer bore children. In the travels of Baumgarten ^ it is re- lated that there was a Santon^ in Egypt who passed for a holy man, eo quod non foeminarum unquain esset ac jmerorum, sed tantum asellarum concubitor atque mularum. Til. Moral science (over and above the instincts like that which makes us seek joy and shun sadness) is not otherwise innate than is arithmetic, for it depends likewise upon demon- strations which internal light furnishes. And as the dem- onstrations do not at once leap into sight, it is no great wonder, if men do not perceive always and at once all that they pos- sess in themselves, and do not read quite readily the characters of the natural laio, ivhich God, according to St. Paid,^ has tvrit- ten in their minds. As morality, however, is more important than arithmetic, God has given to man instincts which prompt 1 This sentence is found in tlie texts of Erdmann and Gerhardt ; it is -^'ant- ing in tliat of Jacques. — Tr. 2 Garcilasso de la Vega, 1540-1616, the son of an Inca princess, and a Span- ish conqueror, a companion of Pizarro. His Commeniarins reales was pub- lished in two parts, the first at Lisbon, 1609, giving an account of the native traditions, customs, and history previous to the Spanish conquest : the second under the separate title of Historia General del Peru, Cordova, 1617, treating of the Spanish conquest. The earlier and more important part of the work has been translated, with "learned and ingenious notes," by Clements R. Markham, and published in the collection of the Hakluyt Society, 2 vols., London: 1869, 1871. — Tr. 3:Martin Baunis-arten, 1473-153.5, Travels throuqh Egypt, Arabia, etr. In Churchill, O. and .J. Col., Vol. 1, 1744. — Tr. ■i Mahometan monk. — Tr. s Rom. 2 : 15 ; cf. 1 : 19. — Tr. 90 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i at once and without reasoning to some portion of tliat which reason ordains ; just as we walk in obedience to the laws of mechanics without thinking of these laws, and as Ave eat, not only because eating is necessary for us, but further and much more because it gives us pleasure. But these instincts do not prompt to action in an invincible way ; the passions may resist them, prejudices may obscure them, and contrary customs alter them. Nevertheless, we agree most frequently with these instincts of conscience, and we follow them also when stronger impressions do not overcome them. The great- est and most healthy part of the human race bears them wit- ness. The Orientals, the Greeks and Romans, the Bible and the Koran agree in respect to theia ; the Mahometan police are wont to punish the thing Baumgarten tells of, and it would be needful to be as brutalized as the American savage in order to approve their customs, full of a cruelty which sur- passes even that of the beasts. Yet these same savages per- ceive clearly what justice is on other occasions ; ^ and although there is no bad practice, perhaps, which may not be authorized in some respects and upon some occasions, there are few of them, however, which are not condemned very frequently and by the larger part of mankind. That which has not been at- tained without reason, and was not attained by reasoning alone, should be referred in part to the natural instincts. Custom, tradition, discipline, are mingled therein, but it is due to in- stinct (le naturel) that custom is turned more generally to the good side of these duties. In the same way,^ the tradition of God's existence is due to instinct {le naturel). Now nature 1 Cf. J. G. Schurman, The Ethical Import of Dancimsm, pp. 256-260, New York": Charles Scribiier's Sons, 1887. He states that " some gropings amid the general darkness incline me, at least tentatively, to the belief that, apart from the domestic virtues, there is no such great difference between the morals of Christians and the morals of savages" (p. 256). This statement is modified further on, pp. 258, 259, and finally takes the following form: " The fighting men, actual and potential, in every uncivilized community recognize the same rights, obligations, and duties toward one another as constitute the essence of civilized morality. You never find a man without a moral nature, a nature essentially like our own ; but the objects he includes within the scope of its outgoings vary" (p. 259). For the real significance of such facts, cf. Ex- Pres. E. G-. Robinson, of Brown University, Principles and Practice of Moral- ity, p. 43, Boston: Silver, Burdett & Co., 1888. — Tr. 2 Gerhardt reads, " C'est comme le naturel," etc.; Erdmaun and Jacques, " Le naturel," etc. — Tr. CH. II] ON HUMAN UNDERSTANDING 91 gives to man and also to most 6f the animals affectionate and tender feeling for those of their species. The tiger even |)a?-- cit cognatis mascuUs ; ^ whence comes this bon mot of a Roman jurisconsult, Quia inter omnes homines natura cognationem constituit, uncle liominum homini insidiari iiefas esse. Spiders form almost the only exception, and these eat one another to this extent that the female devours the male after having enjoyed him. Besides this general instinct of society, which may be called pMlcmtliropy in man, there are some more par- ticular forms of it, as the affection between the male and the female, the love which father and mother bear toward the chil- dren, which the Greeks call o-ropyr/,^ and other similar inclina- tions which make this natural law, or this image of law rather, which, according to Roman jurisconsults, nature has taught the animals. But in man in particular there is found a certain regard for dignity, for propriety, wdiich leads him to conceal the things which lower u.s, to be sparing of shame, to have repugnance for incests, to bury dead bodies, not to eat men at all, nor living animals. One is led further to be careful of his reputation, even beyond need, and of life ; to be subject to remorse of conscience, and to feel these laniatus et ictus, these tortures and torments of which Tacitus, following Plato, speaks ; ^ besides the fear of a future and of a supreme power which arises, moreover, naturally enough. There is reality in all that ; but at bottom these natural impressions, whatever they may be, are only aids to the reason and indices of the plan of nature. Custom, education, tradition, reason, contrib- ute much, but human nature ceases not to participate therein. It is true that without the reason these aids Avould not suffice to give a complete certitude to morals. Finally, will you deny that man is naturally led, for example, to withdraw from vile things, under a pretext that races are found who like to speak only of filth, that there are some, indeed, whose mode of life obliges them to handle excrements, and that there are people of Boutan, where those of the king pass as an aromatic ? I think that jOn are of my opinion at bottom in regard to these natural instincts which tend toward what is right and decent ; 1 Juv. Sat., 15, 159-160. — Tr. 2 The reading (nom. crropyn) of Erdmann and Jacques. Gerhardt's reading, hpyriv, is evidently an error. — Tr. 3 Gorgias, 524 E ; Ann. 6, 6. — Tr. 92 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i although you will say, perhaps^ as you have said with regard to the instinct which prompts to joy and felicity, that these impressions are not innate truths. But I have already replied that every feeling is the perception of a truth, and that the natural feeling is the (perception) of an innate truth, but very often confused, as are the experiences of the external senses ; thus you can distinguish the innate truths from the natural light (which contains only the distinctly knowable), as the genus must be distinguished from its species, since the innate truths comprehend both the instincts and the natural light.] § 11. Ph. A person who knew the natural limits of justice and injustice, and (who) would not cease confusing them with each other, could only be regarded as the declared enemy of the repose and the welfare of the society of which he is a mem- ber. But men confuse them every moment, consequently they do not know them. Th. [That is taking things a little too theoretically. It happens every day that men act contrary to their knowledge in concealing these (limits) from*themselves when they turn the mind elsewhere, in order to follow their passions ; Otherwise, we should not see people eating and drinking what they know must cause them sickness and even death. They would not neglect their business ; they would not do what entire nations have done in certain respects. The future and reason rarely make so strong an impression as the present and the senses. That Italian knew this well, who, before being put to torture, proposed to have the galloAvs continually in sight during the torments in order to resist them, and they heard him say some- times, " lo ti vedo'^ which he explained afterward when he had escaped. Unless you firmly resolve to look upon the true good and the true evil with the purpose of following or shunning them, 3^ou find yourself carried away, and it happens, with re- gard to the most important needs of this life, as it happens with regard to paradise and hell in the case of those, indeed, who believe in them the most : — Cantantur liaec, lauclantur haec, Dicuntur, audiuntur. Scribuntur htec, leguntur hsec, Et lecta negliguntur.] CH. ii] ON HUMAN UNDERSTANDING 93 Ph. Every principle which you suppose innate can only be known by each one as just aiid advantageous. Th. [You always return to this supposition, which I have refuted so many times, that every innate truth is known alwaj^s and by all.] § 12. Ph. But a public permission to violate the law proves that this law is not innate ; for example, the law requiring the love and preservation of children was violated among the ancients when they permitted their exposure. Th. [This violation supposed, it follows only that you have not well read these characters of nature written in our soul, but sometimes obscure enough by reason of our excesses, not to mention that, in order to have a perfectly clear perception of the necessity of duties, men must see the demonstration of them — a condition that is rarely fulfilled. If geometry were as much opposed to our passions and present interests as is ethics, we should contest it and violate it but little less, notwith- standing all the demonstrations of Euclid^ and of Archimedes,^ which you would call dreams an^ believe full of paralogisms ; and Joseph Scaliger, Hobbes,- and others, who have written against Euclid and Archimedes, would not find themselves in such a small company as at present. It was only the passion for glory, which these authors believed they found in the quad- rature of the circle and other difficult problems, which could 1 Euclid, not to be confounded with Euclid of Megara, a pupil of Socrates, founder of the Megarian school, the fundamental principle of whose philosophy was the union of the Eleatic idea of heing with the Socratic idea of the good. The date of neither his birth nor death is known. Proclus, the Neo-Platonist, 410-485 A.D., says that Euclid lived in the time of Ptolemy I., king of Egypt, who reigned from 323-285 B.C., and that he was younger than Plato's associates, but older than Eratosthenes, "276-2 — 196-2 B.C.," "the celebrated scholar whose chronological dates were adopted for the history of philosophy" (Zeller, Outlines, §§ 3, 66), and Archimedes, 287-212 b.c. Proclus preserves Euclid's reply to King Ptolemy, who asked him if there were no easier way to learn geometry than by studying his elements. "There is no royal road to geom- etry."— Tr. - Thomas Hobbes, 1588-1679. The statement of his geometrical principles in opposition to those of Euclid is found in the Appendix to the English trans- lation of the Be Corpore, which appeared about the middle of 1656, entitled Six Lessons to the Professors of Mathematics, one of Geometry, the other of Astronomy, in the University of Oifford, English Works, Vol. 7, pp. 181-356. For an account of the controversy in which these appeared, cf. George Croom Robertson, Hobbes, pp. 167-178 (Philosophical Classics). Edinburgh: William Blackwood & Sons, 1886. — Tk. 94 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i blind to such a point persons of so great merit. And if others had the same interest, tliey wouhl make use of it in much the same manner.] Pli. Every duty carries the idea of law, and a law cannot be known or supposed without a legislator who has prescribed it, or without reward and without punishment. Th. [There can be natural rewards and iMnalties without a legislator ; intemperance, for example, is punished by disease. As this, however, does not injure all at first, I admit that there are few precepts to which you would necessarily be bound if there were not a God who leaves no crime without chastise- ment, no good act without reward.] Ph. The ideas of a God and of a life to come must then also be innate. Th. [I am agreed in the sense in which I have explained myself.] Ph. But these ideas are so far from being written by nature in the minds of all men, that they even do not appear very clear and very distinct in the minds of many students, who also pro- fess to examine things with some accuracy ; so far are they from being known by every human being. Th. You return again to the same proposition, which main- tains that what is not known is not innate, which I have, hoAv- ever, refuted so many times. What is innate is not at first known clearly and distinctly as such; often much attention and method is necessary in order to its perception, the student- class do not always adduce it, still less every human being. § 13. Ph. But if men can be ignorant of or call in question that which is innate, it is in vain for you to speak to us of in- nate principles, and to claim to show us their necessity ; very far from their being able to serve as our instructors in the truth and certitude of things, as is maintained, we shall find our- selves, with these principles, in the same state of uncertainty as if they were not in us. Th. You cannot call in question all the innate principles. You were agreed in regard to identical propositions or the principle of contradiction, admitting that there are incontest- able principles, although you would not then recognize them as innate : but it does not at all follow that everything which CH. ii] ON HUMAN UNDERSTANDING 95 is innate and necessarily connected Avith these innate princi- ples, is also at first indubitably evident. Fh. No one that I know of has yet undertaken to give us an exact catalogue of these principles. Th. But has any one hitherto given us a full and exact catalogue of the axioms of geometry ? § 15. Ph. My Lord Herbert ^ has been pleased to point out some of these principles, which are : 1. There is a supreme God. 2. He ought to be served. 3. Virtue united with piety is the best worship. 4. Repentance for sin is necessary. 5. There are penalties and rewards after this life. I agree that these are evident truths and of such a nature that when well explained a reasonable person can scarcely avoid giving them his consent. But our friends say that they are very far from being so many innate impressions, and if these five propositions are common notions written in our souls by the finger of God, there are many others which we ought also to put into this class. Th. I agree with you, sir, for I take all the necessary truths as innate, and I connect with them also the instincts. But, I agree with you, that these five propositions are not innate prin- ciples ; for I hold that they can and ought to be proved. § 18. Ph. In the third proposition, that virtue is the wor- ship most agreeable to God, it is not clear what is meant by virtue. If you understand it in the sense most commonly given to the term, I mean that which passes as praiseworthy according to the different opinions which prevail in different countries, this proposition is so far from being evident that it is not even true. If you call virtue^ t\\Q acts which are con- formed to the will of God, this will be almost idem x>er idem, and the proposition will teach us nothing of importance ; for it would mean only that God is pleased with that which is con- formed to his will. It is the same with the notion of sin in the fourth proposition. 1 Lord Edward Herbert of Cherbury, 1581-1G48. His Be Veritate, Paris, 1G24, has had considerable influence on Englisli i^hilosophical and reli.^ious thought, and is of some importance in the interpretation of the polemic ol Locke's Essay. — Tr. - For an excellent but brief statement and discussion of the main theories of virtue, of. E. G. Robinson: Principles and Practice of Morality, pp. 140- 180.— Tb. 96 LEIBNITZ'S CKITIQUE OF LOCKE [bk. i Til. I do not remember to have remarked that virtue is commonly taken as something which depends upon opinion ; at least, the philosophers do not make it that. It is true that the name of virtue depends upon the opinion of those who give it to different habits or actions, according as they deem them good or bad and use their reason ; but all are sufficiently agreed as to the notion of virtue in general, although they dif- fer in its application. According to Aristotle^ and several others, virtue is a habit of restraining the passions by the rea- son, and still more, simply a habit of acting according to rea- son. And that cannot fail to be agreeable to him who is the supreme and final reason of things, to whom nothing is indif- ferent, and the acts of rational creatures less than all others. § 20. Pli. You are wont to say that the custom, the educa- tion, and the general opinions of those with whom you con- verse may obscure these principles of morality which you suppose innate. But if this reply is a good one, it annihilates the proof which you pretend to draw from universal consent. The reasoning of many men reduces to this : The principles which men of right reason admit are innate ; we and those of our mind are men of right reason ; consequently our princi- ples are innate. A pleasant method of reasoning, which goes straight on to infallibility ! Th. For myself, I make use of universal consent, not as a principal proof, but as a confirmatory one ; for innate truths taken as the natural light of reason bear their marks with them as does geometry, for they are wrapped up in the im- mediate principles which you yourselves admit as incontesta- ble. But I grant that it is more difficult to distinguish the instincts and some other natural habits from custom, although it may very often be possible so to do. Eor the rest, it appears to me that people who have cultivated their minds have some ground for attributing the use of right reason to themselves rather than to the barbarians, since in subduing them almost as easily as they do animals they show sufficiently their supe- 1 Eih. Nic. II. 6, ad init. Cf. Zeller : Outlines of the Hist, of Greek Philos., § 61 ; and E. Wallace : Outlines of the Philos. of Aristotle, 3d ed., § 59, pp. 97- 99. Cambridge : University Press, 1883. In connection with each section of his brief English statement and exposition, Wallace gives the Greek text of " the more important passages in Aristotle's writings," with references to the Berlin Academy edition of Aristotle. — Tr. CH. II] ON HUMAN UNDERSTANDING 97 riority. But if they cannot always succeed in this, it is be- cause just like the animals they conceal themselves in the thick forests, where it is difficult to hunt them down and the game is not worth the candle. It is doubtless an advantage to have cultivated the mind, and if we may speak for barbarism as against culture, we shall also have the right to attack rea- son in favor of the animals, and to take seriously the witty sallies of M. Despreaux,^ in one of his satires, where, in order to contest with man his prerogative over the animals, he asks, whether, The bear is afraid of tlie jDasser-by, or the passer-by of the bear ; And if, by decree of tlie shepherds of Libya, The lions would vacate the parks of Numidia, etc. We must, however, admit that there are some points in which the barbarians surpass us, especially as regards vigor of body ; and as regards the soul even we may say that in certain respects their practical moralit}^ is better than ours, because they have not the avarice of hoarding nor the ambition of ruling. And we may even add that association with Christians has made them worse in many respects.- They have taught them drunkenness (when carrying them the water of life), swearing, blasphemy, and other vices, which were little known to them. There is Avith us more of good and of evil than with them : a bad Euro- pean is Avorse than a savage — he refines upon evil.^ Still, nothing should prevent men from uniting the advantages which nature gives to these peoples with those which reason gives us. 1 Nicolas Boileau-Despreaiix, 1636-1711. The passage quoted is from Sat. 8, 62-64. The text as given by all the editions I have been able to consult, twelve, ranging from 1716-1873, reads thus : "L'ours a peur du passant, ou le passant de I'ours; Et si, sur un edit des patres de Nuhie, Las lions de Barca videraient la Lybie;" etc. Lines 63 and 64 of the text, as given by Leibnitz, editions of Gerhardt and Erdmanu, Jacques modernizing the spelling and correcting the misplacement of " de " and " des " in line 63, read thus : " Et si par un edit de pastres des Lybie Les Lions vuideroient les pares de Nnmidie," etc. It seems evident that Leibnitz misquoted the lines. ^- Tr. 2 Compare J. G. Schurman: The Ethical Import of Barivinism, pp. 256-260 as above. — Tr. 3 The French is : "11 rafiue sur le mal." — Tr. 98 LEIBNITZ'S CRITIQUE OF LOCKE • [bk. i Ph. But what reply do you make, sir, to this dilemma of one of my friends ? I would be pleased, he says, to have the advocates of innate ideas tell me whether these principles can or cannot be effaced by education and custom. If they cannot be effaced we ought to find them in all men, and they should clearly appear in the mind of each particular man. If they can be altered by extraneous ideas, they ought to appear more distinctly and with more lustre the nearer they are to their source. I mean in children or illiterate people, upon whom' extraneous opinions have made less impression. Let them take which side they please, they will clearly see, he says, that it is contradicted by indubitable facts and by continual expe- rience. Th. I am astonished that your clever friend has confounded obscurity with effacement, as some in your party confound non- being with non-appearance. Innate ideas and truths cannot be effaced, but they are obscured in all men (as they are now) by their inclination toward the needs of the body, and oftener still by the occurrence of bad customs. These characteristics of the internal light would always be shining in the under- standing and would give fervor to the will, if the confused perceptions of sense did not engross our attention. It is the straggle of which Holy Scripture no less. than ancient and modern philosophy speaks. Ph. Thus, then, we find ourselves in darkness as thick and in uncertainty as great as if there were no such light. Th. God forbid; we should have neither science nor law, nay, not even reason. § 21, 22, etc. Ph. I hope that you will at least admit the force of prejudice, which often causes that to pass as natural which has come from the bad instruction to which children have been exposed, and the bad customs which education and association have given them. Th. I admit that the excellent author whom you follow says some very fine things upon that subject, and which have their value if they are taken as they should be ; but I do not believe that they are opposed to the doctrine properly understood of nature or of inriate truths. And I am confident that he will not extend his remarks too far ; for I am ecpially persuaded that a great many opinions pass for truths which are only the effects CH. ii] ON HUMAN UNDERSTANDING of custom and of credulity, and that there are many such opin- ions, too, wliich certain philosophers would fain account for as matters of prejudice, wliich are, however, grounded in right reason and in nature. There is as much or more ground for de- fending ourselves from those who through ambition oftenest make pretensions to innovation, than for challenging ancient im- pressions. And after having meditated sufficiently upon ancient and modern thought, I have found that the majority of the re- ceived doctrines may bear a good sense. So that I wish that sensible men would seek to satisfy their ambition by occupy- ing themselves rather in building and advancing than in retro- grading and destroying. And I desire them to resemble the Romans who constructed beautiful public works, rather than that Vandal king ^ whom his mother charged to seek the de- struction of these grand structures, since he could not hope for the glory of equalling them. Ph. The aim of the clever class who have contended against innate truths has been to prevent men from handing round their prejudices and seeking to cover their idleness beneath this fair name. Th. We are agreed upon this point, for, very far from ap- proving that doubtful principles be received, I would, for my- self, seek even the demonstration of the axioms of Euclid, as some ancients also have done. And when you ask the means of knowing and examining innate principles, I reply, following what I said above, that with the exception of the instincts whose reason is unknown, you must try to reduce them to first principles, that is to say, to axioms identical or immediate by means of definitions, which are nothing else than a distinct exposition of ideas. I do not doubt even but that your friends, who have hitherto been opposed to innate truths, would ap- prove this method, which appears consonant with their princi- pal aim. 1 Clirocus, who with the Sueves and Alans is said to have passed over the Rhine near Mayence, and following the evil counsel of his mother, to have ravaged in the most frightful manner in Germany as in Gaul. The story is given in the Chronicle of Idatius, chap. 62. Cf. Bouquet, Rerum Gall, et Franc. Scriptores, Tom. 2, p. 464. — Tr. 100 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i CHAPTEK III OTHER CONSIDEKATIOISrS TOUCHING INNATE PRINCIPLES, BOTH SPECULATIVE AND PRACTICAL § 3. Ph. You wish to reduce truths to first principles, and I grant you that if there is any such principle, it is without gainsaying this ; it is impossible for a thing to be and not to be at the same time. It appears, however, difficult to maintain its innate character, since you must be convinced at the same time that the ideas of impossibility and identity are innate. Th. It is quite necessary that those who favor innate truths maintain and be convinced that these ideas are also innate, and I admit that I am of their opinion. The ideas of being, of possibility of identity, are so completely innate that they enter into all our thoughts and reasonings, and I regard them as essential to our mind ; but I have already said that we do not always pay them particular attention and that we discern them only Avith time. I have said hitherto that we are, so to speak, innate unto ourselves, and since we are beings, the being we is innate ; and the knowledge of being is wrapped up in that knowledge which Ave have of ourselves. There is some- thing similar in the case of other general notions. § 4. Ph. If the idea of identity is natural, and consequently so evident and so present to the mind that we ought to recog- nize it from the cradle, I would be pleased to have a child of seven years, and even a man of seventy, tell me whether a man who is a creature consisting of body and soul, is the same (man) when his body is changed, and whether, metempsychosis sup- posed, Euphorbus would be the same as Pythagoras. Th. I have stated sufficiently that what is natural to us is not known to us as such from the cradle ; and even an idea may be known to us without our being able to decide at once all ques- tions which can be formed thereupon. It is as if some one main- tained that a child cannot have a knowledge of the square and its diagonal, because he will have difficulty in recognizing that the diagonal is incommensurable with the side of the square. As for the question itself, it appears to me demonstratively CH. Ill] ON HUMAN UNDERSTANDING 101 solved by the doctrine of Monads, which I have elsewhere^ shown in its true light, and we shall speak more fully of this matter in the sequel. 1 Cf. the Essay, without title, Gerhardt, 4, 427 sq., writteu at the beginning of 1686, and referred to as " uu petit discours de Metaphysique," in Leibnitz's letter, Feb. 1-11, 1686, to the Landgraf Ernst vou Hesseu-Rheiufels, G. 2, 11. This ' Discours,' regarded by Leibnitz as tlie beginning of his philosophy, con- tains a summary, centring about the idea of the individual substance, of all his previous philosophical speculation. He gained this idea, and with it a seemingly satisfactory solution of the principal philosophical problem, at the end of 1685 or the beginning of 1686. For this idea, still in process of devel- opment, possessing the elements of force and individuality, but lackiug those of continuity and perceptive activity evolved between 1686 and 1697, Leibnitz, in 1697, when the idea possessed all the elements essential to its comx^leteness in his system, appropriated the term "monad." This term he borrowed, not from Giordano Bruno, 1548-1600, who used it in a similar though not precisely the same sense, but from Francois Mercure Van Helmont, 1618-1699. So far as known, the term "monad" is first meutioned in the letter to Fardella, Sept. 3-1;H, 169(j, first published by Foucher de Careil, Nouv. lettr. et opusc. de Leibniz, p. 328, Paris, 1857. The doctrine in substance till 1697, and thereafter in name, Leibnitz frequently set forth with increasing clearness and complete- ness in letters to his numerous correspondents, and in the " Acta Eruditorum " aud the " Journal des Savans." Reference may be made, among others, to the following: Correspondence with Autoine Arnauld, 1612-1694, especially the letter dated Venice, Mar. 23, 1690, G. 2, 134; Erdmann, 107; Jacques, 1, 443; trans.. Appendix, ; the two systematic elaborations of his system of the year 1695, the mathematical in the Specimen dynamicum pro admirandis nature Icf/ibus, etc., Gerhardt, Leibniz, math. Schrift., 6, 234 sg.; the meta- physical in the Systeme nouveau de la nature, etc., G. 4, 477; E. 124; trans., Appendix, ; De ipsa natura, etc., 1698, espec. §§ 11, 12, G. 4, 504 ; E. 154 ; J. 1,455 (in French) ; trans., Appendix, ; Response {Replique,'Evd.miim\) anx reflexions continues dans la seconde edition du Dictionnaire Critique de M. Bayle, etc., 1702, G. 4, 554; E. 183; trans.. Appendix, ; Letters to Rud. Christ. Wagner De vi activa corporis, June 4, 1710, G. 7, 528 : E. 465 ; trans., Duncan, Philos. Wks. of Leibnitz, 190; to Bierling, Aug. 12, 1711, G. 7, 500; E. 677; Principes de la nature, etc., c. 1714, G. 6, 598; E. 714; trans., Duncan, 209; La Monadoloc/ie, 1714, G. 6, 607; E. 705; trans., Duncan, 218, F. H. Hedge, "Jour. Spec. Philos.," Vol. 1, p. 129; Letters to Des Bosses, G. 2, 285 sq., imssim, which present most penetrating discussions of Leibnitz's metaphysic and form the most ample commentary on the 3fonadolor/ie ; to De Voider, 1643-1709, G. 2, 139 sq., passim, proving the intimate connection of Leibnitz's dynamic and metaphysic; to Bourguet, Dec. 1714, G. 3, 575; E. 720; to Remond (de Montmort, E. 724), Feb. 11, 1715, §§ 3, 4, G. 3, 635; to Dangi- court, Sept. 1716, Dutens, Leibnit. opera omnia, 3, 499; E. 745. Of the pieces cited the most important are : The Letter to Arnauld, Mar. 23, 1690, the Systeme nouveau, the De ipsa natura, the Principes de la nature, and the Monado- lor/ie. As Leibnitz was occupied, more or less as circumstances permitted, with the composition and revision of his ' New Essays,' from 1700, when Coste's translation of Locke's 'Essay' appeared, to 1709 aud perhaps later (rid. ante, p. 9 aud note), possibly even as late as 1714 or 1716, the relative date of com- position of the several pieces here cited to that of the ' New Essays ' can easily 102 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i § 6. Pli. [I see very well that to you I should object in vain that the axiom which declares that the loliole is greater than its part is not innate, under pretext that the ideas of whole and part are relative, dependent upon those of number and exten- sion; since you would apparently maintain that there are ideas conditionally innate, and that those of number and extension are to such a degree innate.^] Th. You are right, and indeed I rather believe that the idea of extension is posterior to that of whole and part. § 7. Ph. [What say you of the truth that God should be worshipped ; is it innate ?] Th. I believe that the duty of worshipping God declares that on occasion you ought to show that you honor him beyond every other object, and that this is a necessary consequence of the idea of him and of his existence ; which signifies with me that this truth is innate. § 8. Ph. But the atheists seem to prove by their example that the idea of God is not innate. And without speaking of those whom the ancients have mentioned, have not entire nations been discovered, who have no idea of God nor of the terms which denote God and the soul, as at the bay of Soldania, in Brazil, in the Caribbee Islands, in Paraguay ? Th. [The late Mr. Fabricius,^ a celebrated, theologian of Heidelberg, has made an apology for the human race in order be approximated. On the whole subject, cf. L. Stein, Leibniz u. Spinoza, chap. 6, PID. 111-219, Berlin : G. Reinier, 1890, who traces the history of the rise of the monad-doctrine from 1680 till all the elements of the complete conception were present in 1697 ; E. Dillmann, E. neue Darstg. d. Leibniz. Monadenlehre auf Grund d. Quellen, Leipzig: O. R. Reisland, 1891, whose monograph is an elab- orate discussion of the entire subject with references to or quotations from all the sources. — Te. 1 The French text is : " puisque yous soutiendres apparemment, qu'il y a des idees innees respectives, et que celles des nombres et de I'etendue sont inne'es aussi." — Tr. 2 joini Lewis Fabricius, 1632-1697. Professor, first of Greek, then of Philos- ophy and Theology, at Heidelberg. In 1664 he received the title of " Conseiller ecclesiastique de I'electeur palatin." Some years after, when Heidelberg was burnins;, he saved the archives of the church and the university, carrying them first to Eberbach, then to Frankfort, where he died. The title of the work referred to in the text (vid. ante, p. 21 also, where the name is given Fabritius, in accord with his own signature in the letter of Feb. 16, 1673, to Spinoza, offering him the professorship of Philosophy at Heidelberg) is: ApoJ- ofiin f/enerif! humani contra calumniam athei.^mi. It appeared in 1662. H'S collected works, with a life, were published by J. H. Heidegger, Zurich, 1698, in 4to. — Tr. CTi. Ill] ON HUMAN UNDERSTANTjING 103 to clear it of the imputation of atheism. He was an author of great accuracy, and decidedly above much prejudice; I do not, however, pretend to enter into this discussion /jf facts. I grant that entire peoples have never thought of the supreme sub- stance, nor of the nature of the soul. And I remember, that when you wished at my request, countenanced by the illus- trious Mr. Witsen, to obtain for me in Holland a translation of the Lord's Prayer into the language of Barantola, you were stopped at this point : Jialloived be thy name, because you could not make the Barantoli understand what halloiued meant. I remember also that in the creed made for the Hot- tentots you were obliged to express Holy Spirit by words ,of. the country which signify a pleasant and agreeable wind.-^ This was not unreasonable, for our Greek and Latin v/ords TTvev/jia. anima, spiritus, mean ordinarily' only the air or wind Ave breathe, as one of the most subtile things which we know through the senses ; and we begin through the senses to lead men little by little to what is beyond the senses. All this diffi- culty, however, which you find in attaining abstract knowledge effects nothing against innate knov^^ledge. There are peoples who have no word corresponding to the word being ; does any one doubt their knowledge of what being is, although they seldom think of it in the abstract ? Besides I find what I have read in our excellent author on the idea of God (Essay on Understanding, Book I., chap. 3,^ § 9) so beautiful and so to my liking that I cannot refrain from quoting it.^ Here it is : " Men can scarcely avoid having some kind of idea of things of which those with whom they converse often have occasion to speak under certain names, and if the thing is one which carries with it the idea of excellence, of grandeur, or of some extraordinary quality which interests in some point and which impresses itself upon the mind under the idea of an absolute and irresistible power which none can help fearing " (I add : and under the idea of a superlatively great goodness which none can help loving), "such an idea ought, according to all 1 Cf. Book III., chap. 1, ^ 5, Th. (2). — Tr. 2 Chap. 4, in Locke's treatise, Bohu's ed. — Tr. 3 The Frencli translation of Locke's original, is, in my Judgment, clearer in form of statement and style than Locke himself. Hence I have retranslated the French into English. If any reader prefers Locke's original, he can easily find it in the Philos. Works, Bohn's ed., Vol. 1, p. 188. — Tr. 104 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i appearances, to make the strongest impression and to spread farther than any other, especially if it is an idea which accords with the simplest insight of reason, and which flows naturally from every part of knowledge. Kow snch is the idea of God, for the brilliant marks of extraordinary wisdom and power appear so plainly in all the works of the creation, that every rational creature who will reflect thereupon cannot fail to dis- cover the author of all these marvels ; and the impression that the discovery of such a Being must naturally make upon the souls of all those who have once heard him spoken of is so great, and carries with it thoughts of so great weight and so adapted to spread themselves in the world, that it appears to me wholly strange that an entire nation of men can be found upon the earth so stupid as to have no idea of God. This, I say, seems to me as surprising as to think of men who should have no idea of numbers or of fire." I would I might always be allowed to copy word for word a number of other excellent passages of our author, which we are obliged to pass by. I will only say here, that this author, in speaking of the simj^lest lights of reason, which agree with the idea of God, and of that which naturally proceeds from it, ap- pears to differ but little from my view of innate truths ; and, concerning this, that it appears to him as strange that there may be men without any idea of God, as it would be surprising to find men who had no idea of numbers or of fire, I will remark that the inhabitants of the Marian Islands, to which has been given the naane of the Queen of Spain, who has protected mis- sions there, had no knowledge of fire when they were dis- covered, as appears from the narrative which Kev. Father Gobien,^ a French Jesuit, charged with the care of distant missions, has given to the public and sent to me.] § 16. Ph. If you are right in concluding that the idea of God is innate, from the fact that all enlightened races have had this idea, virtue ought also to be innate because enlightened races have always had a true idea of it. Th. [Not virtue, but the idea of virtue, is innate, and per- haps you intend only that.] 1 Charles le Gobien, 1653-1708. Professor of Philosophy at Tours; secre- tary and procurator of Chinese missionaries ; wrote and published a number of works on these missions in China; his Histoire des Isles Mariannes, Paris, 1700, 12mo.— Tr. CH. Ill] ON HUMAN UNDERSTANDING 105 Ph. It is as certain that there is a God, as it is certain that the opposite angles made by tlie intersection of two straight lines are equal. And there has never been a rational creature who applied himself sincerely to the examination of the truth of these two propositions who has failed to give them his con- sent. Nevertheless, it is beyond doubt that there are many men who, having never turned their thoughts in this direction, are ignorant equally of these two truths. Th. [I admit it ; but that does not prevent them from being innate — that is to say, does not prevent you from being able to find them in yourself.] § 18. Ph. It- would be more advantageous to have an innate idea of substance ; but it turns out that we do not have it, either innate or acquired, since we have it neither through sensation nor reflection. Th. [I am of opinion that reflection suffices to discover the idea of substance within ourselves, who are substances. And this notion is one of the most important. But we shall speak of it, perhaps more fully, in the sequel of our con- ference.] § 20.^ Ph. If there are innate ideas in the mind without the mind's being actually aware of their presence, they must at least be in the memory, whence they must be drawn by means of revii)HScence — that is to say, be known, when memory re- calls them, as so many perceptions which have been in the mind before, unless reminiscence can subsist without reminis- cence. For this conviction, where it is an inwardly certain one, that a given idea has previously been in our mind, is properly wdiat distinguishes reminiscence from every other kind of thinking. Th. [In order that knowledge, ideas, or truths be in our mind, it is not necessary that we have ever actually thought of them ; they are only natural habitudes ; i.e. dispositions and aptitudes, active and passive, and more than a tabula rasa. It is true, however, that the Platonists believed that we have already actually thought of that which we recognize in our- selves ; and to refute them it is insufficient to say that we do not at all remember it, for it is certain that an infinite number 1 Gerhardt's reading. So also Locke, Philos. Works, Vol. 1, p. 197, Bohn's ed. — Tr. 106 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i of thoughts recur to us which we have forgotten that we had. It has happened that a man believed he had composed a new verse, Avhich it turned out he read word for word a long time previous in some ancient poet. And often we have an extraordinary facility of conceiving certain things, because we formerly conceived them, without remembering them. It is possible that a child, having become blind, forgets ever having seen light and colors, as happened at the age of two and a half years from small-pox in the case of the celebrated Ulric Schoen- berg, a native of Weide, in the Upper Palatinate, who died at Konigsberg, in Prussia, in 1649, where he taught philosojjhy and mathematics to the admiration of every one. It may be that such a man has remaining effects of former impressions withoiit remembering them. I believe that dreams often thus revive in us former thoughts. Julius Scaliger,^ having cele- brated in verse the illustrious men of Verona, a certain self- styled Brugnolus, a Bavarian by birth, but afterward estab- lished at Verona, appeared to him in a dream and complained that he had been forgotten. Julius Scaliger, not remembering to have heard him spoken of before, did not allow himself to make elegiac verses in his honor in consequence of this dream. At length, the son, Joseph Scaliger,^ travelling in Italy, learned more particularly that there had been formerly at Verona a celebrated grammarian or learned critic of this name, Avho had contributed to the re-establishment of polite literature in Italy. This story is found in the poems of Scaliger the father, to- gether with the elegy, and in the letters of the son. It is related also in the "Scaligerana,"^ which are culled from the 1 Julius Cffisar Scaliger, 1484-1558. His Latin verse appeared in successive volumes in 1533, 1534, 1539, 154G, 1574. His tastes Avere, however, philosophi- cal and scientific rather than literary. His seieutific works, in the form of commentaries, have only a historical interest. The Ex.otericarum exercitatio- num liber, Paris, 1557, 4to, a philosophical treatise on the Be Sitbtilitate, 1552, of Cardan (vid. ante, p. 67, note 1), is the work which best makes known Scaliger as a i>hilosopher. It was a popular text-book until the final fall of Aristotle's physics. — Tr. - Joseph Justus Scaliger, 1540-1609, reputed the greatest scholar of modern times. He was the first to set forth and apply sound principles of textual criticism and emendation in his editions of some of the classical authors, and with him arose a new school of historical criticism. He reconstructed the lost Chronicle of Eusebius, a work of considerable importance in the study of ancient history. — Tr. 3 Two collections of anecdotes concerning Joseph Scaliger, numbered accord- CH. Ill] ON HUMAN UNDERSTANDING 107 conversations of Joseph Scaliger. It is very likely that Julius Scaliger had known something of Brugnol which he no longer remembered, and that the dream Avas partly the revival of a former idea, although he may not have had that reminiscence, properly so called, which makes us know that we have already had this same idea ; at least, I see no necessity which obliges us to assert that there remains no trace of a perception wlien there is not enough of it to remind us that we have had it.] § 24. Pli. [I must admit that your reply is natural enough to the diflfi-culties which we have framed against innate truths. Perhaps, also, our authors do not contest them in the sense in which you maintain them. Thus I return only to say to you, sir] that we have had some reason to fear that the view of innate truths serves as a pretext for laziness, for exempting ourselves from the trouble of research, and gives opportunity to masters and teachers to lay down as a principle of principles that principles must not be questioned. Th.. [I have already said that if it is the aim of your friends to advise the search for the proofs of the truths which they can receive, v/ithout distinguishing whether or not they are innate, we are entirely agreed ; and the view of innate truths, of the manner in which I take them, should deter no one from such search, for, besides being well to seek the reason of the instincts, it is one of my great maxims that it is good to seek demonstrations of the axioms also, and I remember that at Paris, when the late Mr. Roberval,' already an old man, was iug to their date of composition. The first was written in Latin by Fran(;ois Vertunien, a friend of Scaliger, who tooli notes of his conversations witli Scaliger, especially of all criticisms or anecdotes worthy of preservation, and afterwards wrote them ont. An advocate, Francois de Sigogne, bought the MS. long after the author's death, and published it at Saumer in 1669. The second was written in French and Latin by two youths named Vassan, who, when students at Leyden, habitually conversed after supper with Scaliger, then Professor of Belles Lettres there, and on their return to their rooms wrote out all they could remember of his conversation. Their MS. was finally jDublished at La Haye, 1666, by Isaac Yossius. The edition of the Snalif/erami, accounted the best, is that of 1740, 12mo. The story is told at length, and the Elegy of the elder Scaliger cited, in the Cologne ed. of the ScuUgerana, 1()95, pp. 69- 71. — Tr. 1 Gilles Personne de Roberval, a French geometer, born 1602, at Roberval, a small village of Beauvais, died 1675 at Paris. He was Professor of Mathematics in the Royal College of France for many years. One of the conditions of the tenure of this chair was that its holder should propose mathematir-al questions for solution, and resign in favor of any one solving them better than himself. 108 LEIBNITZ'S CRITIQUE OF LOCKE [bk. i laughed at because he wished to demonstrate those of Euclid after the example of Apollonius ^ and Proclus/ I illustrated the utility of this investigation. As for the principle of those who say that it is wholly unnecessary to argue against the one who denies principles, it has no authority whatever in regard to these principles which can admit neither doubt nor proof. It is true that, in order to avoid scandal and disturbance, regula- tions may be made regarding public disputations and some other lectures, in virtue of which the discussion of certain established truths may be prohibited. But this is rather a question of police than of philosophy.] Roberval kept the chair till his death. He is best kuowu for his original method for the coustrnction of tangents. — Tr. 1 Apollonius of Perga, born probably about 250 B.C., died in the reign of Ptolemy Philopater, 222-205 B.C. Next to Archimedes, he was the most noted of the Greek geometers. His fame has been transmitted to modern times chiefly by his treatise on the Conic Sections, the best edition of which, and the only one containing the Greek text that has yet apjjeared, is : A-pollonii perc/aei conicorum libri octo, etc., ed. Halley : Oxford, 1710, folio. He was the first to show that all three of the conic sections can be cut from the same cone by changing the position of the intersecting plane. — Tr. ^ Proclus Diadochus, 410-485, " the great schoolman of Neo-Platonism," the doctrines of which received at his hands the final form in which they have come down to us. He came to Athens in his twentieth j^ear, and remained there teaching and writing till his death. Among his writings now extant are a Treatise on the Sphere, Commentaries on Euclid, and on several of Plato's dialogues, and the wholly independent works ^roixei'^o'ts ©eoAoytxr), or Institutes of Theology, and the six books «'s rriv OAdTcoi'o? ©eoAovtai-, or Platonic Theology. His philosophical work is found for the most ps,H in the Commentaries on Plato. For his mathematical work, cf. In primum Eucliclis Elementorum librum Conunentarii, ex recognitione G. Friedlein : Lipsife, 187.3 ; also George Johnston Allman, Greek Geometry from Thales to Euclid, Dublin: University Press, 1889; and in " Hermathena," a series of papers on literature, science, and phi- losophy, by members of Trinity College, Dublin, Nos. 5, 7, 10-13, Dublin: 1878, 1881, 1884-1887. For his philosophy, "c/". Zeller, Die Philos. d. Griech., 3d ed., 1881, Vol. 3, pp. 774 sq., and Outlines, § 101 ; Hegel, Gesch. d. Philos., 2d ed.,. Vol. 3, pp. 61-79; Alfred William Benn, The Greek Philosophers, Vol.2, pp. 358-360, London: Kegan Paul, Trench, & Co., 1882. The Philosophical and Mathematical Commentaries on the First Book of Euclid's Elements, etc., were translated by Thomas Taylor, London, 1792, 2 vols, in 1, 4to. — Tr. NEW ESSAYS ON HUMAN UNDERSTANDING .Book II. — Ideas CHAPTEE I WHICH TREATS OF IDEAS IN GEjSTERAL, A^^D EXAMI^fES BY THE WAY WHETHER THE MIXD OF MA>f ALWAYS THINKS § 1. Ph. Having examined the question of innate ideas, let us consider their nature and their differences. Is it not true that the idea is the object of thought ? Th. [I admit, it, provided you add that it is an immediate internal object, and that this object is an expression of the na- ture or the qualities of things. If the idea were the/oriM of thought, it would spring up and cease with the actual thought to which it corresponds ; but being the object it may exist pre- vious to and after the thoughts. External sensible objects are only mediate because they cannot act immediately upon the soul.^ God alone is the external immediate object. We might say that the soul itself is its own immediate internal object ; but it is this in so far as it contains ideas, or what corresponds to things. For the soul is a little world,^ in which distinct ideas are a representation of God, and in which confused ideas are a representation of the universe.] § 2. Ph. We who suppose that at the beginning the soul is a tabida rasa, void of all characters and without an idea, ask how it comes to receive ideas, and by what means it acquires this ^ Cf. Book IV., chaps. 9 and 11. The opposition here set up between mediate and immediate knowledge corresponds to Kant's a- ■posteriori and a priori knowledge. — Tr. 2 Microcosm. — Tr. 109 110 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii prodigious quantity of them ? To tliat question the reply in a word is : From experience. Til. [This tabula rasa, of which so much is said, is in my opinion only a fiction which, nature does not admit, and which is based only upon the imperfect notions of philosophers, like the vacuum, atoms, and rest, absolute or relative, of two parts of a whole, or like the primary matter^ whicli is con- ceived as without form. Uniform things and those which con- tain no variety are never anything but abstractions, like time, space, and the other entities of pure mathematics. There is no body whatever whose parts are at rest, and there is no sub- stance whatever that has nothing by which to distinguish it from every other. Human souls differ, not only from other souls, but also among themselves, although the difference is not at all of the kind called specific. And, according to the proofs which I believe we have, every substantial thing, be it soul or body, has its own characteristic relation to every other; and the one must always differ from the other by intrinsic connotations. Not to mention- the fact that those who speak so frequently of this tabula rasa after having taken away the ideas cannot say what remains, like the scholastic philoso- phers, who leave nothing in their primary matter.-^ You may perhaps reply that this tabula rasa of the philosophers means that the soul has by nature and originally only bare fac- ulties. But faculties without some act, in a word the pure powers of the school, are also only fictions, which nature knows not, and which are obtained only by the process of ab- straction. For where in the world will you ever find a faculty which shuts itself up in the power alone without performing any act ? There is always a particular disposition to action, and to one action rather than to another. And besides the disposition there is a tendency to action, of which tendencies there is always an infinity in each subject at once ; and these tendencies are never without some effect. Experience is nec- essary, I admit, in order that the soul be determined to such or such thoughts, and in order that it take notice of the ideas which are in us ; but by what means can experience and the senses give ideas ? Has the soul windows, does it resemble tablets, is it like wax ? It is plain that all who so regard the 1 Materia Prima. — Tr. CH. i] ON HUMAN UNDERSTANDING 111 soul, represent it as at bottom corporeal. You oppose to me this axiom received by the philosophers, that there is iiotJiing in the soul which does not come from the senses. But you must except the soul itself and its affections. Nihil est in intellectu, quod non fuerit in sensu, excipe : 7iisi ipse intellectus. Kow the soul comprises being, substance, unity, identity, cause, perception, reason, and many other notions which the senses cannot give. This view sufficiently agrees with your author of the Essay, who seeks the source of a good part of ideas in the spirit's reflec- tion upon its own nature. Ph. [I hope, then, that you will agree with this skilful author that all ideas come through sensation or through re- flection, that is to say, from observations which we make either upon objects exterior and sensible or upon the inner workings of our soul.' Th. [In order to avoid a discussion upon what has delayed us too long, I declare to you in advance, sir, that when you say that ideas come to us from one or the other of these causes, I understand the statement to mean their actual perception, for I think I have shown that they are in us before they are perceived so far as they have any distinct character. § 9. Ph. [In the next place let us inquire when we must say that the soul begins to perceive and actually to think of ideas. I well know that there is an opinion which states that the soul always thinks, and that actual thought is as inseparable from the soul as actual extension is from the body. § 10. But I cannot conceive that it is any more necessary for the soul always to think than for the body always to be in motion, per- ception of ideas being to the soul what movement is to the body. That appears to me very reasonable at least, and I would gladly know your view, sir, thereupon. Th. You have stated it, sir. Action is no more connected with the soul than Avith the body, a state without thought in the soul and an absolute repose in the body appearing to me equally contrary to nature, and without example in the world. A substance once in action, will be so always, for all the im- pi'essions remain and are merely mingled with other new ones. Striking a body, we arouse therein or determine rather an infinite number of vortices as in a liquid, for at bottom every solid has a degree of liquidity and every liquid a degree of 112 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii solidity, and there are no means of ever stopping entirely these internal vortices. Now we may believe that if the body is never at rest, the soul, which corresponds to it, will never be without perception either.] Ph. But it is, perhaps, a privilege of the author and conserver of all things, that being infinite in his perfections, he never slum- bers nor sleeps. This is not granted to any finite being, or at least not to such a being as is the soul of man. Th. [It is certain that we slumber and sleep, and that God is exempt from both. But it does not follow that we have no perception while asleep. Rather just the contrary is found to be the case, if we consider it carefully.] Ph. There is something in us which has the power to think ; [but it does not thereby follow that it is always in action.] Th. [Eeal powers are never simple possibilities. ■ They have always tendency and action. Ph. But this proposition — the soul always thinks — is not self-evident. Th. I do not say it is. A little attention and reasoning is necessary to discover it ; the common people perceive it as little as they do the j^ressure of the air or the roundness of the earth.] Ph. I doubt if I thought las't night ; this is a question of fact, it must be decided by sensible experiences. Th. [It is decided as it is proved, thatjjiere are imperceptible bodies and invisible movements, although certain persons treat them as absurd. There are also numberless perceptions little noticed which are not sufficiently distinguished to be perceived or remembered, but they become known through certain conse- quences.!] Ph. There was a certain author who raised the objection that we maintain that the soul ceases to exist, because we are not sensible of its existence during our sleep. But this objection can arise only from a strange prepossession, for we do not say that there is no soul in man because we are not sensible of its existence during our sleep, but only that man cannot think without being aware of it. Th. [I have not read the book which contains this objection, but it would not have been wrong merely to object to you that it does not follow because the thought is not perceived, that it ceases for that reason ; for otherwise it could be said for the I CH. I] ON HUMAN UNDERSTANDING 113 same reason that there is no soul during the time in which it is not perceived. And to refute this objection it is necessary to point out in particular the thought that it is essential to it that it be perceived.] § 11. Ph. It is not easy to conceive that a thing can think and not be conscious that it thinks. Th. There is, doubtless, the knot of the affair and the diffi- culty which has embarrassed able men. But here are the means of extricating ourselves therefrom. We must consider that we think of many things at a time, but we attend onl}^ to the thoughts which are most distinct, and the process cannot go on otherwise, for if we should attend to all, we would have to think attentively of an infinite number of things at the same time, all of which we feel and which make an impression upon our senses. I say even more : there remains something of all our past thoughts, and none can ever be wholly effaced. Now when we sleep without dreaming and when we are stunned by some blo'\^^, fall, symptom, or other accident, an infinite number of minute confused sensations take form within us, and death itself can produce no other effect upon the souls of animals, who ought, doubtless, sooner or later, to acquire distinct per- ceptions, for all goes on in an orderly way in nature. I admit, however, that in this state of confusion, the soul would be with- out pleasure and without pain, for these are noticeable percep- tions. § 12. Ph. Is it not true that those vv'ith whom we have at present to do, [i.e. the Cartesians, Avho believe that the soul always thinks,] grant life to all animals, differing from man, without giving them a soul which knows and thinks ; and that these same (Cartesians) find no difficulty in saying that the soul can think independentl}^ of a body ? Th. [For myself, I am of another opinion, for although I agree with the Cartesians in their affirmation that the soul thinks always, I am not agreed with them in the two other points. I believe that the beasts have imperishable souls and that human and all other souls are never without some body. I hold also that God alone, as being an actus 2)urus, is wholly exempt therefrom.] Ph. If you had been of the opinion of the Cartesians, I should have inferred therefrom, that the bodies of Castor or Pollux I 114 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii could be sometimes with, sometimes without a soul, thdugh being always alive, and the soul having the ability also to be sometimes in one body and sometimes elsewhere, we might suppose that Castor and Pollux had only a single soul, which was active alternately in- the body of these two men sleeping and awake by turns ; thus it would be two persons as distinct as Castor and Pollux could be. Th. I, in my turn, will make you another supposition, which appears more real. Is it not true that we must always admit that after some interval or some great change, one may fall into a state of general forgetfulness ? Sleidan ^ (they say), before his death, forgot all he knew ; and there are many other examples of this sad event. Suppose that such a man became young again and learned all anew, will he be another man on that account ? It is not then memory which, properly speaking, makes the same man. Nevertheless, the fiction of a soul Avhich animates different bodies in turn, without concern- ing itself in one of these bodies with that which happ'ens to it in the other, is one of those fictions contrary to the nature of things which arise from the imperfect notions of philosophers, as space without body and body without motion, and which dis- appear when one penetrates a little deeper ; for you must know 1 John Sleidan, original name Philipsohn, c. 1506-1556, the annalist of the Reformation. He was secretary for five years from 1536 to Cardinal du Bellay, minister of Francis I. of France. He was wont to copy all documents bearing ui3on the Reformation to which he had access, and upon the suggestion of Bucer to Philip of Hesse, after some delay was appointed, with the consent of the heads of the Schmalkaldic League, historian of the Reformation, with a salary and access to all necessary documents. He finished the first volume of his great work in 1545. His work was then interrupted by a diplomatic mis- sion in a French embassy to Henry VIII. of England. While there he improved every opportunity to collect materials for his history. In 1551 he was a mem- ber of the Council of Trent for Strassburg. On his return he was made Pro- fessor of Law at Strassburg, a position which enabled him to devote his whole attention to his great work. It was finished for the press in 1554, and published at Strassburg in 1555. It is entitled: Commentariorwn de statu religionis et reipublicx Carolo Quinto, Csesare, libri XXVI. The ed. of 1555 contained only 25 books ; that of 1559 the 26th and an apology of Sleidan, written by himself. The best edition is that of Francfort, 1785-86, 3 vols., 8vo. The work is "the most valuable contemporary history of the times of the reformation, and contains the largest collection of important documents." It is especially noteworthy for its acciaracy, impartiality, and piirity of style. There are two English translations, by John Daws, 1560, and G. Bohum, 1689. There are also translations in other languages. Cf. H. Baumgarten, Ueber Sleidanus Leben und Briefwechsel, 1878; Sleidans Briefwechsel, 1881. — Tr. CH. I] ON HUMAN UNDERSTANDING 115 that each soul preserves all its preceding impressions, and cannot divide itself equally in the manner just mentioned; the future in each substance is perfectly united to the past ; this is what constitutes the identity of the individual. Memory, furthermore, is not necessary, nor even always possible, because of the multitude of present and past impressions which co-op- erate in our present thoughts, for I do not believe that there are in man thoughts of which there is not some effect at least confused or some remnant mixed with subsequent thoughts. We can forget many things, but we could also remember them long after if we would recall them as we ought. § 13. Pli. Those who chance to sleep without dreaming can uever be convinced that their thoughts are active. Til. [One is feebly conscious in sleep, even when it is dream- less. The process of waking up itself shows this, and the easier you are awakened the more you are conscious of what goes on without, although this consciousness is not always strong enough to cause you to awake.] § 14. Ph. It appears very diiScult to conceive that the soul is thinking at this moment in a sleeping man and the next in one awake, without remembering its thoughts. Th. [Xot only is that easy to conceive, but also something like it is observed every day that we are awake ; for we always have objects which strike our eyes and ears, and, as a result, the soul is touched also, without our taking notice of it, because our attention is bent upon other objects, until this object becomes strong enough to draw it to itself, by redoubling its action or by some other means ; it is like a particular sleep with reference to that object, and this sleep becomes general when our atten- tion ceases to regard all objects together. Division of attention, in order to weaken it, is also a means of putting yourself to sleep.] Ph. I learned from a man, who in his youth had applied him- self to study and had a tolerably felicitous memory, that he never had a dream until he had had the fever, from whicli he had just recovered at the time he spoke with me, at the age of twenty-five or twenty-six years. Th. [I have also been told of a student, more advanced in years, who never had a dream. But it is not upon dreams alone that you must base the perpetuity of the soul's perception, since I have shown how, even while asleep, it has some perception of Nvhat goes on without.] ll(j LEIBNITZ'S CKITIQUE OF LOCKE [bk. n § 15. Ph. To think frequently and not to preserve a single moment the memory of your thought, is to think in a useless manner. Th. [All impressions have their effect, but all the effects are not always perceptible ; when I turn to one side rather than to the other, it is very often through a series of minute impressions of which I am not conscious, and which render one movement a little more uncomfortable than the other. All our unpre- meditated actions are the results of a concurrence of minute perceptions, and even our customs and passions, which influ- ence so much our deliberations, come therefrom; for these habits grow little by little, and, consequently, without the minute perceptions, we should not arrive at these noticeable dis- positions. I have already remarked that he who would deny these effects in the sphere of morals, would imitate the poorly taught class who deny insensible corpuscles in physics ; and yet I see that among those who speak of liberty are some who, taking no notice of these unperceived impressions, capable of inclining the balance, imagine an entire indifference in moral actions, like that of the ass of Buridan ^ equally divided between two meadows. Concerning this we shall speak more fully later. I admit, however, that these impressions incline with- out necessitating. Ph. Perhaps we might say that in the case of a man awake who thinks, his bodj^ counts for something and that memory is preserved by means of marks in the brain, but when he is asleep the soul thinks apart by itself. 1 John Buridan, a celebrated Nominalist of the 14th century, the date of whose birth and death is unknown. He studied at Paris under William of Occam (died 1347) and was for many years Professor of Philosophy in the University of Paris, and in 1327 its rector. In philosophy his only authority was reason. In the third book, first question, of his Qusestiones in decern libros ethicorum Aristotelis, 1489, he discussed in an "independent and interesting manner " the question of the freedom of the will, reaching conclusions similar to those of Locke. In his view the liberty possessed by the soul consists in "a certain power of suspending the deliberative process, and determining the direction of the intellect; otherwise the will is entirely dependent on the view of the mind, the last result of examination." The story of the ass as an illus- tration of the indetermiuism of the will " is not," as Sir William Hamilton says (Reid, 8th ed., Vol. 1, p. 238, note) he has ascertained, " to be found in his writings." On Buridan, c/. Ueberweg, Hist, of Philos., English transla- tion, Vol. 1, pp. 465-466; Prantl, Gesch. d. Logik, Vol. 4, 14-38; Stockl, Gesch. d. Philos. d. Mittelalters, Vol. 2, 1023-1028. — Tr. CH. I] UN HUMAN UNDERSTANDING 117 Th. I am very far from saying that, since I believe there is always an exact correspondence between the body and the soul, and since I employ the impressions of the body of which we are not conscious, whether awake or asleep, in order to prove that the soul has in itself similar ones. I maintain even that something goes on in the soul which cor- responds to the circulation of the blood and to all the internal movements of the viscera, of Avhich we are never conscious however, just as those who live near a water-mill do not per- ceive the noise it makes. In fact, if there were impressions in the body during sleep or waking hours, by which the soul was not touched or in any wise affected, limits would be given to the union of the soul and of the body, as if corporeal impressions required a certain form and size in order for the soul to perceive them ; which is not at all tenable if the soul is incorporeal, for there is no relation between an incorporeal substance and this or that modification of matter. In a word, it is a great source of error to believe that there is no perception in the soul besides those of which it is con- scious. § 16. Ph. The greater part of the dreams which we remem- ber are extravagant and incoherent. We should then say that the soul owes the power of rational thought to the body, or that it retains none' of its rational soliloquies. Th. [The body responds to all the soul's thoughts, rational or not, and dreams have also their marks in the brain as well as the thoughts of those who are awake. § 17. Ph. Since you are so sure that the soul is always actually thinking, I wish you would tell me what the ideas are which are in the child's soul before it is united to the body, or just at the time of its union, before it has received any idea by means of sensation. Th. It is easy. to satisfy you by our principles. The soul's perceptions correspond always naturally to the constitution of the body, and when there are a inultitude of movements con- fused and little distinguished in the brain, as happens in the case of those who have little experience, the soul's thoughts (following the order of the things) cannot be more distinct. Yet the soul is never deprived of the help of sensation, because it always expresses its body, and this body is always impressed 118 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n by its surroundings ^ in an infinite number of ways, but Avhicli often give only a confused impression. § 18. Ph. But here is still another question which the author of this Essay asks. I very much wish (says he) that those who maintain so confidently that the soul of man or (what is the same thing) man thinks always, would tell me how they know it ? Til. [I do not know but that more confidence is necessary to deny that anything goes on in the soul of which we are not conscious ; for that which is perceivable must be composed of parts which are not so, nothing can spring into being at once, thought no more than motion. In short, it is as if some one asked to-day how we know the insensible corpuscles. § 19. Ph. I do not remember that those who tell us that the soul always thinks ever say that man always thinks. Th. [I think that is because they understand their state- ment of the separated soul, and yet they voluntarily admit that man always thinks during the union. For myself, who have reasons for holding that the soul is never separated from the entire body, I believe that we can state absolutely that man always does and will think.] Ph. To say that the body is extended without having parts, and that a thing thinks without being conscious that it thinks, are two assertions which appear equally unintelligible. Th. [Pardon me, sir ; I am obliged to tell you that when you advance the statement that there is nothing in the soul of Avhich it is not conscious, you beg the question which has al- ready prevailed in all our former discussion, or you have been desirous to use it to destroy innate ideas and truths. If we agree to this principle, in addition to the fact that we believe it contrary to experience and reason, we should surrender with- out reason to our feeling, which, I believe, I have rendered sufficiently intelligible. But besides the fact that our oppo- nents, skilful as they are, have brought no proof of that which they urge so often and so positively, it is easy to show them the contrary ; i.e. that it is impossible for us always to think ^ Gerhardt reads : " frappe par les ambians d'une infinite de manieres, raais qui souvent ne donnent qu'une impression confuse." Erdmann and Jacques read: "frappe par les autres, qui Tenvironneut, d'une infinite de manieres, mais qui souvent ne font qu'une impression confuse." — Tr. CH. I] ON HUMAN UNDERSTANDING 119 expressly upon all our thoughts ; otherwise, the spirit -would reflect upon each reflection to infinity without ever being able to pass to a new thought. For example, in my consciousness of some present feeling, I should always think that I think, and still think that I think of my thought, and thus to infinity. But it is very necessary that I cease reflecting upon all these reflections, and that there be at length some thought which is allowed to pass without thinking of it ; otherwise, we should dwell always upon the same thing.] Ph. But would there not be as good ground for maintaining that a man is always hungry, by saying that he can be hungry without feeling it ? Th. There is just the difference ; hunger has particular rea- sons which do not always exist. Nevertheless, it is true also that even when you are hungry you do not think of it every moment ; but when you do think of it you feel it, for it is a very marked disposition ; there is always irritation in the stomach, but it is necessary for it to become very strong to cause hunger. The same distinction ought always to be made between thoughts in general and remarkable thoughts. Thus, what appears to put a ridiculous construction upon our opinion, serves to confirm it.] § 23. Ph. One can now ask, when man begins to have ideas in his thought ? And it seems to me that the reply must be, when he has some sensation. Th. [I am of the same opinion; but it is by a principle a little peculiar, for I believe that we are never without thoughts, and also never without sensation. I distinguish only between ideas -^ and thoughts; for we always have all pure or distinct ideas independently of the senses ; but thoughts always corre- spond to some sensation.] § 25. But the mind is passive only in the perception of simple ideas, which are the rudiments or materials of knowl- edge, while it is active when it forms complex ideas. Th. [How can it be that the mind is passive merely Avith regard to the perception of all simple ideas, since, accord- ing to your own admission, there are simple ideas whose per- 1 Gerhardt reads: " Je distingue seuleraent entre les idc'es etles pensees"; Erdmann and Jacques read: . " Je distingue seulement entre sensations et pensees." — Tr. 120 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii ception comes from reflection, and since the mind ^ gives itself thoughts from reflection, for it is itself which reflects ? Whether it can refuse them is another question, and doubtless it cannot (refuse them) without some reason, which turns it aside from them, when there is some occasion for it.] Ph. [It seems that hitherto we have discussed ex professo. Now that we are going to come to the detail of ideas, I hope that we shall be more agreed, and that we shall differ only in some particulars.] Th. [I shall be delighted to see able men adopting the views which I hold to be true, for they are adapted to improve them and to show them in a good light.] CHAPTER II SIMPLE IDEAS § 1. Ph. I hope then that you will admit that there are simple and complex ideas ; thus heat and softness in wax, and cold in ice, furnish simple ideas, for the soul has a uniform conception of them, which is not distinguishable into different ideas. Th. [I believe that we can affirm that these sense-ideas are simple in appearance, because, being confused, they do not give the mind the means of distinguishing their contents. In like manner distant things appear round, because their angles can- not be discerned, although some confused impression of them is received. It is manifest, for example, that green arises from a mixture of blue and yellow ; thus it is possible to believe that the idea of green is also composed of these two ideas. And yet the idea of green appears to us as simple as that of blue or that of warmth. So we are to believe that the ideas of blue ajad warmth are not as simple as they appear. I readily consent, however, to treat these ideas as simple ideas, because at least our apperception does not divide them, but it 1 Gerhai'dt reads : " et que I'esprit se donne " ; Erdmann and Jacques read; " et qu'au moins I'esprit se douue," aud since the mind at least gives itself. — Tk. CH. Ill] ON HUMAN UNDERSTANDING 121 is necessary to proceed to their analysis by means of other experiences and by reason, in proportion as they can be ren- dered more intelligible.-^ And it is also seen thereby that there are perceptions of which we are not conscious. For the perceptions of ideas simple in appearance are composed of per- ceptions of the parts of which these ideas are composed, with- out the mind's being conscious of them, for these confused ideas appear simple to it.] CHAPTER III OF IDEAS WHICH COME TO US BY ONE SENSE ONLY Ph. jSTow we can arrange simple ideas according to the means by which we perceive them, for that is done, 1, by means of one sense only ; 2, by means of more than one sense ; 3, by reflection , or 4, by all the ways ^ of sensation as well as by reflection. Thus of those which enter by a single sense which is particularly adapted to receive them, light and colors enter only by the eyes ; all kinds of noises, sounds, and tones enter by the ears ; the different tastes by the palate ; and odors by the nose. These organs or nerves carry them to the brain, and if any one of these organs chance to be disordered, these sensations cannot be admitted by any artificial gate. The most considerable qualities belonging to the touch are cold, heat, and solidity. The others consist either in the configura- tion of the sensible parts, as smooth and rough, or in their union, as compact, hard, soft, brittle.^ Th. [I quite agree, sir, with what you say, although I may remark that, according to the experiment of the late M. Mariotte * upon the defect of vision with regard to the optic 1 Erdmann's and Jacques's texts of chap. 2 end here ; Gerhardt's text adds the following: " Et Ton voit encor par la qu'il y a des perceptions dont on ne s'appercjoit point. Car les perceptions des idees simples en apparence sont composees des perceptions des parties dont ces idees sont compose'es, sans que I'esprit s'eu apperc^oive, car ces idees confuses luy paroissent simples." — Tr. 2 Locke's expression. Philos. WorJof, Vol. 1, p. 227, Bohn's ed. — Tr. 8 Locke uses these forms, instead of the more common abstract forms end- ing in -ness. Hence I have used them in the translation. — Tr. 4 Edme Mariotte, a celebrated French physicist, born about 1620, died lfi84. He was in some sense the initiator of experimental physics in France. The experiment here referred to, and the resulting discovery of the blind spot at 122 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii nerve, it seems to me that the membranes receive the sensa- tion rather than the nerves, and there is an irregular en- trance for the hearing and the taste, since the teeth and the vertex assist in causing any sound to be lieard, and that tastes make themselves known to some extent through the nose, by reason of the connection of these organs. But all that makes no change in the foundation of things as regards the explica- tion of ideas. As for the qualities belonging to touch, you can say that smoothness or roughness, hardness or softness, are only modifications of resistance or solidity.] CHAPTEK IV OF SOLIDITY § 1. Ph. You will doubtless agree that the idea of solidity is caused by the resistance we find in a body to the en- trance of another body into the place it occupies until it has left it. That which thus hinders the approach of two bodies when they are moved one toward another I call solidity. If any one finds it more to the purpose to call it impenetrahiUty, I give my consent. But I believe that the term solidity bears a more positive character. This idea seems most intimately connected with and essential to body, and can be found only in matter. Til. It is true that we find resistance in touch, when another body reluctantly gives place to our own, and it is also true that bodies dislike to occupy the same place. ]\Iany, how- ever, doubt whether this repugnance is invincible, and it is well also to consider that the resistance which is found in matter is derived in more than one way and by means of reasons quite different. A body resists another either when it must leave the place which it has already occupied, or Avhen it fails to enter the place into which it was ready to enter, because the other tries to enter also, in which case it may happen that, the one not yielding to the other, they stop or mutually repel each the entrance of the optic nerve, was made in 1668. An account of it is given in a short paper in tlie second volume of his collected works. (Euvres de Mariotte, 2 vols.. Leyden: 1717, 4to. — Tr. CH. IV] ON HUMAN UNDERSTANDING 123 other. The resistance is seen in the change of that (body) to which resistance is offered, whether it loses its force, changes its direction, or both happen at once. Now you can say in general that this resistance arises from the repugnance which two bodies have to occupy the same place, which may be called impenetrability. Thus when one body makes an effort to enter, it at the same time forces the other to attempt to leave or to prevent its entrance. But that kind of incompati- bility which makes one or the other, or both together, yield, being once assumed, there are several reasons besides the one named which make one body resist another which endeavors to compel its departure. They are either in it or in the neigh- boring bodies. There are two which are in itself; one is pas- sive and constant, the other active and variable. The first is what I call inertia,^ after Kepler ^ and Descartes, which impels matter to resist motion, and which it is necessary to destroy by force in order to move a body, supposing that there were neither gravity nor adhesion. Thus a body which undertakes to drive forward another, experiences for that reason this re- sistance. The other cause, which is active and variable, con- sists in the impetuosity of the body itself, which does not yield without resistance at the moment its oAvn impetuosity carries it into a place. The same reasons reappear in the neighboring bodies when the body which resists is unable to yield without causing the others to yield also. But then a new consideration comes in — viz.: compactness (fermet^) or the adhesion of one body to another. This adhesion^ makes it impossible to move one body without at the same time mov- ing the other to which it adheres, and this causes a kind of traction in reference to this other. This adhesion so acts that, even should we put aside inertia and manifest impetuosity, there would be resistance ; for if space is conceived as filled with matter perfectly fluid, and if a single hard body were placed within it, this hard body (supposing there were in the fluid neither inertia nor impetuosity) will be moved therein without finding any resistance ; but if space were full of little 1 Gerhardt reads " incertie " ; evidently an error. — Tr. 2 John Kepler, 1571-l()o0, one of the creators of modern astronomy. His complete works were edited by Dr. Ch. Frisch, Joannis Kej)leri opera omnia, 8 vols., Frankfort: 1858-1871. —Tr. 2 Erdmann and Jacques add " souvent," often. — Tr. 124 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii cubes, the resistance wliich the hard body would find, should it be moved among the cubes, would come from the fact that the little hard cubes, on account of their hardness or because of the adhesion of their parts one to another, would with diffi- culty be separated as much as would be necessary to make a circle of movement, and to fill up the place of the body moved at the moment it departs. But if two bodies should enter at the same time by the two ends into a tube open on both sides, and should fill it to its capacity, the matter in this tube, how- ever fluid it be, would resist by its impenetrability alone. Thus, in the resistance of which we are here treating, we have to consider the impenetrability of bodies, inertia, impetuosity, and adhesion. It is true that, in my opinion, this adhesion of bodies arises from a more subtile motion of one body toward another ; but, as this is a point which may be disputed, it must not be assumed at first. And for the same reason we must only assume at first an original, essential solidity, which makes the place always equal to the body, that is to say that the in- compatibility, or, to speak more accurately, the non-consistenee ^ of bodies in the same place is a perfect impenetrability which receives neither more nor less, since many maintain that sensi- ble solidity can arise from a repugnance on the part of bodies to be found in the same place, but which will not prove to be an invincible repugnance. For all the ordinary Peripatetics and many others believe that the same matter can fill more or less space, which phenomenon they call rarefaction or conden- sation, not in appearance only (as when water is squeezed from a sponge), but rigorously, like the scholastic conception of the air. I am not of this opinion ; but I do not think that I ought at first to assume the opposite opinion, the senses, apart from the reasoning faculty, not sufficing to establish this perfect im- penetrability, which I hold to be true in the order of nature, but which is not learned by sensation alone. And some one may claim that the resistance of bodies to compression arises from an effort of the parts to spread themselves when they have not their entire liberty. For the rest the eyes aid greatly in proving these qualities, coming to the assistance of 1 Leibnitz's word is " I'inconsistence," and, as it is apparently technical, I have decided to transfer it, merely changing the form of the negative in- to non- to avoid ambiguity. — Tr. CH. IV] ON HUMAN UNDERSTANDING 125 touch. And at bottom solidity, so long as it presents a dis- tinct idea, is conceived by pure reason, although the senses furnish the reasoning faculty with the proof that it is in nature. § 4. Ph. We are at least agreed that the solidity of a body carries with it the filling of the space it occupies in such a way as absolutely to exclude every other body [if a space can be found in which there was none before], while hardness [or the consistence rather which some call compactness {fer- mete)^ is a strong union of certain parts of matter, which make up masses of a sensible size, so that the whole mass does not easily change its form. Th. [This consistence, as I have already remarked, is pre- cisely what makes it difficult to move one part of a body with- out the other, so that when one part is pushed, the other, which is not pushed, and which does not fall within the line of tendency, is nevertheless induced to go from that side by a kind of traction; and, further, if this last part finds any obsta- cle which holds or pushes it back, it draws it along, or holds back, also, the first part ; and this action is always reciprocal. The same thing sometimes happens in the case of two bodies which do not touch and which do not form a continuous body whose parts are contiguous ; and yet, the one pushed compels the other to go without pushing it, so far as the senses can give us knowledge. Of this the animant/ electrical attraction, 1 See Kraiith-Fleming, Vocah. Philos. Sciences, pp. 28, 29, and 571, edition of 1877, New York: Sheldon & Co., 1883. The animant is that which pos- sesses and imparts life. Together with its cognates aniinality, animalish, animaUst, used frequently hy Cudworth. See Intell. Syst., 514, " Ut sit Aniinans, that it be Animant, or endued with Life, Sense, and Understand- ing." Hjid., 198. "But no Atheist ever acknowledged conscious animcdity to be a first principle in the universe ; nor that tlie whole was governed by any animalist, sentient, and understanding nature, presiding over it as the head of it." The term being technical, and, with its cognates, more or less current in the seventeenth century, it seemed best to retain it, defining and illustrating as al)0ve. Its meaning is, I think, sufficiently evident. It is to be noticed, however, that Erdmann, in his Errores Typographici, prefixed to his edition, reads aimant instead of animant. Jacques's text also has airnant. The translation would then be: The loadstone or magnet; and Schaarschmidt, following this reading, renders it " der Magnet," in his German translation of the Nouveavx Essais, in J. H. v. Kirchmann's Philos. Bibliothek, Berlin, 1873. As I translate on the basis of Gerhardt's text I retain his read- ing and its translation, with the note explaining the terra, altliough at the present writing the reading of Erdmann and Jacques seems more congruous with the context, and so more likely to be the true one. — Tr. 126 LEIBNITZ'S CRITIQUE OE LOCKE [bk. ii and that "which was formerly ascribed to the fear of a vacuum, furnish examples.] Ph. It seems that, in general, hard and soft are names which we give to things solely as related to the particular constitu- tion of our bodies. Th. [But then many philosophers would not ascribe hard- ness to their atoms. The notion of hardness does not depend upon the senses, and its possibility can be conceived by the reason, although we are further convinced by the senses that it is actually found in nature. I should, however, prefer the word compactness — fermete (if I were allowed to use the word in this sense) — to that of hardness, for there is some compact- ness even in soft bodies. I seek even a more suitable and general term, like consistence or cohesion. Thus I would oppose hard to soft, solid to fluid, for wax is soft, but, unless melted by heat, it is not fluid and preserves its bounds ; and in fluids even there is ordinarily cohesion, as is shown in drops of water and of mercury. I am also of opinion that all bodies have some degree of cohesion, as I also believe that there are none which do not have some fluidity, and whose cohesion is not capable of being overcome ; so that, in my opinion, the atoms of EjDicurus,-^ whose hardness is supposed to be invinci- ble, cannot occur any more than the subtile, perfectly fluid matter of the Cartesians. But this is not the place to justify this opinion or to exj^lain the rationale of cohesion. Ph. The perfect solidity of bodies seems to be justified by experiment. For example, water incaxDable of yielding, passed through the pores of a hollow globe of gold, in which it was confined, when this globe was put under pressure in Florence. Th. [There is something to be said as to the inference which you draw from this experiment, and from what happened in the case of the water. The air as well as the water is a body, which is compressible at least ad sensuni, and those who would maintain a complete rarefaction and condensation Avill say that water is already too compressed to yield to our machines, as air very much compressed would resist also a further compres- sion. I admit, however, on the other hand, that if any slight change should be noticed in the volume of the water, it might be ascribed to the air which is enclosed in it. Without enter- 1 Epicurus, December, 342, or January, 341-270 B.C. — Tr. CH. IV] ON HUMAN UNDERSTANDING 127 ing now into the discussion whether pure water is not itself compressible, as it is found that it is dilatable when it evapo- rates, I am, nevertheless, decidedl}' of the opinion of those wlio believe that bodies are perfectly impenetrable, and that there is, save in appearance, neither condensation nor rarefaction. But this kind of experiment is as little capable of proving this as the tube of Torricelli ^ or the machine of Guerike - are suffi- cient to prove a perfect vacuum.^ § 5. Ph. If the body were strictly capable of rarefaction and compression, it might change in volume or exteiisiou, but that not being so, it will be always equal to the same space ; and, moreover, its extension will be always distinct from that of space. Th. [The body might have its own extension, but it does not thereby follow that it would be always determinate or equal to the same space. I^evertheless, although it may be true that in the conception of body something besides space is conceived of, it does not thereb}' follow that there are two extensions — that of space and that of body ; for it is as Avhen in conceiving several things at once, one conceives something besides the number, viz. : res numeratce ; and, moreover, there are not two multitudes, the one abstract — i.e., that of number; the other concrete — i.e., that of the things enumerated. Likewise one can say that it is not necessary to think of two extensions — the one abstract, of space, the other concrete, of body, the con- 1 Evangelista Torricelli, 1608-1647, a celebrated Italian physicist and mathe- matician, the inventor of the mercurial barometer, long called the "Torricel- lian tube." He had a controversywith Roberval {vid. ante, p. 107 and note) as to the discovery of the quadrature of the cycloid. Torricelli found the area of the curve, and furnished the demonstration of it, which he published in a tract, l>e motu f/)'(u:ium naturaliter accelerato in his Opera geontetrica, Florence, 1641. — Tr. ^ Otto von Guerike, 1602-1686, a German physicist, who devoted himself especially to experimenting upon the vacvmni, and who, after many attempts, finally, in 1651, hit upon an air machine, which enabled him to undertake a series of experiments upon the different effects of vacuum. His labors and principal observations have been published under the title, Experimenta nova, v.t vacant, Maf/deburc/ica, de vacuo spatio, etc., Amsterdam, 1672. — Tr. 3 Descartes maintained the impossibility of a vacuum. Of. Prin. Philos., II., § 16; English translation by .John Veitch, LL.D., The Method, Meditations, and Selections from the Principles of Descartes, etc., 8th ed., p. 241, Edin- burgh: William Blackwood & Sons, 1881: also vid. ante. p. 16, and the fifth letter to Samuel Clarke. § 34, Gerhardt. Vol. 7. p. 396; Erdmaiin, p. 766, b: translation, Duncan, Philos. Works of Leibnitz, p. 262. — Tr. 128 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii Crete existing as sucli only through the abstract. And as bodies pass from one part of space to another — i.e., change order among themselves — things also pass from one part of the order or of a number to the other, when, for example, the first becomes the second and the second the third, etc. In fact, time and space are only kinds of order,^ and in these orders the vacant place (which in relation to space is called vacuum), if there were any, would show the possibility only of that which is lacking together with its relation to the actual. Ph. I am nevertheless very glad that you agree with me that matter does not change in volume. But you seem to go too far, sir, in not recognizing two extensions, and you re- semble the Cartesians, who do not distinguish space from mat- ter.^ Now it seems to me that if a class is found who, not having these distinct ideas (of space and of solidity which fills it), blends them and makes of the two one only, we cannot see how these persons can converse with others. They are like a blind man who, when another man speaks to him of scarlet, thinks it resembles the sound of a trumpet. Th. [But I hold at the same time that the ideas of exten- sion and solidity, like that of scarlet-color, do not consist in an I Jcnoiv not tohat.^ I distinguish extension and matter, contrary 1 Cf. Letter to Des Bosses, June 16, 1712, Gerharclt, Vol. 2, p. 450 ; Erdmann, p. 682, b : " Spatium tit ordo coexisteutium ijlifeiiomeiiorum, lit tempus succes- sivoi'um," i.e. "Space is the order of co-existing, as time of successive jplie- nomena " ; also the letters to Clarke, Gerhardt, Vol. 7, pp. 345 sq. ; Erdmann, pp. 746 sg., translation, Duncan, Philos. Works of Leibnitz, pp. 238 sq.; Kant, Kritik d. r. Vernunft, Erst. Th., Absch. 1 und 2, §§ 2-7, and translations of Max Miiller, and Watson in The Philosophy of Kant, as contained in extracts from his oion ivritings. New York: Macmillan & Co., 1888. — Tk. 2 Cf. Descartes, Fria. Philos. II., §§ 8-15 ; Veitch's translation, pp. 236-240. — Tr. 3 Leibnitz's expression is "un .?e ne say qiioi." Schaarsclimidt trans- lates it " ein undenkbares Etiuas." It seems to be equivalent to an indef- inite somewhat which is the ultimate essence of things, and which is the cause of, and by differentiation becomes, the particular. Leibnitz, then, means to say that the ideas of extension and solidity are distinct. Cf. John Dewey, Ph.D., Leibniz's Nevj Essays concerning the Human Understanding, a Criticcd Exposition, p. 134. As applied to personal beings, it seems to be equivalent to the "unconscious presentations" — i.e. "the dark side of the soul-life," " the proper basis of Individuality." " Genius, disposition, feeling, are the terms by which a later time has designated what Leibnitz calls the je ne sais quoi, whereby every one is preformed by nature to something par- ticular" (" Ganz wie bei dem blossen Monaden ihre individuelle Beschaffen- heit in dem Momente der Schranke, der materia prima, lag, ganz so werden CH. v] ON HUMAN UNDERSTANDING 129 to the view of the Cartesians. Still I do not believe that there are two extensions ; and since those who dispute over the dif- ference between extension and solidity are agreed on several truths upon this subject and have some distinct notions, they can find therein the means of extricating themselves from their disagreement ; thus the assumed difference upon ideas ought not to serve as a pretext for eternal disputes, although I know that certain Cartesians, otherwise very able, are accustomed to intrench themselves in the ideas which they pretend to have. But if they would avail themselves of the means which I have before given for recognizing ideas true and false, and of which Ave shall speak also in the sequel, they would retire from a position which is not tenable. CHAPTER V OF SIMPLE IDEAS WHICH COME BY DIFFEREIS^T SENSES Pli. The ideas, the perception of which comes to us from more than one sense, are those of space, or extension, or fig- ure, of motion and rest. Til. [The ideas which are said to come from more than one sense, like those of space, figure, motion, rest, are rather from common-sense, that is to say, from the mind itself, for they are ideas of the pure understanding, but related to externality, and which the senses make us perceive; they are also capable of definition and demonstration.] liier diese imbewussten VorsteUuugen, cl. h. wircl die duukle Seite des Seelen- lebens, als der eigentliche Grund der Individualitat bestimmt. Genius, Gemiitli, Gefiihl siud die Worte, mit denen eine spiitere Zeit das bezeichnet hat, was Leibnitz das ,;> nc sais qiioi nemit, wodurch Jeder von Natur zu etwas Besondereni praformirt ist." Erdmaun, Gnnidriss d. Gesch. d. Pliilos., 3te Auflage 2te Bd. § 288, 5, s. 161. Berlin, 1878 ; English translation. Vol. 2, p. 191, London: Swan Sonnenscliein & Co., 1889). Cf. also Leibnitz, New Essays, Preface, vid. ante, pp. 47 sq., Book IL, chap. 1, § 15, Th., sq., and Erdmann's exposition of the same, op. cii., s. 160, 161. Also Professor Dewey's most excellent work cited above. — Tk. K 130 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii CHAPTER VI OF SIMPLE IDEAS WHICH COME BY REFLECTION Ph. The simple ideas which come by reflection are the ideas of the understanding and of the will [for we ourselves per- ceive them in reflecting upon ourselves.] Tli. [It is doubtful if all these ideas are simple^ for it is clear, for example, that the idea of the will includes that of the understanding, and that the idea of motion contains that of figure. CHAPTER VII OF IDEAS WHICH COME BY SENSATION" AND REFLECTION § 1. Ph. There are some simple ideas which make themselves perceived in the mind by all the avenues of sensation and by reflection also — viz.: pleasure, pain, power, existence, unity. Th. [It seems that the senses cannot convince us of the exist- ence of sensible things without the aid of the reason. Thus I should think that the idea^ of existence comes from reflection. That of power also and of unity come from the same source, and are of a wholly different nature from the perceptions of pleasure and pain.] CHAPTER VIII OTHER CONSIDERATIONS UPON SIMPLE IDEAS § 2. Ph. What shall we say of ideas of privative qualities? It seems to me that the ideas of rest, darkness, and cold are as positive as those of motion, light, and heat. Nevertheless, in proposing these privations as the causes of privative ideas I follow the common view ; but in the main it will be difficult 1 The French is "la consideration de I'existence." — Tr. CH. viii] ON HUMAN UNDERSTANDING 131 to determine whether there is really any idea which arises from a privative cause until it has been determined whether rest any more than motion is a privation. Th. [I had not believed that we could have reason to doubt the privative nature of rest. It suffices it that motion in the body be denied, but it does not suffice for motion to deny rest, and it is necessary to add something more to determine the de- gree of motion, since it receives materially more or less, while all rest is equal. It is another thing when we speak of the cause of rest, which must be positive in the secondary^ matter or mass. I should furthermore regard the very idea of rest as privative — i.e., that it consists only in negation. It is true that the act of denial is positive.] § 9. Ph. The qualities of things being the faculties they have of producing in us perception of ideas, it is well to distinguish these qualities. They are primary and secondary. Extension, solidity, figure, number, mobility are the original qualities inseparable from body which I call primary. § 10. But I call 1 Leibnitz constantly distinguishes between x^rimary and secondary matter. Primary matter is tlie primitive passive power belonging to each separate being as such, by which it is distinguished from God and in which is grounded the possibility of representing itself as different. It is essential to and insepa- rable from the eutelechy, or principle of activity, which it completes, the two united producing the perfect substance or monad. By itself it is a pure abstraction or potentiality, and not a substance. It is equivalent to confused ideas, thus to an imperfect manifestation or phenomenon of spirit — since all matter is ultimately spirit or has its final reason or source in spirit — but a potentiality of spirit capable sometime of realizing perfectly all its intrinsic, but now latent, activity. Secondary matter is a mass resulting from the union of many monads or complete substances, each having its own primary matter and its own entelechy, with their derived forces, activities, receptivities. It is not, however, a substance ; and its extension resulting from the union of non-extended simple substances is only phenomenal, though not on that account unreal, being due to our confused perception, and consisting in the impenetrability, resistance, or inertia of the monad on its passive side ; an extension which will disappear when the activity of the monad becomes pure and perfect. Cf. Letters to Tolomei, Dec. 17, 1705, Gerhardt, Vol. 7, pp. 467- 468; Des Bosses, March 11, Oct. 16, 1706, March 16, 1709, Gerhardt, Vol. 2, pp. 304, 324, 368 ; Erdmann, pp. 435, 440, 456; De anim.a brvtorvm, 1710, G. 7, 328 ; E. 463 ; Letters to Rud. Christ. Wagner, June 4, 1710, G. 7, 528, E. 465 ; translation, Duncan, Philos. Works of Leibnitz, p. 190 sq. ; Bierling, Aug. 12, 1711, G. 7, 500-502, E. 677-678 ; Remond, Nov. 4, 1715, G. 3, 656-660 ; E." 735- 737 ; Feb. 11, 1715, § 4 (reply to Remond's fourth difficulty stated in his letter to Leibnitz, Jan. 9, 1715), G. 3, 636, E. 725 ; also the writing dated July, 1714, and first published by Gerhardt, 3, 622-624. Cf. also Erdmann, Grimd. d. Gesch. d. Philos.,3d ed., § 288, 2, 3 ; Dewey, Leibnitz, New Essays, chaps. 7 and 8. — Tr. 132 LEIBNITZ'S CKITIQUE OF LOCKE [bk. ii secondary qualities the faculties or powers of bodies to produce certain sensations in us, or certain effects in other bodies, as the fire, for example, produces a certain effect in the wax when melting it. Th. [I think we can say that Avhen the power is intelligible, and can be distinctly explained, it should be reckoned among the primary qualities ; but when it is only sensible and gives only a confused idea, it should be put among the secondary qual- ities.^ • § 11. Ph. These primary qualities show how bodies act upon one another. Now, bodies act only by impulse, at least so far as we can conceive the j)rocess, for it is impossible to under- stand how bodies can act upon what they do not touch, which is equivalent to imagining that they can act where they are not. Th. [I am also of the opinion that bodies act only by impulse. Yet, there is some diiSculty in the proof of what I have just heard ; for attraction sometimes occurs without contact, and we can touch and draw without any visible impulse, as I have shown above ^ in speaking of hardness. In the case of the atoms of Epicurus, the one part pushed would draw the other with it, and would touch it in putting it in motion without impulse. And in the case of attraction between contiguous things we cannot say that the one which draws with itself acts where it is not. This reason would militate only against attractions, from a distance, as would be the case in reference to what are called vires centripetcB advanced by some scholars.] § 13. Ph. ISTow, certain particles, striking our organs in a cer- tain way, cause in us certain sensations of colors or tastes or other secondary qualities which have the power of producing these sensations. And it is no more difficult to conceive that God can attach. such ideas (as that of heat) to motions, with which they have no resemblance, than it is difficult to conceive that he has attached the idea of pain- to the motion of a piece of iron which divides our flesh; which motion the pain in no manner resembles. Th. [It is not necessar}^ to suppose that ideas like those of color or of pain are arbitrary and without relation or natural connection with their causes ; it is not the custom of God to 1 Cf. Bk. II., Chap. 4, § 4, Th., ante, p. 125, sg. — Tb. CH. viii] ON HUMAN UNDERSTANDING 133 act with so- little order and reason. I should rather say that there is a kind of resemblance, not complete and, so to speak, in terminis, but expressive, or a kind of orderly relation, as an ellipse, and even a parabola or hyperbola resemble in some sense the circle of which they are a projection upon a plane, since there is a certain exact and natural relation between what is projected and the projection which is made, each point of the one corresponding by a certain relation to each point of the other. This the Cartesians do not sufficiently consider, and for once you have deferred to them more than has been customary with you, and without reason for so doing.] § 15*. Ph. I tell you what appears to me, and the appear- ances are that the ideas of the primary qualities of bodies resemble these qualities, but the ideas produced in us by the secondary qualities resemble them in no way. Th. [I have just shown how there is resemblance or exact relation in respect to the secondary as well as the primary qualities. It is certainly reasonable that the effect correspond to its cause ; and how assert the contrary, since you know dis- tinctly neither the sensation of blue (for example) nor the motions which produce it ? It is true that pain does not resemble the motion of a pin, but it may very well resemble the motions which this pin causes in our body, and represent these motions in the soul, as I have no doubt it does. It is also for this reason that we say that the pain is in our body and not that it is in the pin ; but we say that the light is in the fire, because there are in the fire motions which are not dis- tinctly sensible apart from it, but whose confusion or con- junction becomes sensible, and is represented to us by the idea of light. § 21. Ph. But if the relation between the object and the sensation be natural, how can it be, as we notice in fact, that the same water may appear warm to one hand and cold to the other ? which shows that the heat is no more in the water than the pain is in the pin. Th. [This proves all the more that heat is not a sensible quality or power of making itself felt absolutely all at once, but that it is relative to the suitable organs ; for a particular motion in the hand may be mixed with it aiid change its appear- ance. Light, furthermore, does not make itself evident to 134 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii badly constituted eyes, and when they are themselves filled with a great light, they are insensible to a less. Even the primary qvialities (according to our classification) — for ex- ample, unity and number — may not appear as they should; for, as Descartes has already stated, a globe touched by the fingers in a certain way appears double, and mirrors or glasses cut in facets multiply the object. It does not then follow that what does not always appear the same is not a quality of the object, and that its image does not resemble it. And as for the heat, when our hand is very warm, the medium heat of the water does not make itself felt, and modifies rather that of the hand, and consequently the water appears to us cold ; as the salt water of the Baltic Sea mixed with the water of the Sea of Portugal^ would lessen its specific saline quality, although the former be itself salt. Thus, in any case, we can say that the heat belongs to the water of a bath, although it may appear cold to any one, as honey is called absolutely sweet, and silver white, although the one appears bitter, the other yellow to some diseased persons, for the classification is made upon the basis of the most common (conditions) ; and yet it remains true that, when the organ and the medium are constituted as they should be, the internal motions and the ideas which represent them to the soul resemble the motions of the object which cause color, heat, pain, etc., or, what is here the same thing, express it by means of a relation suffi- ciently exact, although this relation does not distinctly appear to us, because we cannot disentangle this multitude of small impressions either in our soul or our body or in what is with- out. § 24. Pli. We consider the qualities which the sun has of blanching or melting wax or hardening mud only as simple powers, Avithout thinking of anything in the sun correspond- ing to this blanching, softness, or hardness ; but heat and light are commonly regarded as real qualities of the sun. Properly considered, however, these qualities of light and heat which in me are perceptions are not in the sun in any other manner than the changes produced in the wax when it is blanched or melted. 1 Obsolete name for that part of the Atlantic which washes the coast of Portusral. — Tr. CH. IX] ON HUMAN UNDERSTANDING 135 Th. [Some have pushed this doctrine so far that they have desired to persuade us that if any one could toucli the sun he would find there no heat. The counterfeit sun which makes itself felt in the focus of a mirror or a burning-glass may disa- buse people of this notion. But as to the comparison between the power of heating and that of melting, I dare affirm that, if the melted or blanched wax >had feeling, it would feel some- thing similar to what we feel when the sun warms us, and would say, if it coiild, that the sun is warm, not because its whiteness resembles the sun — for when faces are tanned in the sun their brown color should likewise resemble it — but because there are in the wax motions which are related to those in the sun which cause them ; its whiteness may come from another cause, but not the motions which it has had in receiving it (whiteness) from the sun.] CHAPTER IX OF peeceptio:n' § 1. Ph. Come we now to the ideas of reflection in particu- lar. Perception is the first faculty of the soul which is occu- pied with our ideas. It is also the first and simj)lest idea which we receive by reflection. Thought signifies often the mind's working upon its own ideas, when it acts and considers a thing with a certain degree of voluntary attention : but in what we call perception the mind is ordinarily purely passive, not being able to avoid perceiving what it actually perceives. Th. [We might perhaps add that the animals have percep- tion, and that it is not necessary that they have thought, that is to say, that they have reflection or what may be its object. We ourselves also have minute perceptions of which we are not conscious in our present state. It is true that we might very well perceive them ourselves, and reflect upon thein, if we Avere not turned aside by their multitude, which distracts our mind, or if they were not effaced, or rather obscured, by greater ones. § 4. Ph. I admit that when the mind is strongly occupied 136 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii in contemplating certain objects it does not perceive in any- way the impression which certain bodies makQ upon tlie organ of hearing, althougli tlie impression may be quite strong ; but no perception arises therefrom if the soul takes no cognizance thereof. Th. [I should prefer to distinguish between j;>erce2Mon and consciousness {s' appercevoir) } The perception of light and color, for example, of which we are conscious, is composed of many minute perceptions, of which we are not conscious ; and a noise which we perceive, but of which we take no notice, becomes apperceptihle by a little addition or increase ; for if what precedes make no impression upon the soul, this little addition would also make none, and the whole Avould make no more. I have already touched upon this point (Ch. II,- of this book, §§ 11, 12, 15, etc.)]. § 8. Ph. It is proper to remark here that the ideas which arise from sensation are often altered by the mental judgment of grown persons Avithout their perceiving the fact. A flat circle Avith various light and shade represents the idea of a globe of uniform color. But, as Ave are accustomed to distin- guish the images of bodies and the changes of the reflections of light according to the figures of their surfaces, Ave put in the place of Avhat appears to us the cause the image itself, and confuse the judgment with the appearance. Th. Nothing is truer, and this it is Avhich gives to painting the means of deceiving us by the artifice of a A^ery extended perspective. When bodies have fiat surfaces, they can be rep- resented without employing shadows by giving only their con- tours and by simply making pictures after the fashion of the Chinese, but better proportioned than theirs. The same 1 Cf. Leibnitz, Principes de la nature et de la rjrace fondea en raison, § 4. "It is well to make a distinction between the perception, which is the internal condition of the monad representing external things, and apperception , which is, consciousness or the reflective knowledge of this internal state; the latter not being given to all sonls, nor at all times to the same soul." For the entire piece, which is a brief statement of his philosophical system prepared by Leibnitz himself, with the greatest care, about 1714, cf. Gerhardt, Yol. 6, pp. 598-606; Erdmann, pp. 714-718; translation, Duncan, PJiUos. Worl-s of Leibnitz, pp. 209-217, and note 66, p. 387 op. cit. Also Hamilton's Reid, 8th ed., Vol. 2, p. 877, note, and Krauth-Fleming, Vocab. Philos., ed. of 1877, articles "Apperception," p. .38, "Consciousness," pp. 109-113,613, "Percep- tion," pp. 373-374, 807-809, "Perceptions (Obscure)," pp. 374-376. — Tr. - This should be chap. 1, I think. — Tr. CH. IX] ON HUMAN UNDERSTANDING 137 custom is observed in designing medals, in order that the draughtsman may be less likely to depart from the precise form of the antique. But we cannot distinguish exactly by means of the design the interior of a circle from the interior of a spherical surface bounded by this circle without the aid of shadows, the interior of each having neither points distin- guished nor distinguishing features, although there is, however, a great difference which ought to be indicated. Desargues ^ has accordingly given precepts upon the force of tints and shades. When, then, a painting deceives us there is a double error in our judgments ; for first we put the cause for the effect, and think we see immediately the cause of the image, in which we resemble a little a dog who barks at a mirror ; for, properly speaking, we see only the image, and we are affected only by the rays of light. And since the rays of light require time (how- ever little it be), it is possible for the object to be destroyed in this interval, and for it no longer to exist when the ray reaches the eye, and that which no longer exists cannot be the object present to the sight. In the second place, we further deceive ourselves when we put one cause for another, and think that what conies only from a flat picture is derived from a body, so that in this case there is in our judgments all at once a me- tonymy and a metaphor ; for even the figures of rhetoric pass into sophisms when they impose on us. This confusion of the effect with the cause, whether true or false, often enters into our judgments, moreover, upon other things. Thus we feel our bodies, or what touches them, and we move our arms by means of an immediate physical influence, which we think. 1 Gaspare! Desarfjues. 1593-1662, a French geometer and engineer, a friend of Descartes, Gassendi, Pascal, and Roberval, who wrote on the application of geometry to the arts as well as on geometry itself. These writings have been lost and their titles are known only through the engraver Bosse. Of his Methode univeraelh de mettre en perspective des objects donnes reellement, ou en devis, avec leurs proportions, mesures, doignments, sans employer aucun point qui soit hors du champ de Vouvrage, 16.30 or 1636, Descartes thus speaks in a letter to Mersenne ("written toward the end of April, 1637," according to Cousin, CEuvres de Descartes, Vol. 6, pp. 250-256, Paris: 1824- 1826), " Je n'ai re^u que depuis pen de jours le petit livre in folio, qui traite de la perspective: il n'.est pas a de'sapprouver, outre que la curiosite et la nettete du langage de son auteur sont a estimer," I received only a few days ago the little book in folio treating of perspective : it is not to be con- demned ; further the exactness and perspicuity of the author's language are to be admired. — Tr. 138 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n constitutes the connection of the soul with tlie body, while in truth we feel and change in that way only what is in us. Ph. I will at this time propose to you a problem which the learned Mr. Molyneax/ who employs so profitably his excel- lent genius in the promotion of the sciences, communicated to the illustrious Mr. Locke. Here it is nearly in his own terms : Suppose a man blind from birth, now grown up, who has learned to distinguish by touch a cube from a globe of the same metal, and almost of the same size, so that when he touches the one or the other he can tell which is the cube and which the globe. Suppose that the cube and the globe being placed upon the table, this blind man comes to enjoy his sight. The question is, if in seeing them without touching them he could distinguish them, and tell which is the cube and which the globe. I pray j^ou, sir, tell me what is your opinion upon the matter. Til. I ought to give some time to thought upon this ques- tion, which appears to me quite curious : but since you press me for an immediate reply, I would venture to say between ourselves that I think that supposing the blind man knows that these two figures which he sees are those of the cube and the globe, he could distinguish them and say, without touch- ing, This is the globe, this the cube. Ph. I fear lest it may be necessary to put you in the crowd of those who have failed to answer Mr. Molyneux ; for he sent word in the letter Avhich contained this question, that, having proposed it upon the occasion of Mr. Locke's Essay on Under- standing to different persons of very penetrating minds, he had found scarcely one among them who at once gave such a reply upon that point as he thinks should be made, although they were convinced of their error after having heard his reasons. The reply of this penetrating and judicious author is negative ; for (he adds) while this blind man has learzied by experience of some kind the globe and the cube as they affect his touch, he does not, however, yet know that what affects the touch in such or such manner must strike the eyes 1 William Moljmeiix, 1656-1698, an eminent mathematician. He founded in Dublin, in January, 1684, a Philosophical Society on tlie model of the Royal Society at London. His principal work, Dioptrica Nova, in two parts, was published at London in 1692-1709, in 4to. — Tk. CH. IX] ON HUMAN UNDERSTANDING 139 in sucli or such manner, nor that the j)rojecting angle of the cube, which presses his hand in an unequal manner, must appear to his eyes as it appears in the cube. The author of the Essay declares himself at once of the same opinion. Th. Perhaps Mr. Molyneux and the author of the Essay are not so far from my opinion as at lirst appears, and the reasons for their view, contained apparently in the letter of the for- mer, who has employed them with success in order to convince men of their error, have been purposely suppressed by the latter in order to give more exercise to the minds of his readers. If you will weigh ni}^ I'eply, you Avill find, sir, that I have placed therein a condition which can be considered as comprised in the question — viz. : that the question is that of distingu-ishing alone, and that the blind man knows that the two figured bodies, which he should distinguish, are there, and that thus each of the appearances which he sees is that of the cube or that of the globe. In this case it appears to me beyond doubt that the blind man who ceases to be such can distinguish them by the principles of reason, united Avith that sense-knowledge with which touch has before furnished him. For I do not speak of that which he Avill do perhaps in fact and immediately, dazzled and confused by the novelt}^, or from some other cause little accustomed to draw inferences. The basis of my view is that in the . globe there are no points dis- tinguished by the side of the globe itself, all there being level and without angles, while in the cube there are eight points distinguished from all the others. If there were not this means of discerning the figures, a blind man could not learn the rudiments of geometry by touch. But we see that those born blind are capable of learning geometry, and have indeed always certain rudiments of a natural geometry, and that most often geometry is learned by sight alone, without the use of touch, as indeed a paralytic or other person to whom touch has been almost denied might and even must do. And these tAvo geometries — that of the blind man and that of the paralytic — must meet and agree, and indeed return to the same ideas, although there are no common images. This again shows how necessary it is to distinguish images from exact ideas, which consist in definitions. It would really be very interesting and instructive to make a complete examination of 140 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii the ideas of a man born blind, to understand the descriptions he makes of figures. For he may come to this, and he may even understand the doctrine of optics, so far as it is depend- ent upon distinct and mathematical ideas, although he could not attain to a concejDtion of dair-confus, that is to say, the image of light and of colors. This is why a certain one born blind, after having attended lessons in optics, which he appeared fully to understand, replied to some one who asked him what he thought light was, that he thought it must be something pleasant like sugar. It would likewise be very important to examine the ideas which a man born deaf and dumb may have of things not figured, whose description we usually have in words, and which he must have in a manner wholly different from, though it may be equivalent to ours, as Chinese writing is in fact equivalent to our alphabet, although it is infinitely different, and might appear to have been in- vented by a deaf man. I learn, through the favor of a great prince, of one born deaf and dumb in Paris, whose ears have at last attained to the performance of their function, that he has now learned the French language (for it is from the court of France that he was summoned not long since), and that he could say very curious things about the conceptions he had in his former condition and about the change of his ideas when he commenced to exercise the sense of heariug. These per- sons born deaf and dumb can go farther than we think. There was one in Oldenburg in the time of the last Count who became a good painter, and showed himself very rational in other respects. A very learned man, a Breton by nation, told me that at Blainville, about ten leagues from Nantes, belonging to the Duke of Rohaii, there was, about 1690, a poor man, who lived in a hut near the castle outside of the town, who was born deaf and dumb, and wdio carried letters and other things to the town and found the houses, following some signs which the persons accustomed to employ him made him. Finally the poor man became blind also, but did not give up rendering some service and carrying letters into the town to whatever place they indicated to him by touch. He had a board in his hut which, extending from the door to the place where his feet were, informed him by its motion when any one entered his house. Men are very negligent in CH. ixj ON HUMAN UNDERSTANDING 141 not obtaining an exact knowledge of the modes of thought of such persons. If he no longer lives, there is probably some one in the vicinity who could still give some information respecting him, and make us understand how they showed him the things he was to do. But to return to what the man born blind, who begins to see, would think of the globe and the cube, seeing them without touching them, I reply that he will distinguish them, as I have just said, if any one informs him that the one or the other of the appearances or perceptions which he has of them belongs to the cube or to the globe ; but, without this previous instruction, I admit that he will not at first venture to think that the kinds of pictures which they make of themselves in the depths of his eyes, and which might come from a flat picture upon the table, represent the bodies, until touch convinces him of the fact, or until, by force of reasoning upon the rays of light according to optics, he understands by the lights and shades that there is a some- thing which arrests these rays of light, and that it must be exactly what remains for him in touch, which result he will finally reach when he sees this globe and this cube revolve, and change the shadows and the appearances in accordance with the motion, or even when, these two bodies remaining at rest, the light which illumines them changes its place, or his eyes change their position. For these are about the means we have of distinguishing from afar a picture or a perspec- tive, which represents a body, from the body itself. § 11. Ph. [Let us return to perception in general.] It 'dis- tinguishes animals from inferior beings. Th. [I am inclined to the belief that there is some percep- tion and appetition also in the plants, because of the great analogy which exists between plants and animals ; and if, as is commonly supposed, there is a vegetable soul, it of necessity has perception. Yet I do not cease to attribute to mechanism all that takes places in the bodies of plants and animals, except their first formation. Thus I agree that the move- ment of the jjlant called sensitive arises from mechanism, and I do not approve of having recourse to the soul when the question is that of explaining the detail of the phenomena of plants and animals.] § 14. Ph. It is true that for myself, indeed, I cannot help 142 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii believing that even in those kinds of animals which are like the oysters and mussels there is some feeble perception ; for quick sensations would serve only to discommode an animal which is constrained to live always in the place where chance has put it, where it is watered with water, cold or warm, pure or salt, according as it comes to it. Th. [Very well, I also believe that we can say almost as much of plants ; but in man's case, his perceptions are accom- panied with the power of reflection, which passes to the act when there is any occasion. But when he is reduced to a state in which he is as it were in a lethargy and almost without feeling, reflection and consciousness cease, and universal truths are not thought of. But the innate and acquired faculties and dispositions, and even the impressions which are received in this state of confusion, do not cease on that account, and are not effaced, though they are forgotten. They will even have their turn one day in contributing to some notable result, for nothing is useless in nature ; all confusion must develop itself; the animals even, having attained to a condition of stupidity, ought some day to return to perceptions more ele- vated; and, since simple substances always endure, we must not judge of eternity by a few years.] CHAPTER X OF RETENTION §§ 1, 2. Ph. The other faculty of the mind, by which it advances farther toward the knowledge of things than by sim- ple perception, is that which I call retention, which conserves the knowledge received by the senses or by reflection. Reten- tion works in two ways : in actually conserving the present idea, which I call contemplation ; and in preserving the power to bring them again before the mind, and this is what is called memory. Th. [One retains also and contemplates innate knowledge, and very often one cannot distinguish the innate from the acquired. There is also a perception of images — either those CH. XI] ON HUMAN UNDERSTANDING 143 which have already existed for some time, or those which are formed anew in us.] § 2. Ph. But you believe with us that these images or ideas cease to be anything as soon as they are not actually matters of consciousness ; and that to say that there are ideas reserved in the memory means at bottom only that the soul has in some instances the power of reviving the perceptions it has already had with a feeling which at the same time convinces it that it has previously had these kinds of perceptions. Th. [If ideas were only forms or modes of thoughts, they would cease with them ; but you yourself have admitted, sir, that they are internal objects, and in this way can subsist. And I am astonished that you can always be satisfied with these naked poicers or faculties, which you would apparently reject in the scholastic philosophers. It would be necessary to explain a little more distinctly in what this faculty consists and how it is exercised; and that would make known that there are dispositions which are the remains of past impres- sions in the soul as well as in the body, but of which we are conscious only when the memory finds some occasion for them. And if nothing restored past thoughts, as soon as we no longer think of them, it would be impossible to explain how the memory can preserve them : and to recur for this purpose to this naked faculty is to speak nowise intelligibly. CHAPTER XI OF DISCERNMENT OR THE FACULTY OF DISTINGUISHING IDEAS § 1. Ph. Upon the faculty of distinguishing ideas depends the evidence and certainty of several propositions which pass for innate truths. Th. I admit that to think of these innate truths and to vmravel them discernment is necessary ; but they do not on that account cease to be innate.] § 2. Ph. Now, vivacity of mind consists in recalling promptly ideas ; but judgment in representing them clearly and distinguishing them exactly. 144 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n Til. [Perhaps each is vivacity of imagination, and judg- ment consists in the examination of propositions according to reason.] Ph. [I am not averse to this distinction of mind and judg- ment. And sometimes tliere is judgment in not employing it too much. For example : to examine certain witty thoughts by the severe rules of truth and good reasoning is in a certain sense an insult. Th. [This remark is a good one ; witty thoughts must have at least some apparent foundation in reason, but it is not necessary to examine them minutely with too much scrupu- lousness, as it is not necessar}^ to look at a picture from a position too near it. It is in this, it seems to me, that Father Bouhours fails more than once in his Art cle penser dcms les ouvrages cV esprit^ as when he despises this sally of Lucan : ^ Victrix causa diis placuit, sed victa Catoni. § 4. Ph. Another operation of the mind in respect to its ideas is the comparison it makes of one idea with another as regards extension, degrees, time, place, or some other circum- stance ; it is upon this that the great number of ideas com- prised under the term relation depends. Th. [According to my view, relation is more general than comparison, for relations are either of comparison or of concur- rence. The first concern the congruity or incongruity (I take these terms in a less extended sense) which comprises resem- blance, equality, inequality, etc. The second comprise some connection, as that of cause and effect, of whole and parts, of position and order, etc.] § 6. Ph. The composition of simple ideas, for the purpose of making complex ideas, is also an operation of our mind. We may refer to this the faculty of extending ideas by uniting those of the same kind, as in forming a dozen from several units. Th. [The one is doubtless as much composition as the 1 Dominique Bouhours, 1628-1702, one of the ablest masters of the French language in the seventeenth century. The title of his work here given follows Gerhardt's text. The correct title is: Maniere de bien penser dans les ouvrages d' esprit, Paris, 1687. There were several editions. — Tr. 2p)i,ars. 1,128. — Tk. CH. XI] ON HUMAN UNDERSTANDING 145 other ; but composition of similar ideas is simpler than that of different ideas.] § 7. Ph. A dog will nurse young foxes, will play with them, and will have for them the same fondness as for her own puppies, if they can be made to suck her so long as is needful for the milk to spread through their entire body. Moreover it does not appear that animals, who have a large number of young at once, have any knowledge of their num- ber. Th. [The love of animals arises from a pleasure which is increased by habit. But as for the precise number, men even can know the numbers of things only by some skill, as in using numerical names in order to count, or figural arrangements which make them know at once without counting if anything is wanting.] § 10. Ph. Animals do not form abstract thoughts. Th. [I agree. They apparently recognize whiteness, and notice it in the chalk or the snow ; but this is not yet abstrac- tion, for that demands a consideration of what is common, separated from Avhat is particular, and consequently there enters into it the knowledge of universal truths, which is not given to the animals. It is well said also that the animals which speak do not use words to express general ideas, and that men deprived of the use of speech and of words do not cease to invent other general signs. I am pleased also to see that you here and elsewhere so Avell observe the advantages of human nature.] § 11. Ph. If animals have some ideas, and are not pure ma- chines, as some maintain, we cannot deny that they have reason in a certain degree, and, for myself, it appears as evident that they reason as that they feel. But it is only upon particular ideas that they reason according as their senses represent these ideas to them. Th. [Animals pass from one imagination to another by the connection which they have felt here before; for example, when his master takes a stick, the dog fears a whipping. And in many instances children with the rest of mankind proceed nowise differently in their passages from thought to thought. This might be called consecution and reasonivg in a very broad sense. But I prefer to conform to the received usage in conse- L 146 LEIBXITZ'S CRITIQUE OF LOCKE \_uk. u crating these terms to man and in limiting them to the knowl- edge of some reason of the connection of perceptions, which sensations alone cannot give ; their effect being* only to canse us naturally to expect at another time this same connection which we have noticed before, although perhaps the reasons are no longer the same, a fact which often deceives those who are governed only by the senses.] § 13. Ph. Idiots lack vivacity, activity, and movement in the intellectual faculties, whereby they are deprived of the use of reason. Madmen seem to be at the opposite extreme, for it does not appear to me that these latter have lost the power to reason, but having wrongly united certain ideas, they take them for truths, and deceive themselves in the same way as those who reason justly upon false principles. Thus you will see a madman who thinks he is king maintaining by a just consequence that he should be served, honored, an«l obeyed according to his rank. Th. \_Idiots do not exercise reason, and they differ from some stupid persons who have good judgment, but, not having prompt conception, they are despised and disturbed as he would be who wished to play ombre with persons of distinction and thought too long and too often of the part he must take. I remember a learned man who, having lost his anemory by the use of certain drugs, was reduced to this condition, but his judgment always appeared. A man wholly mad lacks judg- ment on nearly every occasion ; but the vivacity of his imagi- nation may make him agreeable. But there are particular madmen who make a false siipposition at an important point in their lives, and reason justly thereupon, as you have well said. There is such a man, well kujown at a certain court, who believes himself destined to redress the affairs of the Protestants and to bring France to reason, for which purpose God caused the greatest personages to pass through his body in order to ennoble it ; he desires to marry all the princesses he sees to be marriageable, but after having made them holy, in order to have a holy progeny who are to rule the land ; he attributes all the misfortunes of war to the little attention paid to his advice. In speaking with a certain sovereign, he takes every necessary measure not to lower his dignity. When they enter into conversation with him, he maintains CH. XII] ON HUMAN UNDERSTANDING 147 himself so well that I have doubted more than once whether his madness is not feigned, for he is not inconvenienced by it. However, those who know him more intimately assure me that his madness is wholly genuine.] CHAPTER XII OF COMPLEX IDEAS Ph. !^he understanding bears not a little resemblance to a room wholly dark, which has only certain small openings to let in from outside exterior and visible images, so that if these images, coming to be painted in this dark room, could remain there and be placed in order, so that they could be found upon occasion, there would be a great resemblance between this room and the human understanding. Th. [To make the resemblance greater, you should suppose that in this room there was a canvas to receive the images, not even, but diversified by folds, rej)resenting the (kinds of) in- nate knowledge ; further, that this canvas or membrane being stretched would have a kind of elasticity or power of action, and also an action and reaction accommodated as much to the past folds as to the newly arrived kinds of impressions. And this action would consist in certain vibrations or oscillations, such as are seen in a stretched string so touched that it gives forth a kind of musical sound. For not only do we receive images or outlines in the brain ; but we form besides new ones, Avhen we look at complex ideas. Thus the canvas that repre- sents our brain is necessarily active and elastic. This com- parison would explain tolerably well what passes in the brain; but as for the soul, which is a simple substance or monad, it represents without extension these same varieties of extended masses and perceives them.^] § 3. Ph. Now complex ideas are either modes or substances or relations. 1 According to the principle of Pre-established Harmony. Cf. Systeme nouveau de la nature, etc., 1695, §§ 14, 15; Gerhardt, 4, 484, 485; Erdmann, 127, 128; Jacques, 1, 475, 476; translation, Appendix, p. . — Tr. /48 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii Th. [This division of the objects of our thouglit into sub- stances, modes/ and relations is sufficiently to my taste. I be- lieve that qualities are only modifications of substances, and that the understanding adds thereto the relations.- From this follows more than you think.] Ph. Modes are either simple (as a dozen, a score, which are composed of simple ideas of the same kind, i.e. of units) or mixed (as beauty), into which enter simple ideas of different kinds. Th. Perhaps dozen or score are only relations, and are con- stituted only in connection with the understanding. Units are separate, and the understanding gathers them together how- ever dispersed they be. Yet, although relations are from the understanding, they are not groundless or unreal. For in the first place understanding is the origin of things ; and indeed the reality even of all things, simple substances excepted, ulti- mately consists only of perceptions of the phenomena of sim- ple substances. It is often the same with regard to the mixed modes ; i.e. it is necessary to refer them rather to the rela- tions.] § 6. Ph. The ideas of substances are certain combinations of simple ideas, which are supposed to represent particular and distinct things, subsisting by themselves, among which ideas the obscure notion of substance, which is assumed without knowing what it is in itself, is always considered as the first and chief. Th. [The idea of substance is not so obscure as you think. You can know what it ought to be, and what it knows of itself in other things ; and indeed the knowledge of the concrete always precedes that of the abstract; the hot (thing) rather than the heat.] § 7. Ph. In regard to substances there are also two kinds of ideas : the one of single substances, like that of a man, or a sheep; the other of several substances joined together, as of an army of men, or a flock of sheep. These collections form also a single idea. 1 Cf. Descartes, Prin. Philos.. I., § 56; Veitcli's translation, 8th ed., p. 217; Spinoza, Etliica, Pt. I., Def. 3; Elwes' translation, Vol. 2, p. 46; Locke, Essay, Bk. II., chap. 12, § 4, Vol. 1, p. 280 (Bohn's ed.).— Tr. 2 Cf. Leibnitz, Neio Essays, Bk. II., chap. 30, § 4. — Tr. CH. XIII] ON HUMAN UNDERSTANDING 149 Til. [This unity of the idea of aggregates is very true ; but ultimately you must admit that this collective unity is only a congruity or relation, whose ground is in that which is found in each of the single substances separately. Thus these beings by aggregation have no other completed unity than the mental ; consequently their entity also is in some mental shape or phe- nomenon, as that of the rainbow.] CHAPTER XIII OF SIMPLE MODES, AND FIEST OF THOSE OF SPACE § 3. Ph. Space considered with respect to the length which separates two bodies is called distance; with respect to length, breadth, and depth it may be called capacity. Til. [To speak more distinctly, the distance between two fixed things (be they points or extensions) is the length of the shortest possible line that can be draAvn from one to the other. This distance may be considered absolutely or in a certain figure which comprises the two distant things. For example, the straight line is absolutely the distance between two points. But these two points, being in the same spherical surface, the distance of these two points in this surface is the length of the shortest great arc of a .circle, which may be drawn from one point to the other. It is well also to notice, that distance is not only between bodies, but also between surfaces, lines, points. It may be said that the capacity or rather the intervcd between two bodies or two other extensions, or between an extension and a point, is the space constituted by all the shortest lines which may be drawn between the points of each. This interval is filled, except when the two fixed things are in the same surface, when the shortest lines between the points of the fixed things must also fall in this surface or must there be expressly formed.] § 4. Ph. Besides that which is in nature, men have estab- lished in their minds the ideas of certain determinate lengths, as an inch or a foot. Th. [They cannot do it. For it is impossible to have the 150 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii idea of a precisely determined length. You can neither say nor understand by the mind what an inch or a foot is. And you can preserve the meaning of these terms only by real measures, which you suppose unchanging, by means of which you can always recover them. Thus Mr. Greaves,^ an Eng- lish mathematician, desired to make use of the pyramids of Egypt, which have endured a long time and will endure appar- ently some time longer, to conserve our measures, by showing posterity the propositions ^ which have been sketched in defi- nite lengths in one of these pyramids. It is true that a little after it was discovered that pendulums serve to perpetuate measures (mensuris rerum ad 2'>osteros transmittendis) , as Huy- gens,^ Mouton,"* and Buratini, formerly maistre de monnoye in Poland, have demonstrated ^ by showing the proportion of our measures of length to that of the pendulum, which beats pre- cisely a second (for example), i.e. the 86400th ^ part of a revolution of the fixed stars, or of an astronomical day ; and Buratini has composed a treatise expressly thereupon, which 1 John Greaves, 1602-1652, Savilian Professor of Astronomy at Oxford, 1643-1648. His Pyramidographia, or a Discourse on the Pyramids in Egypt, 1646. — Tr. 2 Gerliardt and Erdmann read: "propositions"; Jacques reads: "j)ropor- tions " ; Scliaarschmidt translates " Verhaltnisse." — T-r. 3 Christian Huygens, 1629-1695, a Dutch ijhysicist, geometer, and astronomer. He discovered tlie laws of double refraction, and was the first to establish on a sure foundation the wave theory of light, in his Traite de la lumiere, Leyden, 1690. His researches in physical optics constitute his chief claim to scientific immortality. His api^lication of the pendulum to regulate the move- ment of clocks, arising from his felt need of an exact measure of time in astronomical observations, dates from 1656. He published his Description de Vhorloge a pendule in 1657, and presented his first " i:)endulum-clock " to the States-General June 16, 1657. This Description w&s, rei^ublished as chap. 1 of his magnum opus, the Horologium oscillatorium, sive de motu 23endulorum ad horologia adaptato, dedicated to Louis XIV., March 25, 1673. In chap. 4 of this work he determined the centre of oscillation of a jjendulum, and conse- quently the length of the simple isochronous pendulum. His works were published in two vols. 4to, Opera varia, Leyden, 1724, and two supplementary vols. 4to, Opera reliqua, Amsterdam, 1728. — Tr. •* Gabriel Monton, 1618-1694, a French mathematician and astronomer, principally known by his Observationes diametroriim solis et lunse apparen- tium, Lyons, 1670. His principal title to honorable mention in the history of science is the invention of the method of differences for the calculation of tables of every kind, afterwards reduced to a system by Sir Isaac Newton, 1642-1727, and known by us as our method of interpolation. — Tr. 5 Erdmann and Jacques read: "pretendu montrer," i.e. claimed to demon- strate. — Tr. 6 Erdmann and Jacques read : " 864,000th," evidently an error. — Tr. CH. xiii] ON HUMAN UNDERSTANDING 151 I have seen in manuscript. But there is, however, this imper- fection in this measure of pendulums, which must be limited to certain countries, for pendulums to beat ia the same time need to be shorter at the equator. And it is furthermore necessary to assume the constancy of the really fundamental measure, viz. : the length of a day or of a revolution of the globe of the earth around its axis, and also of the cause of gravitation, not to speak of other circumstances.] § 5. Pli. Observing how extremities are terminated either by straight lines which form distinct angles, or by curved lines in which no angle can be perceived, we form the idea oi figure. Th. [A superficial figure is terminated by a line or by lines : but the figure of a body can be limited without determined lines, as for example that of a sphere. A single straight line or plane surface cannot enclose any space or make any figure. But a single line can enclose a superficial figure, for example the circle, the oval, as also a single curved surface can enclose a solid figure, like the sphere and the spheroid. Yet, not only several straight lines or plane surfaces, but also several curved lines or several curved surfaces, can concur together and form even angles between themselves, when the. one is not the tan- gent of the other: It is not easy to give the definition of figure in general according to the usage of geometers. To say that it is a limited extension would be too general, for a straight line, for example, although terminated by the two ends, is not a figure and even two straight lines cannot make one. To say that it is an extension limited by an extension is not general enough, for the entire spherical surface is a figure and yet it is not limited by any extension. It may be said, however, that figure is a limited extension, in which there are an infinite num- ber of paths from one point to another. This definition com- prises limited surfaces without terminating lines which the preceding definition did not comprise, and excludes the lines, because from one point to another in a line there is only one path or a determined number of paths. But it will be still better to say that figure is limited extension, which may admit an extended section, or better which has breadth, a term which hitherto had not been further defined.] § 6. Ph. At the least all figures are only simple modes of space. 152 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii Th. [According to your view, the simple modes repeat the same idea, but in iigures there is not always the repetition of the same mode. Curves differ much from straight lines and between themselves. So I do not know how the definition of the simple mode will be in place here.] § 7. Ph. [We need not take our definitions too strictly. But let us pass from figure to place.'] When we find all the pieces upon the same squares of the chess-board where we left them, we say that they are all in the same place, although per- haps the chess-board has been moved. We say also that the chess-board is in the same place, if it remains in the same part of the cabin of the vessel, although the vessel has sailed. The vessel is also said to be in the same place su.pposing it keeps the same distance Avith reference to the parts of the neighboring countries, although the earth has perhaps turned round. Th. [_Place is either jxirticular when considered with regard to certain bodies, or universal when it relates to all, and with reference to which all the changes possible in relation to any body are taken into account. And if there were nothing fixed in the universe, the place of each thing could still be deter- mined by reasoning,^ if there were means of m'aking a record of all the changes, or if the memory of a creature could suffice for them, as they say, the Arabs play chess by memory and on horseback. What we cannot understand, however, is neverthe- less determined in the truth of things.] § 15. Ph. If any man asks me what space is, I am ready to tell him when he tells me what extension is. Th. [I wish I could speak of the nature of fever or any other malady with the same certainty with which I believe the nature of space is expounded. Extension is the abstract of the ex- tended. Now the extended is a continuum whose parts are coexistent, or exist at the same time.] § 17. Ph. If any one asks whether space without body is 1 Schaarscliraidt says that the statements here made by Leibnitz have since found their confirmation and accomplishment tlirough Gauss' Theoria motus corporum coelestium. The work was pul)lished at Hamburg, in 1809, and "gave a powerful impulse to the true methods of astronomical observation." The author, Carl Friedrich Gauss, 1777-1855, was an eminent German mathe- matician. His collected works, edited by E. J. Sehering, have been published by the Royal Society of Gottiugen, 7 vols., Ito. Gottingen : 1863-1871. — Tr. CH. xiii] ON HUMAN UNDERSTANDING 153 substance or accident, I should reply without hesitation that I know nothing about it. Til. [I fear you may think me vain in wishing to determine what you, sir, admit you do not know. But if it is expedient to judge, (I fear) that you know more about the matter than you state or think you do. Some have believed that God is the place of things.^ Lessius and Guericke, if I am not mis- taken, were of this opinion, but then place contains something more than what we attribute to the space which we deprive of all activity ; and in this way it is no more a substance than time, and if it has parts it cannot be God. It is a relation, an order, not only between existences, but also between possibili- ties as they may exist. But its truth and reality, like all eternal truths, is grounded in God.] Ph. [I am not far from your view, and you know the pas- sage of St. Paul, who says that Ave live and move and have our being in God.^ Thus, according to different ways of con- sidering the matter, it may be said that space is God, and also that it is only an order or a relation.] Th. [The better statement then will be that space is an order, but that God is its source.] § 18. Ph. [Yet to know whether space is a substance, it would be needful to know in Avhat the nature of substance in general consists. But in this there is a difficulty. If God, finite spirits, and bodies participate in common in an identical substantial nature, would it not follow that they differ only as different modifications of this substance ?] 1 This doctrine appeared very early. Schaarschmidt refers to the collection of poems of uncertain origin called Orphica, where (Fragt. vi., p. 457, ed. Her- mann, V. 8 and 9) it is poetically expressed thus : " All that has been and here- after will be, is formed together in the bosom of Zeus." Again (v. 17-20): "One is the ruling Being, in whom the All moves, fire, water, earth and air, day and night, reason, the first principle and joyful love — all this lies in the great bosom of Zeus," etc. Malebranche represents a phase of the same view in his doctrine that we see all things in God. Cf. his De la Recherche cle la Verite, III., ii., 6: "We abide thus in the view that God is the intelligible world or the place of spirits, just as the material world is the place of bodies. From His power they receive all their modifications, in His wisdom they find all their ideas, by His love they are moved in all their moral inclinations. But because His power and His love are nothing else than Himself, we will believe with St. Paul, that He is not far from any one of us, and that in Him we live and move and have our being." Cf. also James Martineau. Types of Ethical Theory, 2d ed.. Vol. 1, p. 170 sq. New York : Macmillan & Co., 1886. —Tr. 2 Acts 17: 28.— Tr. 154 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii Th. [If this result follows, it ^vould follow also, that God, finite spirits, and bodies, participating in common in an iden- tical nature of being, would differ onl}^ as different modifica- tions of this being.] § 19. Ph. Those who first thought of regarding accidents as a kind of real beings, which need something in which to inhere, were constrained to invent the word substance to serve as a support to the accidents. Th. [Do you then think, sir, that the accidents can subsist apart from the substance ? or do you mean that they are not real beings ? You seem to multiply difficulties- without reason, and I have remarked above that substances or concretes are conceived rather than accidents or abstracts.] Ph. The words substance and accident are in my view of little use in philosophy. Th. [I admit that I am of another opinion, and I believe that the consideration of substance ■' is one of the most important and fruitful points of philosophy.] § 21. Ph. [We have now spoken of substance only by the way, while asking if space is a substance. But it is sufficient for us that it is not a body.] jSTo one will dare to make body infinite like space. Th. [Descartes and his followers have said, nevertheless, that matter has no limits, in making the world indefinite, so that it is not possible for us to conceive of its extremities. And they have changed the term infinite into indefinite with some reason ; for there never is an infinite whole in the world, 1 Cf. Neio Essays, Bk. II., chap. 23, § 2; De primse philosophise emenda- tione et de notione substantias, 1694, Gerliardt, Vol. 4, pp. 468-470; Erdmann, pp. 121-122; A. Jacques, GEuvres de Leihniz, Vol. 1, pp. 452-454 (in Freuch) ; translation, Appendix, jap. ; Systeme nouveau de la nature et de la communication des substances, aussi Men que de I'union qu'il y a entre I'dme et le corps, 1695, §§ 2, 3, Gerliardt, Vol. 4, pp. 477 sq. ; Erdmann; pp. 124-128; Jacques, Vol. 1, pp. 469 sq.; translation, Ajjpendix, pxj. ; De ipsa natura, sive de vi insita actionibusque creaturum, 1698, Gerliardt, Vol. 4, pp. 504-516 ; Erdmann, pp. 1.54-160 ; Jacques, Vol. 1, pp. 455-468 (in French) ; trans- lation. Appendix, pp. ; Considerations sur le principje de vie et siir les natures plastiqnes, 1705, Gerhardt, Vol. 6, pp. 5.39-546; Erdraanu, pp. 429-432; translation, Duncan, Philos. Works of Leibnitz, pp. 16:3-169; Prin- ciples de la nature et de la grace fondes en raison, c. 1714, Gerhardt, Vol. 6, pp. 598-606; Erdmann, pp. 714-718; translation, Duncan, op. cit., pp. 209-217; La Monadologie, 1714, Gerhardt, Vol.6, pp. 607-623; Erdmann, pp. 705-712; translation, Duncan, op. cit., pp. 218-232 ; also F. H. Hedge, in " The Jour. Spec. Philos.," Vol. 1, pp. 129-137. — Tr. CH. XIV] ON HUMAN UNDERSTANDING 155 although there are always some wholes greater than others to infinity, and the universe even cannot pass for a whole as I have elsewhere ^ shown. Ph. Those who take matter and extension as one and the same thing maintain that the inner sides of a hollow vacuous body would touch. But the space which is between two bodies suffices to prevent their mutual contact. Th. [I am of your opinion, for although I do not admit a vacuum, I distinguish matter from extension, and I admit that if there were a vacuum in a sphere, the opposite poles in the hollow space would not on that account touch. But I believe that this is a case which the divine perfection does not allow.] § 23. Ph. It seems, however, that motion proves a vacuum. When the least part of the divided body is as large as a grain of mustard-seed, a void space equal to the size of a grain of mustard is requisite in order to make room for the parts of this body to move freely ; the same condition will hold good when the parts of the matter are one hundred million times smaller. Th. [It is true, that if the world were full of hard corpus- cles, which could neither yield nor divide, as the atoms are depicted, motion would be impossible. But in truth, there is no original hardness ; on the contrary, fluidity is the original condition, and bodies are divided as needful, since there is nothing to prevent it. This takes away all the force in the argument for a vacuum drawn from motion.] CHAPTER XIV OF DURATIOIf AND ITS SIMPLE MODES § 10. Ph. To extension corresponds duration. And a part of duration in which we remark no successions of ideas we call an instant. Th. This definition of a?i instant ought (I believe) to mean the popular notion, like that Avhich the common people have 1 Cf. ante, pp. 16, 17; also Weiv Essays, Bk. II., chap. 17, § 1. The proof that the universe is not, strictly speaking, a whole, is given in the letter to Des Bosses, March 11, 1706, Gerhardt, Vol. 2, p. 304 sq., Erdmaun, pp. 435-436. — Te. 156 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n of a poiut. For strictly the point and the instant are not parts of time or space, neither have they parts. They are extremities only, § 16. Ph. It is not motion, but a constant succession of ideas which gives us the idea of duration. Th. [A succession of perceptions awakes in us the idea of duration, but it does not make it. Our perceptions never have a succession sufficiently constant and reg-ular to correspond to that of time, which is a continuum uniform and simple, like a straight line. Changing perceptions furnish us the occasion for thinking of time, and we measure it by uniform changes. But were there nothing uniform in nature, time could not be determined, as space likewise could not be determined if there were no fixed or immovable body. So that knowing the rules of different motions, we can always refer them to the uniform intelligible motions, and see beforehand by this means what will happen through the different motions taken together. And in this sense time is the measure of motion, i.e. uniform motion is the measure of non-uniform motion.] § 21. Ph. No two parts of duration can certainly be known to be equal; [and you must admit that observations can attain only approximate equality.] After exact research the dis- covery has been made that there is really an inequality in the diurnal revolutions of the sun, and we do not know but that the annual revolutions are unequal also. Th. [The pendulum has made us realize and see the in- equality of the days from one noon to another : Solem dicere falsum aiidet. It is true that men knew this already, and that this inequality has its rules. As for the annual revolution, which makes good the inequalities of solar days, it may change in the course of time. The revolution of the earth about its axis which is commonly attributed to the primum mobile,^ is our best measure up to the present time, and clocks and watches serve to divide it for us. Furthermore this same daily revolu- 1 In Aristotle's philosophy, to Trpwrov kivovv, i.e. God, who, himself unmoved, is the necessary first and unceasing source of the eternal movement of the uni- verse. Of. Metaphys., li, 6-10, 1071 sq.; Phys., VIII., 6,258b lO; also Zeller, Outlines, § 56, 3, and Die Philos. d. Griech., 3d ed., 1879, Vol. 4, p. 358; Wallace, Outlines of the Philos. of Aristotle, 3d ed., § 39; Hegel, Gesch. d. Philos., 2d ed., Vol. 2, p. 289 sg.; Benn, The Greek Philosophers, Vol. 1, pp. 348-350. — Tr. CH. XIV] ON HUMAN UNDERSTANDING 157 tion of the earth may also change in the course of time : and if any pyramid could endure long enough, or if we should build new ones we could perceive it by observing there the length of pendulums a known number of whose beats occurs now during this revolution ; we could also know in some way the change by comparing this revolution with others, as with those of Jupiter's satellites, for it is not apparent that, if there is any change in one or the other, it will always be proportional. Pit. Our measure of time would be more exact if we could preserve a past day in order to compare it with the days to come, as we preserve the measures of space. Th. [But instead of that we are reduced to preserving and watching bodies which move in nearly equal times. Also we cannot say that a measure of space, as for example, an ell which is preserved in wood or metal remains perfectly the same.] § 22. Ph. Now since all men manifestly measure time by the motion of the heavenly bodies, it is very strange that one is not j)ermitted to define time as the measure of motion. Th. [I just stated (§ 16) how that should be understood. It i-s true that Aristotle says ^ that time is the number and not the measure of motion. And in fact, it may be said that duration is known by the number of periodic equal motions of which one begins when another ends, for example, by so many revolu- tions of the earth or the stars.] § 24. Ph. Nevertheless to anticipate these revolutions and say that Abraham was born in the year 2712 of the Julian era, is to speak as unintelligibly, as if you counted from the begin- ning of the world, although you suppose that the Julian era commenced several hundred years before there were any days, nights, or years marked by any revolution of the sun. Th. [This vacuum which may be conceived in time, indicates, like that of space, that time and space extend to the possible as well as to the actual. Besides, of all the chronological methods, that of reckoning the years since the beginning of the world is the least convenient, although this would be, without touching upon other reasons, only because of the great difference exist- ing between the Septuagint and the Hebrew text.] 1 Phys., IV., 11, 219b 1, 219b 8; cf. Wallace, Outlines of the Philos. of Aris- totle, od ed., § 44. Wallace quotes the Greek of the first passage here referred to. — Tr. 158 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii § 26. Ph. One may conceive the beginning of motion, al- though he may not comprehend that of duration taken in all its extension. One may give limits to the body, but cannot do it with regard to space. Th. [It is as I just said that time and space indicate the possibilities beyond the supposition of existences. Time and space are of the nature of eternal truths which consider equ.ally the possible and the actual.] § 27. Fh. In fact the ideas of time and eternity come from the same source, for Ave can in our thought add certain lengths of duration to one another as often as Ave please. Th. [But in order to draw from them the notion of eternity, it is necessary to think besides that the same reason ahvays exists for going farther. It is this rational consideration AAdiich achicA^es the notion of the infinite or the indefinite in possible progress. Thus the senses alone cannot suffice to cause the formation of these notions. And ultimately it may be said, that the idea of the absolute^ is anterior in the nature of things to that of the limits Avhich are added, but Ave notice the former only as we commence Avith what is limited and strikes our senses.] CHAPTEK XV OF DURATION AXD EXPAXSIOX COXSIDEKED TOGETHER § 4. Ph. One admits more easily an infinite duration of time than an infinite expansion of space, because we conceive infinite duration in God, and attribute extension only to matter which is finite, and call the space beyond the universe imaginary. But (§ 2) Solomon seems to haA'-e other thoughts AAdien, speak- ing of God, he says : the heaven and the heaven of heavens can- not contcdn Thee;- and for myself I belieA^e that he magnifies too highly the capacity of his OAvn understanding Avho imag- ines he can extend his thoughts farther than the place Avhere God exists. 1 The idea of the absolute belongs to our reason as such, cf. Neiv Essays, Bk. IT., chap. 17, § 3, Th., § 16, Th., though we tirst become aware of it through our consciousness of the particular ideas of the reason as limitations of the idea of the absolute. — Tr. 2 1 Kings 8 : 27 ; 2 Chron. 6 : 18. — Tr. CH. xvj ON HUMAN UNDERSTANDING 159 Til. If God were extended, he would have parts. But dura- tion grants these only to his works. However in relation to space immensity must be attributed to him, which gives also parts and order to the immediate works of God. He is the source of possibilities as of actualities, of the one by his essence, of the other by his will. Thus space like time has its reality only from him, and he can fill the void when it seems to him good. Thus it is that in this respect he is everj^where.^] § 11. Ph. We do not know what relations spirits have with space, nor how they participate therein. But we know that they participate in duration. Til. [All finite spirits are always united to some organic body, and they represent to themselves other bodies by means of relations to their own. Thus their relation to space is as evident as that of bodies. For the rest, before leaving this subject, I would add a comparison between time and space to those which you have given; viz;.: — if there were a vacuum in space (as, for instance, if a sphere were hollow within), you could determine its size; but if there were a vacuum in time, i.e. a duration without changes, it would be impossible to determine its length. Whence it comes that you may refute the one who would maintain that two bodies, between which there is a vacuum, touch ; for geometry defends the proposition that two opposite poles of a hollow sphere would not touch : but you cannot refute the one who would maintain that two worlds, the one of which succeeds the other, touch as to dura- tion, so that the one necessarily begins when the other ends, without the possibility of an interval. You could not refute it, I say, because this interval is indeterminable. If space were only a line, and if body were immovable, it would no longer be possible to determine the length of the vacuum between two bodies. 1 God, according to Leibnitz, is actus pitrus. a pure spirit, without body and without extension. All other beings require bodies. His omnipresence is dynamic. Cf. Nev) Essays, Bk. II., chap. 1, § 12, Th., ante, p. 113; Letter to Des Bosses, Oct. 16, 1706, Gerhardt, Vol. 2, p. 325, Erdmaun, p. 440, b. — Tr. 160 LEIBNITZ'S CRITIQUE OF LOCKE [bis. 3; CHAPTER XVI OF 2fUMBER § 4. Ph. In numbers ideas are both more precise and more accurately to be distinguished the one from the other than in extension, where you cannot observe or measure each equality and each excess of size as easily as in numbers, because in sj)ace we cannot by thought attain a certain definite smallness beyond which we cannot go, like the unit in number. Th. [That should be understood of the integer. For other- wise number in its extent, comprising the fraction, the surd, the transcendent, and all that may be assumed between two inte- gers, is proportional to the line, and there is there as little of a minimum as in the continuum. Thus the definition of num- ber as a multitude of units is in place only among the integers. The precise distinction of ideas in extension does not consist in size : for to distinguish size clearly one must have recourse to integers, or to other (measures) known by means of inte- gers ; thus from continuous quantity it is necessary to recur to discrete quantity, in order to have a distinct knowledge of size. Thus the modifications of extension, when not joined to num- bers, cannot be distinguished by figure, taking this term so generally that it means everything which makes two exten- sions dissimilar the one to the other.] § 0. Pit. By repeating the idea of a unit and joining it to another unit, we make a collective idea, which we call tico. And whoever can do that and advance always by adding one more to the last collective idea to which he gives a particular name, can count so long as he has a set of names and sufficient memory to retain them. Th. [By this means alone one cannot advance very far. For memory would be too heavily loaded if it must retain an entirely new name for each addition of a new unit. That is why a certain order and a certain repetition of these names is necessa,ry by recommencing in accordance with a certain pro- gression.] Ph. The different modes of numbers are capable of no other CH. xvii] ON HUMAN UNDERSTANDING 161 difference than that of more or less ; [this is why there are simple modes like those of extension.] Th. [That may be said of time and of the straight line, but not of figures, and still less of numbers, which are not only different in size but further unlike. An even number may be divided into two equal numbers, but not an uneven. Three and six are triangular numbers, four and nine are squares, eight is a cube, etc. And this principle has place in numbers still more than in figures, for two unequal figures may be per- fectly similar to each other, but never two numbers. But I am not astonished that you are often deceived thereupon, be- cause one does not commonly have a distinct idea of what is similar or dissimilar. You see then, sir, that your idea or your application of simple or mixed modes is greatly in need of correction.] § 6. Ph. [You were right in remarking that it is well to give numbers their own names to be retained.] Thus I believe that it would be convenient in computation to say a billion for brevity's sake instead of a million of millions, and instead of a million of millions of millions, or a million of billions, to say a trillion, and thus in order to nonillions, for there is little need of going farther in the use of numbers. Th. These denominations are good enough. Let a,' = 10. That posited, a million will be x'^, a billion a;^-, a trillion x^^, etc., and a nonillion x^\ CHAPTER XVII OF INFIN^ITY § 1. Ph. One of the most important notions is that of the finite and the infinite, which are regarded as modes of quantity. Th. [Properly speaking, it is true that there is an infinite number of things, i.e. that there are always more of them than can be assigned. But there is no infinite number, neither line nor other infinite quantity, if these are understood as veritable wholes, as it is easy to prove. The schools have meant or have been obliged to say that, in admitting a syncategorematic in- M 162 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii finite/ as they call it, and not a categorematic infinite. The true infinite exists, strictly speaking, only in the absolute, which is anterior to all composition, and is not formed by the additions of parts. ^] Ph. When we apply our .idea of the infinite to the first Being, we do it primarily in respect to his duration and ubi- quity, and, more figuratively, to his power, his wisdom, his goodness, and his other attributes. Th. [ISTot more figuratively, but less immediately, because the other attributes make their importance known through relation to those into which enters the consideration of parts.] § 2. Ph. I thought it Avas established that the mind regards the finite and the infinite as modifications of extension ^ and duration. Th. [I do not find that it has been established that the con- sideration of the finite and the infinite takes place wherever there is bulk and magnitude. And the true infinite is not a modification, it is the absolute ; on the contrary, when it is modified, it is limited and forms a finite.] § 3. Ph. We have believed that since the power of the mind to expand without limit its idea of space by new addi- tions is always the same, it is thence that the idea of an infi- nite space is derived. Th. [It is well to add that this is because the same ratio is seen always to hold good. Let us take a straight line and prolong it iintil it is double the length of the first. Now it is clear that the second line, being perfectly similar to the first, may be itself doubled in order to have a third, which is still similar to the preceding ; and the same ratio holding good always, it is never possible to stop the process ; thus the line may be prolonged to infinity, so that the consideration of the infinite arises from that of similarity or from the same ratio, and its origin is the same with that of universal and necessary truths. This shows us how what gives completion ^ An incompletely defined infinite, capable of or needing still further defini- tion, but infinite only so far as it cannot really be defined, the indefinite- infinite (infl.nitum-indefinitum) . — Tk. '•■2 Cf. ante, pp. 16, 17; also New Essay.", Bk. II., chap. 13, § 21. — Tr. 3 Locke has: "expansion," Philos. Works, Vol. 1, p. 331 (Bohn's ed.). — Tr. CH. xvii] ON HUMAN UNDERSTANDING 163 to the conception of this idea is found in ourselves, and can- not come from the experience of our senses, just as necessary- truths cannot be proved by induction nor by the senses. The idea of the absolute is in us internally, like that of being ; these absolutes are nothing else than the attributes of God, and it may be said that they are not less the source of ideas, because God is himself the principle of beings. The idea of the abso- lute in relation to space, is only that of the immensity of God, and so of the others. But you deceive yourself in wish- ing to imagine an absolute space which is an infinite whole composed of parts ; there is none such, it is a notion which implies a contradiction, and these infinite wholes, and their opposed infinitesimals, are used only in the calculations of geometers, just like the imaginary roots of algebra.] § 6. Ph. [We conceive furthermore a magnitude without understanding thereby parts outside of parts.] If to the most perfect idea I have of the whitest whiteness, I add another of an equal or less brilliant whiteness (for I cannot add the idea of a whiter than I have, which I suppose the whitest that I actually conceive), it neither increases nor extends my idea in any way ; therefore the different ideas of whiteness are called degrees.'] Th. [I do not fully understand the force of this reasoning, for nothing prevents me from receiving the perception of a whiter whiteness than what is actually conceived. The true reason why we are inclined to believe that whiteness cannot be infinitely increased is because it is not an original quality ; the senses give us only a confused knowledge of it ; and when we have a distinct knowledge of it, we shall see that it arises from the structure, and is limited by that of the organ of vision. But as regards original or distinctly knowable quali- ties, Ave see that there are sometimes means of going to infinity, not only in the case of extension or, if you prefer, diffusion or what the scholastic philosophy calls partes extra partes, as in time and place, but also in the case of intention or degrees, for example, as regards velocity.] § 8. Ph. We have no idea of infinite space, and nothing is plainer than the absurdity of an actual idea of an infinite number. Th. [I am of the same opinion. But this is not because we 164 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n cannot have the idea of the infinite, but because the infinite cannot be a true whole.] § 16. Ph. Por the same reason we have then no positive idea of an infinite duration or of eternity, any more than of immensity. Th. [I believe we have a positive idea of both, and this idea is a true one, provided it is not conceived as an infinite whole, but as an absolute or attribute without limits which exists in reference to eternity, in the necessity of the existence of God, without depending upon parts and without the notions being formed by an addition of time. We see furthermore in that way, as I have said already, that the origin of the notion of the infinite comes from the same source as that of necessary truths.] CHAPTEE XVIII OF OTHER SIMPLE MODES Ph. There are besides many simple modes formed from simple ideas. Such are (§2) modes of motion, as sliding, rolling; those of sound (§3) which are modified by notes and airs, as colors by degrees, not to speak of tastes and smells (§6). These always^ have neither measures nor distinct names any more than in the case of the complex modes (§ 7), because use regulates them, and we will speak of them more fully when we come to words. Th. [The majority of modes are not sufficiently simple and can be reckoned with the complex, for example, to explain what sliding and rolling is besides motion, you must consider sur- face-resistance.] CHAPTER XIX OF THE MODES OF THINKING § 1. Ph. [Let US pass from the modes which come from the senses to those given us by reflection.] Sensation is, so to speak, the actual entrance of ideas into the understanding by 1 Locke: "ordinarily," Philos. Works, Vol. 1, p. 346 (Bobu's ed.). — Tr. CH. XIX ] ON HUMAN UNDERSTANDING 165 means of the senses. When the same idea comes again into the mind, without the action upon our senses, of the external object which at first caused it to spring up, the act of the mind is called remembrance ; if the mind tries to recall it, and only after considerable effort finds and brings it to view, it is recollection (recueillement) .^ If the mind looks upon it atten- tively for a long time it is contemplation; when the idea floats about in the mind without any attention on the part of the understanding, it is called reverie. When the mind reflects upon ideas, which present themselves, and when it, so to speak, registers them in its memory, it is attention; and when the mind fixes itself upon an idea with much application, considers it on all sides, and will not be turned aside notwithstanding other ideas which come in the way, we call it study or intense- ness of thought. Sleej) accompanied by no dream is a cessa- . tion of all these things ; and dreaming is having these ideas in the mind while the outer senses are closed, so that they do not receive the impressions of external objects with their usual quickness. It is, I say, having ideas without any sug- gestion from any external objects or known occasion, and apart from any choice or determination in any way of the understanding. As for that w^hich we call ecstasy, I leave others to judge whether it is not dreaming with the eyes open. Til. [It is well to clear up these notions and I will try to aid in the work. I will say then that it is sensation when an external object is perceived; that remembrance consists in the repetition without the reappearance of the object ; but when we know we have had it, it is memory. Recollection (i-ecueille- ment) is commonly understood in a sense different from yours, viz. : as a state in which we disengage ourselves from things in order to apply ourselves to some meditation. But since there is no word known to me corresponding to your notion, sir, one may apply to it that which you employ. We give attention to objects which we distinguish and prefer to others. Attention continuing in the mind, whether the external object continues or not, and even whether it is found there or not, is 1 Cf. below, where the French " recueillement," here employed as a trans- lation of the English "recollection," is shown to have a different meaning and use from that of the English word. As " recueillement " is, however, used as an equivalent for the English word, I have translated it in the second para- graph accordingly. — Tr. 166 LEIBNITZ'S CRITIQUE OF LOCKE [bic. ii consideration ; which, tending to knowledge without reference to action, will be contemjolation. Attention, whose aim is to learn {i.e. the attainment of knowledge for the sake of keep- ing it), is study. To consider in order to form a plan is to meditate; but reverie appears to be nothing else than following certain thoughts for the pleasure one takes therein, with no other end ; this is why reverie may lead to madness ; we forget ourselves, we forget the die cur hie, we approach dreams and chimeras, we build castles in Spain. We can distinguish dreams from sensations only because they are not united with them, they are like a world apart. Sleep is a cessation of sen- sations, and in this way ecstasy is a very deep sleep from which one finds difficulty in being awakened, a condition which arises from some internal passing cause, which is added in order to exclude this profound sleep, arising from some narcotic or from some continuous injury to the functions, as in lethargy. Ecstasy is sometimes accompanied with visions; but there is vision without ecstasy, and vision seems to be nothing but a dream wdiich passes for a sensation just as if it acquainted us with the truth of objects. And when visions are divine, there is actually truth in them, which may be known for instance when they contain particular prophecies which the outcome justifies.] § 4. Ph. From the different degrees of intensity ^ or relaxa- tion of the mind, it follows that thought is the act and not the essence of the soul. Th. [Doubtless thought is an act and cannot be the essence : but it is an essential act, and all substances are of this charac- ter. I have shown above that we always have an infinite number of little perceptions, without being conscious of them. We are never without ^:>erce25ifons, but we are necessarily often without apperceptions, viz. : when there are no distinct per- ceptions. It is from not having considered this important point that a relaxed philosophy, as little noble as solid, has prevailed with so many excellent minds, and that we have hitherto almost ignored that which is most beautiful in the soul. This is also the reason why so much probability has been found in that error, which teaches that souls are by nature perishable.] 1 Locke has: "intention and remission," Philos. Works (Bolin's ed.), Vol. 1, p. 349.— Tr. CH. XX] ON HUMAN UNDERSTANDING 167 CHAPTER XX OF MODES OF PLEASURE AND PAIN § 1. Ph. As the sensations of the body, like the thoughts of the mind, are either indifferent or followed by pleasure or pain, the ideas of them cannot be described any more than all other simple ideas, nor can the words which serve to designate them be defined. Th. [I believe that there are no perceptions which are wholly indifferent to us, but it is enough that their effect be not notable in order that they may be thus spoken of, for pleasure and pain appear -to consist in a notable aid or impedi- ment. I admit that this definition is not at all nominal and that one may give none at all.] § 2. Ph. The good is that which is fitted to produce and increase pleasure in us, or to diminish and cut short some pain. Evil is fitted to produce or increase pain in us, or to diminish some pleasure. Th. [I am also of this opinion. The good is divided into the virtuous, the agreeable, and the useful, but ultimately I believe that it must be either agreeable itself, or serving some- thing else which may give us an agreeable feeling, that is to say, the good is agreeable or useful, and virtue itself consists in a pleasure of mind.] §§ 4, 5. Ph. From pleasure and pain come the passions. We have love for that which can produce pleasure, and the thought of sadness or of pain that a present or absent cause can produce is hatred. But hatred or love which relates to beings capable of happiness or misery is often an uneasiness or delight which we feel to be produced in us by the considera- tion of their existence or of the happiness which they enjoy. Th. [I also gave nearly this definition of love when T explained the principles of justice, in the preface to my "Codex juris gentium diplomaticus," ^ viz.: that] to love is to"^ 1 The Codex juris gentium diplomaticus, 1693, a collection of public acts and treatises, etc. An excerpt from the Preface of this work, entitled l)e no- tionibus juris et justitise, is given by Erdmann, pp. 118-120; translation, Dun- can, Philos. Works of Leibnitz, note 48, pp. 379-382. — Tr. 168 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii be inclined to take pleasure in the complete perfection or hap- piness of the object loved. And for that reason one neither considers nor asks for any other pleasure proper than that indeed which is found in the good or pleasure of the one who is loved ; but in this sense we do not, properly speaking, love what is incapable of pleasure or happiness, and we enjoy things of this nature without loving them for that reason, unless by a prosopopoeia, and as if we imagined that they themselves enjoy their perfection. It is not, then, properly love when one says that he loves a beautiful picture for the pleasure which he takes in feeling its perfections. But it is allowable to extend the sense of terms, and their usage varies. Philoso- phers and theologians even distinguish two kinds of love, viz. : the love which they call the love of complacency, which is nothing but the desire or feeling which we have for the one who gives us pleasure, without concerning ourselves whether he receives it; and the love of benevolence, which is the feeling that one has for the one who, by his pleasure or happiness, gives us some. The first makes us have in view our pleasure and the second that of another, but as making or rather consti- tuting ours, for if it did not reflect upon us in some way we could not concern ourselves with it since it is impossible, although they affirm it, to be separated from the good proper. And see how it is needful to understand disinterested or non- mercenary love, in order to reach a favorable conception of nobility and not to fall meanwhile into the chimerical one.] J § 6. Ph. The uneasiness (French incjuietucle) which a man feels in himself at the absence of anything which if present would give him pleasure is called desire. Uneasiness is the prin- cipal, not to say the only stimulus which excites human industry and action for whatever good is proposed to man ; if the absence of this good is followed by no displeasure or pain, and he who is deprived of it can be content and at his ease without its pos- session, he does not think of desiring, and less still of making any efforts to enjoy it. He feels for this kind of good only a bare velleity,^ the term used to signify the lowest kind of desire, 1 Schaarschmidt translates the French " velleite " by the German " Willens- neigung," i.e. inclination of will. The term is borrowed from the Scholastic "velleitas," and is here equivalent to iwijerfect volition (imperfecta I'olitio) or that condition of the soul in which the will, though not in a state of indiffer- CH. XX] ON HUMAN UNDEESTANDING 169 which approaches nearest to that state in which the soul finds itself with regard to anything which is wholly indifferent to it, when the displeasure which the absence of anything causes is so inconsiderable that it is carried only to feeble longings without being compelled to avail itself of the means of obtain- ing it. Desire is moreover extinguished or abated by the opinion that the wished for good cannot be obtained in propor- tion as the soul's uneasiness is cured or allayed by that con- sideration. [For the rest, I have found what I stated to you about uneasiness in this celebrated English author, whose views I often relate to you. I was a little in difficulty as to the definition of the English word uneasiness. But the French translator ^ whose skill in the fulfilment of this task cannot be called in question, remarks at the foot of the page (chap. 20, § 6,) that by this' word the English author understands the state of a man not at his ease, the lack of ease and of tran- quillity of soul, which in this regard is purely passive, and that it must be translated by the (French) word inquietude, which does not express exactly the same idea, but approaches it very nearly. This caution (he adds) is above all needful with regard to the following chapter, "Of Power," in which the author reasons much upon this kind of uneasiness ; for if you should not attach to this word the idea which has just been indicated, it would be impossible exactly to understand the matters treated of in this chapter and which are the most important and delicate in the entire work.] Th. [The translator is right and the reading of his excellent author shows me that this consideration of xmeasiness is a capi- tal point, in which this author has particularly shown his pene- trating and profound mind. For this reason I gave it some attention, and after having well considered the matter, it al- most appears to me that the (French) word inquietude {restless- ness) , if it does not express quite the meaning of the author, nevertheless sufficiently agrees with the nature of the thing ; and that the (English) word uneasiness, if it indicated a dis- pleasure, fretfulness (chagrin), inconvenience, in a word some effective pain, would not suit his meaning. For I should pre- ence, has not as yet sufficient force to pass over into action (volitio). Cf. Neio Esmys, Bk. II., chap. 21. § 5 sg., also § 30, Th. — Tr. 1 M. Pierre Coste. — Tr. 170 LEIBNITZ'S CRITIQUE OF LOCKE [ek. ii fer to say that in the desire in itself there is rather a disposi- tion and preparation for pain than pain itself. It is true that this perception sometimes differs from that which is in pain only more or less, but it is the degree which is the essence of pain, for it is a notable perception. The same is also seen in the difference between appetite and hunger, for when the stomach's irritation becomes too strong it is uncomfortable, so that we must also apply here our doctrine of perceptions too small to be perceived, for if that which goes on in us when we have appetite and desire, were great enough, it would cause us pain. Hence the infinitely wise author of our being arranged it for our good, when he so arranged it that Ave should often be in ignorance and among confused perceptions, in order to act more promptly by instinct, and in order not to be disturbed by too distinct sensations of a multitude of objects, which do not recur immediately and the nature of which could not go on to obtain their ends. How many insects we SAvallow without noticing them, how many persons we see who, having a too penetrating odor, are annoying, and how many disgusting ob- jects we should see if our vision were penetrating enough. It is also for the sake of this skill that nature has given us the stimuli of desire, like the rudiments or elements of pain, or so to speak, of semi-pains, or (if you Avish to speak extravagantly in order to express yourself more forcibly) the little impercep- tible pains, in order that Ave might enjoy the advantage of evil without its inconvenience ; for otherwise if this perception were too distinct, Ave would ahvays be miserable Avhile aAvait- ing the good, Avhile this continual victory over these semi- pains Avhich are felt in pursuing our desire and satisfying in some Avay this appetite, or this longing, gives us a quantity of semi-pleasures, whose continuity and mass (as in the continuity of the impulse of a heavy body Avhich falls and acquires im- petuosity) becomes at last a complete and genuine pleasure. And finally, without these semi-pains there would be no pleas- ure at all, nor any means of perceiving that something aids and relieves us Avhile there are some obstacles Avhich prevent us from putting ourselves at ease. It is furthermore in this that Ave recognize the affinity of pleasure and pain Avhich Soc- rates in Plato's " Phaedo," ^ noticed Avhen his feet itched. This 1 P/iietZo, 60 b.— Tr. CH. XX] ON HUMAN UNDERSTANDING 171 consideration of little aids or little releases and imperceptible deliverances from the fixed tendency, whose result at last is a notable pleasure, serves also to give a more distinct knowl- edge of the confused idea which we have, and ought to have, oj pleasure and of pain; just as the sensation of heat and of light results from a quantity of little motions which express those of objects, as I said above (chap. 9, § 13) and differ from them only in appearance and because we ourselves are not conscious of this analysis : while many to-day believe that our ideas of sense-qualities differ totv genere from notions and from all that goes on in objects, and are something primitive and inexpli- cable, and indeed arbitrary, as if God made the soul sensible of whatever seems good to him, instead of what goes on in the body, a view which is far removed from the true analysis of our ideas. But to return to uneasiness, that is to say to the little imperceptible solicitations which keep us always in suspense ; these are confused determinations, so that often we do not know what we lack, while in the case of the inclinations and passions we at least know what we ask for, although confused perceptions enter also into their methods of acting, and the passions themselves also cause this uneasiness or longing. These impulses are like so many little springs which try to release themselves, and which make our machine go. And I have already remarked above that it is in this way that we are never indifferent, when we most appear to be so, for example, in turning to the right rather than to the left at the end of a path. For the side we take arises from these insensible deter- minations, mixed with the actions of objects and the interior of the body, which makes us find ourselves more at ease in the one or the other manner of bestirring ourselves. The pendulum of a clock is called Unruhe in German, i.e. uneasiness. We may sa}^ that the same condition exists in our body which can never be perfectly at ease ; because if it might be so, a new impression of objects, a slight change in the organs, in the ves- sels and in the viscera would at once alter the balance and caiise them to make some slight effort to put themselves again in the best state possible : this produces a perpetual strife, which causes, so to speak, the uneasiness of our clock, so that this appellation is quite to m}^ taste.] § 6. Ph. Joy is a pleasure felt by the soul when it consid- 172 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii ers the possession of a present or future good as assured, and we are in possession of a good when it is so in our power that we can enjoy it wlien we wish. Th. [Languages lack words sufficiently suitable to distin- guish kindred notions. Perhaps the Latin gaudium draws nearer this definition of joy than ketitia, which is also trans- lated by the word Joy; but then it appears to me to signify a state in which pleasure predominates in us, for during the pro- foundest sorrow and in the midst of the most poignant grief one may take some pleasure as in drinking or hearing music, but the unpleasant feeling predominates and so in the midst of the most acute pain the mind can be joyful, as in the case of the martyrs.] § 8. Ph. Sorrow is an uneasiness of the soul when it thinks of a lost good which it might have enjoyed a longer time, or when it is tormented by an actually present evil. . Th. [ISTot only the actual presence, but also the fear of coming evil may make one sad, so that I believe the definitions of joy and sorrow Avhich I have just given agree the better wdth usage. As to uneasiness, there is in pain and consequently in sorrow something more: and there is uneasiness even in joy, for it makes a man awake, active, full of hope to go farther. Joy has been capable of causing death by excess of emotion, and then there was in it still more than uneasiness.] § 9. Fh. Hope is the contentment of the soul which thinks of the enjoyment which it is destined probably to have in a thing suited to give it pleasure. § 10. And fear is an uneasiness of the soul, at the thought of a future evil that may happen. Th. [If uneasiness signifies trouble I admit that it always accompanies fear ; but taking it as this insensible spur which pushes us on, it may be applied also to hope. The Stoics regarded the passions as thoughts ; thus hope was to them the thought of a future good, and fear the thought of a future evil. But I prefer to say that the passions are neither satis- factions nor displeasures, nor thoughts, but tendencies or rather modifications of the tendency, which come from thought or feeling and which are accompanied by pleasure or displeas- ure.] § 11. Ph. Despair is the thought one has that a good cannot be obtained, causing sometimes pain and sometimes rest. CH. XX] ON HUMAN UNDERSTANDING 173 Th. [Despair taken as passion is a kind of strong tendency which linds itself suddenly arrested, a condition which causes a violent struggle and much displeasure. But when despair is accompanied with rest and indolence it is rather a thought than a passion..] § 12. Ph. Anger is the uneasiness or discomposure we feel after having received some injury, and which is accompanied with a present desire to avenge ourselves. Th. [Anger seems to be something simpler and more gen- eral, since animals are susceptible to it to whom no injury is done. There is in anger a violent effort tending to annul the evil. The desire for vengeance may remain when one is in cold blood and has hatred rather than anger.] § 13. Ph. Envy is the uneasiness (displeasure) of the soul which arises from the consideration of a good we. desire, but which another possesses, who in our opinion should not have had it in preference to ourselves. Th. [According to this notion envy would be always a praiseworthy passion and always based upon justice, at least in our opinion. But I know not whether men do not often bear envy towards recognized merit, which they would not hesitate to treat ill, if they had the power. They even bear envy towards persons regarding a good which they themselves would not care to have. They would be content to see them deprived of it, without thinking of profiting from their despoil- ments, and indeed without being able to hope for it. For some good things are like pictures painted in fresco, which can be destroyed, but which cannot be taken away.] § 17. Ph. Most of the passions make in many persons impressions on the body, and cause therein various changes, but these changes are not always sensible ; for example, shame which is a felt uneasiness of the soul when it comes to consider that it has done something indecent or which may lessen the esti- mate others have of us, is not always accompanied by blushing. Th. [If men would study to observe more closely the ex- ternal movements which accompany the passions, it woixld be difficult to cojiceal them. As for shame, it is worthy of consid- eration that modest persons sometimes feel movements similar to those of shame, when they are witnesses only of an indecent action.] 174 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii CHAPTEE XXI OF POWER AND FREEDOM § 1. Ph. [The mind observing how one thing ceases to be, and how another which was not before comes to exist, and concluding that there will be in the future parallel cases, pro- duced by parallel agents, comes to consider in one thing the possibility that one of its simple ideas may be changed, and in another the possibility of producing that change, and in that way the mind forms the idea of power.] Th. [If power corresponds to the Latin potentia, it is opposed to act, and, the passage from power to act is change. This is what Aristotle understands by the word motion, when he says ^ that it is the act or perhaps the actuation of that which is in power.' It may be said then that power in general is the possi- bility of change. ]^ow change or the act of this possibility, being action in one subject and passion in another, there will be two powers, one passive, the other active. The active may be called faculty, and perhaj)s the passive might be called capacity or receptivity. It is true the active power is sometimes taken in a more complete sense, when besides the simple faculty there is a tendency ; and it is thus that I take it in my dynamical considerations.^ The word force might be appropriated to it in particular ; and force would be either entelechy or effort ; for entelechy (although Aristotle takes it so generally that it comprises also all action and all effort) appears to me more appropriate to primitive acting forces, and that of effort to the derivative. There is even also a kind of passive poiver more particular and more endowed with reality ; namely, that which is in matter in which there is not only mobility, which is the 1 Cf. Phys. III., 1, SOI" 10; MetapMjs. K, 9, 1065'' 16. — Te. 2 Cf. J)e primse philo.^ophisR emendatione, etc., published in the "Acta Eruditorum," 1694, p. 110 sg., Gerhardt, Vol. 4, j)p. 468-470; Erdmann, pp. 121-122 ; Jacques, Vol. 1, pp. 452-454, in French ; translation, Duncan, Philos. Works of Leibnitz, pp. 68-70; also, Beilage, May, 1702, appended by Gerhardt to the letter to Fabri, Gerhardt, Lelbnizens Math. Schriften, Vol. 6, pp. 98 sq., especially p. 101 ; Specimen dynamicum, published in the " Acta Erudi- torum," April, 1695, Gerhardt, Leihnizens Math. Schriften, Vol.6, pp. 234 sg — Tr. CH. XXI] ON HUMAN UNDERSTANDING 175 capacity or receptivity for motion, but also resistance, which includes impenetrability and inertia. Entelechies, i.e. primitive or substantial tendencies, when accompanied by perception, are souls.] § 3. Ph. The idea of power expresses some kind of relation. But what one of our ideas of whatever kind does not include some relation? Our ideas of extension, of duration, of number, do they not all contain in themselves a secret relation of parts ? The same thing is noticed in a still more visible manner in figure and motion. Sensible qualities, what are they bat the powers of different bodies in relation to our perception, and do they not depend in themselves upon bulk, figure, the con- texture and motion of the parts ? Avhich puts a kind of rela- tion between them. Thus our idea of power may very well be placed in my opinion among the other simple ideas. Th. [At bottom the ideas which we have just enumerated are composite ; those of sensible qualities hold their place among the simple ideas only because of our ignorance, and the others which we know distinctly, keep their place only by an indulgence which it were better they should not have. It is almost the same with regard to the common axioms, which might be and which deservedly should be proved among the theorems, and which are allowed to pass nevertheless as axioms, as if they were primitive truths. This indulgence does more harm than we think. It is true we are not always in a position to do without it.] § 4. Pli. If we consider the matter carefully, bodies do not furnish us by means of the senses with so clear and so distinct an idea of active power as that which we have from reflection upon the workings of our mind. There are, I believe, but two kinds of actions of which we have an idea, viz. : thinking and motion. Of thought, body gives us no idea, and it is only through reflection that we have it. Neither have we from the body any idea of the beginning of motion. Th. [These considerations are most excellent, and although here I take thought in a manner so general that it includes all perception, I do not wish to dispute the use of terms.] Ph. When the body is itself in motion, this motion in the body. is an action rather than a passion ; but Avhen a billiard- ball yields at the stroke of the cue, it is not an action of the ball, but a simple passion. 176 LEIBNITZ'S CRITIQUE OF LOCKE Imk. n Th. [There is something to be said upon that point, for tlie bodies did not receive motion in the impact, according to tlie laws observed therein, if they already had not motion in themselves. Bnt pass we now this point.] Ph. The same is true when it pushes another ball which it iinds in its way and puts in motion ; it only communicates to it the motion it had received, and itself loses just as much. Th. [I see that this erroneous view, which the Cartesians have brought into fashion, as if bodies lost as much motion as they give to others, which is to-day overthrown by experi- ments and by reason, and abandoned moreover by the illustri- ous author of " The Search after Truth," ^ who has published a brief treatise for the express purpose of retracting it, still gives scholars occasion to be mistaken in constructing trains of reasoning upon so ruinous a foundation.] Ph. The transfer of motion gives us only a very obscure idea of an active power of motion in the body so long as we see nothing else than that the body transfers motion but does not in any way produce it. Th. [I do not know whether they here maintain that motion passes from subject to subject, and that the same motion (idem numero) is transferred. I know that some, contrary to the view of the entire scholastic philosophy, have gone that far, among others the Jesuit, Father Casati. But I doubt whether this is your view or that of your scholarly friends, ordinarily far removed from such fancies. If, however, the same motion is not transferred, we must admit that a new motion is produced in the body which receives it : thus the one which gives Avould really act, although it would be passive at the same time while losing its force. For although it is not true that the body loses as much motion as it gives, it is always true that it loses some motion and that it loses as much force as it gives, as I have elsewhere explained, so that it is always nec- essary to admit in it force or active power. I iinderstand power in the more noble sense which I have explained a little before, in which tendency is united with faculty. Nevertheless, 1 Malebranche, De la Recherche de la Verite, 1674. The "brief treatise" referred to is entitled: Traite de la commiaiication du movement, and may be found in Vol. 3 of the German translation of Malebranche's works, Halle, 1777-80. — Tr. CH xxi] ON HUMAN UNDERSTANDING 177 I am always agreed with you, that the clearest idea of active power comes to us fi-om the mind. It is also only in things which are analogous to the mind, that is to say, in enteiechies, for matter properly speaking shows only passive power.] § 5. Ph. We find in ourselves the power to begin or not to begin, to continue or to end many actions of our soul and many motions of our body, and this simply by a thought or choice of our mind, which determines and commands, so to speak, that such a particular action be done or not done. This power we call Will. The actual use of this power is called Volition; the cessation or production of the action which fol- lows such a command of the soul, is called voluntary, and all action done without such direction of the soul is called inool- tmtary. Til. [1 find all that very good and just. However, to speak more fairly, and to go perhaps a little farther, I will say that volition is the effort or tendency [conatus) towards what is considered good and against that considered bad, so that this tendency results immediately from the consciousness one has of them. And the corollary of this definition is this cele- brated axiom : that will and power united, action follows, since from all tendency action follows when it is not hin- dered. Thus not only the internal voluntary actions of our minds follow from this conatus, but also the external, that is to say, the voluntary movements of our bodies, in virtue of the union of the soul and the body, the reason of which I have elsewhere given; There are besides the efforts resulting from the insensible perceptions, of which we are not conscious, which I prefer to call appetitions rather than volitions (al- though there are also apperceptible appetitions), for those actions alone are called voluntary of which we may be con- scious, and upon which our reflection may fall wheti they fol- low the consideration of good and evil.] Ph. The power of perceiving we call ?(?(f?ersto);f?i»g'.- it in- cludes the perception of ideas, the perception of the signifi- cation of signs, and, finally, the perception of the agreement or disagreement existing between any of our ideas. Til. [We perceive many things within and without us, which we do not understand, and we understand them, when N 178 LEIBNITZ'S CEITIQUE OF LOCKE [bk. ii we have distinct ideas of them, together Avith the power of reflection and of drawing from them necessary truths. Ani- mals therefore have no understanding, at least in this sense, although they have the faculty of perceiving impressions more remarkable and more distinct, as the boar perceives a person who shouts at him, and goes straight for this person, of whom he had had before only a cloudy perception, but con- fused as of all other objects which fell under his eyes, and whose rays struck his crystalline humor. Thus in my view the understanding corresponds to what among the Latins is called intellectus, and the exercise of this faculty is called intellection, which is a distinct perception united with the fac- ulty of reflection, which is not in animals. Every perception united with this facult}^ is a thought, which I do not accord to the animals any more than understanding, so that we may say there is intellection when thought is distinct. For the rest, the perception of the signification of signs does not deserve to be distinguished here from the perception of the ideas signified.] § 6. Ph. It is commonly said that the understanding and the will are two faculties of the soul, a term suitable enough if used as we ought to use all words, taking care that they cause no confusion to spring up in the thoughts of men, as I suspect has happened here in the case of the soul. And when we are told that the will is that superior faculty of the soul which rules and orders all things, that it is or is not free, that it deter- mines the lower faculties, that it follows the dictamen of the understanding ; although these expressions may be understood in a sense clear and distinct, I fear, however, that they have caused to arise in many persons the confused idea of so many distinct agents acting distinctly in us. Th. The question has exercised the scholastics a long time whether there is a real distinction between the soul and its faculties, and whether one faculty is really distinct from another. The Realists have said yes, and the Xominalists, no, and the same question has been agitated as to the reality of many other abstract entities, which should meet the same fate. But I do not think we need here decide this question and plunge into these difficulties, although I remember that CH. XXI] ON HUMAN UNDERSTANDING 179 Episcopius ^ found it of such importance that he thought he could not maintain the freedom of man if the faculties of the soul were real entities. However, if they were real and dis- tinct entities, they can pass for real agents only in extravagant speech. It is not the faculties or qualities which act, but sub- stances by means of the faculties. § 8. Ph. So long as man has the power to think or to refrain from thinking, to move or not to move according to the preference or choice of his own mind, so long he is free. Th. [The term freedom is very ambiguous. There is free- dom of right and of fact. As regards that of right a slave is not at all free, a subject is not wholly free, but a poor man is as free as a rich man. Freedom of fact consists either in the power to ivill as one ought, or in the power to do what one wills. It is of the freedom to do of which you speak, and it has its degrees and varieties. Generally he who has the mos-t means is the freest to do what he wills : but in imrticxdar freedom is understood of the use of things which are ordinarily in our power, and above all, of the free use of our body. Thus the prison and the diseases which prevent us from giving to our body and our limbs the motion we wish and which we can ordinarily give them detract from our freedom : thus a prisoner is not at all free, and a paralytic has no free use of his limbs. Freedom of tvill is furthermore understood in two different senses. The first is when it is opposed to the imperfection or the slavery of the spirit, which is a coaction or constraint, but internal like that arising from the passions. The other sense has place when freedom is opposed to necessity. In the first sense the Stoics said that the wise man alone is free ; and in fact the spirit is not at all free when it is filled with a great passion, for one cannot then will as he should, that is to say, with the deliberation which is requisite. Thus God alone is perfectly free, and created spirits are so, only to the extent that they are superior to their passions. And this freedom concerns properly our understanding. But the freedom of spirit, opposed to necessity, concerns the naked will, and in so far as it is distinguished from the understanding. This is ^ Simon Episcopius, 1583-1643. The piece referred to is the De Ubero arbi- irio, particularly the second chapter; it is found in his Opera Theolof/ica, Vol. 1, p. 198, Div. II., 2d ed. London and Rotterdam, 1665-1678, 2 vols., fol. — Tr. 180 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii wh.a,t is called free-iLu'Il (franc arbitre) and. it consists in this, that we will that the strongest reasons or impressions which the understanding presents to the will do not prevent the act of the will from being contingent, and do not give it an abso- lute, and, so to speak, metaphysical necessity. And it is in this sense that I am accustomed to say that the understanding can determine the will, according to the prevalence of percep- tions and reasons, in a manner which, even where it is certain and infallible, inclines without compelling.'^ § 9. Ph. It is well also to consider that no one has yet thought of taking as a, free agent a ball, whether in motion by the stroke of a racket or at rest. This is because we do not conceive of a ball as thinking or as having any volition, Avhich makes it prefer motion to rest. Th. [If that were free which acts without hindrance, a ball once in "motion in a level horizon would be a free agent. But Aristotle has already well remarked that to call acts free, we demand not only that they be sjyontaneous, but further that they be deliberate.-'] Ph. This is why we consider the motion or rest of balls under the idea of a necessary thing. Th. [The appellation necessary requires as much circumspec- tion as that oi free. This conditional truth, viz.: supposing the hall to he in motion in a level horizon toithout hindrance, it will continue the same motioyi, may pass as in some sort necessary, although at bottom this consequence is not entirely geometri- cal, being only presumptive, so to speak, and based upon the wisdom of God who changes not his influence without a reason, which it is presumed is not at present to be found. But this absolute proposition : the hall here is noio in motion in this ]}lane, is only a contingent truth, and in this sense the ball is a contingent, not a free, agent.] § 10. Ph. Suppose that a man, while in a profound sleep, is carried into aroom, where is a person, whom he much longs to 1 Cf. Essais de Theodicee, Pt. I., §§ 51, 52, Gerhardt, 6, 130-131 ; Erdmann, 517; also Eduard Dillmann, JElne neue Darstellurifi der Leibnizischen Monad- enlehre auf Grund der Quellen, pp. 416 sq. ; Leipzig: O. R. Reisland, 1891. — Tk. 2 Cf. Eth. Nic, III., 4, ad fin-, 5; 1111 sq.; translation by F. H. Peters, M.A., London: C. Kegan Paul & Co., 1881. — Tr. CH. XXI] OX HUMAN UNDERSTANDING 181 see and to meet, and that the door is locked upon him ; this man wakes up and is deliglited to lind himself with this per- son, and lives thus in the room with pleasure. I think no one presumes to doubt that he remains voluntarily in that place. Yet he is not at liberty to go out if he wishes. Thus freedom is not an idea belonging to volition. Til. [I find this example very well chosen to show that in a sense, an act or a state may be voluntary without being free. Still when philosophers and theologians dispute upon/ree loill, they have altogether another sense in view.] § 11. Ph. Freedom is wanting when paralysis prevents the limbs from obeying the determination of the mind, although, in the case of the paralytic even, to remain sitting still might be voluntary so long as he prefers sitting still to changing h.is place. Voluntary is not then opposed to necessary, but to involuntary. Til. [This precision of expression would be agreeable enough to me, but usage is far from it ; and those w^ho oppose freedom to necessity, mean to speak not of external acts, but of the act itself of willing.] § 12. Ph. A man awake is no more at liberty to think or not to think, than he is at liberty to prevent or not to prevent his body from touching any other body. But to transfer his thoughts from one idea to another is often within his deter- mination. And in that case he is as much at liberty as regards his ideas, as he is as regards the bodies upon which he rests, being able to transfer himself from one to the other as the fancy arises. There are, however, ideas, which, like certain (bodily) movements, are so fixed in the mind, that, in certain circumstances, you cannot avoid them whatever effort you make. A man upon the rack is not at liberty to put aside the idea of pain, and sometimes a violent passion acts upon our mind as the most violent wind acts upon our body. TJi. [There is order and connection in ideas, as there is in (bodily) movements, for the one corresponds perfectly to the other, although the determination in the movements be uncon- scious and free, or with choice in the thinking being whom good and evil only cause to incline without forcing him. For the soul, while representing bodies, preserves its (own) perfections, and although dependent upon the body (in seizing the good) in the ^ 182 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ir voluntary acts, it is independent and makes the body depend upon itself in others. But this dependence is only metaphysical, and consists in the considerations which God has for the one while ruling the other, or rather for 'both, according to the original perfections of each ; whilst ^^hyskal dependence Avould consist in an immediate influence, which the one would receive from the other on which it depends. For the rest, there come to us involuntary thoughts, partly from outside by means of objects which strike our senses, and partly from within by reason of the impressions (often insensible) which remain from preceding perceptions Avhose action continues and which mingle with those which appear for the first time. As regards these we are passive, and even when we wake up, images (under which designation I include not only the representa- tions of figures, but also those of sounds and other sensible qualities) come to us, as in dreams, without being called. The German language calls them Jliegende Gedanlxen, that is, flying thoughts {pensees volantes), which are not within our control, and among which there are sometimes many absurdi- ties which raise scruples in good people, and furnish exercise to casuists and directors of consciences. It is as in the magic lantern, which makes figures appear upon the wall according as something Avithin is turned. But our mind, perceiving some image which recurs to it, may say : stop there, and, so to speak, arrest it. Moreover, the mind enters, as seems good to itself, into certain trains of tJiought, which lead it on to others. But this is true only when internal or external impres- sions do not at all prevail. It is true that in this thing men differ very much, both according to their temperament and according as they have exercised their control, so that one can master impressions where another lets them go. § 13. Ph. Necessity takes place wherever thought is wholly Avanting. And this necessity, when found, is an agent capable of volition, and when the commencement or continuation of any action is contrary to the preference of his mind, I call it compulsion ; when the hindering or stopping of an action is contrary to his volition, I may call it restraint. Agents which have absolutely neither thought nor volition are in all respects necessary agents. Th. [It seems to me that, properly speaking, altliongh cii. -XXI] UN HUMAN UNDERSTANDING 183 volitions are contingent, necessity should not be opposed to volition, but to contingency, as I have alueady remarked in § 9, and that necessity should not be confounded with determina- tion, for there is no less connection or determination in thoughts than in movements (to be determined being a wholly different thing from being pushed or forced by compulsion). And if we do not always notice the reason which determines us or by which we determine ourselves, it is because we are as little capable ourselves of perceiving the entire play of our mind and its thoughts, very often imperceptible and confused, as we are of recognizing all the machinery which nature causes to play in the body. Thus, if by necessity, you mean the cer- tain determination of man, which a perfect knowledge of all the circumstances within and without could make a perfect mind foresee, it is certain that thoughts being as determined as the motions they represent, every free act would be a neces- sary act. But necessity must be distinguished from contingency although determined ; and not only are contingent truths not at all necessary, but further, their connections are not always of an absolutely necessary character; for it must be admitted that there is some difference in the manner of determining between consequences which take place in necessary matter and those which take place in contingent matter. Geometrical and metaphysical consequences necessitate, but physical and moral incline without necessitating ; the physical even having something of the moral and voluntary as related to God, since the laws of movement have no other necessity than that of (the principle, or choice, of — Tk.) the best. Now God chooses freely although he is determined to choose the best ; and as bodies themselves do not choose (God having chosen for them), usage has decided that they be called necessary agents, to which I am not opposed, provided we do not confound the necessary and the determined, and do not suppose that free beings act in an indeterminate manner, an error which has prevailed in cer- tain minds and which destroys the most important truths, even this fundamental axiom : that nothing hajipens without reason, Avithout which neither the existence of God nor other great truths could be satisfactorily demonstrated. As for compulsion it is well to distinguish two kinds, the one physical, as when a man is carried in spite of himself into prison, or thrown 184 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii down a precipice ; the other moral, as, for exaiiiple, the con- straint of a greater evil, and this act,^ although in a sense -forced, does not cease to be voluntar}'-.- One may be compelled also, by the consideration of a greater good, as when a man is tempted by proposing to him a too great advantage, although it is not customary to call this constraint.] § 14. Ph. Let us see now if we cannot put an end to that long agitated, and in my opinion very unreasonable, because unintelligible, question : Wlietlier man^s tvill is free or no. Th. [There is much reason for the exclamation with respect to the strange manner of men who torment themselves by agi- tating badly conceived questions : They seek for ivhat they knoiv, and know not for lohat they seek.^ Ph. Freedom, which is only a power, belongs only to agents and cannot be an attribute or modification of the will, which is itself nothing else than a power. Th. [You are right, sir, according to the proper use of words. One can, however, in some measure excuse received usage. Thus it is customary to attribute power to heat or to other qualities, i.e. to the body in so far as possessed of that quality : and in like manner the intent here is to ask if man is free in willing.] § 15. Ph. Freedom is the power a man has of doing or not doing any act conformably to his will. Th. If men understood only that by freedom, when they ask whether the will, or the arbiter is free, their question would be truly absurd. But you will see presently what they a,sk, and indeed I have already touched upon it. It is true but by another principle, that they (at least many) do not cease to ask for the absurd and the impossible, in desiring a freedom of equilibrium absolutely imaginary and impracticable, and which indeed would not serve them, were it possible for them to have it, i.e. to have the freedom of willing against all the impressions which can come from the understanding, which would destroy true freedom together with the reason, and lower us below the beasts. 1 Gerhardt reads: "et cette action, qiioyque forcee en quelque fa(;on"; Erdmann and Jacqxies: " car Taction, qu'elle fait faire," i.e. for the act which it makes you do. — Tr. 2 Cf. Kant, Kritik d.prakt. Vermmft, Th. I., Bd. I., Hpst. 1, § fi, Anm.; translation by T. K. Abbott, 4th ed., revised and enlarged. London : Longmans, 1889. — Tr. cii. XX i] ON HUMAN UNDERSTANDING 185 § 17. Ph. He who should say that the power of speaking directs the power of singing, and that the power of singing^ obeys or disobeys the power of speaking, Avould express him- self in as proper and intelligent a manner, as he who says, as has been usual, that the will directs the understanding, and that the understanding obeys or disobeys the will. § 18. Nevertheless this manner of speaking has prevailed, and has caused, if I am not mistaken, much confusion, although the power of thinking operates no more upon the power of choos- ing and the contrary, than the power of singing upon that of dancing. § 19. I grant that this or that thought may furnish man the occasion of exercising his power of choosing and that the mind's choice may be the cause of its actually thinking on this or that thing, just as actually singing a certain tune may be the occasion of dancing such a dance. Th. [There is a little more than the furnishing of occasions, since there is some dependence ; for you can will only what you find to be good, and according as the faculty of under- standing is improved the choice of the will is better, as on the other hand, according as man has vigor of will he determines his thoughts according to his choice, instead of being deter- mined and carried away by involuntary perceptions.] Pli. Powers are relations, not agents. Th. [If the essential faculties are only relations and add nothing whatever to the essence, the qualities and tlie faculties that are accidental or subject to change are something else, and we may say of these last that the one often depends upon the other in the exercise of their functions.] § 21. Ph. In my opinion the question should not be, whether the will is free, — that is to speak in a very improper manner, — but whether the man is free. That granted, I say that so long as any one can by the direction or choice of his mind prefer the existence of an action to its non-existence, and the contrary, i.e. can make it exist or not exist according as he wills, so long he is free. And we can scarcely say how we could possibly conceive a being freer than so far as he is able to do what he wills. So that man seems to be as free in refer- 1 Gerhardt reads: "parler," a MS. or typographical error; cf. Locke, Philos. Works (Bohn's ed.), Vol. 1, p. 370. Erdmann and Jacques read: " chanter," which the translation follows. — Tr. 186 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii ence to those actions which depend upon this power he finds in himself, as it is possible for freedom to make him, if I may so express myself. Th. [When we reason about the freedom of the will or upon free-will {franc arbitre), we do not ask if man can do what he wills, but if there is enough independence in his will itself. We do not ask if he has free limbs or elbow-room, but if he has a free spirit, and in what it consists. In this respect one intelligence might be freer than another, and the supreme intelligence will exist in perfect freedom of which creatures are not at all capable.] § 22. Ph. Men naturally inquisitive, and who love to remove as much as they can from their minds the thought of guilt, although it be by reducing themselves to a state worse than that of a fatal necessity, are not, however, satisfied with this. Unless freedom extends still farther, it is not to their taste, and in their opinion it is a very good proof that man is not at all wholly free, unless he has as well the freedom to will as that of doing what he wills. § 23. Concerning which I believe that man cannot be free in reference to this particular act of willing an action which is in his power, when this action has been once proposed to his mind. The reason therein is wholly manifest, for the action depending upon his will, must una- voidably exist or not exist, and its existence or non-exist- ence following without fail exactly the determination and choice of liis will, he cannot avoid willing the existence or non-existence of this action. Th. [I should think he could suspend his choice, and that this happens very often ; above all, when other thoughts inter- rupt deliberation : thus, although the action deliberated upon necessarily exists or not, it does not at all follow that you must necessarily determine upon its existence or non-existence ; for non-existence may happen again for want of resolution. Thus the Areopagites actually released the man whose case they had found too difficult to decide, deferring it to a term far distant, and taking a hundred years to consider it.] Ph. In making man free in this fashion, I mean in making the act of willing depend upon his will, another will or ante- rior faculty .of volition is necessary in order to determine the acts of this will, and another to determine that, and thus to CH. XXI] ON HUMAN UNDERSTANDING 187 infinity ; for wherever you stop, the actions of the last will could not be free. Th. [It is true you speak incorrectly when you speak as if we willed to will. We do not will to Avill, but we will to do, and if we willed to will, we should wall to will to will, and this would go on to infinity : meanwhile it is not necessary to conceal that by some voluntary acts we contribute often indi- rectly to other voluntary acts, and although one cannot will what he will, as he cannot even judge what he will,^ he can, however, so act in advance that he judges or wills at the time what he would wish to be able to will or judge to-day. Men attach themselves to persons, lectures, and considerations favor- able to a certain party, they give no attention to that which comes from the opposite party, and by these addresses and a thousand others which they employ, most frequently without definite design and without thought, they succeed in deceiving themselves or at least in changing and converting or per- verting themselves according to what the}^ meet.] § 25. Ph. Since then it is evident that man is not at lib- erty to luill to icill or not., the next thing demanded is, ivhether man is at liberty to wilt ivhich of the two he pleases, for example, motion or rest? But this question is in itself so visibly absurd that it may suffice to convince any one who will reflect that freedom in no case concerns the will. Eor to ask whether a man is free to Avill Avhat he pleases, motion or rest, speech or silence, is to ask whether a man can will what he wills, or be pleased with that with which he is pleased, a question which, in my opinion, needs no answer. Th. [It is true, nevertheless, that men find here a difficulty which deserves to be removed. They say that after having known and considered all, it is still within their power to will not only what pleases them the most, but furthermore wholly the contrary, merely to show their freedom. But you must consider that this caprice or obstinacy, or at least this reason which hinders them from following other reasons, also enters into the balance and makes that please them which w^ould otherwise not do so, so that choice is always determined by perception. They do not then will what they would, but what ^ The French is: " et quoyqu' on ne puisse point vouloir ce qu' on veut, eomme on ne pent pas meme juger ce qu' on veut." — Tr. 188 LEIBNITZ'S CRITIQUE^ OF LOCKE [bk. ir pleases, although the will can contribute indirectly and as it were from afar to make anything pleasurable or otherwise, as I have already remarked. And as men scarcely recognize all these separate considerations, it is not astonishing that the mind is so perplexed in regard to this matter which has so many concealed windings.] § 29. I*h. When men ask what it is that determines the will, the true reply is, the mind. If this answer is not satis- factory, it is plain that the meaning of the question reduces to this : Wliat moves the mind on each 2')articular occasion to deter- mine to such particular motion or rest its general poiver of direct- ing its faculties toivards motion or rest? To this I reply that what leads us to remain in the same state or continue the same action, is solely the present satisfaction we find therein. On the other hand, the motive which incites to change is always some uneasiness. Th. [This uneasiness, as I have shown (in the preceding chapter), is not always a displeasure, as ease when found is not always a satisfaction or pleasure. It is often an insensible perception, which cannot be distinguished or recognized, which makes us lean to one side rather than the other, without our being able to give a reason for so doing.] § 30. Ph. Will and desire should not be confounded : a man desires to be freed from the gout, but understanding that the removal of this pain may cause the transfer of a dangerous humor into some more vital part, his will cannot be determined to any action, which may serve to remove this pain. Th. [This desire is a kind of an inclination of will (velleitey as compared with a complete volition. We should will, for example, if there were no greater evil to be feared, if we obtained what we wish, or if perhaps there were a greater good to be hoped for if we went forward. But we can say that man wills to be delivered from the gout with a certain degree of volition, but which does not always go on to the last effort. This volition is called Velleity when it includes some imperfection or impotency.] § 31. Ph. It is well to consider, however, that what deter- mines the will to act is not the greater good, as is ordinarily supposed, but rather some actual uneasiness, and ordinarily 1 Cf. Xew Essays, Book. II., chap. 20, § 6, Ph. and note, ante, p. 168. — Tr. CH. xxi] ON HUMAN UNDETiSTANDING 189 that which is most pressing. We may give it the name of desire, which is really an uneasiness of mind, caused by the want of some absent good, over and above the desire of being freed from pain. All absent good does not produce a pain proportionate to the degree of excellence which it has or which we acknowledge it to have; whilst all pain causes a desire equal to itself; because the absence of good is not always an evil, as is the presence of pain. Therefore we can look upon and consider an absent good without pain. But in proportion as there is anywhere desire, so is there uneasiness. § 32. Who is there who has not felt in desire what the wise man says of hope, " that being deferred it makes the heart sick " (Prov. 13:12) ? Eachel cries "Give me children, or I die" (Gen. 30:1). § 34. When man is perfectly content with the state he is in, or when he is absolutely free from all uneasiness, what will can remain to him but to continue in that state ? Thus the wise Author of our being has put in men the inconvenience of hunger and thirst and other natural desires, in order to arouse and determine their wills to the proper conservation and continuation of their species. " It is better to marry than to burn," says St. Paul (1 Cor. 7:9). So true it is that the present sensation of a little burning has more power over us than the attractions of greater pleasures .looked at in the distance. § 35. It is true that this maxim, it is the good and the greatest good which determines the will, is so firmly established that I am not at all surprised at having formerly regarded it as beyond doubt. But after strict inquiry I am forced to conclude that the good and the greatest good, although jiidged and acknowledged such, does not deter- mine the will ; unless coming to desire it in a manner propor- tional to its excellence this desire makes u^s uneasy at our deprivation of it. Suppose a man convinced of the utility of virtue so far as to see that it is necessary to the man who pro- poses anything great in this world, or hopes to be hapj^y in the other : but until this man hungers and thirsts after right- eousness, his will will never be determined to any action in search for this excellent good, and any other uneasiness com- ing in the way will drag his will to other things. On the other hand, siippose a man given to wine considers that by leading the life he leads he is ruining his health and wastina: his 190 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii property, that lie is coming to be dishonored, in the world, to bring upon himself disease and to fall at last into poverty until he no longer has wherewith to satisfy this passion for drink which so strongly possesses him : nevertheless, the returns of uneasiness which he feels in being absent from his companions in debauch, drag him to the tavern at the hours he has been wont to go there, though at the time he has before his eyes the loss of his health and estate, and perhaps even that of the happiness of the other life, happiness which he cannot regard as a good inconsiderable in itself, since he admits that it is much more excellent than the pleasure of drinking or the vain chatter of a company of debauchees. It is not then for want of casting the eyes upon the sovereign good that he persists in this intemperance ; for he sees it and acknowledges its excellence, to the extent that during the time that intervenes between his drinking hours, he resolves to apply himself to the search for this sovereign good ; but when the uneasiness of being deprived of his accustomed pleasure comes to torment him, this good which he acknowl- edges more excellent than that of drinking, has no longer power over his mind, and it is this actual uneasiness which determines his will to the action to which it is accustomed, and which thereby making very strong impressions prevails again at the first occasion, although at the same time he binds himself, so to speak, by secret promises no longer to do the same thing, and imagines that this will be the last time that he will act against his highest interest. Thus he finds himself from time to time reduced to saying : Video meliora proboque, Deteriora sequor.i I see the better way, I approve it, and I take the worse. This sentence which we acknowledge as true, and which is only too well confirmed by a constant experience, is easy to understand in this way, and there is perhaps no other sense in which it can be taken, Th. [There is something beautiful and solid in these consid- erations. But I would not have jow believe on that account that we must abandon those ancient axioms that the will 1 Ovid, Metamorxjli. 7 . 21. — Txs,. cu. xm] o:: human understanding loi follows the greatest good, or that it flies from the greatest evil that it perceives. The source of the little application to true goods arises mainly from the fact that in matters and on the occasions where the senses act but little, the greater part of our thoughts are, so to speak, surd^ (I call them cogitationes ccecce in Latin) i.e. void of perception and feeling, and consisting in the wholly empty employment of characters, as happens in the case of those who make algebraic calculations without con- sidering from time to time that the geometrical figures in question and the words ordinarily produce the same effect in this regard as the characters of arithmetic or algebra. One often reasons in words without having quite the same object in mind. Now this knowledge cannot move ; something living is necessary in order to arouse us. But thus it is that men most frequently think of God, of virtue, of happiness ; they speak and reason without definite ideas. Not that they can- not have them, since they are in their mind. But they do not trouble themselves to press their analysis. Sometimes they have ideas of an absent good or evil, but very feeble. It is then no wonder that they are scarcely affected. Thus if we prefer the bad it is because we perceive the good which it includes without perceiving either the bad therein or the good in the contrary consideration. We assume and believe, or rather we make the statement merely upon another's belief, or at most upon belief in the memory of our past reasonings, that the greatest good is on the better side, or the greatest evil on the other. But when we do not look at these at all, our thoughts and reasonings contrary to the feeling are a kind of 2)sUtacism " which furnishes nothing at present to the mind ; and if we take no measures to remedy it, it is idle talk, as I have already remarked above (Bk. I., chap. 2, § 11), and the most beautiful precepts of morality together with the best rules of prudence take effect only in a soul which is sensible (either directly, or, because that cannot always be, at least ni- directly, as I shall show presently) and which is no longer sensible to that which is contrary thereto. Cicero well says ^ The French is : " sourdes." Cf. p. 193, near the end of Th. — Tr. 2 Littre thus defines " psittacisme," quoting this passage and the one further on, § 37, Th.,hy way of ilhistration : "Etat d'esprit dans lequel on ne pense on n narle qu'en perroquet," i.e. a state of the mind in which one thinks or soeaiis ouly as a parrot. — Tb. 192 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii somewhere ^ that if our eyes could see the beauty of virtue, we should love it warmly ; but that not being at all the case, nor anything equivalent, we must not be astonished if in the strug- gle between the flesh and the spirit, the spirit so many times yields, since it does not clearly perceive its advantages. The struggle is nothing else than the opposition of different ten- dencies, which spring from confused and distinct thoughts. Confused thoughts often make themselves clearly felt, but our' distinct thoughts are ordinarily clear only potentially ; they might be clear, if we would apply ourselves to the penetration of the sense of the words or characters ; but not doing so, either through negligence, or because of the shortness of time, we oppose mere M^ords, or at least, too feeble images to living feelings. I knew a man influential in church and state, whose infirmities made him resolve to diet ; but he ad- mitted that he had not been able to resist the odor of the viands, which, passing before his apartment, were carried to others. It is doubtless a disgraceful weakness, but it is just what men have done. But if the mind made good use of its advantages, it would triumph grandly. It would be necessary to begin with education, which should be so regulated as to render true good and true evil as sensible as possible, by in- vesting the notions which are formed of them with circum- stances more suited to this design ; and a full-grown man Avho lacks this excellent education should commence rather late, than never, to seek pleasures enlightened and reasonable, in order to oppose them to those of the senses, which are con- fused but impressive. And in fact, divine grace itself is a pleasure ^ which gives light. Thus when a man is in the midst of good impulses, he ought to make laws and regulations for 1 Perhajas in De Fin., 2, 16, § 52: " Oculorum, inquit Plato, est in nobis seusus acerrimus, quibus sapientiam non cernimus. Quani ilia ardentes aniores excitaret sni, si videretur," where, however, the discourse is concerned with the particular virtue of wisdom, rather than with virtue in general. The pas- sage of Plato referred to is in the Phsedrus, 250 D. Cf. also, Be Off., 2, 37: " Quis non admiretur splendorem pulchritudinemque virtutis " ; and De Off., 1, 5: " Formam quidem ipsam, Marce fill, et tanquam faciem honesti vides; qufB si oculis cerneretur, mirabiles araores excitaret sapientiiB." — Tr. 2 Cf. Spinoza, Ethica, Part V., Props., 32, 33, sq.; translation by R. H. M. Elvves, 7 he Chief Works of Benedict de Spinoza, Vol. 2, pp. 263 sq. (Bohn's Philos. Library), London: George Bell & Sons, 1884. The best edition of Spinoza's Works is that of Van Vloten and Land, The Hague, 1882-1883. —Tr. CH. xxi] ON HUMAN UNDERSTANDING 193 the future, and execute them rigorously, tearing himself away from those causes able to corrupt him, either brusquely or gradually, according to the nature of the circumstances. A journey expressly undertaken will cure a lover ; a retreat will draw us from the companions who support us in some bad in- clination. Francis of Borgia, General of the Jesuits, who has at last been canonized, being wont to drink largely when he was a man in high life, reduced himself little by little, upon a small scale, when he thought of retiring (from the world) by causing a drop of wax to fall daily into the bottle which he was wont to empty. To dangerous sensibilities we shall op- pose some other innocent sensibility, as agriculture, garden- ing ; we shall shun idleness ; we shall collect curiosities of nature and art ; we shall make experiments and researches ; we shall engage in some indispensable occupation, if we have none, or in conversation, or useful and agreeable reading. In a word, we must profit from good impulses as from the voice of God which summons us to make effective resolutions. And as we cannot always analyze the notions of true goods and true evils until we perceive the pleasure and joain they in- clude, we must once for all make this law in order to be moved by them : to attend to and follow henceforth the conclusions of reason once for all understood, although perceived after- ward and ordinarily only by thoughts sicrd^ merely, and desti- tute of sense attractions ; and this in order to put yourselves finally in possession of control over the passions as well as of the insensible inclinations or uneasinesses, by acquiring this habit of acting according to reason, which makes virtue pleasant, and as it were natural. But it is not our business here to give and teach the precepts of morality, or the spiritual directions and address for the exercise of true piety ; it is enough that in considering the procedure of our soul, we see the source of our weaknesses, the knowledge of which gives, at the same time, that of their remedies.] § 36. Ph. The present uneasiness which presses us, works only upon the will, and naturally determines it in view of that happiness to which we all aim in all our actions ; because every one regards pain and uneasiness (i.e. the restlessness, or rather inconvenience, which prevents us from being at our ease) as ^ Cf. p. 191, near the beginning of Tli., and note.^-TR. O 194 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii incompatible with happiness. A little pain suffices to corrupt all the pleasures we enjoy. Consequently that which deter- mines incessantly the choice of our will to the succeeding action will always be the removing of pain, as long as we feel any touch of it ; this removal being the first step towards happiness. Th. If you take your uneasiness or inquietude as a veritable displeasure, in this sense I do not admit that it is the sole in- centive. Most frequently these are the little insensible per- ceptions which might be called imperceptible pains if the notion of pain did not include a.2:)perception. These little im- pulsions consist in delivering themselves- continually from little obstacles towards which our nature works withoiit think- ing of them. This uneasiness consists in truth in this, that we feel without knowing it, which fact makes us act in passion as well as when we appear most tranquil ; for we are never without some action and motion, which arises only from the fact that nature always labors to put herself more at her ease. And this it is which, determines also before all consultation in the cases ivhicli appear to us the most indifferent, because we are never perfectly in suspense and we cannot be exactly equally divided between tAvo cases. Now if these elements of pain (which degenerate into veritable pain or displeasure sometimes when they overgrow) were true pains, we should always be miserable in pursuing the good that we seek with uneasiness and spirit. But it is wholly the contrary ; and as I have already said above (§ 6 of the preceding chapter), the mass of these continual little successes of nature, which puts it more and more at ease in reaching for the good and enjoying its image, or lessening the feeling of pain, is already a consider- able pleasure, and often worth more than the enjoyment even of the good; and very far from being obliged to regard this un- easiness as iiicompatible ivith haiypiness, I find that uneasiness is essential to the happiness of created beings which never con- sists in complete possession,^ — this makes them insensible, and 1 Cf. the famous passage of Lessing, 1729-1781, regarding the ' search after truth, rather than its possession,' in the Theolog. Streitschriften, EineDuplik, 1778, I. ad fin., Werke, Bd. 10, s. 19, Stuttgart, 1869: " Nicht die Wahrheit, in deren Besitz irgend ein Mensch ist, oder zu sein vermeint, sondern die aut- richtige Miihe, die er angewandt hat, liinter die Wahrheit zukommen, macht den Werth des Meuschen. Denn nicht durch den Besitz, sondern durch die CH. XXI] ON HUMAN UNDERSTANDING 195 as it were stupid, — but in a progress continuous and uninter- rupted towards the greatest good, which cannot fail to be ac- companied by a desire, or at least, a continual uneasiness, but which, as I have just explained, does not go sq far as to incon- venience, but limits itself to those elements or rudiments of pain, partly unconscious, which do not cease to be sufficient to serve as an incentive and to arouse the will ; as does appetite in a man who is well when it does not go to that inconvenience which makes us impatient and torments us by a too great at- tachment to the idea of what we lack. These appetitions, small or great, are what are called in the schools motus primo primi, and are truly the first steps which nature makes us take not so much towards happiness as towards joy, for they relate only to the present ; but experience and reason teach us to rule these appetitions and to control them so that they may con- duce to happiness. I have already spoken to this effect (Book I., chap. 2, § 3). The appetitions are like the natural ten- dency of the stone, which goes the most direct, but not always the best path towards the centre of the earth, not being able to see beforehand that it will meet rocks upon which it will break in pieces, whilst it would approach its end more directly if it had mind and the means of turning aside from them. Thus it is that going straight towards present pleasure we sometimes fall over the precipice of misery. Hence, reason opposes thereto images of the greatest good or evil to come, and a firm resolution and habit of thinking before acting, and then of following what shall have been recognized as the best, Nachforschung der Wahrheit erweitern sich seine Krafte, worin allein seine immer wachsende Vollkommenheit bestelit. Der Besitz niaclit rnhig, trage, stolz . . ." ; i.e. " Not the truth, in possession of which at any time a man is, or thinks he is, but the genuine effort he has made to discover the truth, con- stitutes the vvortli of the man. For not through possession, but through the search after the truth, are his powers expanded, wherein alone consists his ever growing perfection. Possession makes (him) quiet, lazy, proud ..." The real significance of this famous passage in relation to the problem of knowledge is not that knowledge is impossible, i.e. Agnosticism, for this is strictly the meaning of the term ; but rather that the attainment of truth is possible, and that the Imman mind, having in its very constitution infinite elements and a capacity for an infinite ideal, can never rest satisfied with any present attainment or form of expression as final, but must continue to strive after the perfect truth as embodied in the infinite. Of. an article by the translator, entitled " Revelation, Inspiration, and Authority," in " The Andover Review," April, 1891. — Tr. 196 LEIBNITZ'S CRITIQUE OF LOCKE [bk. h even when the sensible reasons of our conclusions are no longer present in the mind, and consist of scarcely more than feeble impressions or even of surd thoughts, which give words or signs destitute of an actual explanation, so that all consists in the: Consider it well, and in the: Be mindful; the first in order to the making of laws, the second for their following, even when you do not think of the reason which has called them into existence. It is, however, well to think of them as much as possible, in order that the soul may be filled with a rational joy and a pleasure accompanied with light.] § 37. Ph. These precautions are doubtless so much the more necessary as the idea of an absent good can counter- balance the feeling of some uneasiness or displeasure by which we are at present tormented, only so far as this good arouses any desire in us. How many men there are to whose minds the unspeakable joys of paradise are represented by lively pictures which they recognize as possible and probable, who nevertheless would willingly content themselves with the hap- piness which they enjoy in this world. It is the uneasiness of their present desire getting the better of them and bearing them rapidly towards the pleasures of this life which deter- mines their wills to seek them : and during all this time, they are wholly insensible to the goods of the other life. Th. [This arises in part from the fact that men very often are but little persuaded ; and, although they say they are, a hidden iinbelief reigns in the depths of their souls ; for they have never understood the excellent reasons which verify this immortality of souls, worthy of the justice of God, which is the foundation of true religion, or rather they no longer re- member that they understood them, one or the other of which conditions however is necessary in order to conviction. Few men indeed think that the future life, as true religion and indeed true reason teaches it, is possible, and they are still farther from thinking it probable, not to say certain. All that they do think about it is but a psittacism, or gross and vain images after the Mahometan fashion, in which they them- selves see little likelihood. For they are very far from being moved by them, as (according to report) were the soldiers of the Prince of the Assassins, the Old Man of the Moun- CH. xxi] ON HUMAN UNDERSTANDING 197 tain,^ who were carried away when fast asleep into a place full of delights, where, believing themselves in the paradise of Ma- homet, they were imbued by the angels or counterfeit saints with such opinions as this prince desired, and whence after having been stupefied anew they were carried to the place whence they had been taken; this emboldened them afterwards to undertake everything, even attempts upon the lives of princes, enemies of their chief. I do not know whether this Lord^ or Old Man of the Mountain was injured ; for not a few great princes may be named whom he had caused to be assassinated, although you may see in the English historians the letter, attributed to him, exon- erating King Richard I. of the assassination of a Count or Prince of Palestine,^ whom this Old Man of the Mountain ad- mitted he had had killed because he had been insulted by him. 1 The usual translation of " Sheikh-al Jebal," the title of the supreme ruler of the Assassins, a secret society whose distinguishing feature was the employ- ment of secret assassination against all enemies; a practice introduced by Hassan Ben Sabbah, the first chief of the sect. Otherwise the princiijles of the society were the same as those of the Ismaelites, viz. 1. No fixed rules of religion or morality, all actions indifferent, internal disposition alone of value. 2. Belief that the Immams of Ismael's line were now invisible, hence implicit obedience on part of true believers due to their vicegerents on earth. 3. Allegorical interpretation of tlie Koran, defending or rejecting any doctrine at pleasure, as occasion required. The society was made up of seven ranks or orders : 1. The Sheikh ; 2. the Daial-Kirhal, or grand-priors; 3. the Dais, or priors; 4. Rejiks, associates not initiated, as were the former, into all the secret doctrines; 5. the Feclais, "devoted ones," a baud of youths uninitiated and bliudly obedient to the chief; 6. Lasiks, or novices; 7. common people, laborers, and mechanics. On these was enjoined the most rigid observance of the Koran. The initiated regarded all positive religion and morality as worthless. The Fedais were the assassins proper. Whenever tlie chief wished for their service he had them intoxicated with hashish, or the hemp-plant, and transported into his splendid gardens, where they were surrounded with every sensual pleasure, and by this foretaste of Paradise which the chief alone could grant led to obey his slightest command implicitly, even to the surrender of their own lives. From this cir- cumstance they were called Hashishin, or hemp-eaters. This word the Euro- peans changed into Assassins, and thus it was transplanted into the Western languages with tlie signification of murderers. See Von Hammer, Gesi-hichte der Assassiiien, 1818; Michaud, Histoire des Croisades, 2, pp. 465-484; F. Walpole, The Ansayrii, or Assassins, 3 vols., 1851.; Gayard, Fraf/ments relatifs a la Doctrine des Ismaelis, 1874; De Sacy,. Memoires de V Listiiut, 4, 1818, discusses the etymology fully. — Tr. 2 Gerhardt reads : " Seigneur ou Senior (Vieux) de la Montague." — Tr. 3 The Margrave Conrad of Montferrat, one of Salad in's brave adversaries. Cf. Gib1)on, Decline and Fall, Milman's ed., chap. 5e ipsa natura, etc., 1698, § 9 ad fin.; Gerhardt, 4, 509; Erdmauu, 157; Jacques, 1, 461 (in Frencli) ; J. H. v. Kirchmann, Dte klein. philos. wlchL Schrift. v. G. W. Leibniz (Philos. Bihliothek, Bd. 81), p. 121 (in Ger- man) , Erick Koschny, Leipzig, 1879 ; also Kuno Fischer, Gesch. d. neiiern Philos., Vol. 2 (G. W. Leibniz), p. 334,. 3d ed., Heidelberg: C. Winter, 1889. —Tk. CH. xxi] ON HUMAN UNDERSTANDING 219 influence upon another. But taking action as an exercise of perception and passion as its contrary, there is action in true substance only wlien their perception (for I grant it to all) is developed and becomes more distinct, as there is passion only when it becomes more confused ; so that in substances capable of pleasure and of pain, all action is a step towards pleasure and all passion a step towards pain. As for motion, it is only a real phenomenon, because matter and mass to which motion belongs is not properly speaking a substance. But there is an image of action in motion as there is an image of substance in mass ; and in this respect we can say that the body acts (agit) when there is spontaneity in its change and that it is passive (patit) when it is urged on or hindered by another ; as in the veritable action or passion of a veritable substance we may take as its action, and attribute to itself, the change by which it tends to its perfection. And in the same manner we can take as passion and attribute to a foreign cause the change by which the contrary happens to it ; although this cause is not immediate, because, in the first case, the substance itself, and in the second the foreign things serve to explain this change in an intelligible way. I allow bodies only an image of substance and action, because that which is composed of parts cannot pass, to speak accurately, as one substance, any more than a flock ; but we can say that there is therein something substantial, of which the unity, that which makes it as it were one being, comes from thought.] Ph. I have thought that the power to receive ideas or thoughts by the operation of some foreign substance was called power of thought, although at bottom it is only a pas- sive poiver or a simple capacity making abstraction from the reflections and internal changes which always accompany the received image, for the expression,^ which is in the soul is, as it should be, that of a living mirror ; but the power which we have of recalling absent ideas at our choice, and of comparing together those that we think to the purpose, is truly an active poicer. Th. [This also agrees with the notions I have just pre- sented, for there is in this a passage to a more perfect state. 1 Gerhardt and Erdmann read: " I'expression " ; Jacques: " rimpres- sion." — Tr. 220 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii But I should suppose that there is also action in sensations so far as they give us more distinct perceptions and consequently the opportunity of making remarks and so to sjDeak of devel- oping ourselves.] § 73. Ph. Now I think it appears that we can reduce the primitive and original ideas to this small number : extension, solidity, mobility (i.e. passive power, or rather capacity of being moved), which come to us in the mind by way of reflec- tion, and finally, existence, duration, and number, which come to us by the two ways of sensation and reflection ; for by these ideas we could explain, if I am not mistaken, the nature of colors, sounds, tastes, odors, and all the other ideas we have, if our faculties were subtile enough to perceive the dif- ferent motions of the minute bodies which produce these sen- sations. Th. To speak the truth, I believe that these ideas, which you here call original and primitive, are for the most part not wholly so, being susceptible in my view of further resolution ; but I do not blame you at all, sir, for having limited yourself and for not having pushed the analysis farther. Moreover,^ I believe that if their number can be diminished by this means, it can be increased by adding other ideas more original or as much so. As to the question concerning their arrangement, I should consider, following the order of the analysis, exist- ence anterior to the others, number to extension, duration to motivity or mobility ; although this analytic order is not ordinarily that of the occasions which make us think of them. The senses furnish us the material for reflection and we should not even think of thought, if we did not think of something else, i.e. of the particular things which the senses furnish. And I am persuaded that created souls and minds are never without organs and never without sensations, as they cannot reason without characters. Those who have desired to main- tain a complete separation and mode of thinking in the sepa- rated soul, inexplicable by all that we know, and separated 1 Gerhardt reads: "D'ailleurs je crois que si le nombre en pourroit estre diminue par ce moyen, il pourroit estre augmente," etc. ; Erdmann and Jacques read: "D'ailleurs si c'est vrai, que le nombre en pourroit etre diminue par ce moyen, je crois qn'il pourroit etre augumente en y ajoutant d'autres Idees plus originales ou autant." — Tr. CH. xxii] ON HUMAN UNDERSTANDING 221 not only from our present experiences, but, what is much more, from the general order of things, have given too much influence to so-called strong minds, and have made the finest and the grandest truths objects of suspicion to many people, having indeed deprived themselves thereby of some excellent means of proving them, which this order furnishes us.] CHAPTER XXII OF MIXED MODES § 1. Ph. Pass we on to the mixed modes. I distinguish them from the more simple modes, which are composed only of simple ideas of the same kind. Moreover, the mixed modes are certain combinations of simple ideas which are not re- garded as characteristic marks of any real being, which has a fixed existence, but as scattered and independent ideas which the mind joins together; and they are thereby distinguished from the complex ideas of substances. Th. [Properly to understand these we must recall our for- mer divisions. According to you ideas are simple or complex. The complex are either substances, modes, or relations. Modes are either simple (composed of simple ideas of the same kind) or mixed. Thus, in your view, there are simple ideas, ideas of modes, both simple and mixed, ideas of substances and ideas of relations. We could, perhaps, divide the terms or the objects of ideas into abstract and concrete ; the abstract into absolute and into those which express relations ; the absolute into attributes and into modifications ; both into simple and composite ; the concrete into substances and into substantial things, made up of or the resultants of true and simple substances.] § 2. Ph. The mind is purely passive, respecting its simple ideas, which it receives as sensation and reflection present them to it. But it often acts by itself, indeed, in reference to the mixed modes, for it can combine the simple ideas in making complex ideas without considering whether they so exist united in nature. This is why we give to these kinds of ideas the name of notion. 222 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n Th. [But reflection which makes us think of simple ideas is often voluntary also, and, moreover, the combinations, which nature has not made, can produce themselves in us, as it were in dreams and reveries by means of memory alone, without the mind's acting more than in the simple ideas. As for the term notion, many apply it to all sorts of ideas or conceptions, to the original as well as to the derived.] § 4. Ph. The mark of several ideas combined in one alone is the name. Th. [That means, if they can be combined, in which respect they are often lacking.] Fh. The crime of killing an old man, not having a name like parricide, is not at first regarded as a complex idea. Th. [The reason why the murder of an old man has no name is that, the laws not having attached thereto a particular pun- ishment, this name would be useless ; but ideas do not depend on names. An ethical author who should invent one for the crime and treat in a special chapter of Gerontophony, showing what is due to old men and how it is a barbarous act not to spare them, would not on that account present us with a new idea.] § 6. Ph. It is always true that the manners and usages of a nation, making combinations familiar to it, cause each language to have particular terms, which cannot always be translated word for word. Thus ostracism among the Greeks and 2^^'oscrij)tio among the Romans were words which other languages cannot express by equivalent words. Therefore, change of customs makes also new words. Th. [Chance also plays its part, for the French do not use horses as much as other neighboring peoples ; but having abandoned their old word, which corresponded to the cavalcar of the Italians, they are forced to say by paraphrase : alter d, cheval — to go on horse-back.] § 9. Ph. We acquire ideas of mixed modes by observation, as when we see two men wrestling; we acquire them also by invention (or a voluntary \inion of simple ideas), thus, he who invented printing had the idea of it before this art existed. We acquire them finally by explaining terms, affecting actions which we have never seen. Th. [We can further acquire them while dreaming or in a CH. xxii] ON HUMAN UNDERSTANDING 223 state of revery without the combiBations being voluntary, for example, when we see in a dream a golden palace without having thought of it before.] § 10. Ph. The simple ideas which have been most modified are those of thought, motion, and power, whence actions are conceived to flow; for the great business of mankind consists in action ; all actions are thoughts' or motions. The power or aptitude to do anything which is found in man constitutes the idea which we call habit, when this power has been acquired by often doing the same thing ; and when we can force it to action upon each occasion that presents itself, we call it disj^osition. Thus, tenderness is a disposition to friend- ship or love. Th. [By tenderness you understand here, I j)resume, the tender heart, but elsewhere you seem to me to regard tender- ness as a quality which one has, as a lover, which renders him very sensible to the good and evil of the object loved. This it is to which it seems to me the chart of affection is moving in the excellent romance Clelie} And, as charitable persons love their neighbor with some degree of tenderness, they are sensi- ble to the good and evil of another, and generally those who have the tender heart have some disposition to love Avith ten- derness.] Ph. Boldness is the power to do or say before others what you wish without being put out of countenance, a self-confi- dence, which, in relation to this last part which concerns dis- course, had a particular name among the GJ-reeks. Th. [It would be Avell to seek a word for this notion, which is here attributed to that of boldness, but which is often em- ployed wholly otherwise, as when we say Charles the Bold. Kot to be put out of countenance is a strength of mind, but one which bad men abuse when they have become impudent ; as shame is a weakness, but excusable and even praiseworthy ill certain circumstances. As for par/'/iesm,^ which you per- haps understand by the Greek word, it is still attributed to writers who speak the truth without fear, although, then not 1 Clelie, Histoire Eomaine, a romance by Mile. Scude'ry, 1607-1701. The scene is laid early in Roman history ; the heroine is Cloelia, wlio escaped from Porsena by swimming the Tiber. —Tr. * TTappriffia. — Tr. 224 LEIBNITZ'S CEITIQUE OF LOCKE [bk. ii speaking in the presence of people, they are not liable to be discountenanced. ] § 11. Ph. As poicer is the source whence proceed all actions, the name of cause is given to the substances in which these powers reside, when they reduce their poioer to act; and they call effects the substances produced by this means, or rather the simple ideas (i.e. the objects of simple ideas), which, by the exercise of power are introduced into a subject. Thus the efficacy by which a new substance or idea (quality) is pro- duced, is called action in the subject exercising this power and passion in the subject in which some simple idea (quality) is altered or produced. Th. [If poiver is taken as the source of action, it means something more than an aptitude or facility, by which power was explained in the preceding chapter ; for it includes, be- sides, tendency as I have already more than once remarked. This is why in this sense I have been wont to appropriate to it. the term entelechy, which is either primitive and answers to the soul taken as an abstract thing, or derivative as it is con- ceived in conation (?e conatus) and in vigor and impetu.osity. The term cause is here understood only as efficient cause ; but it is also understood as Jinal or the motive, not to speak here of matter and form which are also called causes in the schools. I do not know whether we can say that the same being is called action in the agent and passion in the patient, and is thus found in two subjects at once like relation, and, whether it is not better to say that there are two beings, one in the agent, the other in the patient.] Ph. Many words which seem to express some action signify only the cause and the effect ; as creation and annihilation contain no idea of action or of the manner, but simply of the cause and the thing which is produced. Th. [I admit that in thinking of creation, we do not con- ceive a mode of acting, capable of any detail, which cannot indeed there be expedient; but, since we express something besides God and the world, for we think that God is the cause and the world the effect, or else that God has produced the world, -it is manifest that we think still of action.]^ 1 Leibnitz regards the concept of creation in the sense of the origination of substances as incapable of further explanation because we can form no idea CH. xxiii] ON HUMAN UNDERSTANDING 225 CHAPTER XXITI OF OUR COMPLEX IDEAS OF SUBSTANCES § 1. Ph. The mind notices that a certain number of simple ideas constantly go together, which, presumed to belong to one thing only, are called by one name when thus tmited in one subject. Whence it comes that, although this is in truth a mass of many ideas joined together, we are afterwards led by inadvertence to speak of them as a single, simple idea. Th. [I see nothing in the accepted expressions which de- serves to be taxed with inadvertence ; and although we recog- nize only one subject and one idea, we do not recognize only one simple idea.] Ph. Not being able to imagine how these simple ideas can subsist by themselves, we are accustomed to assume something which sustains them (^substratum), in which they subsist or Avhence they result, to which for this effect we give the name of substance.~\ Th.^ [I believe that there is reason in thus thinking, and we have only to accustom ourselves to it or to assume it, since, at first, we conceive several predicates in one and the same subject, and these metaphorical words, sup2Jort (soiitieyi) or sub- stratum mean only this ; so that I do not see why it should cause any difficulty. On the contrary, it is rather the concretum, as wise, warm, shining, which arises in our mind, than the abstractions or qualities (for these and not the ideas are in the substantial object), as knowledge, heat, light, etc., which are much more difficult to comprehend. We may even doubt whether these accidents are veritable existences, as in fact they are very often only relations. We know also that it is these abstractions which cause the greatest difficulties to spring up when we wish to examine them minutely, as those of the process. For some other exjjressions concerning it, cf. La Monaclo- lorjie, § 47, Gerhardt, 6, 614 ; Erdmann, 708, b. ; Letter to Bayle, Gerhardt, 3, 58; Erdmann, 191. Gerhardt, .3, 61. and note, says the original is without date; Erdmann gives it 1702. Cf. also Dillmann, Eine neue Barstc/. d. Leib- niz. Monadenlehre, j>. 451 sq. — Tr. ■ ^ Erdmann has "Ph.," a typographical error. — Tb. 226 LEIBNITZ'S CRITIQUE OF LOCKE [uk. ii know who are familiar Avith the subtilties of the scholastics, the most intricate of which falls at once if we will banish abstract existence and. resolve to speak ordinarily only by concretes and. admit no other terms in scientific demonstra- tions but those which represent substantial subjects. Thus it is nodum quaerere in scirpo,^ if I may so speak, and reversing things to take the qualities or other abstract terms as the easier and the concrete as something very difficult.] § 2. Ph. We have no other notion at all of pure substance in general, than of an indescribable subject, which is to us altogether unknown and which is supposed to be the support of qualities. We speak like children to one who has no sooner asked them what a certain thing unknown to them is, than they make this reply very satisfactory to their taste that it is something, but, which employed in this way, means that they do not know what it is. Th. [In distinguishing two things in substance, the attri- butes or predicates, and the common subject of these predi- cates, it is no wonder that we can conceive nothing particular in this subject. It must be so, indeed, since we have already separated from it all the attributes in which we could conceive any detail. Thus to demand something more in this pure subject in general than what is necessary in order to conceive that it is the same thing (for example, which understands and wills, which imagines and reasons), is to demand the impossible, and to act contrary to our own supposition, which has been made in making abstraction and conceiving separately the subject and its qualities or accidents. We could apply the same pretended difficulty to the notion of being and to all that is clearer and more primitive ; for we could demand of the philosophers what they conceive when conceiving pure being in general; for all detail being excluded by that means there will also be little to say, when we are asked what is pure sub- stance in general. Thus I believe that the philosophers do not deserve to be laughed at, as is here done, in comparing them with an Indian philosopher, who, being asked upon what the earth rested, replied, upon a great elephant ; and then when asked what sustained the elephant, replied, a great tor- 1 To seek a knot in a bnlrush, to tind a difificulty when there is none. Cf. Plant. Men. 2, 1, 22 ; Ter. AinL .", 4, .38. — Tr. cii. xxiiij ON HUMAN UNDERSTANDING ^1 toise; and, at last, when pressed to say upon what the tortoise rested, was compelled to say something, I knoiv not tvhat. But this consideration of substance,^ entirely slender as it appears, is not so empty and sterile as you think. It gives rise to many consequences of greatest importance in philosophy, and which are capable of giving it a new aspect.] § 4. Ph. We have no clear idea of substance in general, and § 5, we have as clear an idea of mind as of body ; for the idea of corporeal substance in matter is as far from our con- ceptions as that of spiritual substance. It is almost as the promoter said to this young doctor of law, who cried to him in the solemnity, to say utriusque : You are right, sir, for you know as much in the one case as the other. Th. [As for myself, I believe that this opinion of our igno- rance arises from that which demands a kind of knowledge of which the object does not admit. The true mark of a clear and distinct notion of an object is the means we have of knowing therein many truths by a priori^ proofs, as I have shown in a discourse on truths and ideas,'^ published in the " Actes de Leipzig " of the year 1684. § 12. Ph. If our senses were sufficiently penetrating, the sensible qualities, for example, the yellow color of gold, would disappear, and instead of that we should see a certain admir- able contexture of parts. This appears evident by means of microscopes. This present knowledge is suitable to the state in which we find ourselves. A perfect knowledge of things 1 In Leibnitz's philosopliy substance is a unitary, individual, spoutane- ously active being, as opposed to the " empty and sterile " conception of Aris- totelian scholasticism ; cf. ante, p. 154 and note. Locke's criticism concerns the scholastic conception only. — Tr. •^ Cf. Neiv Essays. Bk. IV., chap. 17, § 1, Th.; Theodicee, I., § 44, Gerhardt, 6, 127; Erdmann, 515, b. For a brief critical history of the concepts of the a priori and the o posteriori, cf. Rudolph Eucken, The Fundamental Concepts of Modern Philosophic Thought, pp. 81-91, D. Appleton and Co., New York, 1880 ; and for Leibnitz's use of the terms, op. cit., p. 82, with the note contain- ing references to the places where a priori occurs in Erdmann 's and Foucher de Careil's editions of his works. — Tr. 3 Meditationes de Cognitione, Veritate et Ideis, in the " Acta Eruditorum," Nov., 1684. Gerhardt, 4, 422 sq. ; Erdmann, 79 sq. The passage referred to is found in Gerhardt, 425 ; Erdmann, 80 b.; translation, Duncan, Philos. Works of Leibnitz, 30. The piece has been translated into German, witli notes, by J. H. V. Kirchmann in his Philos. Bihliothek, Bd. 81, Die klein. philos. icicht. Schrifteii v. G. W. Leibniz ; Bd. 82, Erliivterunfien. — Tr. 228 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii which surround us, is, perhaps, beyond the capacity of every finite being. Our faculties suffice to make us know the Crea- tor, and to instruct us as to our duties. Should our senses become more acute, such change would be incompatible wjith our nature. Th. [All that is true; and I have said something to the same effect above. But the color yellow does not cease to be a reality like the rainbow, and we are apparently destined to a state far beyond the present, and can even go on to the infinite, for there are no elements in the corporeal nature. If there were atoms, as the author appeared to believe in another place, perfect knowledge of the body could not be beyond every finite being. For the rest, if some colors or qualities should disappear from our eyes better armed or become more penetrating, others would apparently spring into being, and it would require a new growth of our perspicacity to make these also disappear, and this could go on to infinity, as the actual division of matter effectively proceeds.] § 13. Ph. I do not know but that one of the great advan- tages which some spirits have over us consists in the fact that they can assume to themselves organs of sensation which are precisely suited to their present design. Th. [We do this indeed in making for ourselves micro- scopes ; but other creatures can go much farther. And, if we could transform our eyes themselves, which we do effectively to some extent according as we wish to see near at hand or at a distance, we should be obliged to have something^ belonging more exclusively to us than they in order to shape them by its means, for it is necessary, at least, that all be done mechan- ically, because the mind cannot operate immediately upon the body. For the rest, I am also of the opinion that genii per- ceive things in a manner which is somewhat related to ours, even if they should have the agreeable advantage which the imaginative Cy^'ano" attributes to some animated natures in 1 I.e. the soul to make use of the capacity of the eyes for accommodation. — Tr. 2 Cyrano de Bergerac, c. 1620 — 1655, in his philosophical romance, Ilistoire comiqiie des etats et empires du soleil. He was author also of the Histoire comique des etats et empires de la lune, or, as the title is sometimes given, Voyage dans la lune. — Tr. CH. xxiii] ON HUMAN UNDERSTANDING 229 the sun, composed of an infinite number of little winged crea- tures, which, by transporting themselves according to the command of the ruling soul, form all kinds of bodies. There is nothing so marvellous that the mechanism of nature cannot produce it ; and I believe that the learned fathers of the Church were right in attributing bodies to the angels.^] § 15. Ph. The ideas of thinking and of moving a body, which we find in that of the mind, can be conceived as clearly and distinctly as those of extension, solidity, and mobility, which we find in matter. Th. [As regards the idea of thought I agree. But I am not of this opinion as regards the idea of moving bodies, for, according to my system of Pre-established Harmony, bodies are so made that being once put in motion, they continue therein, according as the actions of the mind require. This hypothesis is intelligible ; the other is not.] Ph. Each act of sensation gives us an equal view of things corporeal and spiritual ; for while sight and hearing give me the knowledge that there is some corporeal being without me, I know in a way still more certain that there is within me a spiritual being which sees and hears. Th. [It is very well said and very true that the existence of the spirit is more certain than that of sensible objects.-] § 19. Ph. Spirits as well as bodies can operate only where they are and in different times and places ; thus I can only attribute change of place to all finite spirits. Th. [I believe that is reasonable, place being only an order of coexistences.] Ph. It is only necessary to reflect upon the separation of the soul and the body by death to be convinced of the move- ment of the soul. Th. [The soul might cease to operate in this visible body ; and if it could cease thinking all at once, as the author has maintained above, it might be separated from the body witli- out being united to another; thus its separation would be without movement. But for myself, I believe that it thinks 1 Cf. Letters to Des Bosses, Sept. 20, Oct. 4, 1706, Gerhardt, 2, 316, .319; Erdmann, 439. Also Descartes' letters, passim. — Tr. 2 Cf. Descartes, Meditations, especially II. and VI. Veitcli's translation, 8th ed., pp. 104 sq., 151 sq. — Tr. 230 LEIBNITZ'S CKITIQUE OF LOCKE [bk. ii and feels always, that it is always united to some body, and, indeed, that it never leaves entirely and all at once the body to which it is united.] § 21. Ph. If anyone says that spirits are not in loco sed in aliqno uhi I do not suppose that now we would rely much upon this method of speaking. But if anyone thinks that it can receive a reasonable sense, I pray him to express it in language generally intelligible, and to draw therefrom after- wards a reason showing that spirits are not capable of motion. Th. [The schools have three kinds of Ubeity, or modes of existing somewhere. The first is called circumscriptive, Avhich they attribute to bodies in space which are there punctatim, in such wise that they are measures according to which we can assign the points of the thing placed corresponding to the points of space. The second is the definitive, when we can define, i.e. determine, that the situated thing is in such a space, without being able to assign the precise points or the peculiar places exclusive of what is there. Thus it has been con- sidered that the soul is in the body, not supposing it possible to assign a precise point at which the soul or some portion of the soul is, without its being also at some other point. More- over, many learned men have thus viewed the matter. It is true that Descartes desired to place narrower limits to the soul by locating it properly in the pineal gland.^ Neverthe- less he did not dare to say that it is exclusively at a certain point in this gland ; and this not being so he gains nothing, and it is in this respect precisely as if he gave it the entire body as its prison or place. I believe that nearly the same statement as that made regarding souls, must be made in respect to the angels, whoixi the great doctor, a native of Aqviino, believed to be in a place only by operation ^ which in my view is not immediate and reduces itself to pre-established harmony. The third ubeity is the repletive, which is attrib- uted to God, who fills all the universe in a still more eminent degree than the disembodied spirits, for he works immediately 1 Cf.. Descartes, Dioptrica, IV., 1 sq.; Passiones Animae, I., 31 sq.; also Prin. Philos., IV., 189, 196, 197, although here the point of contact in the brain of the soul and body is not designated by name. — Tr. 2 Cf. Thomas Aquinas, 1225 or 1227-1274, Summa Theologica, Pt. I. Quest. 52, Article, 2; also Quest. 53. — Tr. cii. xxiii] ON HUMAN UNDERSTANDING 231 upon all creatures by continually producing them, while finite spirits cannot exercise any immediate influence or operation. I do not know whether this doctrine of the schools deserves to be ridiculed, as it seems some try to do. But we can always attribute a kind of movement to souls at least in rela- tion to the bodies with which they are united, or in relation to their mode of perception.] § 23. Ph. If any one says he knows not how he thinks, I reply that he knows no more how the solid particles of the body are united to make an extended whole. Th. [It is difficult enough to exj)lain cohesion; but this cohesion of parts does not appear necessary to make an extended whole, since we can say that matter perfectly subtile and fluid constitutes an extension, without the particles being united the one to the other. But, to speak the truth, I believe that perfect fluidity belongs only to the lyrimary matter,^ i.e. matter in the abstract, and, as an original quality, just as repose ; but not to secondary matter, such as is actually found, invested with its derivative qualities ; for, I believe that there is no mass, which is of the utmost subtil- ity; and that there is more or less connection everywhere, which arises from movements so far as they are conspirant aud would be disturbed by separation, which cannot take place without some violence and resistance. For the rest, the nature of perception and thus of thought furnishes a notion of the most original conditions. I believe, further, that the doctrine of substantial unities or monads will throw much light ujion it.] Fh. As for cohesion, many explain it by means of the sur- faces by which two bodies touch, which an ambient fluid - (for example, the air) presses one against another. It is very true that the pressure § 24 of an ambient fluid can hinder the avulsion of two polished surfaces from one another in a line perpendicular to them ; but it cannot hinder them from separat- ing by a movement parallel to these surfaces. This is why, if there were no other cause of the cohesion of bodies, it woiild be easy to separate all their parts, by making them thus 1 Cf. ante, p. 131 and note. — Tr. 2 Locke's term, Philos. Works, Vol. 1, p. 438, § 24 (Bohn's ed.). — Tr. 232 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii slide laterally, taking therefor any plane you wish which intersects any mass of matter. Th. [Yes, no doubt if all the smooth particles applied to each other were in one and the same plane or in parallel planes ; but that not being so nor capable of so being, it is manifest that in trying to make the one slide, you will act altogether differently upon an infinite number of others, whose plane will make an angle with the first ; for you must know that it is difficult to separate two congruent surfaces, not only when the direction of the movement of separation is perpen- dicular, but further when it is oblique to the surfaces. Thus it may be conceived that there are leaves applied to one another in every direction in the polyhedral bodies that nature forms in ores and elsewhere. Eut I admit that the pressure of the ambient fluid upon smooth surfaces applied to each other does not suffice to explain the basis of all cohesion, for it is tacitly assumed that the tables applied the one against the other already have cohesion.] § 27. Pli. I have always supposed that the extension of a body was something else than the cohesion of solid particles. Til. [That does not appear to me to agree with your own preceding explanations. It seems to me that a body in which there are internal movements or whose particles are in the act of detaching themselves one from another (as I .believe hap- pens always) cannot be extended. Thus the notion of exten- sion appears to me wholly different from that of cohesion.] § 28. Pli. Another idea we have of body is the poiver of communicating motion by impulse; and another we have of the soul is the pmcer of producing motion by thought. ExjDerience clearly furnishes us each day these two ideas ; but if we wish to investigate further how this is done, we find ourselves equally in the dark. For, as regards the communication of motion, wherein one body loses as much motion as another receives, which is the most ordinary case, we conceive there nothing else than a motion which passes from one body into another ; which is, I think, as obscure and as inconceivable as the manner in which our mind moves or stops our bodies by thought. It is still more difficult to explain the increase of motion by means of impulse, which is observed or believed to happen in certain cases. CH. xxiii] ON HUMAX UNDERSTANDING 233 Til. [I am not astonislied. that you find insurmountable dif- ficulties where you seem to assume a thing so inconceivable as the passage of an accident .from one subject to another ; but I see nothing which compels us to an assumption which is no less strange than that of the scholastics of accidents with- out a subject, which they have taken care however to attribute only to the miraculous action of the divine omnipotence, Avhile here this passage w^ould be merely an ordinary one. I have already said something about it above (chap. 21, § 4-^), where I also remarked that it is not true that a body loses as much motion as it gives to another ; which they seem to conceive as if motion were a substantial thing and resembled salt dissolved in water, which comparison is actually the one M. E,ohaut,^ if I mistake not, has used. I add here that this is not even the most usual case, for I have elsewhere demonstrated that the same quantity of motion is maintained only wdien the two bodies which come into collision proceed in one and the same direction before the collision and still proceed in one and the same direction after the collision. It is true that the veritable law^s of motion are derived from a cause superior to matter. As for the power of producing motion hy thought, I do not think we have any idea of it, as we have no experience of it. The Cartesians themselves admit that souls cannot give a new force to matter, but they pretend that they give it a new determination or direction of the force it has already. For myself, I maintain that souls change nothing in the force nor in the direction of bodies ; that the one would be as incon- ceivable and unreasonable as the other, and that you must avail yourself of the pre-established harmony in order to explain the union of the soid and the body.] Ph. It is w^orth our consideration whether active power is not the proper attribute of spirits and passive power of bodies ? Whence we might conjecture that created spirits, 1 Cf. ante, p. 176. — Tr. 2 James Rohaut or Eohault, 1620-1675, a French phj'sicist, a follower of Descartes. His chief work, the Physics, was written in French, and trans- lated into Latin, with valuahle notes, by Dr. Samuel Clarke, 1675-1729, and into English hy his hrotlier Dr. John Clarke. It was a text-book in the Uni- versity of Cambridge, until supplanted by the treatises of Sir Isaac Newton. The original work first appeared in 1671, and enlarged, in two vols., in 1682. Clarke's Latin version, 8vo., in 1697; the 4th and best edition, Jacobi Rohaulti Physica, Svo., 1718. — Tb. 234 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n being active and passive, are not totally separate from simply passive matter ; and that these other beings, which are active and passive at the same time, partake of both. Th. [These thoughts greatly please me and entirely express my conviction, provided you explain the word spirit so gener- ally that it comprises all souls, or rather (to speak still more generally) all the entelechies or substantial unities, which are analogous to spirits.] § 31. Ph. I much wish that you would show me in the notion we have of spirit anything more confused^ or nearer a contradiction than what the very notion of body includes. I mean infinite divisibility. Th. [What you here say further in order to make evident that we understand the nature of the spirit as well or better than that of the body is very true ; and Froniondus,^ who has published a book, De compositione continui, was right in enti- tling it Labyrinth. But the question arises from a false idea you have of the nature of body as well as of space.] § 33. Ph. The idea of God indeed comes to us as others do, the complex idea of God we have being composed of the simple ideas which we receive from reflection and which we extend by the idea we have of the infinite. Th. [Upon that question I refer to what I have already said in several places in order to make evident that all these ideas, and particularly that of God, are in us originally, and that we only make ourselves take notice of them, and that above all, the idea of the infinite is not formed by an extension of finite ideas.^] § 37. Ph. The majority of the simple ideas which compose our -complex ideas of substances are, properly considered, only 2Jowers, whatever our inclination to take them as positive quali- ties. 1 Locke's word is "perplexed," Pliilos. Works, Vol. 1, p 443 (Bohn's ed.). — Tr. 2 Libert Froidmont or Fromont — Latin, Fromondus — 1587-1653, a Flemish theologian, Professor of Philosophy and Theology in the University of Lou- vain. His tlieological, philological, and scientific knowledge was very exten- sive. Descartes esteemed highly both his knowledge and his person. Cf. Descartes' letters. His book, Lahyrinthus sive de compositione continui, ap- peared at Antwerp in 1631. — Tr. 3 Cf.ante, pp. 16, 17; Xew Essays, Book II.. chap. 14, § 27, Th., and note 1, ante, p. 158; chap. 17, § 1, Th., ante, p. 162. — Tr. CH. XXV] ON HUMAN UNDERSTANDING 235 Th. [I think that the poivei^s, which are not essential to substance and which inchide not only an cqMtade, but also a certain teiiclency, are properly what is or ought to be under- stood by real qualities.^ CHAPTER XXIV OF COLLECTIVE IDEAS OF SUBSTANCES § 1. Ph. After simple substances we come to the aggregates. Is it not true that the idea of this mass of men composing an army, is as much a single idea" as that of one man? Th. [You are right in saying that this aggregate (ens per aggregationem, to use the language of the school), makes one single idea, although, properly speaking, this mass of sub- stances does not form in truth one substance. This is a result to which the soul by its perception and its thought gives its last achievement of unity. You may, however, say in a sense that it is something substantial, i.e. comprising substances.] CHAPTER XXV OF RELATION" § 1. Ph. It remains to consider the ideas of relations which are the poorest in reality. When the mind regards one thing in comparison with another, this is a relation or respect,^ and the denominations or relative terms, which are produced, are, like so many marks which serve to lead our thoughts beyond the subject to something distinct from it, and these two are called subjects of the relation {relata). Th. [Relations and orders have something of the essence of reason, although they have their foundation in things ; for we can say that their reality, like that of eternal truths and possi- bilities, comes from the supreme reason.] § 5. Ph. There may, however, be a change of relation with- out any change happening in the subject. Titius, whom to- 1 Locke's word, Philos. Works, Vol. 1, p. 449 (Bohn's ed.). — Tr. 236 LEIBNITZ'S CEITIQUE OF LOCKE [bk. u day I consider as a father, ceases to be such to-morrow withoiit any change being made in himself, by the sole fact of his son's death. Th. [That statement may very well be made dn view of things which are perceived ; although in metaphysical strict- ness it is true that there is no entirely exterior denominatiou {denominatio pure extrinseca) because of the real connection oi all things.] § 6. Ph. [I think that relation is only between two things.] Th. [There are, however, examples of relation between sev- eral things afonce, as that of order or that of a genealogical tree, which expresses the rank and connection of all the terms or members, and even a figure like that of a polygon includes the relation of all the sides.] § 8. Ph. It is well to consider also that the ideas of rela- tions are often clearer than those of the things which are the subjects of the relation. Thus the relation of father is clearer than that of man. Th. [That is because this relation is so general tha.t it may also suit other substances. Moreover, as a subject may have clearness and obscurity, the relation might be grotinded in the clear. But if the form itself of the relation involved the knowledge of that which is obscure in the subject, it would participate in this obscurity.] § 10. Ph. The terms which necessarily lead the mind to other ideas than those which are supposed really to exist in the thing to which the term or word is applied are relative ; the others are absolute. Th. [You have well added tliis " necessarily " and you might add " expressly " or " at first,^' for you can tliink of black, for example, without thinking of its cause ; but it is by remaining within the limits of a knowledge which presents itself at first and Avhicli is confused or very distinct, but incomplete ; the one when there is no resokition of the idea, the other when you limit it. Otlierwise there is no term so absolute or so loose as not to include relations and the perfect analysis of which does not lead to other things and even to all others ; so that you can say that relative terms indicate expressly the rela- tion they contain. I here oppose the absolute to the relative, and it is in another sense that I have opposed it above to the limited.'] CH. xxvi] ON HUMAN "UNDERSTANDING 237 CHAPTER XXVI OF CAUSE AND EFFECT AND SOME OTHER RELATIONS §§ 1, 2. Ph. Cause is that which produces a simple or in- complex idea ; effect is that which is produced. Th. [I see, sir, that you often understand by idea the objec- tive reality of the idea or the quality which it represents. You define only efficient cause, as I have already remarked above. You must admit that, in saying that efficient cause is that which produces and effect that which is produced, you make use only of synonyms. It is true that I have heard you say a little more distinctly, that cause is that which makes another thing commence to exist, though this word "makes'' passes over also the princij)al difficulty entirely. But that will be explained better elsewhere.] Ph. In order further to touch some other relations, I remark that there are terms employed to designate time Avhich are ordinarily regarded as signifying only positive ideas, which are nevertheless relative, as young, old, etc., for they involve a relation to the ordinary duration of the substance to which you attribute them. Thus a man is called young at the age of twenty years, and very young at the age of seven years. But we call a horse old at twenty years, and a dog at seven. But we do not say that the sun and the stars, a ruby or a diamond, is young or old, because we do not know the ordinary periods of their duration. § 5. The same is true regarding place or extension, as when a thing is said to be high or loio, great or small. Thus a horse which will be large according to the idea of a Welshman, appears very small to a Fleming; each thinks of the horses which are raised in his country. Th. [These remarks are very good. It is true we some- times swerve a little from this sense, as when we say that a thing is old when comparing it not with those of its kind, but with other kinds. For exainple, we say that the world or the sun is very old. Some one asked Galileo if he believed that the sun was eternal. He replied : eterno nd ma ben antico — eternal, no, but very ancient. '238 LEIBNITZ'S CRITIQUE OF LUCivE [bk. u CHAPTEE XXVII WHAT IDEXTITY OK DIVERSITY IS § 1. Ph. A relative idea of the greatest importance is that of identity or diversity. We never find and we cannot conceive it possible that two things of the same kind exist in the same time in the same place. Therefore when we ask ivhetJier a thing is the same or not, the question always relates to a thing Avhich at such a time exists in such a place ; whence it follows that a thing cannot have two beginnings of existence, nor two things one beginning only in relation to the time and the place. Th. [It is always necessary that besides the difference of time and place there be an internal principle of distinction, and, though there are many things of the same kind, it is never- theless true that none of them are ever perfectly alike : thus although time and place (i.e. external relation) serve us in distinguishing things which we do not easily distinguish by themselves, the things do not cease to be distinguishable in themselves. The essence (le precis) of identity and diversity consists, then, not in time and place, although it is true that the diversity of things is accompanied by that of time or of place, because they bring with them different impressions of the thing ; not to say that it is rather by the things that one place or one time must be distinguished from another, for in themselves they are perfectly alike, but they are not, there- fore, substances or complete realities. The mode of distin- guishing which you seem to propose here, as unique in things of the same kind, is based upon the supposition that penetra- tion is not conformable to nature. This supposition is reason- able, but experience indeed makes it evident that it is not closely applied here, when the question concerns distinction. We see, for example, two shadows or rays of light which in- terpenetrate, and we might invent for ourselves an imaginary world wherein bodies would act in the same way. But we do not cease to distinguish one ray from another by the very rate of their passage even when they cross each other.] CH. xxvii] ON HUMAN UNDERSTANDING 239 § 3. Ph. What is called the principle of individuation {prin- cipium individuationis) in the schools, where they torment themselves so much to know what it is, consists in existence itself which determines each being to a particular time and place incommunicable to two beings of the same kind. Th. The 2>^inciple of individuation ^ reappears in individuals in the principle of distinction of which I just spoke. If two individuals were perfectly alike and equal and (in a word) indistinguishable in themselves, there would be no principle of individuation; and I even venture to assert that there would be no individual distinction or different individuals under this condition. This is why the notion of atoms is chimerical, and arises only from the incomplete conceptions of men. For if there were atoms, i.e. bodies perfectly hard and perfectly unalterable or incapable of internal change and capable of differing among themselves only in size and shape, it is plain that in the possibility of their being of the same shape and size they would then be indistinguishable in them- selves, and could be distinguished only by means of external denominations without an internal basis, which is contrary to the highest principles of reason. But the truth is that every body is alterable, and indeed actually changes so that it differs in itself from every other. I remember that a distinguished princess,^ who is of a pre-eminently excellent mind, said one 1 Leibnitz discussed this principle in his disputation for the degree of Bachelor of Philosophy, entitled, Disputatio metaphysica de principio indi- vidui, which in his sixteenth year he publicly defended at Leipzig, March 30, 1()63; cf. Guhrauer, Leibniz. Leben, 1, 27 sq. This piece is found in Gerhardt, 4, 15-2H, where the title-page gives the date of the public defence, May 30, 1663; Erdniann, 1-5; it has also been edited, with an extended critical intro- duction, from a copy found in the Library at Hannover by Dr. G. E. Guhrauer, and published at Berlin in 1837. J. H. von Kirchmann has published a German translation with elaborate and extensive notes in his Pliilos. Bibliothek, Bd. 81, Die kleia. pJiilos. ivicht, Schriften G. W. Leibniz ; Bd. 82, ErUlutervngen. For a recent discussion of the principle of individuality, cf. R. Eucken, The Fundamental Concepts of Mod. Philos. Thought, pp. 231-248. New York, 1880. — Tr. 2 Sophie Charlotte, 1668-1705, the first Queen of Prussia, the friend and in a certain sense the pupil of Leibnitz in philosophy. The Theodicee originated in his philosophical conversations with her. Cf. Gerhardt, 6, 39; Erdmann, 474 b. Leibnitz's correspondence with her is found in O. Klopp, Die Werke von Leibniz, Vol. 10, Hannover, 1877 ; the letters of philosophical importance, in Gerhardt, 3. 343 sq. : 6, 488 sq. ; 7, 544 ; the letter in G. 6, 499 sq. is translated in Duncan, Philos. Works of Leibnitz, 149 sq: Cf. also Kuno Fischer, Gesch. d. n. Philos., Vol. 2, p. 261 sq., 3d ed., 1889. — Tk. 240 LKIBNITZ'S CRITIQUE OF LOCKE [bk. it day while walking in her garden that she did not believe there were two leaves perfectly alike. A gentleman of dis- tinction, who was walking with her, thought he would easily find some. But although he searched long, he was convinced by his eyes that he could always note the difference. We see by these considerations, hitherto neglected, how far we have wandered in philosophy from the most natural notions, and how far we have departed from the great principles of true metaphysic] § 4. Ph. That which constitutes the unity (identity) of one and the same plant is the possession of such an organization of parts in a single body, as participates in a common life which endures while the plant subsists, although the parts change. Th. [The organization or configuration without an existing principle of life, which I call a monad, would not suffice to cause the continuance of idem numero or the same individual ; for the configuration can abide specifically without abiding^ individually. AVhen a horseshoe is changed into copper in a mineral spring of Hungary, the same figure in kind remains, but not the same as an individual ; for the iron is dissolved, and the copper, with which the water is impregnated, is pre- cipitated and insensibly takes its place. Now figure is an accident which does not pass from one subject to another (de subjecto in suhjectum). So we must say that bodies as well organized as others do not remain the same in appearance, and, speaking strictly, not at all. It is almost like a river which always changes its water, or like the ship of Theseus Avhich the Athenians were always repairing.^ But as regards 1 Erdmann and Jacques omit " specifiquement, sans demeurer," the reading of Gerhard t. — TR. 2 Cf. Plato, PhsBclo. 58 A ; Xeno^jhon, Memorahilia, 4, 8, 2. The sacred ship, sent yearly to Dales by the Athenians in consequence of a vow made to Apollo by Theseus when on his way to Crete with the seven youths and seven maidens, the annual tribute of the Athenians to the Minotaur, that if rescued he would send annually to Delos a ship with gifts and sacrifices as a thank- offering for their deliverance, was repaired piece by piece as necessary, so that in form and appearance it remained the same old ship in which Theseus himself sailed, while its substance continually changed. The vessel served the philosophers as an instance in discussions concerning identity and what constitutes it, and as an illustration of a numerical substance continuously the same, though constantly changing by the decay and rejection of old and the growth and acquisition of new parts, as in the case of the living body. — Tb. CH. xxvii] ON HUMAN UNDERSTANDING 241 substances, which are in themselves a true and real substantial unity, to which may belong actions properly called vital, and as regards substantial beings, qucB uno spiritu, continentur, in the words of an ancient jurisconsult/ i.e. which a certain indivisible spirit animates, you are right in saying that they remain perfectly the same individual through this soul or this spirit which constitutes the ego in thinking beings.] § 5. Ph. The case is not very different in animals and in plants. Th. [If vegetables and animals have no soul, their identity is only apparent ; but if they have, individual identity is in truth strictly speaking there, although their, organized bodies do not preserve it.] § 6. Ph. This also shows wherein tlie identity of the same man consists, viz. in the fact alone that he enjoys the same life, continued by particles of matter which are in a perpetual flux, but which in this succession are vitally united with the same organized body. Th. [That may be understood in my sense. In fact, the organized body is not the same from one moment to another ; it is only equivalent. And if it were not related to the soul, there would no longer be the same life or vital union. Thus this identity would be only apparent.] Pit. Whoever shall connect the identity of man with any- thing else than a well-organized body, in a certain instant, and which thence continues in this vital organization by a succes- sion of different particles of matter which are united to it, will have difficulty in making an embryo, a man of years, a fool, and a wise man the same man, unless it follows from this supposition that it is possible for Seth, Ismael, Socrates, Pilate, St. Augustine ^ to be one and the same man, . . . and this would agree still worse with the notions of those philosophers who recognize transmigration and believe that men's souls can be sent for punishment of their irregularities into the bodies of animals ; for I do not believe that any one who was assured that the soul of Heliogabalus existed in a hog would mean that this hog was a man, and the same man as Heliogabalus. 1 Sextus Pomponius, died 1.38 a.d. The phrase occurs in the Digest, 41, .3, 30, Vol. 2, p. 522, ed. Th. Mommsen, Berlin: Weidraann, 1S70. — Tr. - Locke has " St. Austin," Philos. Works, Vol. 1, p. 403 (Bohn's ed.). — Tr. R 242 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii Til. [There is here a question of name arid of thing. As for the thing, the identity of one and the same individual sub- stance can be maintained only by the conservation of the same soul, for the body is in a continual flax, and the soul does not dwell in certain atoms appropriated to itself, nor in a little incorruptible (indomptahle) bone, such as the Luz^ of the Rabbis. Moreover there is no transmigration by which the soul wholly leaves its body and passes into another. It keeps always, even in death, an organized body, a part of the pre- ceding, although what it keeps is always subject to insensible dissipation and to reparation, and indeed to undergoing in a certain time a great change. Thus instead of a transmigra- tion of the soul there is a transformation, envelopment, or development, and finally a fluxion of the body of this soul. Van Helmont,^ the son, thought that souls pass from body to body, but always within their kind, so that there will always be the same number of souls of one and the same kind, and consequently the same number of men and of wolves, and that the wolves if diminished or extirpated in England would be proportionally increased elsewhere. Certain meditations pub- 1 The bone which the Jews regarded as incapable of decay, remaining until the last day and forming the nucleus of the resurrection body. Schaarschmidt says: " According to the opinion of the Rabbis, says Ulrich in his note to this place, the body which we are to receive at the resurrection is already at hand in our backbone. This body or bone, TO {Luz), as it is properly called, they held for this reason to be incorruptible. In the Jalkut chaclasch, Fol. 142, title Maschiach, n. 44, the following account is given of it: This bone decays not, and the holy giving God will make it soft with the dew, and out of it will build the body. The reason why this little bone is not to be exposed to cor- ruption, they place in the fact that it has not enjoyed the pleasures of this world, as the rest of the members. This doctrine is with them no empty speculation. The old Rabbis of blessed memory have not only seen this bone, but have found it actually so strong and hard that their hammer and rock flew in pieces before this little bone "was injured in the least. See Askoth Rochel in the 4th part," etc. — Tr. 2 Franqois Mercure van Helmont, 1618-1698, a j)articular friend of the Countess of Counaway, in whose Opuscula philosophica, Bk. I., chap. 6, §§ 7, 8, and chap. 7, § 4, London, 1690, this view of his is found in detail. On Leibnitz's relations with Van Helmont, cf. Stein, Leibniz and Spinoza, pp. 210 sq., and the references in Stein's notes; also Beilagen, XV., XVI., op. cit. pp. 329-337. Leibnitz composed for him, at the request of his cousin, the Baroness of Merode, a Latin epitaph; cf. Burckhard, Historia Biblioth. Av- gustss, II., p. 326; also Stein, op. cit. pp. 336-337. Leibnitz treats of him and his doctrine in his Miscellanies, cf. Otium Hanovcranum, ed. J. F. Feller, pp. 226-230, Lipsise, 1718. — Tr. CH. xxvii] ON HUMAN UNDERSTANDING 243 lislied in France would also seem to tend in that direction. If transmigration is not taken strictly, i.e. if any one thought that souls dwelling in the same subtile body change only from a coarser body, it would be possible, even to the passage of the same soul into a body of a different kind after the fashion of the Brahmins and Pythagoreans. But all that is possible is not for that reason conformed to the order of things. But the question whether, in case such a transmigration were true, Cain, Ham, and Ismael, supposing, according to the Babbis, they were the same soul, would deserve to be called the same man, is only one of name ; and I have observed that the cele- brated author, whose ojDinions you have maintained, recognizes and explains it very' well (ui the last i^ctragraph of this chapter). The identity of substance would occur therein, but in case there were no connection of memory between the different persons, as the same soul would make, there would not be sufficient moral identity to say that it would be one and the same person. And if God willed that the human soul should go into the body of a hog, forgetting the man and performing no rational acts, it would not constitute a man. But if in the body of the animal it had the thoughts of a man, and even of the man whom it animated before the change, like the Golden Ass of Apuleius, one would perhaps have no difficulty in say- ing that the same Lucius, who had come into Thessaly to see his friends, lived under the ass's hide, where Photis had put him in spite of herself, and wandered from master to master until the roses he ate restored him to his natural form.^ 1 Cf. Apuleius, Metamorph., Bk. III., Vol. 1, pp. 229 sq. ; Bk. XL, pp. 770 .sq., edition in 6 vols., paging continuous, A. J. Valpy, London, 1825. The Meta- morphoses is in contents very similar to a work entitled, Aoukio? ij oi-o? (Lucius or Ass), ascribed -to Lucian, a contemporary of Apuleius who flourished about 160 A.D., and is most probably an imitation of it. The incidents and adven- tures in both are nearly identical, the names only being changed, both writers, however, calling the hero Lucius. In the course of his adventures Lucius became involved in a love-affair with a waiting-woman by the name of Fotis, whose mistress practised the art of magic, and changed at will herself and others into various animals by the use of certain ointments. Lucius, very desirous to learn all about this wonderful art, finally jjersuaded Fotis, who claimed that she understood her mistress's art, to try it on him. She did so, intending to change him into an owl, into which form her mistress in the sight of them both had just changed herself, but in her haste and confusion using the wrong ointment, she changed him, "in spite of herself," into an ass. The work of Apuleius is much more extended than that of Lucian, and, in 244 LEIBNITZ'S CRITIQUE OF LOCKE [bk. u § 9. Ph. I think we can boldly advance the idea that who- ever of us saw a creature made and formed like himself, although it had never exhibited more reason than a cat or a parrot, v^ould not cease to call it a man ; or if he heard a parrot discoursing rationally and in a philosophical manner would call or think it only a parrot, and would say of the former of these animals that it is an uncultivated man, duH and destitute of reason, and of the latter that it is a parrot full of intelligence and good sense. Th. [I should be more of the same opinion upon the second point than upon the first, although there is still something to be said thereupon. Few theologians would be venturesome enough to agree at once and absolutely to the baptism of an animal in human form, but without appearance of reason, if he were taken while young in the woods and some priest of the Roman church should perhaps say conditionallyj if you are a man I baptize you; for they would not know whether he is of the human race and whether a rational soul dwells therein, and this might be an ourang-outang, an ape externally very like a man, such as that one whom Tulpius ^ speaks of as having seen, and that one an account of whose anatomy a learned physician has published. It is certain (I admit) that man can become as stupid as an ourang-outang, but the interior of a rational soul would abide there in spite of the suspension of the exercise of reason as I have explained above ; thus it is a point of which we cannot judge by appearances. As for the second case, nothing prevents there being rational animals of a different kind from ourselves, as those inhabitants of the poetic kingdom of the birds in the sun, where a parrot having come from this world after its death, saved the life of a trav- eller who had treated him well here below. But if it hap- pened, as it happens in the country of the fairies or of Mother spite of its irony, abounds in a mysticism not found in the Av'kio; t; oi'o?. A brief sketcli of Lucian's work may be found in tlie Encyclopaedia Britannica, 9th ed., under tlie article "Lucius." On Apuleius, and the relation of his work to that of Lucian, cf. Teuffel, Gesch. d. Rom. Lit., § 367, 3, 4th ed., Leipzig: B. G. Teubner, 1882; § 367, 1, 5th ed. by Ludwig Schwabe, Leipzig: Teubner, 1890, and from this ed., the Englisli translation in 2 vols., by Geo. C. W. Warr, M.A., Geo. Bell and Sons, London, 1891. — Tr. 1 Nicolas Tulp, 1.593-1674, a Dutch physician and magistrate, in Bk. III., chap. 56, of his Observationum medicarum Hbritres, Amsterdam, 1641, 8th ed., revised with additions, Leyden, 1752. — Tk. CH. xxvii] ON HUMAN UNDERSTANDING 245 Goose, that a parrot was a transformed daughter of a king and became known as such while speaking, doubtless her father and mother would caress her as their daughter whom they thought they possessed though concealed under this strange form. I should not oppose myself, however, to him who should say that in the Golden Ass as the self or the individual re- mained for the sake of the same immaterial spirit, so Lucius or the person remained for the sake of the apperception of this ego, but that this is no longer a man ; as in fact it seems necessary to add something of the figure and constitution of the body to the definition of man, when we say that he is a rational animal ; otherwise in my view the genii would also be men.] § 9. Ph. The word person carries with it a thinking and intelligent being, capable of reason and reflection, that can consider itself indeed as the same, as one and the same thing which thinks at different times and in different places ; which it does only by that consciousness ^ which it has of its own acts. And this knowledge always accompanies our sensations and our present perceptions [when they are snfiiciently dis- tinguished, as 1 have more than once before remarked] and it is by this that each one is to himself what he calls himself. It is not considered in this case whether the same self is con- tinued in the same or in different substances. For since consciousness ^ always accompanies thought, and is that which makes each one to be what he calls himself and by which he is distinguished from every other thinking being ; it is also in this alone that personal identity consists, or that which makes a rational being always to be the same ; and as far as this consciousness can be extended over actions or thoughts already past, so far the identity of this person extends, and the self is at present tlie same as it was then. Th. [I am also of this opinion that consciousness or the perception of the ego proves a moral or personal identity. And it is by this that I distinguish the incessahility ^ of the soul of an animal from the immortality of the soul of man . i The French is " sentiment." — Tr. 2 The French text is "la conscience {consciousness ou conscienciosite)," Gerhardt ; " consciosite," Erdmann and Jacques. — Tr. 3 The French is " incessabilite," i.e. continuity or ijerpetuity. — Tr. 246 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii both preserve physical and real identity, but as for man, he is conformed to the rules of divine providence so that the soul preserves also identity moral and apparent to ourselves, in order to constitute the same person, capable consequently of feeling chastisements and rewards. It seems that you, sir, hold that this apparent identity could be preserved, if there were no real identity. I should think that that might perhaps be by the absolute power of God, but according to the order of things, identity apparent to the person himself who perceives the same, supposes real identity to every proximate transition, accompanied by reflection or perception of the ego, a perception intimate and immediate naturally incapable of deception. • If man could be merely a machine and with that have conscious- ness, it would be necessary to be of your opinion, sir; but I hold that this case is not possible at least naturally. Neither would I say that personal identity and even the self do not dwell in us and that I am not this ego which has been in .the cradle,, under pretext that I no more remember anything of all that I then did. It is sufficient in order to find moral identity by itself that there be a middle bond of consciousness between a state bordering upon or even a little removed from another, although a leap or forgotten interval might be mingled therein. Thus if a disease had caused an interruption of the continuity of the bond of consciousness so that I did not know how I came into the present state, although I remember things more remote, the testimony of others could fill the void in my memory. I could even be punished upon this testimony, if I had just done something bad of deliberate purpose in an inter- val that I had forgotten a little after on account, of this disease. And if I had just forgotten all past things and^ would be obliged to let myself be taught anew even to my name and even to reading and writing, I could always learn from others my past life in my previous state, as I have kept my rights without its being necessary for me to share them with two persons, and to make me the heir of myself. All this suffices to maintain moral identity, which makes the same person. It is true that if others should conspire to deceive me (as I might indeed be deceived by myself, by some vision, dream, or illness, believing that what I had dreamed had hap- 1 Gerhardt reads : "et"; Erdmaun and Jacques : " que," so that.— Tr. CH. xxvii] ON HUMAN UNDERSTANDING 247 pened to me) the appearance would be false. But there are cases in which we can be morally certain of the truth upon the relation of another, and with God whose social connection with us constitutes the principal point of morality, the error cannot have place. As for the self, it will be well to dis- tinguish it from the phenomenon of self and from conscious- ness. The self constitutes identity real and physical, and the phenomenon of self accompanied by truth, joins thereto per- sonal identity. Thus not wishing to say that personal iden- tity extends no farther than memory, I would say still less that the self or physical identity depends upon it. Eeal and personal identity is proved with the utmost possible certainty by present and immediate reflection ; it is proved sufficiently for ordinary purposes by our memory of the interval or by the conspiring testimony of others. But if God should change in an extraordinary manner real identity, personal identity would remain, provided man preserved the appearances of identity, as well the internal (that is to say, consciousness) as the external, like those which consist in that which appears to others. Thus consciousness is not the sole means for consti- tuting personal identity, and the testimony of another or even other proofs can supply it. But there is some difficulty if contradiction occurs between those diverse appearances. Con- sciousness may be silent as in forgetfulness ; but if it should alter very clearly things which were contrary to the other appearances, we should be embarrassed in the decision and as it were suspended sometimes between two possibilities, that of the error of our memory and that of some deception in external appearances.] § 11. Ph. [You will say] that the members of the body of every man are a part of himself [and that thus, the body being in a perpetual flux, the man cannot remain the same]. Th. [I should rather prefer to say that the I and the He are without parts, because it is said, and with reason, that the same substance, or the same physical ego, is really preserved. But we cannot say, speaking according to the exact truth of things, that the same whole is preserved when a part is lost. Now whatever has corporeal parts cannot fail to lose some of them at every moment.] § 13. Ph. The consciousness which one has of his past 248 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii actions cannot be transferred from one thinking substance to another [and it would be certain tliat the same substance abides, because we feel ourselves the same], if this conscious- ness were a single and indeed an individual act [i.e. if the act of reflecting were the same as the act upon which you reflect in perceiving it]. But as it is only an actual representation of a past act it remains to be shown how it is impossible for what has never really been to be represented to the mind as truly having been. Th. [Memory after an interval may deceive; we have ex- perienced it often, and there are means of conceiving a natural cause of this error. But present or immediate memory, or the memory of what passed immediately before, i.e. the conscious- ness or reflection which accompanies internal action, cannot naturally deceive ; otherwise we should not be certain indeed that we think of this or that thing, for this statement is made internally only of the action already past, and not in connection with the action itself. Now if these internal, immediate experiences are not certain, there will be no truth of fact of which we can be assured. And I have already said that there may be intelligible reasons for the error which ex- poses itself in perceptions mediate and external, but in those immediately internal we cannot find any unless by recurring to the omnipotence of God.] § 14. Pli. As for the question whether the same immaterial substance remaining there may be two distinct persons, see upon what it is based. It is this : If the same immaterial being can be deprived of all consciousness (sentiment) of its pasi existence, and lose it wholly, without the power of ever recov- ering it, so that beginning, so to speak, a new account from a new period, it has a consciousness (conscience) which cannot extend beyond this new state. All those who believe in the pre-existence ^ of souls are evidently of this mind. I have seen 1 I.e. existence before this eartlaly life. The doctrine was set forth with more or less fulness by the Pythagoreans, Plato, Philo, Origen, and more recently, among others, by Lessing, Erziehung des Menschengeschlechtes, § 94 sq.; Kant, Die Religion innerhalh der Grenzen der blossen Vernunft, bk. I., 4; Julius Muller, Die christ. Lehre von der Silnde, Bk. IV., chap. 4, Vol. 2, pp. 486 sq., Breslau, 1844, and English translation of the same, 2d ed., from the 5th German ed., Halle, 1866, Vol. 2, pp. 357 .sq., Edinburgh : T. & T. Clark, 1868. The doctrine has been used chiefly to explain the origin of CH. xxvii] ON HUMAN UNDERSTANDING 249 a man who was persuaded that his soul had been the soul of Socrates ; and I can assure you that in the post he filled and which was not one of little importance he passed for a very rational man, and he appeared by his works which have seen the light to lack neither intelligence nor learning. jSTow souls being ^ indifferent to any portion of matter whatever this may he, as far as we can know it by their nature, this supposition (of the same soul passing into different bodies) involves no apparent absurdit3\ But he who now has no conscious- ness of that which Nestor or Socrates ever did or thought, does he or can he conceive himself the same person as Nestor or Socrates? Can he take part in the actions of these two ancient Greeks? Can he attribute them to himself or think them his own actions rather than those of some other man Avho has already existed? He is no more the same person with one of them than if the soul now present in him had been created when it began to animate the body which it now possesses. This would no more contribute to make him the same person as Nestor, than if some of the particles of matter which once formed part of Nestor were now a part of this man. For the same immaterial substance without the same consciousness no more makes the same person to be united to such or such a body than the same j^trtides of matter, united to a body without a common consciousness, can make the same person. Th. [An immaterial being or a spirit cannot be stripped of all perception of its past existence. There remain for it some impressions of all that has formerly happened to it, and it even has some presentiments of all that will happen to it ; but these feelings are most often too small to be capable of being distinguished and perceived, although they may perhaps sometime be developed. This continuation and bond of per- evil or sin; but it is an explanation which does not explain, its assumed solu- tion being merely an evasion of the real difficulty by pushing the problem back unsolved into past time. Cf. O. Pfleiderer, Religionsphilosophie an/ gesch. Grundlage, Vol. 2, p. 382, 2d ed., Berlin: G. Reimer, 1884; English translation, Vol. 4, p. 29, London : Williams & Norgate, 1888. For a critique of the theory as held by Julius Miiller, cf. I. A. Dorner, System d. christlichvn Glaubenslehre, § 77, 3; § 82, 2, Berlin : Wm. Hertz, 1881 ; English translation, Edinburgh: T. & T. Clark, 1882. — Tr. 1 Gerhardt and Jacques read: "les ames estant" (" etant," J.) ; Erdmann reads: "tant." — Tr. 250 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii ceptions constitutes in reality the same individual, but the apperceptions (i.e. when past feelings are perceived), prove besides a moral identity and make real identity appear. The pre-existence of souls does not appear to us through our per- ceptions, but if it were true, it might sometime make itself known. Thus it is not reasonable that the restitution of memory becomes forever impossible, the insensible percep- tions (whose use I have set forth on so many important occa- sions) serving here, moreover, to preserve the seeds. The late Henry More, a theologian of the English church, was con- vinced of the truth of pre-existence and has written in its defence.^ The late M. Van Helmont, the son, went much farther, as I just said, and believed in the transmigration of souls, but always into . bodies of one and the same species, so that according to him the human soul always animated a man. He believed with some Rabbis in the passage of the soul of Adam into the Messiah as into the new Adam. And I do not know but that he thought he had himself been some ancient, altogether clever man that he was elsewhere. Now if this pas- sage of souls was true, at least in the possible way that I have explained above (but which does not appear probable), i.e. that souls, keeping their subtile bodies, pass at once into other coarse bodies, the same individual would always subsist in Nestor, in Socrates, and in any modern, and he could even make his identity known to any one who would penetrate sufficiently into his nature, on account of the impressions or marks Avhvch would there remain of all that Nestor or Soc- rates have done, and which any genius sufficiently penetrat- ing could there read. But if the modern man had no means internal or external of knowing what he had been, it would be as far as the moral is concerned as if he had not been. But it appears that nothing is neglected in the world in relation even to the moral, because God is the monarch thereof \\ hose government is perfect. Souls according to my hypothesis are not indifferent regarding any portion of matter whatever, as it seems to you ; on the contrary, they originally express those portions to which they are and ought to be united by nature. 1 Cf. Opera, 1, 750-754, London, 1679; following the Kabbala, he thinks all souls were created at the same time as the world, 2, 539; and, like Leibnitz, regards them as always united with some kind of matter, 2, 3i)5,-3i)6. — Tr'. CH. xxvii] ON HUMAN UNDERSTANDING 251 Thus, if they pass into a new body coarse or sensible, they would always preserve the expression ^ of all that they had perceived in the old, and it would even be necessary for the new body to manifest it so that the individual continuity will always have its real marks. But whatever our j)ast state may have been, the effect it leaves cannot always be for us apperceivable. The clever author of the Essay on Understand- ing, whose views you had espoused, had remarked (Bk. II., chap. 27. On Identity, § 27) that a part of these suppositions or fictions of the passage of souls, assumed as possible, is founded upon the common view of the mind as not only inde- pendent of matter but also as indifferent to every sort of mat- ter. But I hope that what you have said, sir, on this subject here and there will serve to clear up this doubt and to make better known what is naturally possible. We see thereby how the acts of an ancient might belong to a modern who had the same soul, although he did not perceive them. But if he should come to recognize it, still more would personal identity follow. For the rest a portion of matter passing from one body into another does not constitute the same human indi- vidual, nor what is called the ego, but it is the soul which constitutes it.] § 16. Ph. It is, however, true that I am as much concerned and as justly responsible for an action done a thousand years since, which is now adjudged as mine by this present con- sciousness (self-consciousness^) thereof, as having been done by myself, as I am for what I have just done in the preced- ing moment. Th. [This view of having done something may deceive in distant actions. Men have taken as true by force of repetition what they dreamed, or what they invented ; this false view may embarrass, but it cannot make them punishable, unless others agree therewith. On the other hand, you can be respon- sible for what you have done, when you have forgotten it, provided the action be verified elsewhere.] § 17. Ph. Every one finds every day that while his little 1 Gerhardt and Erdmann read: " I'expression " ; Jacques: "limpression." — Tr. - Gerhardt's readin,^ ; Erdmann and Jacques have, as before (p. 245, note 2) , " consciosite' ou consciousness." — Tr. 252 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii finger is comprehended nnder this consciousness, it constitutes as much a. part of himself (of him) as that which is most so. Th. [I have said (§ 11) why I would not advance the view tliat my linger is a part of me ; but it is true that it belongs to me and that it constitutes a part of my body.] Pit. [Those who hold another view will say that] in the event of this little finger being separated from the rest of the body, if this consciousness accompanies the little finger and leaves the rest of the body, it is evident that the little finger would be the person, the same person, and that then the self would have nothing to do with the rest of the body. Th. [Nature does not admit these fictions, which are de- stroyed by the System of Harmony or the perfect correspon- dence of the soul and the body.] § 18. Ph. It seems, however, that if the body should con- tinue to live and to have its particular consciousness, in which the little finger had no share, and that meanwhile the soul was in the finger, the finger could not own any of the actions of the rest of the body, and we could no longer impute them to it.i Th. [The soul also which would be in the finger would not belong to this body. I admit that if God caused conscious- nesses to be transferred to other souls, it would be necessary to treat them in accordance with moral notions, as if they were the same ; but this would disturb the order of things without reason, and make a divorce between the appercepti- ble and the truth, which is conserved by the insensible percep- tions, which would not be reasonable, because the perceptions insensible at present may some day be developed, for there is nothing useless, and eternity gives a large field for changes.] § 20. Ph. Human laws do not punish the madman for the acts which the sober ^ man does, nor the sober man for what the madman does, thereby making them two persons. Thus they say: he is beside himself. Th. [The laws threaten to chastise and promise to recom- pense in order to prevent bad and further good acts. Now a madman may be such that the threats and promises do not operate sufficiently upon him, reason no longer being master ; 1 Locke reads: "him," Philos. Wor'k.<<,'Vo\. 1, p. 475 (Bohn's ed.). — Tr. 2 Locke's word; Philos. Works, Vol. 1, p. 475 (Bohu's ed.). — Tr. ciL xxvii] ON HUMAN UNDERSTANDING 253 thus in proportion to his weakness the severity of the pain should cease. On the other hand we wish the criminal to feel the effect of the evil he has done in order that he may fear further to commit crimes, but the madman not being sensitive enough, we are well content to wait a good while in order to execute the sentence which punishes him for what he did when sober. Thus what the laws or the judges do in these instances comes not from the conception of two persons.] § 22. Ph. In fact in the party whose opinions I represent to you, this objection is made, that if a man who is drunk and who is afterwards no longer drunk, is not the same person, he should not be punished for what he did while drunk, since he is no longer conscious of his act. But they reply that he is altogether as much the same person as a man who during his sleep walks and does many other things and who is responsi- ble for all the evil he has happened to do in that state. Th. [There is much difference between the acts of a drunken man and those of a true and recognized somnambu- list. We punish drunkards because they can avoid drunken- ness and can even have some memory of pain while drunk. But it is not so much within the power of somnambulists to abstain from their nocturnal walk and from what they do. But if it were true that by giving them a good flogging we could make them stay in bed, we should be right in doing it, and we should not fail either, although this would be rather a remedy than a punishment. In fact it is said that this remedy has restored them.] Ph. Human laws punish both in accord with a justice con- formed to the mode in which men understand things, because in these sorts of cases they cannot certainly distinguish what is real from what is counterfeit ; thus ignorance is not re- ceived as an excuse for what they have done while drunk or asleep. The deed is proved against the one who has done it, and you cannot prove in his case lack of consciousness. Th. [The question is not so much about this, as about what must be done when it has been verified, as it may be, that the drunkard or somnambulist were beside themselves. In this case the somnambulist would be considered only as a maniac ; but as drunkenness is voluntary, and the disease is not, the one is punished but not the other.] 254 LEIBNITZ'S CKITIQUE OF LOCKE [bk. ii Ph. But in the great and terrible day of judgment, when the secrets of all hearts shall be uncovered, it is right to think that no one will have to answer for what is wholly unknown to him and that each one will receive what is due him, his own conscience accusing or excusing ^ him. Th. I do not know wliether it will be necessary for the memory of man to be exalted at the day of judgment in order for him to remember all he had forgotten, or whether the knowledge of others and above all of the just judge who can- not be deceived will not suffice. We might devise a fiction lit- tle agreeing with the truth, but nevertheless conceivable, to the effect that a man at the day of judgment believed he had been bad and that the same appeared true to all other created spirits, who would be able to judge of it, without its having been true : could we say that the supreme and just judge, who alone knows the contrary, could condemn this person and judge contrary to his knowledge ? - Yet it seems that that would follow from the notion you gave of moral personality. You will perhaps say that if God judges contrary to appear- ances he will not be sufficiently glorified and will bring pain upon others ; but the reply could be made that he is for him- self his unique and supreme law, and that in this case others should consider themselves mistaken.] § 23. Ph. Could we suppose either two distinct and incom- municable consciousnesses acting by turns in the same body, the one constantly during the day, the other by night, or that the same consciousness acts at intervals in two different bodies ; I ask if, in the first case, the day and night man, if I may so express myself, would not be two as distinct persons as Socrates and Plato, and in the second ease would he not be a single person in two distinct bodies ? It matters not that this same consciousness which affects two different bodies, and these consciousnesses which affect the same body at different times, belong the one to the same immaterial substance, and the two others to two distinct immaterial substances, which introduce these different consciousnesses into these bodies, 1 Erdmann and Jacques omit : " ou excuse." — Tr. 2 Gerhardt reads : " juger centre ce qu'il salt?" Erdmann and Jacques: "jviger centre ce qu'ils font?" i.e. "pass a judgment contrary to what they do." — Tr. CH. xxvii] ON HUMAN UNDERSTANDING since personal identity would equally be determined by the consciousness, whether that consciousness were attached to some individual immaterial substance or not. Further, an immaterial thinking thing may sometimes lose sight of its past consciousness, and recall it anew. Now suppose these intervals of memory and forgetfulness return with every day and night, then you have two persons with the same immate- rial spirit. Whence it follows that the self is not determined by the identity or diversity of substance, which it cannot be sure of, but only by the. identity of consciousness. Th. [I admit that if all the appearances were changed and transferred from our spirit to another, or if God made an exchange between two spirits, giving the visible body and the appearances and consciousnesses of the one to the other, per- sonal identity, instead of being attached to that of substance, would follow the constant appearances which human morality must have in view ; but these appearances would not consist in the consciousnesses alone ; and it will be necessary for God to make the exchange not only of the apperceptions or conscious- nesses of the individuals in question, but also of the appear- ances which present themselves to others regarding these persons, otherwise there would be a contradiction between the consciousnesses of the one and the testimony of the others, which would disturb the moral order of things. But you must also agree with me that the divorce between the insensi- ble and sensible world, i.e. between the insensible perceptiojis which would remain in the same substances, and the appercep- tions which would be changed, would be a miracle, as when you suppose that God makes the vacuum ; for I have stated above why that is not in agreement with the natural order. Here is another supposition much more suitable : it may be that in another place in the universe or at another time a globe may be found which does not differ sensibly from this earthly globe, in which we live, and that each of the men who inhabit it does not differ sensibly from each of us who corresponds to him. Thus there are at once more than a hundred million pairs of similar persons, i.e. of two persons with the same appear- ances and consciousnesses ; and God might transfer spirits alone or with their bodies from one globe to the other without their perceiving it ; but be they transferred or let alone, what 256 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii will you say of their person or self according to your authors ? Are they two persons or the same? since the consciousness and the internal and external appearance of the men of these globes cannot make the distinction. It is true that God and the spirits capable of seeing the intervals and external rela- tions of times and places, and even internal constitutions, insensible to the men of the two globes, could distinguish them ; but according to your hypotheses consciousness alone discerning the persons without being obliged to trouble itself with the real identity or diversity of the substance, or even of that which would appear to others, how is it prevented from saying that these two persons who are at the same time in these two similar globes, but separated from each other by an inexpressible distance, are only one and the same person ; which is, however, a manifest absurdity. For the rest, speak- ing of what may be in the course of nature, the two similar globes and the two similar souls of the two globes would remain so only for a time. For since there is an individual diversity, this difference must consist at least in the insensible constitutions which must be developed in the course of time.] § 26. Ph. Suppose a man punished now for what he has done in another life and of which he could cause himself to have absolutely no consciousness ; what difference is there between such treatment and that which would be done him in creating him miserable ? Til. [The Platonists, disciples of Origen, some Hebrews and other defenders of the pre-existence of souls believed that the souls of this world were placed in imperfect bodies, in order to suffer for the crimes committed in a preceding world. But it is true, if they neither know nor have ever learned the truth, neither by recall of memory, nor by any traces, nor by the knowledge of another, you cannot call it punishment ac- cording to ordinary notions. There is, however, some room for doubt, while speaking of punishments in general, whether it is absolutely necessary that those who suffer should one day learn the reason for their suffering, and whether it would not very often suffice that better informed minds should find therein a motive for glorifying the divine justice. However, it is more likely, at least in general, that the sufferers will know the reason of their suffering.] CH. xxvii] ON HUMAN UNDERSTANDING 257 § 29. Ph. [Perhaps in the main you can agree with my author who concludes his chapter on identity by saying : that the question whether the same man abides, is a question of name, according as you understand by man either the rational spirit alone or the body alone of this form which is called human, or finally the spirit united to such a body. In the first case the spirit separated (at least from the coarse body) will be still the man ; in the second an ourang-outang, perfectly similar to us, reason excepted, would be a man ; and if man were deprived of his rational soul and received a soul of an animal, he would continue the same man. In the third case both must remain together with the union itself; the same spirit, and the same body in part, or at least equivalent, as far as the sensible corporeal form is concerned. Thus you could continue the same being physically or morally, i.e. the same person without remaining man, in case you consider this figure an essential to man according to this last sense.] Th. [I admit that in this respect it is a question of name, and in the third sense the same animal is as it were now caterpillar or silk-worm and now butterfly, and some as it were have imagined that the angels of this world were men in a past world. But we have devoted ourselves in this confer- ence to discussions more important than those about the meaning of words. I have shown you the source of true physical identity ; I have made it appear that morality con- tradicts it no more than memory ; that they cannot always assign physical identity to the person indeed, whose (iden- tity) is at stake, nor to those who are in connection with him; but that nevertheless they never contradict physical identity and never are completely '^ divorced from it ; that there are always some created spirits who know or may know what it is ; but that there is room to consider that what is indifferent regarding the persons themselves can be so only for a time.] 1 Erdmann and Jacques omit : "entier." — Tr. 258 LEIBNITZ'S CRITIQUE OF LOCKE [bk. CHAPTER XXVIII OF SOME OTHER RELATIONS, AND ESPECIALLY OF MORAL RELATIONS § 1. Ph. Besides the relations founded upon time, space, and causality, of which we have just been speaking, there are an infinite number of others, some of which I am going to propose for discussion. Every simple idea capable of parts and of degrees, furnishes an occasion for comparing the sub- jects in which it is found, for example, the idea of more (or less or equally) white. This relation may be called p'^'opor- tional. Th. [There may be, however, excess without proportion ; and this is in reference to a magnitude which I call imperfect, as when we say that the angle which the ray makes with the arc of its circle is less than a right angle, for it is impossible that there be a proportion between these two angles, or between one of them and their difference, which is the angle of contingence.] § 2. Ph. Another occasion of comparing is furnished by the circumstances of origin which found the relations of father and child, brothers, cousins, countrymen. With us people seldom think of saying this bull is grandfather of such a calf, or these two pigeons are cousins-german ; for languages are proportioned to use. But there are countries in which men less curious about their own pedigree than about that of their horses have not only names for each particular horse, but also for their different degrees of relation. Th. [We can furthermore join the family idea and names to those of relationship. It is true we do not observe under the empire of Charlemagne and for a sufficiently long time before and after family names in Germany, Erance, and Lom- bardy. It is moreover not long that there have been families (even noble) in the North who had no name, and in which a man would be recognized in his natal place only by calling his name and that of his father, and besides (in case he trans- planted himself) by joining to his own the name of the place cii. xxviii] ox HUMAN UNDERSTANDING 259 whence he came. The Arabs and the Turcomans have also the same custom (I believe), having but few particular family names, and content themselves with naming the father and grandfather, etc., of any one, and they pay the same honor to their valuable horses, which they call by a proper name and the name of the father and even beyond. Thus the}^ spoke of the horses which the Monarch ^ of the Turks sent to the emperor after the peace of Carlowitz ; " and the late count of Oldenburg, the last of his branch, whose studs were famous, and who lived a very long time, had genealogical trees of his horses so that he could prove their nobility, and went so far as to have portraits of their ancestors {imag- ines majorum) which were so much in demand among the Eomans. But to return to men, there are among the Arabs and the Tartars names of tribes, which are like great families, which are much enlarged in the course of time. And these names are taken either from the progenitor as in the time of Moses, or from the place of abode, or from some other circum- stance. Mr. Worsley, an observing^ traveller, who is informed of the present state of Arabia Deserta, where he has been for some time, affirms that in all the countries between Egypt and Palestine, and where Moses passed, there are to-day only three tribes, who can bring together five thousand men, and that one of these tribes is called Scdi from the progenitor (as I believe) whose tomb posterity honors as that of a saint, casting upon it dust which the Arabs put upon the heads of themselves and their camels. For the rest consanguinity exists when there is a common origin of those whose relation is considered; but we could say there is alliance or affinity between two persons, Avhen they may have consanguinity with one and the same person without there being any for that reason between them- selves, which happens through the intervention of marriages. But as it is not customary to say that there is affinity between husband and wife, although their marriage may cause affinity in relation to other persons, it would perhaps be better to say that there is affinity between those who would have con- 1 Erdmann and Jacques read : " grand Seigneur." — Tr. 2 Jan. 26, 1699. — Tr. 3 Erdmann and Jacques read: "curieux"; Gerhardt reads: " observatif." — Tr. 260 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii sanguinity between themselves if husband and wife were taken as one and the same person. § 3. Ph. The foundation of a relation is sometimes a moral right, as the relation of a general of an army or of a citizen. These relations depending upon the agreements men have made between themselves are voluntary or by institution, and may be distinguished from the natural. Sometimes the two correlatives have each its name, as patron and client, general and soldier. But it is not so always ; as, for example, it is not so in the case of those who are related to the chancellor. Til. [There are sometimes natural relations which men have invested and enriched with certain moral relations, as, for example, children have the right to claim the legitimate por- tion of the estate of their fathers or mothers ; young persons are under certain restraints and the aged have certain immu- nities. But it also happens that some relations are taken as natural which are not so ; as when the laws say that the father is he who married the mother within the time which makes it possible for the child to be attributed to him ; and this substitution of the instituted in the place of the natural is sometimes only presumption, that is to say, a judgment which causes that to pass as true which perhaps is not so, whilst its falsity is not at all proved. Thus it is that the maxim : j)citer est quern nuptice demonstrant is understood in Roman law and among the most of the peoples where it is received. But they tell me that in England it avails nothing in proving his alibi ; provided he has been in one of the three ki'ngdoms, so that the presumption in that case changes into fiction or into what some doctors g^M prmsumtio juris et de jure.] § 4. Ph. A moral relation is the conformity or disagreement which is found between the voluntary acts of men and a rule which makes us judge whether they are morally good or bad. § 5. And moral good or moral evil is the conformity or the opposition which is found between voluntary acts and a cer- tain law which brings upon us good or evil (physical) by the will and power of the lawgiver (or of him who wills to main- tain the law) and it is this we call reward and punishment. Th. [Authors, as clever as he whose views you, sir, repre- sent, are allowed to adapt their terms as they think proper. But it is also true that according to this notion one and the CH. xxviii] ON HUMAN UNDERSTANDING 261 same act Avould be morally good and morally bad at the same time under different legislators, entirely as our clever author understood virtue 'above as that which is praised, and conse- quently the same act would be virtuous or not according to the opinions of men. Xow that not being the ordinary sense that is given to morally good and virtuous acts, I prefer for myself, to take as the measure of moral good and of virtue the invariable rule of reason which God is charged with main- taining. We can also be assured that by his mediation all moral good becomes physical,^ or as the ancients say, every thing virtuous is useful ^ ; while in order to express the notion of the author, it would be necessary to say that moral good or evil is an imposed or instituted good or evil, which he who has the power tries to make us follow or shun by punishments and rewards. The good is that which by the general institu- tion of God is conformed to nature or to reason.] § 7. Ph. There are three sorts of laws : the divine laio, the civil law, and the law of opinion or reputation. The first is the rule of sins or duties, the second of actions crimincd or innocent, the third of virtues or vices. Til. [According to the ordinary sense of terms virtues and vices differ from duties and sins only as habits differ from 1 What does Leilmitz here mean by " jAysical " ? Possibly " physical " is here equivalent to "real," i.e. actnal, concrete, objectively realized as distin- guished from that which is purely subjective and abstract, and exists in idea only {cf. Bk. II., chaj). 27, § 9, Tli.p?'ope ./?«., ante, p. 247, line 7, where the two terms are united in one phrase " real and physical," and seem to be mutually interpretative and emphatic). Or, possibly, "phj^sical" is here used in the sense of "natural," the meaning of the passage being that moral good is realized by the mediation of God through the natural forces and in accord with the natural laws of the universe, which with Leibnitz have their ultimate source and ground in the nature of God and his choice of " the best and most perfect," as the universal principle of creation. The true view of the world is, according to Leibnitz, both physico-mechanical and moral-teleological, the two finding a higher unity in this principle of "the best and most perfect," the moral-teleological prevailing in case of collision, because of this princi- ple and because the physical is in its last analysis and ground spiritual and possessed of an inner teleological character which is realized by means of mechanism while resting upon the principle of the divine choice of the best. Cf. Discours de Metaphr/siqiie, § 19 sq., Gerhardt, 4, 444 sq.; letter to Bayle, G. 3, 54 ; Erdmann, 108. — Tr. 2 Cf. Cicero, De Officiis, Bk. III., chaps. 3 and 7, who shows on the author- ity of Panaetius and others that the virtuous and the useful — honestum and vtile — are identical, a chief point of the Stoic philosophy. Cf. also Zeller, Die Philos. d. Griech., III., 1 [Vol. 5] , p. 212, 3d ed. 1880. —Tr. 262 LEIBNITZ'S CRITIQUE OF LOCKE " [bk. n actions, and virtue and vice are not understood as sometliing dependent upon opinion.^ A great sin is called a crime, and the innocent is not opposed to the criminal but to the blame- worthy. The divine law ^ is of two sorts, natural and positive. Civil law is positive. The law of reputation deserves the name of law only improperly, or is comprised under the natural law, as though I said, the law of health, the law of the family, when actions naturally attract some good or evil, as the approbation of another, health, gain.] § 10. Ph. The claim is in fact everywhere made that the terms virtue and vice signify actions good and bad in their nature, and so far as they are really applied in this sense, vir- tue agrees perfectly with the divine (natural) law. But what- ever the claims of men, it is evident^ that these names, con- sidered in their particular aj)plications, are constantly and solely attributed to such or such actions as in each country or in each society are reputed honorable or shameful : otherwise men tvould condemn themselves. Thus the measure of what is called virtue and vice is this approbation or this contempt, ■ this esteem or this blame, which is formed by a secret or tacit consent. For although men united in political societies have resigned into the hands of the public the disposition of all their forces, so that they cannot employ them against their fellow-citizens beyond what the law j)ermits, they nevertheless always retain the power of thinking well or ill, of approval or disapproval. Th. [If the clever author, who thus explains himself, should declare with you, sir, that it has pleased him to assign this present arbitrary nominal definition to the terms virtue and vice, we could only say that it is allowed him in theory for the 1 Leibnitz maintains, as against Locke's theory of relativity, the absolute and objective character of Moral Law. It is objective and universal, not sub- jective and particular ; not dependent upon the opinions of men, but grounded in "the general institution of God," and ultimately in his inlinitely perfect moral nature, and is thus valid for and binding ujion all moral beings as such. This is Moral Law absolute and ideal which changes not ; it is progressively and approximately attained or realized in the history of the individual and the race according to men's apprehension of its nature and requirements and their strength of purpose and effort in its pursuit. — Tb. 2 .(Jf. the discussion of Moral Law, in Principles and Practice of Morality, )>p. 79s(7., by E. G. Robinson, D.D., LL.D., Ex-President of Brown University. Boston: Silver, Burdett & Co., 1888. — Tr. 3 Locke has: "visible," Philos. Works, Vol. 1, p. 488 (Bohn's ed.). — Tr. CH. xxviii] ON HUMAN UNDERSTANDING 263 convenience of expression for want perhaps of other terms ; but we shall be obliged to add that this meaning is not conformed to usage, nor indeed useful for edification, and that it would sound ill in the ears of many people, if any one should intro- duce it into practical life and conversation, as this author seems himself to admit in his preface. But it is (for us) to go on farther here, and although you admit that men claim to speak of that which is naturally virtuous or vicious according to immutable laws, you maintain that in fact they mean to speak only of that which depends on opinion. But it seems to me that by the same reasoning you could further maintain that truth and reason and all that could be named as most real, depends upon opinion, because men are mistaken when they judge of it. Is it not better then on all accounts to say, that men understand by virtue as by truth, that which is conformed to nature, but that they are mistaken often in its application ; besides they are mistciken less than they tlihik, for what they praise ordinarily deserves it in certain respects. The virtue of drinking, i.e. of well carrying wine, is an advantage, which served Bonosus, in conciliating the Barbarians and in drawing from them their secrets.^ The nocturnal powers of Hercules, in which the same Bonosus claimed to resemble him, were no less a perfection. The craft of thieves was praised among the Spartans, and it is not the skill, but the unseasonable use which has been made of it, which is blamable, and those whom we harass in (time of) complete peace may serve sometimes as excellent partisans in time of war. Thus all depends upon the application and the good or bad use of the advantages you pos- sess. It is also very often true and should not be taken as a very strange thing, that men condemn themselves, as when they do what they blame in others, and there is often a contradiction between actions and words which scandalizes the public, when what a magistrate or preacher does and defends leaps to the eyes of the whole world.] § 11.^ Ph. Everywhere that which passes as virtue is that which is thought worthy of praise. Virtue and praise are often designated by the same name. Sunt hie etiam sua prcemia hiidi, says Vergil (Aen. I. 461) and Cicero, Nihil habet natura 1 C/. Vopiscus, Script, hist. Avgust., Vol. 2, pp. 213, 214, ed. Peter. — Tr. - Gerhardt and Locke; Erdmann and Jacques have § 12. — Tr. 264 LEIBNITZ'S CKITIQUE OF LOCKE [bk. ii praestantius quam honestatem, quam laudem, quam dignitatem, quam decus} {Qucest. Tuscul. Bk. 2. chap. 20) and he adds a little after: Hisce ego plurihics nominibus unam rem declarari volo} Th. [It is true that the ancients have designated virtue by the name honesty (Vlionneste) , as when they have praised in- coctum generoso pectus honesto.^ It is true also that honesty {Vhonneste) has its name of honor or of praise. But this means not that virtue is that which is praised but that it is that which is worthy of praise and which depends upon truth, and not upon opinion.] Ph. Many do not think at all seriously of the law of God, or hope that they will one day be reconciled with its author, and as regards the laio of the state they flatter themselves with im- punity. But they do not think that he who does anything ' contrary to the opinions of those with whom he associates, and to whom he wishes to commend himself, can avoid the pain of their censure and of their disdain. JSTo one who retains any consciousness of his own nature can live in society constantly despised; this is the force of the laio of reputation. Th. [I have already said that it is not so much the pain of a law, as a natural pain which the act draws upon itself. It is, however, true that many people are but little concerned about it, because ordinarily, if they are despised by some on account of some blameworthy act, they find accomplices or at least partisans, who do not despise tliem, if they are ever so little commendable in some other respect. They forget even acts the most infamous, and it often suffices to be bold and im- pudent like that Phormio of Terence in order that all may be overlooked. If excommunication produced a truly constant and general contempt, it would have the force of this law of which our author speaks : and it had in fact this force with the first Christians and for them took the place of the right, which they lacked, to punish the guilty ; nearly as artisans maintain, certain customs among themselves in spite of the laws, through 1 The quotation is not exact. Cf. oj). cit., ed. Klotz, Lipsiae, B. G. Teub- ner, 1870, where the text reads thus: "Nihil enim habet praestantius, nihil quod magis expetat quam honestatem, quam laudem, quam dignitatem, quam decus. Hisce ego pluribus nominibus unam rem declarari volo, sed utor, ut quam maxime significem, pluribus." — Tr. 2 Persius. Sat. 2, 74. — Tr. CH. XXIX] ON HUMAN UNDERSTANDING 265 the contempt which they show for those who clo not observe them. And it is this which has also maintained duels con- trary to the ordinances. It would be desirable for the public to agree with itself and with reason in its praise and blame ; and that the great above all do not encourage the bad by laugh- ing at their bad actions, in w^hich it oftenest seems that not he who has done them, but he who has suffered them is punished by contempt and ridiculed. We shall see also generally that men despise not so much vice as weakness and misfortune. Thus the law of reputation would need to be greatly reformed, and also to be better observed.] § 19. Ph. Before leaving the consideration of relations, I would remark that we usually have a notion as clear or clearer of the relation than of its ground. If I believed that Sempronia took Titus from beneath a cabbage, as they used to tell little children, and that afterwards she had had Cains in the same manner, I should have as clear a notion of the relation of brother between Titus and Caius, as if I had all the knowledge of the midwives. Th. But when they once said to a child, that his little brother, who had just been born, had been drawn from a well (a reply which they make use of in Germany to satisfy the curiosity of children upon this subject) the child replied that he wondered that they did not throw him back again into the same well when he cried so much and disturbed his mother. The fact is this explanation did not make him know any rea- son for the love his mother showed for the child. We can say then that those who do not know the ground of relations have only concerning them what I call thoughts, surd in part and insufficient, although these thoughts may suffice in certain respects and upon certain occasions.] CHAPTER XXIX or CLEAR AND OBSCURE, DISTINCT AND CONFUSED IDEAS § 2. Ph. We come now to some differences of ideas. Our simple ideas are dear when they are such as the objects them- selves, from whence they are received, represent or may 266 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii represent them with all the circumstances requisite to a well- ordered sensation or perception. While the memory retains them in this way, they are in this case clear ideas, and so far as they lack this original exactness or have lost anything so to speak of their first freshness, and are, as it were, tarnished or faded by time, so far are they obscure. Complex ideas are dear, when the simple ideas which compose them are clear and the number and order of these simple ideas are fixed. Til. [In a brief discourse on ideas,^ true or false, clear or obscure, distinct or confused, inserted in the " Leipsic Acts " of the year 1684, I have given a definition of dear ideas, common to the simple and complex and which gives the rea- son of what you say here. I said then that an idea is clear when it suffices to recognize and distinguish the thing: as when I have a very clear idea of a color, I shall not take another instead of that which I ask for, and if I have a clear idea of a plant, I shall distinguish it among other neighboring ones; without this the idea is obscure. I believe that we have but few perfectly clear ideas of sensible things. There are colors which approach each other in such a way that we can- not distinguish them by memory, and yet we will sometimes distinguish them by placing one near the other. And when we think we have fully described a plant, we can bring one from the Indies which will have all we have put into our description and' which will not cease making itself known as a different species : thus we can never perfectly determine species infamce, or the lowest species.] § 4. Ph. As a dear idea is that whereof the mind has such a full and evident perception as it receives from an external object operating duly upon a well-disposed organ ; so a distinct idea is that wherein the mind perceives a difference, which distinguishes it from every other idea ; and a confused idea is that which cannot be sufficiently distinguished from another from which it should be different. Th. [According to this notion which you give of the dis- tinct idea, I do not see how you distinguish it from the dear idea. This is why I have been wont to follow here the lan- guage of Descartes, with whom an idea may be clear and con- "^ Meditationes de Cognitione, Veritate et Ideis. Cf. ante, p. 14, note 2; p. 227, note 3. — Tr. CH. XXIX] ON HUMAN UNDERSTANDING 267 fused at the same time ; and such are the ideas of sensible qualities, appropriate to the organs, such as color or heat. They are clear, for they are easily recognized and distinguished the one from the other, but they are not distinct, because they are not distinguished by what they include. Thus we cannot give a definition of them. We make them known only by examples, and for the rest we must say it is an indefinite somewhat, until we can decipher its contexture. Thus although in our view distinct ideas distinguish one object from another ; nevertheless, as the ideas clear, but confused in themselves, do so also, we call distinct not all those which are very discrimi- nating or which distinguish objects, but those which are well distinguished, i.e. which are distinct in themselves and dis- tinguish in the object the marks which make it known, which an analysis or definition of it gives ; otherwise we call them confused. And in this sense the confusion which reigns in ideas can be exempt from blame, being an imperfection of our nature; for we cannot discern the causes, for example, of odors and tastes, nor the content of these qualities. This confusion can, however, be blameworthy, when it is important and within my power to have distinct ideas, as, for example, if I took adulterated gold as the true, for want of making the necessary assays which contain the marks of good gold. § 5. Ph. But you will say that there is no idea confused (or rather according to your view, obscure) in itself^ for it can be only such as it is perceived by the mind, and that distin- guishes it sufficiently from all others. § 6. And in order to remove this difficulty it is needful to know that the defect of ideas is related to names, and what renders it faulty is the fact that it can as well be designated by another name as the one which we use to express it. Th. [It seems to me that we ought not to make this depend upon names. Alexander the Great had seen (they say) in a dream a plant able to cure Lysimachus, which has since been called Lysimacliia, because it effectually cured this friend of the king. When Alexander had a quantity of plants brought, among which he recognized that which he had seen in his dream, if unfortunately he had not had a sufficient idea of it to recognize it and had needed as Nebuchadnezzar a 1 Erdmann aud Jacques omit : " en elle meme." — Tr. 268 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii Daniel to enable him to recall Ms dream, it is plain that the idea he wonld have had of it would have been obscure and imperfect (for it is thus I should prefer to call it rather than confused) , not for vyant of appositeness in a certain name, for there was none, but for want of application to the thing, i.e. to the plant which was to heal. In this case Alexander would be reminded of certain circumstances, but he would have been in doubt about others ; and the name serving us to designate anything makes us, when we fail in the application to names, fail ordinarily in regard to the thing which is promised by this name.] § 7. Ph. As complex ideas are the most subject to this imperfection, it may arise from the fact that the idea is composed of too small a number of simple ideas, as is, for example, the idea of an animal which has the skin spotted, (a term) which is too general, and which does not suffice to dis- tinguish the lynx, the leopard, or the panther, which are besides distinguished by particular names. Th. [If we were in the condition Adam was in before he had given names to the animals, this defect would not cease to have place. For supposing we knew that among the spotted animals there is one which has extraordinarily pene- trating sight, but that we did not know whether it is a tiger or a lynx, or some other species ; it is an imperfection not to be able to distinguish it. Thus the question is not so much about the name as about that which may give occa- sion for it, and which renders the animal worthy of a particu- lar name. It thereby appeq,rs also that the idea of a spotted animal is good in itself, and without confusion and obscurity, when it is to serve only the genus ; but when joined with some other idea which is not sufficiently remembered it is to designate the species, the complex idea is obscure and imperfect.] § 8. Ph. There is an opposite defect when the simple ideas which make up the complex idea are sufficient in number, but too confused and involved, like some pictures, which appear so confused that they must be only the representation of the sky covered with clouds, in which case also we could not say that there is confusion any more than if it were another pic- ture made to imitate that one ; but when we say that this CH. XXIX] ON HUMAN UNDERSTANDING 269 picture should make us see a portrait, we shall have reason to say that it is confused because we cannot say whether it is that of a man, or of a monkey, or of a fish, but it may be that when we look at it in a cylindrical mirror, the confusion will disappear, and that we shall see that it is a Julius Caesar. Thus some mental paintings (if I may so express myself) can- not be called confused from any way in which the parts are joined together ; for whatever these paintings are, they can obviously be distinguished from every other, until they are ranked under ,some ordinary name, to which we cannot see that they belong any more than to some other name of a different signification. Th. [This picture whose parts we see distinctly, without noticing the result to which they in a certain way point, resembles the idea of a heap of stones, which is truly confused not only in your sense, but also in mine, so far as we have distinctly conceived their number and other properties. If there were thirty -six of them (for example), we would not know, looking at them heaped together without arrangement, that they may produce a triangle or indeed a square, as in fact they can, because thirty-six is a square as well as a tri- angular number. Thus it is that, in looking at a figure of a thousand sides, we shall have only a confused idea of it, until we know the number of the sides which is the cube of ten. The question, then, is not of names but of the distinct proper- ties which are to be found in the idea when we have cleared up its confusion. And it is sometimes" difficult to find the key, or the manner of looking at it from a certain point, either by the intervention of a certain mirror or glass in order to see the purpose of him who has caused the thing.] § 9. Ph. It cannot be denied that there is yet a third defect in ideas, which depends in truth upon the bad use of names ; it is when our ideas are uncertain or undetermined. Thus we may see every day men who, making no difficulty of availing themselves of the ordinary words of their mother tongue, before they have learned their precise meaning, change the idea which they attach to them almost as often as they use them in their discourse. § 10. Thus we see how much names contribute to this denomination of ideas distinct and confused, and, without the consideration of distinct names 270 LEIBNITZ'S CRITIQUE OF LOCKE [bk. n understood as signs of distinct things, it will be very difficult to say what a confused idea is. Th. [I have, however, just explained it without considering the names, whether in the case where the confusion is under- stood with you as what I call obscurity, or in that where it is understood in my sense as the defect in the analysis of the notion we have. And I have also shown that every obscure idea is in fact indeterminate or uncertain, as in the example of the spotted animal we have seen, where we know that some- thing further must be added to this general notion, without clearly remembering it ; so that the first and third defect which you have specified come to the same thing. It is, how- ever, very true that the abuse of words is a great source of errors, for a kind of error in calculating occurs therefrom, as if in calculating we did not notice carefully the place of the counter, or if we wrote the figures so badly that we could not distinguish a 2 from a 7, or if we omitted or changed- them through inadvertence. Tiiis abuse of words consists either in not connecting ideas with the whole or in connecting them with an imperfect one, of which a part is empty and abides so to speak in blank ; and in these two cases there is a certain void and surd in the thought which is filled only by the name. Or, finally, the defect is in attaching to the word different ideas, whether we are uncertain which should be chosen, which makes the idea obscure as well as when a part of it is surd ; or whether we select them by turns, and avail ourselves sometimes of one, sometimes of the other as the sense of the same word in one and the same course of reasoning in a way capable of causing error, without consider- ing that the ideas do not agree. Thus the uncertain thought is either void and without idea, or fluctuates between several ideas. This does harm whether ^ we wish to designate some definite thing or whether we wish to give a word a certain sense corresponding either to that of which we have already availed ourselves, or to that which others have used, above all in ordinary language, common to all, or to the artisans. And from this arise an infinite number of vague and vain dis- putes in conversation, in lecture-rooms, and in books, which we 1 Erdmann and Jacques omit: " soit qu'on veuille designer quelque chose determinee," the reading of Gerhardt. — Tr. CH. XXIX] ON HUMAN UNDERSTANDING 271 may sometimes avoid by distinctions, but which most fre- quently serve only to confuse the moi-e, by putting in the place of a vague and obscure term other terms still more vague and obscure, as those often are which the philosophers employ in their distinctions, without having good definitions of them.] § 12. Ph. If there is any other confusion in ideas, than this which has a secret relation to names, this at least casts more disorder than any other into the thoughts and discourse of men. Th. [I agree, but most frequently some notion of the thing and the purpose which we have in availing ourselves of the name is mixed with it ; as, for example, when we speak of the church, many have in view a government, while others think of the truth of the doctrine.] Ph. The way to prevent this confusion is constantly to apply the same name to a certain mass of simple ideas united in a fixed number and into a determined order. But as that suits neither the laziness nor the vanity of men, and as it can be used only in the discovery and the defence of the truth, which is not always the end they propose to themselves, such precision is one of the things that is rather to be wished than hoped for. The vague application of names to ideas inde- terminate, variable, and almost wholly empty (in the surd thoughts) is on one side a covering of our ignorance and on the other a confusing and embarrassing of others, which passes as true learning and as a mark of superiority in point of knowledge. Th. [The affectation of elegance and wit has further con- tributed much to this intricacy of language ; for in order to express thoughts beautifully and agreeably we make no diffi- culty of giving words in a tropical manner a sense different from the ordinary, sometimes more general or more limited, which is called synecdoche, sometimes transferred according to the relations of things whose names we change, either by concurrence in metonymy, or by comparison in metaphor, not to speak of irony, Avhich makes ^^se of a terra in a sense directly opposite to its real meaning. Thus these changes are named when recognized ; but they are recognized only rarely. And in this indeterminateness of language, in which there is 272 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii lacking a kind of law which regulates the meaning of words, as there is something in the title of the digests of the Roman Law, De Verborum Signijicationibus, persons the most judic- ious, when they write for ordinary readers, would be deprived of that which gives charm and force to their expression if they should confine themselves rigorously to the fixed mean- ings of terms. They need only take care that their variation does not cause any error or false reasoning to spring up. The distinction of the ancients between the exoteric,^ i.e. popular, and the acroamatic ^ mode of writing, which belongs to those who are occupied in the discovery of truth, has place here. And if any one wished to write in mathematical fashion in metaphysics or ethics, nothing would prevent him from so doing with rigor. Some have professed to do this, and we have a promise of mathematical demonstrations outside of mathematics ; but it is very rare that they have been success- ful. This is, I believe, because they are disgusted with the trouble it is necessary to take for a small number of readers where they could ask as in Persius : Quis leget liaec, and reply : Vel duo vel nemo.^ I believe, however, that if they would undertake it in the proper way they would not be likely to repent it. And I have been tempted to try it.] § 13. Ph. You will agree with me, however, that complex ideas may be very clear and distinct in one aspect, and very obscure and confused in another. Th. [There is no reason to doubt it ; for example, we have very distinct ideas of a good part of the solid visible parts of the human body, but we have but few of the liquids which enter therein.] Ph. If a man speaks of a figure of a thousand sides, the 1 Cf. Leibnitz, De Stilo pliilos. Nizolii, Gerhardt, Vol. 4, p. 146 ; Erdmann, p. 63. " Acroamatic" {ante, p. 42), from a.Kp6a.ixa, anything heard, the verb aKpoatrflat, the regular word for hearing or attending lectures, the adjective dxpoa/iaTiKos, designed for hearing only, and, when used of the doctrines of philosophers, meaning the esoteric, i.e. the doctrines in their most rigorous and exact scientific form, their custom being to give these orally to their pupils, while treating them in a more popular, exoteric manner in their writ- ings. Such was the method of Plato and of Aristotle, one of whose works is called ) aKpoatris. Schaarschmidt refers to Bernays, Die Dialoge d. Aris- totles, p. 30 sq. Berlin, 1863, and Madvig, Excursus VII. to his edition of Cicero's De Finibus. — Tr. ^ Sat. 1, lines 2,3.— Tk. CH. xxix] ON HUMAN UNDERSTANDING 273 idea of this figure may be very obscure in his mind, although that of the number may be very distinct therein. Th. [This example is not in point here ; a regular polygon of a thousand sides is known as distinctly as the millenary number, because we may discover and demonstrate all kinds of truth.] Ph. But we do not have a precise idea of a figure of a thousand sides, so that we can distinguish it from another, which has only nine hundred ninety-nine. Th. [This example shows that you here confound the idea with the image. If any one places before me a regular poly- gon, sight and imagination cannot make me comprehend the millenary therein ; I have only a confused idea both of the figure and of its number, until I distinguish the number by counting. But having found it, I know very well the nature and the properties of the proposed polygon, as far as they are those of the chiliagon, and consequently I have this idea of it ; but I cannot have the image of a chiliagon, and it would be necessary to have senses and imagination more exquisite and better exercised in order to distinguish it thereby from a polygon which had one side less. But the knowledge of figures no more than that of numbers depends upon the imag- ination, although it is of service therein ; and a mathematician can know exactly the nature of a nonagon and a decagon, because he has the means of making and examining them, though he could not discern them at sight. It is true that a workman or an engineer, who does not perhaps know their nature sufficiently, can have this advantage beyond a great geometer that he can discern them by sight only without measuring them, as there are some street-porters^ (faquins) or pedlers, who will state the weight of what they are to carry within a pound, in which respect they will surpass the most skilful statistician in the world. It is true that " this empiri- cal knowledge acquired by a long practice may be very useful for prompt action, such as an engineer very often needs to perform because of the danger to which he is exposed in delaying. But this clear image or this feeling which we may 1 Erdmann and Jacques omit: " faquins ou," the reading of Gerhardt. — Tr, 2 Erdmann and Jacques omit: " II eSt vray que," tlie reading of Gerhardt. — Tr. 27i LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii have of a regular decagon or of a weight of ninety-nine pounds consists only in a confused idea, since it is of no avail in dis- covering the nature and properties of this weight or of this regular decagon, which demands a distinct idea. And this example conduces to the better understanding of the differ- ence of ideas, or rather that of the idea and the image.] § 15.^ Ph. Another example : We are led to believe that we have a positive and complete idea of eternity, which is as much as to say that there is no part of that duration which is not clearly known in our idea ; but, however great may be the duration that is represented, as it is a question of an extension without limits, there always remains a part of the idea beyond what is represented which continues obscure and undetermined; and thence it comes that, in discussions and reasonings concerning eternity or any other infinite, we are apt to involve ourselves in manifest absurdities. Th. [This example does not appear to me to square with your design either ; but it is very appropriate to mine, which is to disabuse you of your notions on this point. For the same confusion of the image with the idea reigns here. We have a complete or just idea of eternity, since we have a definition of it, although we have no image of it. But the idea of the infinite is not formed by the composition of parts, and the errors which we meet in reasoning upon the infinite do not arise from tlie defect of the image.^] § 16.^ Ph. But is it not true that when we speak of the infinite divisibility of matter, although we have clear ideas of the division, we have only very obscure and very confused ideas of the parts ? For I ask whether a man taking the 1 Erdmaun and Jacques have § 25. Gerhardt and Locke, Philos. Works, Vol. 1, p. 505 (Bohn's ed.), have § 15.— Tr. '^ The difficulties and errors in the discussion of the infinite arise not " from the defect of the image" but from tlie attempt to imagine or picture that vphich can only he thought. We can think the infinite and absolute, but we cannot form an adequate image or picture of it. The " confusion of the image with the idea," which Leibnitz here speaks of, is one of the causes vitiating much of the "reasoning upon the infinite" in the history of thought, and lying at the basis of all theories, like those of Hamilton, Mansel, and Spencer, which maintain the impossibility on man's part of a knowledge of the infinite. Cf. John Caird, An Tntroduction to the Philos. of Religion, p. 36. New York : Macmillan & Co., 1880. — Tr. 3 So Gerhardt and Locke, Philos. Work.<( (Bohn's ed.), Vol. 1, p. 505; Erd- mann has § 18 ; Jacques § 30. — Tr. CH. XXX] ON HUMAN UNDEESTANDING 275 smallest atom of dust he ever saw has any distinct idea of the difference between the one hundred thousandth ^ and the millionth part of this atom ? Th. It is the same qui pro quo of the image for the idea, which I am astonished to see so confused. The possession of an image of so great a smallness is not at all the question, It is impossible according to the present constitution of our body, and if we could have it, it would be much the same as that of those things Avhich now appear to us appercejytible ; but in compensation what is now the object of our imagination would escape us and become too great to be imagined. Size has no images in itself, and those which it has depend only upon comparison with the organs and other objects, and it is useless here to employ imagination. Thus it appears by all that you, sir, have said to me here that you are ingenious in devising difficulties without reason, in demanding more than is necessary.] CHAPTER XXX OF REAL AND FANTASTICAL IDEAS § 1. Ph. Ideas in relation to things are real or fantastical, adequate or inadequate, true or false. By real ideas I under- stand those which have a foundation in nature, and which are conformed to a real being, to the existence of things, or to their archetypes ; otherwise they are fantastic or chimerical. Th. [There is a little obscurity in this explication. The idea may have a foundation in nature, without being con- formed to this foundation, as when we maintain that the per- ceptions we have of color and heat do not resemble any orig- inal or archetype. An idea is also real when it is possible, although no existing being corresponds thereto. Otherwise if all the individuals of a species were lost, the idea of the species would become chimerical.] § 2. Ph. Simple ideas are all real, for, although [according to many] whiteness and coldness are no more in snow than is pain, yet their ideas are in us as effects of powers connected 1 Erdmann and Jacques read : "la 10,000me et la lOOOme." — Tr. 276 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii with external things, and these constant effects serve us in distinguishing things as much as if they were exact images of tliat wlaich exists in the things themselves. Th. [I have examined this point above : but it appears thereby that you do not always demand a conformity to an archetype, and, according to the opinion (which, however, I do not approve) of those who think that God has arbitrarily assigned us ideas, destined to mark the qualities of objects without any resemblance or even natural relation, there would be also in that case less conformity between our ideas and the archetypes than there is between the words which we use by institution in language and the ideas, or the things them- selves. ] § 3. Ph. The mind is passive as regards its simple ideas; but the combinations it makes of them to form complex ideas, where many simple ideas are comprised under one and the same name, have somewhat of the volitional element ; for one man admits into the complex ideas he has of gold or of justice simple ideas which another does not admit. Th. [The mind is, however, active in reference to simple ideas when it detaches them one from another to consider them separately, — an act which is voluntary as well as the combination of many ideas ; whether it is done to call atten- tion to a complex idea resulting therein, or whether it is the purpose to comprehend them under the name given to the combination. And the mind cannot be deceived therein pro- vided it does not unite incompatible ideas and provided this name is still virginal, so to speak, that is to say, a name to which some notion has not already been attached, which might cause confusion with that which is newly attached thereto, and make arise either impossible notions by joining together what cannot take place, or notions superfluous and containing some obreption,^ by joining ideas, one of which may and ought to be derived from the other by demonstration.] § 4. Ph. Mixed modes and relations having no other reality than that which they have in men's minds, all that is requisite to make these sorts of ideas real is the possibility of existence or of compatibility together. Th. \_Iielations have a reality dependent upon the mind ^ I.e. Concealment of the truth. — Tr. CH. xxx] ON HUMAN UNDERSTANDING 277 like truths; but not the mind of men, since there is a supreme intelligence which determines them all for all time. Mixed modes, which are distinct from relations, may be real acci- dents. But be they dependent or not dependent upon the mind, it suffices for the reality of their ideas that these modes be possible or, what is the same thing, distinctly intelligible. And for this result it is necessary that their ingredients be compossible, i.e. capable of existing together.] . § 5. Ph. But the complex ideas of substances, as they are all formed in relation to things existing outside of us, and as representative of substances such as really exist, are real only so far as they are combinations of simple ideas really both united and coexisting in things coexisting without ns. On the contrary those are chimerical ^ which are composed of such collections of simple ideas as have never been really united and found together in any substance ; like those which form a centaur, a body resembling gold, save in weight, and lighter than water, a body similar in relation to the senses, but endowed with perception, voluntary movement, etc. Th. [If I take in this manner the terms real and chimeri- cal otherwise in relation to the ideas of the modes than in relation to those which form a substance, I do not see what common notion in each case you give to real or chimerical ideas ; for the modes are real to you when they are possible, and substances have real ideas with you only when they are existent. But in desiring to tally with existence, we can determine but little whether an idea is chimerical or not, because what is possible, although not found in our place or time, may have existed formerly or will perhaps some day exist, or may indeed be found already present in another world, or even in ours without our knowing it, like the idea which Democritus had of the Milky Way ^ which the telescopes have verified : so that it seems better to say that .possible ideas only become chimerical when we attach to them without foundation the idea of effective existence, as those do who promise themselves the philosopher's stone or, as those 1 Locke has: "fantastical," Philos. Works, Vol. 1, p. 510 (Bohn's ed.).^ Tr. 2 Cy. Aristotle, Meteorologica, Bk. I., chap. 8, 345=, 25: "The Milky Way is the light of certain stars." Zeller, Die Philos. d. Griech., 3d ed.. Vol. 1, p. 724, note 1 ; 5th ed., 1892, 1. 2 [Vol. 2], p. 897, note 8. — Tr. 278 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii would do who should believe that there had been a nation of centaurs. Otherwise in not regulating ourselves by exist- ence we shall deviate unnecessarily from the received language, which does not allow us to say that he who speaks in winter of roses or pinks speaks of a chimera, unless he imagines he is able to find them in his garden, as the story is told of Albert the Great' or of some other pretended Magician.] CHAPTER XXXI OF ADEQUATE^ AND INADEQUATE IDEAS § 1. Ph. Real ideas are complete when they represent per- fectly the originals whence the mind supposes them to be taken, which they represent, and' to which it refers them. Incomplete ideas re|)resent only a part of these originals. § 2. All our simple ideas are complete. The idea of white- ness or of sweetness, which is noticed in sugar, is complete, because it suffices for this, — that it corresponds entirely to the powers that God has put into this body to produce these sensations. Th. [I see, sir, that you call complete or incomplete ideas those which your favorite author calls idem adcequatce aut inadcequatce; you might call them perfect or imperfect. I have sometimes defined idea admquata (a perfect idea) as that which is so distinct that all its ingredients are distinct, and such is nearly the idea of a number. But when an idea is distinct and contains the definition or the reciprocal marks of the object, it may be inadoequata or imperfect, viz. : when 1 Albertus Magnus, 1193-1280. Schaarschmidt states that " like many other scholars of those dark centuries (Michael Scotus, Roger Bacon, etc.) he was suspected of Magic," and adds that " Trithemius in particular, who, moreover, takes the philosopher into his protection, gives an account thereof in his An- 7ialeg Hirsaiigienses, Vol. 2, p. 40. Naude in his Apologie des Grands Homines SoiipQonn^s de Magie, chap. 18, Bayle in his Dictionary, see under Albert Le Grand, and Brucker, Hist. Philosophias, 3, 793 sq., have likewise defended iiim." On his life and philosophy, cf. Erdmann, Grundriss d. Gesch. d. Philos. §§ 199-202, Vol. 1, pp. 356 sq., and English translation of same ; also Stockl, Gesch. d. Philos. d. Mittelcdters, Vol. 2,"pp. 352 sq., §§ 101-119. — Tr. 2 Locke's title; the French might be rendered " complete and incomplete," cts in the text. — Tb. CH. xxxi] ON HUMAN UNDERSTANDING 279 these marks or these ingredients are not also all distinctly known ; for example, gold is a metal which resists the cupel and aqua fortis ; it is a distinct idea, for it gives the marks or the detinition of gold; but it is not perfect for the nature of cupellation and the working of aqua fortis is not suliiciently known to us. Whence it comes tiiat, when there is only an imperfect idea, the same subject is susceptible of many delini- tions independent the one of the other, so that we cannot always derive one from the other nor see beforehand that they must belong to one and the same subject, and then experience alone teaches us that they all belong to it at once. Thus gold may still be defined as the heaviest of our bodies, or the most malleable, without speaking of other definitions which might be invented. But we shall be able to see why it belongs to the heaviest of metals to resist these two tests of the assay- ers only when men shall have penetrated farther into the nature of things ; whilst in geometry, where we have perfect ideas, the case is different, for we can prove that the sec- tions of the cone and of the cylinder, made by a plane, are the same, viz. ellipses, and this cannot be unknown to us, if we take notice of it, because the notions we have of them are perfect. With me the division of ideas into perfect and im- perfect is only a sub-division of distinct ideas, and it appears to me that only the confused ideas, like that we have of sweet- ness, of which you, sir, speak, deserve this name ; for although they express the power which produces the sensation, they do not express it wholly, or at least we cannot know this, for if we comprehended what is in this idea of sweetness we have we could judge whether it is sufficient as a rational expression of all that experience causes us to notice therein.] § 3. Ph. From simple ideas let us come to the complex; they are either of modes or of substances. Those of modes are the voluntary collections of simple ideas which the mind puts together without regard to certain archetypes or real and actually existing models ; they are complete and cannot be otherwise, because not being copies but archetypes, which the mind forms in order to avail itself of them in ranking things under certain denominations, they can lack nothing, because each includes siich a combination of ideas as the mind has desired to form, and consequently such perfection as it had 280 LEIBNITZ'S CEITIQUE OF LOCKE [bk. u planned to give thereto, and we cannot conceive that the understanding of any one can have a more complete or more perfect idea of a triangle than that of a figure of three sides and three angles. He who put together the ideas of danger of execution, of the trouble that fear produces, of a calm con- sideration of what it would be reasonable to do, and of an actual application to its execution without being frightened by the danger, formed the idea of courage, and had what he desired, viz. : a complete idea conformed to his good pleasure. It is otherwise in our ideas of substances in which we main- tain that which really exists. Til. [The idea of triangle or of courage has its archetype in the possibility of things as well as the idea of gold. Ancl it is a matter of indifference, so far as the nature of the idea is concerned, whether it was invented in advance of experi- ence, or whether it was retained after the perception of a combination which nature had made. Combination also, which produces the modes, is not wholly voluntary or arbi- trary, for we can put together what is incompatible, as those do who invent machines for .perpetual motion, while others can invent those which are good and practicable which have no other archetypes Avith us than the idea of the inventor which has as its archetype the possibility of things or the divine idea. Now these machines are substances. We can also invent impossible modes, as when we maintain the parallelism of parabolas, by imagining that we can find two parabolas parallel to each other, like two straight lines or two circles. An idea, then, whether it be that of a mode, or that of a substance, may be complete or incomplete according as we understand well or ill the partial ideas which form the total idea : and it is a mark of a perfect idea when it makes known perfectly the possibility of the object.] CH. xxxm] . ON HUMAN UNDEESTANDING 281 CHAPTER XXXII OF TRUE AND FALSE IDEAS § 1. Ph. As truth ^ or falsehood belongs only to proposi- tions,^ it follows that when ideas are termed true or false there is some tacit proposition or affirmation ; § 3. or a tacit assumption of their conformitj'' to something, § 5. above all with what others designate by this name (as when they speak of justice) item to what really exists (as man exists but not the centaur) item to the essence, upon which depend the prop- erties of the thing ; and in this sense our ordinary ideas of substances are false when we think of certain substantial forms. Besides, ideas deserve rather to be called accurate or faulty, than true or false. TJi. I believe that true or false ideas might be so under- stood, but as these different senses do not agree between them- selves and cannot be conveniently ranked under a common notion, I prefer to call the ideas true or false in relation to another tacit affirmation which they all include, which is that of possibility. Thus possible ideas are true, impossible false.'\ CHAPTER XXXIII OF THE ASSOCIATION OF IDEAS § 1. Ph. We often notice something odd in the reasonings of people, and everybody is subject to this. § 2. It is not alone obstinacy or self-love ; for often people who are well disposed are guilty of this fault. It does not indeed suffice to 1 Cf. New Essmjs, Bk. IV., chap. 5. — Tr. 2 Cf. Aristotle De Anima, III. 6,430=-, 27, and E. Wallace, Aristotle's Psychol- ogy in Greek and English, with Introduction and Notes, pp. 160, 161, Cam- bridge: University Press, 1882; also De Interpret. 1, 16^, 12, and E. Wallace, Outlines of the Philos. of Aristotle, 3d ed., § 11, p. 27. For Leibnitz, the true is the thinkable, i.e. that which is free from contradiction in itself and of other truth. Thought-necessity is his criterion of possibility and of truth. — Tr. 282 LEIBNITZ'S CRITIQUE OE LOCKE [bk. n attribute it to education and to prejudice. § 4. It is rather a kind of madness, and we should be foolish if we should always act thus. § 5. This fault arises from a non-natural connection of ideas, which has its origin in chance or custom. § 6. Inclination and interest enter into it. Certain tracts of the repeated course of animal spirits become beaten roads ; when we know ^ a certain air, we find it as soon as we begin it. § 7. Thence arise the sympathies or antipathies which are not born with us. A child has eaten too much honey and has been surfeited by it, and then having become a full-grown man, he cannot hear the name honey without a rising of the stomach. § 8. Children are very susceptible to these impres- sions, and it is well to be careful of them. § 9. This irregu- lar association of ideas has a great influence in all our actions and passions natural and moral. § 10. Darkness revives the idea of ghosts in children because of the stories told them about them. § 11. You do not think of a man whom you hate without thinking of the evil he has done or may do. § 12. You shun the room in which you have seen a friend die. § 13. A mother who has lost a very dear child sometimes loses with it all her joy, until time effaces the impression of this idea, which sometimes never ^ happens. § 14. A man perfectly cured of madness by an extremely painful operation acknowledged all his life his obligation to the one who per- formed this operation ; but it was impossible for him to endure the sight of the operator. § 15. Some hate books all their life because of the bad treatment they received in school. Some one having once gotten the upper hand of another upon some occasion keeps it always. § 16. A man was found who had learned to dance finely, but could not execute the dance unless there was in the room a trunk like the one which had been in the room where he had learned. § 17. The same non-natural bond is found in the intellectual habits ; you bind matter to being, as if there were nothing immaterial. § 18. The sectarian party in jDli^ilosophy, religion, and the state is attached to its opinions. Til. [This remark is important and wholly to my taste, and can be fortified by an infinite number of examples. Descartes 1 Gerhardt reads: " sait " ; Erdmann and Jacques: "suit," follow. — Tr. 2 Gerhardt reads : "jamais"; Erdmann and Jacques : "pas." — Tr. CH. xxxiri] UN HUMAN UNDERSTANDING 283 having had in his youth some affection for a squint-eyed per- son could not prevent himself from having all his life an incli- nation towards those who had this defect. Hobbes, another great philosopher, could not (they say) remain alone in a dark place, without having his mind frightened by images of ghosts, although he did not believe in them, this impression having remained from the stories told to children. Many persons well informed and sensible, and who are decidedly superior to superstition, cannot bring themselves to be thir- teen at a repast withoiit being extremely disconcerted, having sometime been impressed by the fancy that one of them must die during the year. There was a gentleman who, having been injured, perhaps in his infancy, by a badly fastened pin, could not see one in this condition without being ready to fall into a swoon. A prime minister, who bore in the court of his master the name of President, was offended by the title of the book of Ottavio Pisani, called Lycurgus, and wrote against this book, because the author, in speaking of the officers of justice whom he thought superfluous, had named also the Presidents, and although this term in the person of this minister meant a totally different thing, he had so attached the word to his person that he was wounded in this word. And this is a case of the most usual of the non-natural associations, capable of misleading, as those of words to things, when indeed there is any ambiguity. In order the better to understand the source of the non-natural bond of ideas, you must consider what I have already said above (Chap. 11, § 11^), in speaking of the reasonings of animals, that man as well as the animal is inclined to put together in his memory and imagination what he has observed united in his perceptions and experience. It is in this that all the reasoning, if so it may be called, of animals consists, and often that of men, so far as they are empirical and govern themselves only by the senses and examples, without examining whether the same reason still has force. And as often the reasons are unknown to us, we must have regard to the examples in proportion to their frequency, for then the expectation or the reminiscence of one perception 1 Cf. ante, p. 145. Gerhardt has § 1 ; Erdmann and Jacques § 11 ; the latter reference is the correct one, aiid has therefore heen placed in the text of the translation. — Tr. 284 LEIBNITZ'S CRITIQUE OF LOCKE [bk. ii on the occasion^ of another perception which is ordinarily connected therewith is reasonable ; particularly when the question is about taking precautions. But as the vehemence of a very strong impression often produces as much effect at once as the frequency and repetition of manj'' moderate impressions would be able to make in a long time, it happens that this vehemence engraves upon the fancy an image as profound and as vivid as long experience." Whence it comes that a chance but violent impression unites in our imagination and memory two ideas, at that time together there,^ altogether as strongly and durably and gives us the same inclination to connect them and to attend to them one after the other, as if a long usage had verified the connection; thus the same result of association is found, although the same reason does not exist. Authority, party,* custom, produce also the same effect as experience and reason, and it is not easy to deliver one's self from these inclinations. But it would not be very difficult to keep one's self from being deceived in these judg- ments, if men would attach themselves seriously enough to the search for truth, or proceed methodically, when they recognize that it is important to them to find it.] 1 Gerhardt reads: " d'une perception a I'occasion," which Erdmann and Jacques omit. — Tr. 2 Erdmann and Jacques add: " auroit pu le faire," could have done. — Tr. 3 Gerhardt reads: " qui y estoient ensemble alors, tout aussi lortement et durablement ; et nous donne," etc. Erdmann and Jacques, " qui deja y etaient ensemble, et uo\is donne," etc. — Tr. 4 Erdmann and Jacques omit : " le parti." — Tr. NEW ESSAYS ON HUMAN UNDERSTANDING Book III. — Words CHAPTER I OF WORDS OR LANGUAGE IN GENERAL § 1. Ph. God having made man to be a social being, has not only inspired him with the desire, and placed him under the necessity of living with those of his species, but has given him also the faculty of speech which is to be the great instru- ment and common bond of this society. Hence it is that words arise, which serve to represent and also to explain ideas. Th. [I rejoice to see that you are averse to the view of Hobbes,^ who did not admit that man was made for society, 1 Thomas Hobbes, 1588-1679, in his De Give, 1642, and Leviathan, 1651, maintained that man, being by nature a selfish and solitary animal, had no natural impulse for society, and that social union sprang simply from fear and from motives of gain, the natural condition being that of universal war. Leibnitz maintains, in agreement vrith Aristotle and Hugo Grotius, 1583-1645, that Nature herself has destined man for society in order not only that he may the better and more easily realize his highest being, but that he may realize it at all, such realization being impossible in isolation and solitude. Cf, Aristotle, Polit. I., 2, 1253^, 2 : on tmv vaii fjiev ecrriv av6pTrjv TTOieiv TOV IJ.aKa.piOv • ouSels yap eAotT* av Ka9' avTOV to. navr' exeiv ayaOa. ' no\iTi.KOV yap 6 avBpuiiro'; Kal a-vi^iv 7r€<|>vKd40, New York: Macmillan & Co., 1892. For the text of the poems ascribed to him, cf. Benj. Thorpe, Csedmon's Metrical Paraphrase of Fart of the Holy Script-are in Anglo-Saxon ; ivith an Eng. Trails., Notes, and a Verbal Index, London: 1832; C. W. M. Grein, Bibliothek der Angel-Sachsischen Poesie, 1857, Vol. 1 ; new ed. by R. Wiilker, Vols. 1-3, 1883-1889, still in prog- ress ; the A^ol. containing Csedmon has not yet (1892) appeared ; T. W. Hunt, Csedmon's Exodus and Daniel, Boston: Ginn & Co., 4th ed., 1889. — Tr. 3 The Codex Argenteus — Silver Codex — so called because written in silver and gold letters upon purple-stained vellum and bound in silver, as was the 296 LEUBNTTZ'S CRITIQUE OF LOCKE [bk. in liar, which, was found in the ancient monastery of the Benedic- tines of "Werden in Westphalia, and has been carried into Sweden, where it is preserved, as with reason it should be, with as much care as the original of the Pandects in Florence, although this version was made by the Eastern Goths and in a dialect far removed from the Scandinavian German; but it is because they believe, with some probability, that the Goths of the Pontus Euxinus came originally from Scandinavia, or at least from the Baltic Sea. Now the language or the dialect of these ancient Goths is very different from the modern ^__^erman, although it has the same linguistic basis. The ancient Gallic was still more different, to judge by the lan- guage most nearly approaching the true Gallic, which is that of the country of Wales, Cornwall, and Basse-Bretagne ; but the Irish differs therefrom still more and shows us traces of a Britannic, Gallic, and Germanic language, still more ancient. But all these languages come from one soui'ce, and may be case vrith costly Mss. in those days, originally consisted of 330 leaves con- taining tlie Gospels in the following order: Matt., John, Luke, Mark, trans- lated into the Gothic language, about the middle of the foui-th century, by BishoiJ Ulfilas (Yulfila), 311-383. Only 177 leaves no-^ remain. Cf. F. L. Stamni, Ulfllas, 1872, new ed. by M. Heyne, Paderboru, 1885, Einleitung, p. ix. The Ms., like all existing Gothic Mss., seems to h^ave been written in Italy during tlie rule of the East Goths in the first half of the sixth century, and, after many adventm-es, was at last carried in 1669 to Upsala, where it now is. It is one of the few sources of our knowledge of Gothic, and, as Ulfilas was a fine scholar, and made his translation of the New Testament from the Greek original, with frequent comparison of the Latin versions, it is of some value in New Testament textual criticism. Editions of Ulfilas may be named as follows: The two earlier, by H. C. v. d. Gabelentz and J. Loebe, 3 vols., Altenburg u. Leipzig, 1843-1846, and H. F. Massmann, Stuttgart, 1855-1856, 2 vols. 8vo, rest upon still older single editions with many faults. Cf. H. Paul. Grundriss d. germ. Philologie, II, 69, Anm. 2. The critical editions of A. Uppstrom: Codex Argentevs, Upsala, 1854-1855; Decern codicis arg. rediviva folia, ih. 1851 ; Fragmenta gothica selecta, ib. 1861; Codices gothici Ambrosiani, Stockh. u. Leipzig, 1864-1868, in whose work for the first time was laid an entirely secure foundation for Gothic text-criticism, and upon whom the later editions rest. Cf. H. Paul, op. cit.; and Stamm-Heyne, Ulfllas, Einl. p. xi. The larger ed. of E. Bernhardt, Vulftla, oder die gotische Bihel, Halle, 1875, is the best for comparison with the Greek ; while his smaller ed.. Die gotische Bihel des Vulfila, Halle, 1884, and that of Stamm-Heyne cited above are the most convenient. The best introduction to Gothic in English is J. Wright, A Primer of Gothic, London and Xew York, Macmillan & Co., 1892. Cf. also W. Scherer, Gesch. d. deutschen Lit., 6th ed., pp. 33-36, Eng. trans., Vol. 1, pp. 28-32; Waitz, Das Lehen des Ulfllas, 1.840: Krafft, .B'/?-c7ie?i- gesckichte d. Deutschen Volker, Abth. 1, 1854, and article " Ulfilas," in Herzog, Realenc2j'klopcidie, Vol. 16, 1885. — Te. CH. II] ON HUMAN UNDERSTANDING 297 taken as modifications of one and the same language, which may be called the Keltic. Thus the ancients called both the Germans and the Gauls Kelts; and in going back farther in order to understand the origin both of the Keltic and the Latin and the Greek, which have many roots in common with the Germanic or Keltic tongues, we may conjecture that this fact arises from the common origin of all these peoples de- scended from the Scythians, who, having come from the Black Sea, passed the Danube and the Vistula, and of whom one part may have gone into Greece, the other have filled Germany and the Gauls ; a consequence of the hypothesis which makes the Europeans come from Asia. The Sarmatian (supposing it to be the Sclavonic) has at least half its origin either Germanic or common with the Germanic. The case appears to be some- what similar, indeed, in the Finnish language, which is that of the most ancient Scandinavians, before the Germanic peoples, i.e. the Danes, Swedes, and Norwegians, had taken possession of the land which is the best and nearest the sea; and the language of the Finns or of the northeast of our continent, which is also that of the Lapps, extends from the German or Norwegian Ocean even to the Caspian Sea (although inter- rupted by the Sclavic peoples which have been thrust in between the two) and has some relation to the Hungarian, having come from the countries which are now in part under the Muscovites, But the Tartar language, which has filled the northeast of Asia, with its variations, appears to have been that of the Huns and Cumans as it is of the Uzbeks or Turkomans, of the Kalmuks and of the Mongols. Now all these languages of Scythia have many roots common among themselves and with ours, and it is found that even the Arabic (under which the Hebrew, the ancient Punic, the Chaldee, the Syriac, the Ethi- opic of the Abyssinians are to be comprised) has so great a number of them and an agreement so manifest with ours that it cannot be attributed to chance alone, nor even to commerce alone, but rather to the migrations of the peoples. So that there is nothing in this to combat and not rather to favor the view of the common origin of all nations, and of a primitive root language.^ If the Hebrew or ' the Arabic approaches the 1 Leibnitz was the first who, from the point of view of a presentiment of the kindred connection, first of the European, and then of tha remaining Ian- y*. 298 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi nearest to it, it must be at least much changed, and the German seems to have, preserved more completely the natural and (to use the language of Jacob Boehme) the Adaniic;^ for if we had the primitive language in its purity, or sufficiently preserved to be recognizable, the reasons of the connections vi^hether natural or of an arbitrary institution would necessa- rily appear wise and worthy of the primitive author. But supposing that our languages are derivative as regards their foundation, they nevertheless have something primitive in hemselves which has arisen from them in relation to new root words ^ since formed among them by chance but upon natural grounds. Those which signify the sounds of animals or have come from them furnish examples. Such, for exam- ple, is the Latin coaxare attributed to the frogs, which has some relation to couaqaen or quaJieu ia German. Now it guages, demauded and himself urged on the comparative study of languages, and in this, as in so many other tilings, was far in advance of his time. For his linguistic work, cf. Dutens, Leibnit. opera omnia. Vols. 5 and 6. — Tr. 1 Jacob Boehme, 1575-lG2i, a celebrated theosophist, in whom Protestant mysticism reached its highest point. He is called philosophus teutonicus, and " in reality through him, for the first time in Germany, did philosophy come forward with a characteristic stamp " ; Hegel, Vorlesuny. ii. d. Gesch. d. Fhilos., Vol. 3, p. 270, 2d ed., Berlin, 1833. O. Pfleiderer, Religionsphilosophie, Vol. 1, p. 20, 2d ed., Berlin, 1883, says, "The theosophy of Boehme shov/s itself as the direct forerunner of the metaphysic of Leibnitz, 1646-1716, Schelling, 1775- 1854, Baader, 1765-1841, Schopenliauer, 1788-1860, etc." For his philosophy, etc., cf. his SdmmtUche Werke, hrsg. v. K. W. Schiebler, Leipzig, 1831-47, 2d ed., 1861 sq. ; also Hegel, op. cit., Vol. 3, pp. 270-297 ; Stock], Gesch. d. Fhilos. d. Mittelalters,Yo].3,iyp. 569-608, §§ 122-128; O. Pfleiderer, op. cit., Vol. 1, pp. 15-23 , Eng. trans.. Vol. 1, pp. 13-23 ; B. Piinjer, Gesch. d. Christ. Religions- philos.. 1880-83, Vol. 1, pp. 180-194; Eng. trans.. Vol. 1, pp. 243-265, T. and T. Clark, Edinburgh, 1887. Vaughan, Hours loith the Mystics, Vol. 2, pp. 79-125, 3d ed., London : 1879. According to Boehme, cf. Das dreyfache Lehen, chap. 8, 2-4; Princ, 10, 8-12; My.^t. Mar/., chap. 15, 1-9, etc. ; also Stockl, op. cit., §§ 125, 126, Vol. 3, pp. 586 sg. ,• Adam, who stands here in Leibnitz's text " as the symbol and representative of the original unity of the race," and of its lan- guage, " was destired to propagate his race in angel-like purity without endangering its integrity." Leibnitz, while acquainted with Boehme's writ- ings, made little use of them in his own thinking, and speaks thus of them in a letter to Fr. S. Loeffler, Jan. 13, 1693, cf. Dutens, op. cit., Vol. 5, p. 409 : "The controversies over the opinions of Boehme I consider idle, and think that he neither understood himself nor have others understood him." — Tr. 2 Gerhardt's text reads: "Qui leur est survenu par rapport a des mots radicaux nouveaux, formes depuis chez elles," etc. Erdmann and Jacques read: "qui leur est survenu par rapport a des mots radicaux et nouveaux radicaux forme's depuis chez elles," etc. ; i.e. new root words and new roots since formed among them, etc. — Tr. CH. II] ON HUMAN UNDERSTANDING 299 seems that the noise of these animals is the primordi^,! root of other words of the German language. For as these animals make much noise, the term is attributed to-day to idle talk and to babblers, who are called quakeler in the diminutive form ; but apparently this same word quaken was formerly under- stood in a good sense and signified all sorts of sounds made with the mouth not even excepting speech. And as these sounds or noises of animals are an evidence of life, and as we know thereby before we see it that there is life there, qiiek in old German has come to signify life or living, as may be observed in the most ancient books, and there are also traces of the same in the modern language, for Quecksilber is quick- silver (vif-argent), and erquicken is to strengthen, and, as it were, to vivify or recreate after exhaustion or some great labor. Certain weeds are called also in Low German Quaken, alive so to speak and running, as they say in German, which spread and propagate themselves easily in the fields to the detriment of the grain ; and in English quickly means promptly andin a^ wide-awake manner. Thus we may consider that as regards these words th'e German language may pass, as the primitive, the ancients having no need to borrow elsewhere a sound which is the imitation of that of the frogs. And there are many others in which the same thing appears. For it seems that the ancient Germans, Kelts, and other peoples allied to them have employed by a natural instinct the letter R • to signify a violent movement and a noise like that of this letter.^ It appears in pew, Jtuo, rinnen, rilren (fluere), rutir (fluxion), the Rhine, Rhone, Roer (Rhenus, Rhodanus, Erida- nus, Rura), rauben (rapere, ravir), Radt (rota), radere (reiser), rauschen, a word difficult to translate into French; it signifies a noise like that which the wind or a passing animal stirs up in the leaves or the trees, or is made by a trailing dress ; reckken (to stretch with violence), whence it comes that reichen is to reach ; that der Rick signifies a long stick or perch useful for suspending anything, in this kind of Plat-tiitsch or Low Saxon which is (spoken) near Brunswick; that Rige, Reihe, 1 Cf. Plato, CraU/kis, iSi sq.; Enijlish Translation by B. Jowett; 2d ed., 1875, Vol. 2, p. 259 sq.; 3d ed., 18!)2, Vol. 1, p. 381 sq., where the author has already made an attempt, similar to that made here and many times l^elors by Leibnitz, to fix the original significance of single letters in the formation of words. — Tr. 300 LEIBNITZ'S CRITIQUE OE LOCKE [bk. hi regula, regere, refer to length or a straight course ; and that Reck has signified a thing or person very extended and long, and in particular a giant, and then a powerful and rich man, as it appears in the reicli of the Germans and in the riclie or ricco of the Semi-Latins. In Spanish ricos liomhres means the nobles or chief men ; and this makes it plain at the same time how metaphor, synecdoche, and metonymy have caused words to pass from one signification to another without our being able always to trace them. This noise and violent movement is noticed also in Riss (rupture) with which the Latin rumpo, -the Greek p-qyvvfii, the French arracher, the Italian straccio are connected. Now as the letter E. signifies naturally a violefit movement, the letter L designates a gentler one. Thus we see that children and others who find the E, too harsh or too diffi- .cult to pronounce substitute for it the letter L, saying, for example, mon Uvelend pUe} This gentle movement appears in 2ehen (vivre — live), laben {conforter — comfort, faire vivre — make live), lind, lenis, lentus {lent — slow), lieben (aimer — love), lauffen (glisser promptenient comme Veau qui coule — to glide quickly like flowing water), lahi {glisser — to touch lightly, labitur uncta vadis abies^), legen {viettre doucement — to place gently), whence comes liegen (coucher — to lie down), lage or laye {un lit, comme un lit de pierres — a bed, as a bed of rocks). Lay-stein {pierre d coaches, ardoise — slate), lego, icli lese (je remasse ce qu^on a mis — I collect what has been invested, it is the opposite of mettre — to place, and then je lis — I read, and finally among the Greeks je parle — I speak ^), Laub (feuille — leaf),, a thing easy to stir, to which are related also lap, lid,* lenken, luo, Xww {solvo), leien^ (in Low-Saxon) to dis- solve, to melt like the snow, whence the Leine has its name, a river of Hanover, which, rising in the mountainous coun- tries, is greatly enlarged by the melted snows ; not to speak of an infinite number of other similar appellations, which prove that there is something natural in the origin of words which indicates a relation between things and the sounds and move- 1 I.e. " Reverend pere." — Tr. 2 cf. Vergil, ^n. 8, 91. — Tr. 3 Erdmann and Jacques omit: " Et puis je lis et enfin chez les Grecs je parle," the reading of Gerhardt. — Tr. 4 Gerhardt's reading ; Erdmann and Jacques have " liel." — Tr. 5 Gerhardt's reading; Erdmann and Jacques have "lien." — Tr. CH. II] ON HUMAN UNDERSTANDING 301 ments of the vocal organs ; and it is furthermore for that reason that the letter L joined to other nouns makes their diminutives with the Latins, the Semi-Latins, and the High Germans. But it must not be pretended that this reason can be noticed everywhere, for the lion, the lynx, the wolf, are anything but gentle. But it may be attached to another acci- dent, the speed (lauf), which makes them feared or compels flight ; as if the one who sees such an animal coming should cry to the others : lauf (fnyez ! — fly !) ; besides by many acci- dents and changes the majority of words are very much altered and diverted from their pronunciation and original signification. Ph. Yet an example would make it better understood. Th. Here is one plain enough and which comprehends manj others. The word oeil (eye) and its parentage may serve us. To show it I will begin a little further back. A (the first letter) followed by a little aspiration makes Ah, and as this is an emission of the air which produces a sound clear enough at its beginning and then vanishing, this sound naturally sig- nifies a light breath (spiritus lenis) when A and H are not very strong. Thence it is that aw, aer, aura, haugh, halare, haleine, ar/xos, Athem, Odem (in German) have had their origin. But as water is also a fluid and makes a noise, it has come (it seems) that ah made roiigher by doubling, i.e. aha or ahha, has been taken as water. The Teutons and other Kelts, the better to indicate the motion, have placed their W before both. Thence wehen, Wind, vent, indicate the motion of the air, and waten, vadum, water, motion of or in the water. But to return to aha, it appears to be (as I have said) a kind of root which means water. The Icelanders, who preserve some- what of the Scandinavian Teutonic, have lessened the aspira- tion of some by saying aa; others, who say Aken (meaning Aix, Aquae grani^), have increased it, as do also the Latins in their aqua, and the Germans in certain places, who say ach in compositions to indicate water, as when Schwarzach^ means black water, Biberach water of the beavers. And instead of Wiser or Weser they said Wiseraha in the old titles, and Wisurach ^ among the ancient inhabitants, of which the Latins 1 I.e. Aquis Granum, Aix-la-Chapelle. — Tr. 2 Gerhardt's reading; Erdmann and Jacques read : " " Schwartzach," " Wiserach." — Tr. 302 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi have made Visurgis, as from Her, llerach, they have made Hargus. From aqua, aigues, aiaie the French have finally made eau, which they pronounce oo, in which there no longer remains anything of its origin. Auive, Auge with the Ger- mans is to-day a place which water often overflows, suitable for pasturage, locus irriguus, pascuus ; but more particularly it signifies an island, as in the name of the monastery of Beichenau (Augia dives), and many others. And this (process) must have gone on among many of the Teutonic and Keltic peoples, for thence it has come that everything which is, as it were, isolated in a kind of plain has been called A^(ge or Ouge, ocidus. Thus it is they name spots of oil upon water among the Germans ; and among the Spaniards ojo is a hole. But Auge, Ooge, ocidus, occhio, etc., have been applied more particularly to the ceil, as it were, pre-eminently, which makes this isolated brilliant foramen in the countenance ; and doubt- less the French oeil comes from it also, but its origin is not at all recognizable, unless by the concatenation I have just given ; and the o/x/xa and oi/fts of the. Greeks appear to come from the same source. Oe or Oeland is an island among the inhabitants of the North, and there is some trace of it in the Hebrew, where i^, Ai, is an island. Bochart - believed that the Phoenicians derived the name which he thinks they gave to the ^F^gean Sea, full of islands, from the same source. Augere, augmentation, comes also from Auue or Auge, i.e. from the effusion of waters, as ooken, auken in old Saxon was to augment ; and Augustus, when speaking as Emperor, was trans- lated by Ooker. The river of Brunswick, which comes from the Hartz Mountains, and consequently is much subject to sudden accretions, is called Ocker, formerly Ouacra. And I mention in passing that the names of rivers, having ordinarily 1 Samuel Bochart, 1599-1667, an eminent French scholar and Protestant theologian, a distinguished orientalist, and a man of profound erudition, thoroughly familiar with all the principal oriental languages, including Hehrew, Clialdaic, Syriac, and Arabic, and so enthusiastic in linguistic studies that even when far advanced in years he desired to learn Ethiopic. His favorite study was Phoenician, and though modest and candid he seeks to derive all languages etymologically " from the Hebrew or Phoenician," a pro- cedure wliich led him into many fanciful etymologies. Cf. Dutens, Leibnit. "'opei-a omnia, Vol. 6, Pt. II., pp. 223, 226. His complete works were published under the title, Scmi. Bochart, opera omnia. Leyden, 1675, 2 vols, fol., 1692. 1712, 3 vols. fol. Leibnitz prized and often cited them. — Tr. cii. II] ON HUMAN UNDERSTANDING 303 come from the farthest known antiquity, show best the old language and the ancient iiihabitants ; hence they deserve particular investigation. And languages in general being the most ancient monuments of peoples, before writing and the arts, show best the origin of cognations and migrations. Hence etymologies much extended would be curious and sig- nificant; but it is necessary to unite the languages of many peoples, and not to make too many leaps from one nation to another far distant without having good verifications, in which process it is especially useful to have intervening peoples as guarantees. And in general credence must be given to ety- mologies only when there is a quantity of concurrent evidence ; to do differently is to goropise. Ph. To goropise? What does that mean? Th. It means that the strange and often ridiculous etymol- ogies of Goropius Becanus,^ a learned physician of the sixteenth century, have passed into a proverb, although otherwise he may not have been excessively wrong in claiming that the German language, which he calls Gimbric, has as many, yes, more, marks of a primitive character than the Hebrew itself. I remember that the late Mr. Clauberg,^ an excellent philoso- 1 John Becan, 1518-1572, a Belgian physician and scliolar, whose real name was Van Gorp — Latinized as Goropius Becanus. He practised medicine for some years at Antwerp, but finally gave himself wholly to the study of antiquity, belles-lettres, and ancient languages. In a public lecture at Liege, he attempted to demonstrate that the language of Adam was the Flemish or Teutonic, a view which he set forth at length in his Origines Antiverpianse sive Cimmeriorum Becceselana, etc., Antwerp, 1569, fol. ; and, as at that time he considered the Netherlands to be the site of Paradise, to derive language in general from the Low-German, which he calls the Cimbric, in his paper Hermathena, Bk. II., p. 25 ,55. Cf. Joannis Goropii Becani opera hactenus in lucem nonedita; nempe, Hermathena, etc., Antwerp, 1580, fol. — Tr. ^ John Clauberg, 1G22-1G65, a German philosopher of the Cartesian school, who, first as a commentator merely and afterwards more independently, introdiiced and expounded the philosophy of Descartes in the universities at Herborn and Duisburg, where he was professor successively of theology and philosophy. He wrote a commentary on the Meditatinnx of Descartes, and in his own speculations anticipated much of the subsequent development of Car- tesianism. In his Be conjunctione anmas et corporis liumani Krriptvrn, he maintained that bodily movements are antecedents only and not strictly causes of mental action, a view similar to that of Malebranche. He proposed for metaphysics the name Ontosophy or Ontology, a hint which Christian Wolf, 167S;t-1754, afterwards followed. Cf. Erdmann, Grund. d. Gesch. d. Philoa., §§ 208, 4, 290, 4, Vol. 2, pp. 33, 187, "Sd ed., Berlin, 1878, and English trans, ad loc His Ontosophia, de cognitione Dei et nostri appeared at M.uhlberg, 1687, 304 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi plier, has published a brief essay upon the sources of the German language which makes one regret the loss of that which he had promised upon this subject. I have myself publislied some thoughts upon the subject, besides inducing the late Gerard Meier/ a theologian of Bremen, to work upon it, which he did till death interrupted him. I hope, however, that the public will yet one day profit from his labors as well as from the similar labors of Mr. Schilter,^ a celebrated juris- consult at Strasburg, but who also has just died. It is certain at least that the Teutonic language and antiquities enter into the majority of the researclies into European origins, customs, and antiquities. And I wish that learned men would make as much of them in the languages of the Wallachians, Bis- cayans, Slavonians, Finns, Turks, Persians, Armenians, Geor- gians, and others, the better to discover the harmony which would particularly be of service, as I have just said, in clearing up the origin of nations.] § 2. Ph. [This design is important, but at present it is time to leave the matter of tcords, and to return to their form, i.e. to 1 vol., 12mo; and his Opera philosophica at Amsterdam, 1691, 2 vols., 4to. Leibnitz had a high regard for him, both as a philologist and philosopher, and in one expression apparently places him even above Descartes; " Carte- sius voluit qusedam emendare in physicis, displicet tamen audacia et fastus nimius conjunctus cum stili obscuritate, confusione, maledicentia. Longe magis mihi probatus Claubergius, discipulus ejus, plenus, perspicuus, brevis, method- icus." Cf. Otium Hanoveranum, ed. J. F. Feller, p. 181, Lipsi*, 1718; Dutens, Leibnit. opera omnia, Vol. 6, Pt. I., p. 311. Leibnitz frequently mentions him and his works, particularly the Meditutiones et collectanea linguse Teutonicse, Duisburgi, 1663, and the booklet Ars etyniolor/ica Teutoniim; cf. Dutens, op. cit., Vols. 5, p. 334; 6, Pt. II., pp. 28, 179, 22o! In the Ars etymol. Teuton. Clauberg puts it forth as a fundamental proposition that the German must be explained as an original language. Cf. L. Neff., G. W. Leibniz als Sprach- forscher vnd Etymologe, Pt. I., p. 16 sq., Heidelberg, 1870. — Tr. 1 Gerard or Gerhard Meier or Meyer, who was incited by Leibnitz to the study of German philology, and collected an abundance of select materials for a Grammatica Germanica and Gloi^sarium Saxonicitm, but was prevented fi-om completing the work begun by his early and sudden death; cf. Eccard, Collectanea etymologica, 2 vols., 8vo, Hannoverae, 1717, Einleitung, p. 52, and Dutens, Leibnit. opera omnia, Vol. 6, Pt II., p. 145, note. Leibnitz states that the Glossar. Saxon, was planned and undertaken with his encouragement, and that it will contain much erudition; cf. Dutens, op. cit. ,Yo\s. 5, p. 115; 6, 114, and note.. For the correspondence between Meyer and Leibnitz, which exhib- its Meyer's method in his etymological work, cf. Dutens, op. cit.. Vol. 6, Pt. II., pp. 145-176. Leibnitz says : " His learning and character are esteemed by all " — " Doctrina ejus, et virtus apud omnes in pretio habentur," Dutens, op. cit.. Vol. 5, p. 105. — Tr. 2 Cf. ante, p. 295, note L — Tr. cu. iij ON HUMAN UNDERSTANDING 305 the meaning which is common to the different languages.} Now you will agree with me in the tirst place, sir, that when one man speaks to another it is of his own ideas that he wishes to give signs; the words cannot be applied by him to things which he does not know. And until a man has ideas of his own he cannot suppose them to correspond to the qualities of things or to the conceptions of another. Til. [It is true, however, that he intends very often to indicate what others think rather than what he himself thinks, as happens only too much in the case of the laity, whose faith is implicit. But I admit that he always means something general, however hollow and destitute of intelli- gence the thought may be ; and he takes pains at least to arrange his words according to the custom of others, content- ing himself with the belief that their sense can be apprehended at need. Thus he is sometimes only the interpreter (trucJie- man) of thoughts, or the bearer of the word of another, just as a letter would be ; and indeed this is the case oftener than you think.] § 3. Fh. [You are right in adding that he always means something general, however idiotic it may be.] A child hav- ing noticed in what he hears called gold only a brilliant yellow color, gives the name of gold to this same color which he sees in a peacock's tail; others will add great weight, fusibility, malleability. Th. [I admit it ; but often the idea ydu have of the object of which you speak, is still more general than that of this child, and I doubt not that a blind person can speak pertinently of colors and make a speech in praise of the light which he does not know, because he has learned its effects and circum- stances.] § 4. Ph. Your remark is quite true. Men often apply their thoughts more to words than to things, and because they have learned most of these words before becoming acquainted with the ideas which they signify, not only children, but also grown- up men often speak like parrots. , § 5. But men ordinarily mean to indicate their own thoughts, and further they attribute to words a secret relation to the ideas of another and to things themselves. For if the sounds were attached to another idea by the one with whom we are conversing, it would be necessary X 306 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi to speak two languages. It is true that one does not stop too much to examine wliat the ideas of others are, and our idea is supposed to be that which the common people and the scholars of the country attach to the same word. § 6. This is particu- larly the case as regards simple ideas and modes ; but as regards substances the belief is more particularly that the words signify also the reality of things. Th. [Substances and modes are equally represented by ideas; and things, as well as ideas, in both cases are indi- cated by words ; thus I see but little difference, save that ideas of substances and of sensible qualities are more fixed. For the rest, it sometimes happens that our idaas and thoughts are the matter of our discourse and constitute the thing itself which we desire to signify, and that reflective notions enter more than we think into those of things. We speak, indeed, sometimes of words in a material way, without in this case being able to substitute with precision in the place of the word its signification or its relation to the ideas or things.^ 1 Leibnitz here points out a source of manifold, far-reaching and influential errors, especially fatal in philosophy, viz. the hypostasizing of concepts, i.e. regarding and using universal thought-symbols as substances, a consequence of the excessive use of abstract terms. To these errors thus arising from the imperfection and abuse of words and their influence on the mind, Francis Bacon, 1561-1626, in his JV^ov. Org. Bk. I., Aphor. 43, 59, 60, gives the name of idolafori, idols of the market-place, and says they are "omnium molestis- sima " — " the most troublesome of all." These words are either names merely of non-existent things or of things supposed to exist because of these names, or are names obtained by "vicious and unskilful abstraction" — "mala et imperita abstractione " — from a few objects and indiscriminately applied to all other things having the faintest analogy thereto. The best ed. of Bacon's Works is that of Ellis, Spedding, and Heath, 2d ed., 7 vols., London: Long- mans, 1870-72. The Nov. Org., in Latin, is in Vol. 1, the Eng. trans, in Vol. i of this ed. Editions of the iVov. Org. (Latin) have been published with Eng. notes, and an Eng. trans, in a separate vol., by G. W. Kitchin, Oxford: Clar- endon Press, 1855; and with Introd., Notes, etc., by Thos. Fowler, Oxford: Clarendon Press, 1878. For Leibnitz's estimate of Bacon, whose De Aug. Scient. he mentions among the writings which happily chanced to come into his hands when a youth, and with others helped to direct his studies in the right path, whom he enumerates among " the founders of modern philosophy," and whose method he applied in his reform of the science of language, cf. Gerhardt, Die philo!:. Schrift. V. G. W. Leibniz, Vols. 1 : 196; 3 : 7, 16; 4 : 143, Erdmann, Leibnit. opera philos., p. 61, b; G. 4 : 64, E. 23, a; G. 4 : 105, E. 45, a, also G. 7 : 325, E. 110, b; G. 4 : 337, 343; 7 : 52, 53, E. 91, b, 92 ; G. 7 : 67; 7 : 495, Dutens. Leibnit. opera omnia, 5: 368; 6 : 303; G. 7 : 518, E. 421, a. Cf. also John Nichol, Bacon, Vol. 2, pp. 238-239 (Philos. Classics), Edinburgh: Wm. Black- cn. Ill] ON HUMAN UNDERSTANDING 307 This occurs not only in speaking as a grammarian, but also in speaking as a lexicographer, in giving the explication of the term.] CHAPTER III OF GENERAL TERMS § 1. Ph. Although particular things alone exist, the larg- est number of words are general terms, because it is impossible, § 2, for each particular thing to have a particular and distinct name ; besides the fact that in such case a prodigious memory would be necessary, in comparison with which that of certain generals who could call by name all their soldiers would be nothing. The matter indeed becomes infinite, if every animal, every plant, and even every leaf of a plant, every grain, in short every grain of sand, which might need a name must have its name. [x4.nd how name the parts of things sensibly uniform, as water, fire ?] § 3. Besides, these particular names would be useless, the principal end of language being to excite in the mind of him who listens to me an idea similar to mine. [Thus the similitude suffices, which is indicated by general terms.] § 4. And particular words alone would not. serve to extend our knowledge, [nor to make us judge of the future by the past, or of one individual by another.] § 5. But as it is often necessary to mention certain individuals, particularly of our species, use is made oi proper names ; which are given also to countries, towns, mountains and other dis- tinctions of place. And horse-jockeys give 'proper names even to their horses, as well as Alexander to his Bucephalus, in order to be able to distinguish this or that particular horse when he is out of their sight. Th. [These remarks are good, and some of them agree with those I was about to make. But I would add, in accord- ance with the observation I have already made, that proper names have been ordinnrily appellatives, that is to say, general wood & Sons, 1889. For a brief comparison of Leibnitz and Bacon and of their pliilnsophies, of. J. T. Merz, Leibniz, pp. 21, 71 (Blackwood's Pbilos. Classics), Edinburgh-: 1884. — Tr. 308 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi in their origin, as Brutus, Caesar, Augustus, Gapito, Lentulus, Piso, Cicero, Elbe, Rhine, Ruhr, Leine, Ocker, Bucephalus, Alps, Brenner or Pyrenees ; for you know that the first Brutus had this name from his apparent stupidity, that Csesar was the name of a child drawn by incision from the womb of his mother, that Augustus was a name of veneration, that Capito is a large head as also Bucephalus, that Lentulus, Piso, and Cicero were names given in the beginning to those who cultivated in particular certain kinds of vegetables. I have already said what the names of these rivers signify, Rhine, Ruhr, Leine, Ocker. And you know that all rivers are still called Elbe in Scandinavia. Finally Al})s are mountains, covered with snow (with which agrees album, white) and Brenner or Pyrenees signifies a lofty pride, for bren was high or chief (as Brennus) in Keltic, as also brinck with Low- Saxons is pride, and there is a Brenner between Germany and Italy as the Pyrenees are between Gaul and Spain. Thus I would venture to say that nearly all words are originally gen- eral terms, because it will only rarely happen that an express name will be invented without reason to indicate one such individual. We can say then that the names of individuals were names of a species which was given jx^''^" excellence or otherwise to some individual, as the name large head to that one of the whole city who had the largest or who was the most important of the large heads which were knoAvn. Thus it is indeed that we give names of genera to the species, i.e. that we shall content ourselves with a term more general or more vague to designate more particular species, when we have no concern for their differences. For example, we are contented with the general name, wormwood, although there are so many species of it that one of the Bauhins ^ has filled a book expressly with them.] 1 Jean Bauhin, 1541-1613, a Swiss physician and naturalist, who devoted himself chiefly to botany, and with his brother Gaspard, 15fiO-lH24, also a physician and botanist, was born at Basel, whither his father, an eminent French physician, had fled in exile because of his conversion to Protestant- ism. He studied with the celebrated botanist Fuchs at Tiibingen, and after travelling and collecting plants in the Alps, in France, and in Italy, became, in 1570, physician to Duke Ulrich of Wiirtemberg at Montbeliard, where he remained till his death. The work of his to which Leibnitz here alludes is entitled De plantis absinthii nomen habentibus. It appeared at Montbeliard CH. Ill] ON HUMAN UNDERSTANDING 309 § 6. Ph. Your reflections upon the origin of x>i'op^r names are very just ; but to come to that of appellative names or general terms, you will doubtless agree, sir, that words become general when they are signs of general ideas, and ideas become general when separated by abstraction from time, place, or such other circumstances as may determine them to this or that particular existence. Th. [I do not deny this use of abstraction, but it is rather in ascending from species to genera than from individuals to species. For (paradoxical as it may appear) it is impos- sible for us to have the knowledge of individuals, and to obtain the means of determining exactly the individuality of anything, at least of keeping it by itself ; for all the circum- 'stances may reappear ; the smallest differences are to us insen- sible ; place or time, far from determining themselves, need themselves to be determined by the things they contain. The most important factor in the problem is the fact that individu- ality includes infinity, and only he who is capable of com- prehending it can have the knowledge of the principle of individuation of this or that thing. This ■ arises from the influence (understanding it healthfully) of all things in the universe upon each other. It is true that this would be the case, if the atoms of Democritus existed, but in that case also there would be no difference between two different individ- uals of the same form and size.] § 7. Ph. It is, however, wholly evident that the ideas which children frame of persons with whom they converse (to con- fine ourselves to this example) are similar to the persons themselves, and particular only. The ideas they have of their nurse and their mother are very well traced in the'ir minds, and the names nurse and mam.ma, which children use, relate only to these persons. Afterwards when time has shown them that there are many other beings resembling in 1593. His most important work, composed with the assistance of his fellow- countryman and son-in-law Cherler, and containing descriptions of about 5000 plants with 3577 figui'es, is the Historia imirerscdis plantarum nova et absolu- tissima, Yverdun, 1650-1G51, 3 vols., fol. An abridgment of this great work was published by Chabre'e, of Geneva, with the title Sriar/raphia, l(i6(), con- taining in one volume all the figures, together with all of importance on the nomenclature and number of species in the great work. He was one of the founders of modern botany. — Tr. 310 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi their father or mother, they form an idea in which they find that all these particular beings equally share, and they, as others, give it the name of man. § 8. They acquire in the same way names and notions more general ; for example, the new idea of animal is not produced by any addition, but only by removing the figure or the particular properties of man, and retaining a body accompanied by life, feeling, and spon- taneous movement. Th. [Very well ; but that shows only what I just said ; for as the child advances by abstraction from the observation of the idea of man to that of the idea of animal, he has come from the more specific idea observed in his mother or father and in other persons to that of human nature. For in order to discern that he had not the precise idea of the individual, it is sufficient to consider that an ordinary resemblance would deceive him easily and make him take as his mother another woman. You know the story of the false Martin Guerre,^ who deceived even the wife of the true, and the near relatives, by resemblance united with skill, and embarrassed for a long time the judges, even when the true Martin had arrived.] § 9. Fh. Thus this whole mystery of genus and species, which makes so much noise in the schools, but which outside of them is with reason so little regarded, this whole mystery, I say, reduces itself solely to the formation of abstract ideas more or less extended, to which certain names are given. ^ 1 Cf. Essais de Thiodicee, Discours iireliraiuaire, § 42, Gerhardt, 6, 74, Erdmann, 491, b, Jacques, 2, 48. In the sixteenth century, Martin Guerre, a gentleman of Gascony, disapjpeared from home. After a long absence, a man by the name of Arnaud du Thil suddenly appeared, claiming to be Martin Guerre, and was acknowledged by the wife of Guerre as her husband. She had by him two children. Learning, afterwards, that her true husband was in Flanders, she angrily delivered the impostor into the hands of justice. The long trial, one of the most celebrated cases of the century, was brought to an end by the sudden and unexpected arrival of the true Martin Guerre, and Du Thil was sentenced to death. For further details, and the sentence in full, cf. P. Larousse, Grand Diet. Universel de X/X« Steele, Vol. 8, p. 1603, b, c. A parallel case in recent times was tlie Tichborne trial in England. — Tr. ^ The philosophies of Locke and Leibnitz present a sharp contrast on the question of genera and species, and the real existence of the universal. Accord- ing to Locke, the question is a wholly empty one, an inheritance from the vuiprotitable discussions of scholasticism. The general term, the universal, is a purely subjective product of the more or less arbitrary activity of man in abstraction, and has nothing whatever to do with reality. Leibnitz maintains that the universal is the inner essence of things, and that the formation of CH. HI] ON HUMAN UNDERSTANDING 311 Til. [The art of classifying things into genera and species is of no little importance and of much use both to the judg- ment and the memory. You know how important this is in botany, not to speak of animals and other substances, and without mentioning also beings moral and notional/ as some call them. Order largely depends upon it, and many good authors so write that their entire discourse can be reduced to divisions and subdivisions, according to a method which has some relation to genera and species, and is of use not only in retaining things, but also in finding them.^ And they who have arranged all sorts of notions under certain titles or pre- dicaments subdivided have done a very useful thing.] § 10. Ph. In defining words, we avail ourselves of the genus general terms is not a mere thought-expedient, but a legitimate and proper apin-ehension of the true and the real. Cf. G. Hartenstein, Locke's Lehre v. d. mensdil. Erkeniitniss in Vergleichung in. Leibniz's Kritik derselben, V., pp. 52 sq., also in his Histor. Philos. Abhandl., Leipzig, 1870, pp. 162 sq. — Tr. 1 Notional or coueeptional beings, begriffliche Wesen, entia rationis, are those which, as Schaarschmidt says, " serve to indicate that which without being in the ordinary sense of the word substantial (first substance in the language of Aristotle," cf. Categor. 5, 2^, 11; Wallace, Outlines of the Philos. of Aristotle, § 10, p. 25 ; Zeller, Philos. d. Griech., XL, 2 [Vol. 4], p. 304 sq., 3d ed., 1879; but cf. also, Metaphys. YII., 7, 1032b, 2; Wallace, op. cit. § 34, p. 67, Zeller, op. cit. II. 2 [Vol. 4], p. 344 sq.) " can still lay claim to an ideal reality." For further discussion of the subjects of this and the note next preceding, cf. New Essays, Bk. III., chaps. 5, 6, Bk. IV., chaps. 4, 6. — Tr. - Cf. Gerhardt, Leibniz, philos. Schrift. 7, 67: " Fuere tamen autores nou contemnendi, qui methodum rebus junxere rit Theodoras Zwingerus, Joli. Thomas Freigius, Bartliol. Kecliermannus, et diligentissimus Joh. Henr. Alstedius, cujus Encyclopaedia mihi pro captu illorura temporum laudanda videtur." Alsted, 1588-1638, was Professor of Philosophy and Theology at Herborn in Nassau, but applied himself chiefly to systemizing the several branches of art and science. His Encyclopiedia. UerhornisB, 1650, 7 Yols.,fol., reprinted Lugduni, 1649, 4 vols., fol. Leibnitz often mentions it (cf. G. 4. 62, 74, E. 22, a, 28, b; Dutens, Leibnit. opera omnia, 5, 405, 567), and wrote down some tlioughts — cogitata qusedani — for its enlargement and improvement; cf. Dutens, 5, 18.3-185. The classified contents of the work are given in the article " Encyclopsedia," in the Encyclop. Brit. 9th ed., Vol. 8, p. 176, b (American Reprint). Schaarschmidt states that the different works of R. Goclen, as well as those of Alsted, are of the kind alluded to in the text. Goclen, 1.547-1626, was Professor of Philosophy at Marburg, and published a Lexicon 2')hilosophicurn, Marburg, 1613, 1 vol., 4to, which, though of little value, enjoyed from its novelty consideraljle celebrity at the time of its appear- ance. Leibnitz refers to this work in his third letter to Clarke : cf. G. 7, 365, E. 7.52, b, J. 2, 426, D. 2, 122. Goclen was the ' discoverer and signalizer ' of the Inverse, Regressive, or Goclenian Sorites, in comprehension; cf. Hamilton, Lects. on Logic. XIX., p. 273, Amer. ed., and Goclenii Isagoge in Organum Aristotelis, p. 255, Francof. 1598. — Tr. 312 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi or the next general term ; and this is for the purpose of spar- ing ourselves the trouble of counting the different simple ideas which this genus signifies, or sometimes perhaps for the pur- pose of sparing ourselves the disgrace of being unable to make this enumeration. But although the shortest way of defining is by means of genus and difference, as the logicians say, it may be doubted, in my opinion, whether it is the best ; at least it is not the only way. In the definition which states that man is a rational animal (a definition which is perhaps not the most exact, but which serves well enough the present pur- pose), instead of the word animal you might put its definition. And this shows the little necessity of the rule which requires that a definition must be composed of genus and difference,^ and the little advantage there is in its strict observance. Thus languages are not always made according to the rules of logic, so that the meaning of each term may be exactly and clearly expressed by two others. And those who made this rule have done ill in giving us so few definitions conformable to it. Th. [I agree with your remarks ; it would be advantageous, however, for many reasons, if definitions might consist of two terms : it would without doubt greatly shorten them, and all divisions could be reduced to dichotomies which are the best species of divisions, and are particularly useful for invention, judgment, and memory. I do not, however, think logicians always demand that the genus or the difference be expressed in a single word ; for example, the term regular polygoyi may pass as the genus of the square, and in the figure of the circle the genus might be a plane curvilinear figure, and the dif- ference might consist in the fact that all points of the circum- ference are equally distant from a certain point as centre.^ 1 Cf. Aristotle, Topica, VI., 4, 141b, 26: Sel fikv Sia toO yeVov? Kai Tuiv SLa4>opo}V bpi^eaOaiTOv (caAco; opt^dnevoi', alSO I., 8, lOo^, 15 : eTrtifirj 6 6piopu}V eo-TiV, and Wallace, Outlines, §§ 14, 15, 25; Zeller, Philos. d. Griech., ii., 'J, [Vol.4], p. 255.— Tr. 2 Leibnitz rightly takes exception to Locke's censure of Aristotle's rule regarding definition, given in the preceding note, viz. : that it must consist of the genus and the species-forming difference, remarking that genus and dif- ference may very often he interchanged, the possibility of this interchange depending upon the principle on which, or the point of view from which, the classification is made, or upon the closeness with which the genus and the species-forming difference approach each other, it being essential to valid interchange that they be actually alike, or so nearly so that the difference is CH. Jiij ON HUMAN UNDERSTANDING 313 For the rest, it is also well to remark that very often the genus may be changed into a difference and the difference into a genus. For example, the square is a regular quadrilateral, or rather a four-sided figure that is regular, so that the genus or the difference seems to differ only as the substantive and adjective ; as if, instead of saying that man is a rational living being (animal raisonnahle) , language allowed the statement that man is a living rational being (rational animahle), i.e. a rational substance endowed with an animal nature ; while genii ^ are rational substances whose nature is not animal or common with the animals. And this interchange of genera and differentia depends iipon the variation of the order of the sub-divisions.] § 11. Pit. It follows from what I have just said, that Avhat is called general and universal belongs not to the being (exist- ence) ^ of things, but that it is a work of the understanding, § 12, and the essences of each species are only abstract ideas. Th. [I do not quite see this consequence. For generality consists in the resemblance of separate things among them- selves, and this resemblance is a reality.] § 13. Ph. I was going myself to say to you that these species are founded upon resemblances. Th. [Why, then, not seek therein also the essence of genera and species ?] § 14. Ph. You will be less surprised to hear me say that these essences are the work of the understanding, if you con- sider that there are at least complex ideas which in the minds of different persons are often different collections of simple ideas, and thus what is avarice in the mind of one man is not so in the mind of another. practically of no account. Cf. New Essays, Bk. III., chap. 3, ante, p. 308. Such definitions, while not strictly logical or scientific in the full sense of these terms, hut tentative rather, and, as it were, popular, are nevertheless useful, and indeed necessary, in ordinary life and in science, where we must classify to a certain extent for the sake of relative clearness, hut where strict logical definition is not essential, or is impossible because of the insuflticiency of our knowledge. Logically exhaustive definition, save in the realm of pure thought and in such sciences as the pure mathematics, is possible only to an infinite mind who possesses exhaustive knowledge of all principles and facts involved. Exhaustive knowledge of an individual demands an exhaustive knowledge of all other individuals. Cf. N. E., Bk. III., chap. 3, § 6, Th., ante, p. 309. —Tr. 1 I.e. angels and archangels. — Tr. ~ Locke has : " real existence," Philos. Wks., Vol. 2, p. 14 (Bohn'sEd.). — Tr. 314 LEIBNITZ'S CRITIQUE OF LOCKE [bk. in Th. [I admit, sir, that there are few cases in which I have less understood the force of your inferences than here, and this troubles me. If men differ in the name, does it change the things or their resemblances ? If one applies the name avarice to one resemblance, and another to another, there will be two different species designated by the same name.] Ph. In that species of substance which is most familiar to us and with which we are most intimately acquainted, it has many times been doubted whether the offspring brought into the world by a woman was a man,^ even to discussing whether he should be fed and baptized. This could not be if the ab- stract idea or the essence, to which the name man belongs, were the work of nature, and not a diverse, uncertain collection of simple ideas which the understanding put together, and to which it attached a name, after having made it general by way of abstraction. So that at bottom each distinct idea, formed by abstraction, is a distinct essence. Th. [Pardon me for telling you, sir, that your language perplexes me, for I do not see its connection. If we cannot always discern by the outside the internal resemblances, are there less of them in nature ? When we doubt whether a monster is a man, we doubt whether it has reason. When we know it has, the theologians will order it to be baptized, and the jurisconsults, to be fed. It is true that we may dispute about the lowest species logically considered, which vary by accidents in one and the same physical species, or species by direct descent (tribu de generation),^ but we do not need to determine these ; we may, indeed, vary them infinitely, as is seen in the great variety of oranges, lemons, and citrons, which experts know how to name and distinguish. The same thing was seen in tulips and pinks when these flowers were in fashion. For the rest, the fact that men unite these or those ideas, or even that nature actually unites them or not, makes no difference as regards essences, genera, or species, since the question only concerns possibilities, which are independent of our thought.] 1 Cf. Locke, Philos. Works, Vol. 2, p. 17, and note (Bohn's Ed.). — Tr. 2 Cf. New Essmjs, Bk. III., chap. 6, § 14, Gerhardt, 5, 288, line 14 ; Erdmann, 313, a; Jacques, 1, 234. The term "species," in Leibnitz's day, denoted not merely similarity of external form and characteristics, but more essentially the genetic relationship of common descent. — Tr. CH. Ill] ON HUMAN UNDERSTANDING 315 § 15. Ph. The species of each thing is ordinarily supposed to have a real constitution, and it is beyond doubt that some real constitution must exist upon which every collection of simple ideas or qualities co-existing in this thing must depend. But as it is evident that things are ranked in sorts or sj)ecies under certain names only as they agree with certain abstract ideas to which we have attached these names, the essence of each genus or species comes thus to be nothing else than the abstract idea signified by the general or specific name, and we shall find this to be the import of the word essence,* according to its most ordinary use. It would not be a bad thing, in ray opinion, to designate these two kinds of essences by two different names, and to call the one 7'ecd, and the other, nominal essence. Th. [It seems to me that our language makes extreme inno- vations in the method of expression. We have indeed spoken hitherto of nominal and causal or real definitions, but not within my knowledge of essences other than real, at least by nominal essences have not been understood false and impos- sible essences, which appear to be essences, but are not; as, for example, would be that of a regular decahedron, i.e. of a regular body comprised within ten planes.^ Essence is at bottom nothing less than the possibility of that which we think. What we assume as possible is expressed by the defi- nition; but this definition is only nominal when it does not express at the same time, possibility ; for then we may doubt whether this definition expresses anything real, i.e. possible, until experience comes to our aid to make us know this reality a 20osteriori,'^ when the thing is actually found in the world : and this suffices for the defect of the reason, which made us know the reality a priori ^ by exposing the cause or the possible generation of the definite thing. It does not then depend on us to unite ideas as seems good to us ; at least, this combination is not justified either by reason which shows it as possible, or by experience which shows it as actual, and consequently, also possible. In order the better to distinguish, also, essence and ^ This figure is impossible, the only possible regular polyhedrons being the tetrahedron, hexahedron, octohedron, dodecahedron, and icosahedron. — Tr. 2 Cf. ante, p. 227, note 2. — Tr. 31G LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi definition, you must consider that there is only one essence of the thing, but tliat there are many definitions whicli express one and the same essence, as the same structure or the same city may be represented by different scenographies according to the different sides from whicli it is regarded.] § 18.^ Ph. You will, I think, agree with me that the real and the nominal are always the same in simple ideas and in the ideas of the modes ; but in the ideas of substances, they are always entirely different. A figure which bounds a space by three lines is the real as well as the nominal essence of the triangle ; for it is not only the abstract idea to which the general name is annexed, but the essence or proper being of the thing, or the foundation whence proceed its properties, and to which they are annexed. But it is wholly otherwise as regards gold. The real constitution of its parts, upon which its color, weight, fusibility, firmness, etc., depend, is unknown to us ; and, having no idea of it, we have no name that is its sign. Yet these are the qualities which cause the matter to be called gold, and are its nominal essence, i.e. which give it a right to the name. Th. [I should prefer to say, in accord with received usage, that the essence of gold is that which constitutes it and which gives it these sensible qualities, which make it known and which make its nominal definition, while we should have the real and causal definition if we could explain this contexture or internal constitution. But the nominal definition is here found real also, not by itself (for it does not make known a priori the possibility or the genesis of bodies), but by experi- ence, because we have experience of a bod}* in which these qualities are found together : but without this we might doubt whether so much weight would be compatible with so much malleability, as it may be doubted, even at present, whether a glass malleable by cold is possible in nature.^ I am not, for the rest, of your opinion, sir, that there is here the difference 1 § 18, in Locke, Philos. Works, 2, p. 19 (Bohn's ed.) ; so Gerhardt : Erdmann, Jacques, and Schaarschmidt in his German translation, have § 19. — Tr. 2 Cf. Pliny the Elder, 23-79, Histor. Natur., Bk. 36, chap. 66; Eng. trans. (Bohn's Class. Lib.), Vol. 6, p. 381, Loudon, 1857. " In the reign of Tiberius, it is said, a combination was devised which produced a flexible glass. . . . This story, however, was, for a long time, more widely spread than well authenti- cated " — " fama crebrior quam certior." — Tb. cii. iiij ON liU.UA^i UXDEKSTANDING 317 between the ideas of substances and the ideas of predicates, as if the definitions of predicates (i.e. of the modes and the objects of simple ideas) were always real and nominal at the same time, and that those of substances were only nominal. I quite agree that it is more difficult to have real definitions of bodies, which are substantial existences because their con- texture is less sensible. But it is not the same with all sub- stances ; for we have a knowledge of true substances or unities (as God and the soul) as intimate as we have of the most of the modes. Besides, there are some predicates as little knoAvn as the contexture of bodies ; yellow or bitter, for example, are objects of simple ideas or notions {phantasies^), and yet we have only a confused knowledge of them.^ The case is the same in mathematics, where one and the same mode may have a nominal as well as a real definition. Fcav people have clearly explained in what consists the difference between these two definitions which must distinguish, also, essence and prop- erty. In my opinion, this difference is that the real shows the possibility of the thing defined, and the nominal does not.^ 1 Schaarsehmidt translates : " die Gegenstande einfacher Vorstellungen oder Phantasiebilder." — Tr. 2 Cf. Neiv Essays, Preface, ante, p. 48, ad fin, and Bk. IV., chap. 6, § 7, Th. (2) , infra, p. 458. According to Leibnitz, sense-knowledge is confused, and needs to be developed into clearness and consistency by the discriminative analysis and unifying jjower of thought. Phenomena such as colors, sounds, etc., the subjective counterpart or resultant of specific sense-energies, resist all further analysis, and while clear as wholes, are composite, insoluble, and so confused as regards their single elements. Such wholes admit only descriptive, not, strictly speaking, logical definition. Cf. Med. de Cog., Ver., et Id. ad init., Gerhardt, 4:. 422, Erdmann, 78, a, trans. Duncan, Philos. Works of Leibnitz, 27. — Tr. 3 Cf. ante, pp. 17, 201, and Med. de Cog., Ver., et Id., Gerhardt, 4, 424, Erdmann, SO, b, trans. Duncan, Philos. Works of Leibnitz, 30; also G. fi, 405, E. 637, a, Dutens, Leibnit. opera omnia, 1, 439; 6, 44; G. 7. 194 and note. As the nominal definition explains a thing according to the name, we may have nominal definitions of objectively non-existent or of impossible things, as centaurs, griffins, or any of the creatures of the fancy or the imagination, or the decahedron mentioned in § 15, Th., of this chapter, ante p. 315. The real definition explains the thing to be defined by exhibiting its cause or generation, its rise out of its conditions, i.e., its possibility; it is thus identical with the genetic definition, and Leibnitz accordingly calls it the causal definition, ante p. 31(3. Cf. also Dewey, Leibniz's New Essays, 210; Hamilton, Logic, 343; Trendelenburg, Ueber d. Element d. Definition in Leibniz. Philosophie in Histor. Beitr. z. Philos., Berlin, 1867, Vol. 3, pp. 48-fi2. Trendelenburg calls special attention to the fact that Leibnitz, in definition, has in mind especially the analytical element, explaining definition as an unfolding of the concept, 318 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi The defiiiition of two parallel straight lines, which states that they are in one and tiie same plane and will not meet although continued to infinity, is only nominal, for we could at once doubt whether that is possible. But when we have under- stood that we can draw a straight line in a plane parallel to a given straight line provided we take care that the point of the style describing the parallel remains always equally distant from the given line, we see at once that the thing is possible, and why they have this property of never meeting, which con- stitutes their nominal definition, but which is the sign of the parallelism only when the two lines are straight, while if one at least were curved, they might be by nature unable ever to meet, and yet not on that account be parallel. § 19. PJi. If essence was something else than the abstract idea it would not be ingenerable^ and incorruptible. A uni- corn, a mermaid, a perfect circle, perhaps do not exist in the world. Th. [I have already told you, sir, that essences are perpetual, because here the question concerns only the possible.] CHAPTER IV OF THE NAMES OF SIMPLE IDEAS § 2. Ph. 1 confess I have always believed that the forma- tion of the modes was arbitrary ; but as regards simple ideas and those of substances, I have been persuaded that, besides possibility, these ideas should signify a real existence. Th. [I see no necessity for it. God has ideas before creating the objects of these ideas, and nothing prevents Him from being able also to communicate such ideas to intelligent creat- ures : there is also no exact demonstration proving that the objects of our senses and of the simple ideas which the senses or its resolution into several concepts equivalent to the one concept — ■ " defiiiire est explicare notionem, resolvere in plures notiones uni aequivalentes ; " cf. Dutens, op. cit., 4, 68 : " definitio nihil aliud, quam accurata nominis explicatio est"; 6. 4, 140, E. 60, b : "definitio enim nihil aliud est, quam signiticatio verbis expressa, sive brevius, signiticatio significata." — Tr. 1 Locke's word, Philos. Works, Vol. 2, p.'20 (Bohu's ed.). — Tr. OH. IV] ON HUMAN UNDERSTANDING 319 present to us are outside iis.^ This fact has especial weight in the case of those who believe with the Cartesians and with our distinguished author, that our simple ideas of sensible qualities have no resemblance to that which is outside us in the objects ; there would then be nothing requiring these ideas to be grounded in any real existence.-] §§ 4, 5, 6, 7. Ph. You will grant me at least this other difference between simple and complex ideas, that the names of simple ideas cannot be defined, while those of complex ideas can be. For definitions should contain more than one term, each of which signifies one idea. Thus you see what can or cannot be defined, and why definitions cannot go on to infinity ; a remark which no one, so far as I know, has up to this time made. Th. [I have also made the statement in the brief Essay upon Ideas,^ inserted in the " Actes de Leipzic " about twenty years since, that simple terms cannot have nominal definitions ; but I have there added at the same time the statement that terms, when they are simple only as regards us (because we have no means of analyzing them so as to reach the elementary 1 The demonstrability of the reality of that which lies at the basis of the phenomena of the senses is one of the most difficult problems in the theory of knowledge — Erkenntnisslehre. Leibnitz seems nowhere to have discussed the question, at least in this form, nor to have asked himself how, agreeably to his philosophical system, a knowledge of the reality of the external world could be demonstrated or a belief therein justified. So far as his system sug- gests any answer consistent -nith itself, that answer is found in his doctrine of pre-established harmony, in the consciousness of which we pass immediately from our inner representative world of ideas to belief in the reality of the external things thus ideally represented. This, however, like Descartes' attempt to bridge the chasm from the subjective to the objective by his doctrine of God's veracity, is mere assumption, not " exact demonstration." The problem belongs to both psychology and metaphysics, and is satisfactorily discussed and solved only when considered in these two aspects. Leibnitz was an idealist in psychology, and a realist in metaphysics, and never really har- monized or i\nited these two points of view. For him, therefore, there could be ''no exact demonstration" of the external reality of "the objects of our senses and of the simple ideas which the senses present to us." Gf. Discours de Metaphysique, §§ 26 sq., Gerhardt, Leibniz, phiios. SchrifU, 4. 451 Sf/., E. Caird, The Grit. Philos. of Immanuel Kant, 1, 80-95. New York, Macmillan &Co., 1889. — Tr. 2 Cf. Neio Essai/!i, Bk. II., chap. 8, §§ 21, 24, ante, pp. 1.3.3-135 ; also Bk. IV., chap. 11. The constancy of sense-phenomena is the constraining reason for referring them to sometliing real. Gf. Dewey, Leibniz's Neio Essays, 173 sq.; Gerhardt, Leibniz, philos. Schrift. 7, 319 sq. — Te. 3 Gf. ante, p. 14, note 2 ; p. 227, note 3. — Tk. 320 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi perceptions of which they are composed), as heat, cold, yellow, green, can receive a real definition which would explain their cause. Thus, the real definition of green is that of an entity composed of blue and yellow thoroughly mixed,^ although green is no more susceptible of a nominal definition by which we may recognize it than blue or yellow. Terms on the other hand which are simple in themselves, i.e. whose conception is clear and distinct, cannot receive any definition, whether nominal or real. You will find in this little Essay, placed in the " Actes de Leipzic," the foundations of a large part of the doctrine concerning the understanding, briefly explained.] §§ 7, 8. Ph. It were well to explain this point and to indi- cate what can be defined, what not. And I am tempted to believe that often great disputes are raised and much nonsense introduced into men's discourse from a failure to consider this matter. These celebrated trifles about which so much stir is made in the schools have arisen from the fact that no attention has been paid to this difference which is found in ideas. The greatest masters in the art have been constrained to leave the majority of simple ideas without defining them, and when they have undertaken to define them, they have not succeeded. What more superfine nonsense, for example, could the mind of man invent than that which is contained in this definition of Aristotle : Motion is the realization of that which is possible so far as it is possible ?^ § 9. And the moderns who define motion as passage from one place into another, merely put one synonymous word in the place of another. Th. [I have already remarked in one of our past conferences that you consider many ideas as simple which are not so. Motion is of this number which I believe to be definable ; and the definition which states that it is a change of place is not to be despised. Aristotle's definition is not so absurd as you 1 This is true of pigments, but not of lights. Blue and yellow lights when mixed produce white light. — Tr. 2 Cf.Neio Essays, Bk. II., chap. 21, § 1, Th. ante, p. 174. For Aristotle's detiuition, Cf. PhyS. Acroas., III., 1, 201b, 4 : 'h toG Swarov, fi Swarov, evreMxei-a. (^arepbv OTt Kt;'7jo"W etrrti', 201*, 11 '• V ^^f* SvvdfX€L ovTO^ ivreXe^eca, fj toiovtov, Kivr\(Tis icTTiV, MetaphyS. K., 9, 1065^, 16: ^V^ toO Swdnei. jj tolovtov itrrLV ivepyiav Ae-yw Kivrjaiv, 23 : V ^V ■'■O'^ Svi'dfiei. oi'TO?, OTav evTe\exeia oy ivepyrj r) avTo rj dAAo jj klvyitov, KiVr)(7ts ecTTtr, also 33 : Wallace, Outlines of the Philos. of Aristotle, § 42, p. 77 ; Zeller, Philos. d. Griec, 3d ed., 1879, II., 2 [Vol. 4] , p. 350 sq., with the notes. — Tr. CH. IV] ON HUMAN UNDERSTANDING 321 think, this supposed absurdity arising from the failure to understand that the Greek KtVf/o-is with him did not signify what we call motion, but w^hat we would express by the word change, whence it comes that he gives it a definition so abstract and metaphysical, while what we call motion is called by him ^opa, latio, and is found among the species of change (t>7s KtvT/o-ews )-J § 10. Ph. But you will not apologize, at least, for the same author's definition of light as the action of the transparent.^ Th. [I find it, as you do, very useless ; ^ and he makes too frequent use of his action, which does not tell us much. Diaphanous is for him a medivim across which we can see ; and light is, according to him, that which consists in the actual passage. Well and good.] § 11. Ph. We agree, then, that our simple ideas cannot have nominal definitions, as we cannot know the taste of pine- apples by the accounts of travellers, unless able to taste things by the ears, as Sancho Panza had the power to see Dulcineaby hearsay,* or as that blind man who, having been heard to speak boldly of the brilliancy of scarlet, thought it must resemble the sound of the trumpet. TJi. [You are right; and all the travellers in the world 1 Cf. PhyS. AcroaS., VII. 2, 243^, 6 Sq. : ^"'^i ^^ rpei; eia-l Kivrja-en, rj T6 Kara totvov Kal Kara to ttolov Kat kolto. to Trocrdf, avdyKiq Kal to. Kivovfj-^fa rpia, r) fj-ki* ovv Kara tottou 4>opa., r) Se Kara. TO ttoiov aAAoifocris, 17 5e Kara, to ttoo'OI' aij^ijiris Kal ^6i(Tt^, Eih. Nic. X., 3, IVii?-, 30: ei yap ia-TLv r) (j)opa KiVrjo-ts -TToeev irol (Alex. Grant, T/ie Ethics of Aristotle, Vol. 2, p. 324, liue 17, 3d ed., London: Longmans, Green, & Co., 1874); Wallace, Outlines, § 42; Zeller, Fhilos. d. Griec, 3d ed., 1879, II., 2 [Vol. 4], p. 389sg.— Tr. . ..,. '^ 67. De Aninin, II., 7, 418'', 9: "^w; Se eo-Ttv ^ toutou evepyeia ToC Stac/)ai'oi}s 17 5ia<|>ave?, 419i, 11 : i? 5' ei'TcAt-\eia toD SLaavov'; <^a)S ecTtV. E. Wallace, AristOtle' S Psycholooy in Greek and English lo. Introd. and Notes, Cambridge : Univ. Press, 1882, pp. 95, 97, translates the two passages: " Light then is the expres- sion of the pellucid qua pellucid," "The full play of this pellucid constitutes light," and, in his Introd., p. Ixxi., combines them thus : " Light therefore may itself be defined as the actual expression or full play of the pellucid as pellucid." Cf. also Zeller, Philos. d. Griec. 3d ed., 1879, II., 2 [Vol. 4], p. 477, note 2. 3 Schaarsehmidt calls attention to "a bad typographical error" in tlie text of Raspe's edition of the Nouveaux Essais at this point. Raspe reads " fort utile," for which Schaarsehmidt proposes " futile." Gerhardt, Erdmann, and Jacques all read " fort inutile," which gives the requisite sense, and is accord- ingly followed in the translation. — Tr. ■* Cf. Cervantes, 1547-1616, Don Quixote, Pt. 2, chap. 9, ad ined. ; also, Pt. 1, chap. 31. — Tr. g22 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iii could not give by their words what we owe to a gentleman of this country who cultivates successfully pine-apples three leagues from Hannover, almost upon the bank of the Weser, and who has found means of multiplying them to such an extent that some day we can perhaps have them of our oavu growing in as great abundance as the oranges of Portugal, though there would apparently be some loss in the flavor.] §§ 12, 13. Ph. It is wholly otherwise with complex ideas. A blind man can understand what a statue is ; and a man who had never seen the rainbow could understand what it is, pro- vided he had seen the colors which compose it. § 15. But though simple ideas are inexplicable, they are the least doubt- ful. [For experience accomplishes more than definition.] Th. [There is, however, some difficulty as to the ideas Avhich are only simple as regards us. For example, it would be diffi- cult to indicate precisely the limits of blue and of green, and in general to discriminate colors closely approaching one another, while we can have precise notions of the terms used in arith- metic and geometry.] § 16. Ph. Simple ideas have further this peculiarity that they have very little subordination in what the logicians call the line of predication iligne predicamentale) ,^ from the lowest 1 Leibnitz here refers to the Tabula logica, in which Porphyry, 23.3-304, and after him the Scholastic logicians, snch as Lambert of Auxerre, c. 1250, Petrus Hispanus, c. 122()-1277, Raimund Lulli, 1234-1315, the Pseudo-Thomas, and Johannes Majoris Scotus, 1478-1540, sought, in connection with the live pre- dicables, to arrange in strict logical subordination by the process of dicho- tomic or bifurcate division, all genera and sj^ecies from the highest genera to the lowest species, between which is found the scale of subordinate notions which are at the same time botli genus and species. This Tabula logica was called by the later commentators, who added the diagram illustrating it, not found in Porphyry, the arbor Porphyriana or the arbor praedicamentaUs, and the line of subordination from the highest genus to the lowest species was called the linea praedicamentaUs or p)raedicabilis, or the ordo praedicamentaUs. Cf. Porphyry, Eio-a-ycoy^ chap. 2, 1 b. 40 .s^. (in Aristotle, ed. Berl. Acad., Vol. 4, p. 1) ; 'Ef))vr;criliilos. Ahhandl., Leipzig, 1870, 469 sq.. Stein, Leibniz u. Spinoza, Berlin, 1890, 158 sq., Dillmann, Eine n. Darstg. d. Leibniz. Monadenlehre, Leipzig, 1891, 225 sq. For Leibnitz's theological use of Aristotle's iovms — elB-q — ef. Theodicee, Pt. IIL, §§ 335-6, and J. H. v. Kirchmann's note 246 thereto. Band 80, p. 133, and note 62 f., Bd. 82, p. 87, of his Philos. Bibliothelc. Leipzig, 1879. On the elSo? and ova-ia. of Plato and Aris- totle, cf. Wallace, Outlines of the Philos. of Aristotle, §§ 10, 31, 32, 34, 37, and Zeller, Philos. d. Griech., II., \ [Vol.3], 658 sq., 4th ed. 1889, IL 2 [Vol. 4], 304 sq., .3d ed., 1879. For the Scholastic doctrine, cf. B. Haureau, Histoire de la philos. schola.ttique, 2d ed., Paris, 1872-80; A. Stock!, Ge.'^ch. d. Philos. d. MittelaUers, Mainz, 1862-66; C. Prantl, Gesch. d. Logik im Abendlande, Leip- zig, 1855-1870, passim. Cf. also G. 1, 16, 22 sq., 4, 208. — Tr. 350 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi Th. True, but persons who study these matters rectify the popular notions. Assayers have found exact means of dis- cerning and separating the metals ; botanists have enriched wonderfully the doctrine of plants, and the experiments made upon insects have opened for us a new path in the knowledge of animals, but we are still very far distant from the half of our course. § 26. Ph. If species were a work of nature they could not be conceived so differently by different persons. Man appears to one person an animal without feathers, with two feet and with large nails, and another after a more profound exami- nation adds to these reason. Many people, however, deter- mine the species of animals by their external form rather than by their hirth, since the question has been put more than once whether certain human /osi?(ses should be admitted to baptism or not, for the sole reason that their external configuration differed from the ordinary form of infants, without knowing whether they were not as capable of reason as infants cast in another mould, some of whom are found, who, although of an approved form, are never able to exhibit during their entire life as much reason as appears in an ape or elephant, and who never give any indication of being governed by a rational soul. Whence it appears evident that the external form which alone has found mention, and not the faculty of reasoning which no one could know would be wanting in its time, has been regarded essential to the human species. And in these circumstances theologians and jurisconsults the most learned have been compelled to renounce their sacred definition of rational animal, and to put in its place some other essence of the human species. " Mr. Menage," (Menagiana Tom. I. p. 278, of the Dutch edition of 1694,)^ " furnishes us the example of a certain abbot of St. Martin, which deserves to be related. When this abbot of St. Martin, he says, came into the world, he had so little the figure of a man, that he resembled rather a monster. For some time they deliberated whether he should be baptized. He was baptized however, and declared a man provisionally, i.e. till time should show what hcAvas. He 1 Menagiana sive excerpta ex ore ^c/idii Menagii, 1st ecL, 1 vol., 12mo, Paris, 1693, 3d.ed., enlarged and corrected by La Monnoye, Paris, 1715. Erd- mann, Jacques, and Schaarschmidt in Ms German trans, erroneously read Kilri). — Tk. CH. VI] ON HUMAN UNDERSTANDING 351 was so disfigured by nature, that tliey called him all his life the Abbot Malotru. He was of Caen." There was a child who came very near being excluded from the human species simply because of his shape. He narrowly escaped as it was, and it is certain that a figure a little more deformed would have deprived him of it for ever and have caused him to perish as a being who ought not to pass for a man. Yet no reason can be given why a rational soul could not have been lodged in him, if the lineaments of his face had been a little more altered ; why a visage a little longer, or a flatter nose, or a wider mouth could not have subsisted as well as the rest of the irregular figure with a soul and with qualities which made him capable, wholly disfigured as he was, of being clothed with dignity in the church. Til. Up to the present time, no rational animal has been found with an external figure very different from ours, there- fore, when the question arose of baptizing a child, race and figure have always been considered only as marks by which to judge whether it was a rational animal or not. Thus theo- logians and jurisconsults have never needed to renounce for that reason their sacred definition. § 27. Ph. But if that monster, of which Licetus,^ Bk. I., chap. 3, speaks, with a man's head and a hog's body, or other monsters, with the heads of dogs and of horses, etc., upon the bodies of men had lived and could have spoken, the difficulty would be much greater. 1 Fortunio Liceti, 1577-1657, a celebrated Italian physician and scholar, who taught logic at Pisa, 1600-1609 ; philosophy at Padua till 1631 ; then philosophy at Bologna ; and finally, theoretic medicine at Padua from 1645 till his death. He was a great admirer of Aristotle, and wished to admit uotliing beyond his doctrines, and thus contributed to render both philosophy and medicine sta- tionary. For the matter to which Leibnitz here refers, cf. Licetus, De spontcmeo viventhim ortu, lib. qiiat., fol., Vicentife, 1618, Bk. I., chap. 28, pp. 34-36, Sexta confirmatio spontanei ortus hominum petita ex huraanis figuris in belluis, ac lapidibus enodatur aperiendo taliuni figurarum caussas, in which chapter Licetus treats of various monsters, referring to his De monstroivini mentioned below, and to his father's, Giuseppe Liceti, an Italian physician, died 1599, Dialogus de genitaUum. vsu et dignitate, or II Ceva, delV ouvero eccellenza ed uso de' genitali, 1598, De mon.itrorum cavssis, natura, et differentiis lib. duo, 2d ed., 4to, Petavii, 1634, pp. 13, 183, 194 : " De monstrorum humanorum reale existentife " ; the same, with additions by Gerard Blasius, 4to, Amstelodami, 1665, pp. 13, 183, 194; the same, in the French trans., Traite des rnonsires, by Jean Palfyn, 1650-1730, in his Description anatomique des parties de lafemme qui servent a la generation, etc., 4to, Leyden, 1708, pp. 13, 197, 208. — Tr. 352 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi Th. I admit it, and if that occurred and if any one had done, as a certain writer, a monk of tlie olden time, named Hans Kalb (Jean le veau — John the calf) who ^ painted himself with a calf's head, the pen in his hand, in a book he had written, which procedure caused some foolishly to think that this writer had in reality a calf's head, — if, I say, that hap- pened, we should be more cautious hereafter in getting rid of monsters. For there is some probability that reason would maintain it with theologians and with jurisconsults in spite of the figure and even in spite of the differences which the anatomy would furnish to the physicians, which would as little injure the quality of man as the reversal of the viscera in that man whose anatomy some persons of my acquaintance have seen at Paris, which has made some stir, in which nature " Peu sage et sans doute en debauche Plaga le foye au coste gauche Et de meme vice versa Le cceur a la droite plaga," i.e. "unwise and doubtless in debauch placed the liver upon the left, side and likewise vice versa the heart upon the right," if I rightly remember some of the verses which the late Mr. Alliot^ the father (a famous physician because he passed as skilful in the treatment of cancers) showed me of his own making upon this prodigy. It is a matter of course, provided the variety of conformation does not go too far in the case of rational animals and that no return is made to the times when animals spoke, for then we should lose our especially peculiar advantage of reason ^ and should henceforth be more attentive to birth and the external in order to be able to dis- 1 Erdmann and Jacques add " qui " after " le veau." — Tr. 2 Pierre Alliot, a French physician of the seventeenth century, horn at Bar-le-Duc, reputed to have great skill in the treatment of cancer and other malignant ulcers. His most distinguished patient was Anne of Austria, the mother of Louis XIV,, whom he treated unsuccessfully in Paris in 1665. Not- withstanding his failure, he was appointed physician to the king. His published works include Theses medicse de rnotu sanguinis circvlato et de morbis ex sere, Pont-a-Mousson, 1663, 8vo ; Epistola de cnncro apparente, and Nuntius profli- gati sine ferro et igne carcinomatis, both Bar-le-Duc, 1664, 12mo. His son, Jean Baptiste Alliot, was physician to Louis XIV., and published Traite du cancer ok Von expliqne sa nature et ou Von propose les moyens les plus surs pour le guerir methodiqiiement, Paris, 1698, 12mo. — Tk. 3 The French text is: " nostre privilege de la raison en preciput," etc. — Tr. CH. VI] , ON HUMAN UNDERSTANDING 353 cern those of Adam's race from those who may descend from a king or patriarch of some canton of apes in Africa ; and our learned author was right in his remark (§ 29) that if Balaam's ass had all her life discoursed as rationally as she did once with her master (supposing it was a prophetic vision), she would always have had difficulty in obtaining rank and a seat among women. Ph. You laugh, I see, and perhaps the author laughed also ; but, to speak seriously, you see that you cannot ahvays assign fixed limits to species. Th. I have already agreed to this ; for when the question concerns fictions and the possibility of things, the passage from species to species may be insensible, and to discern them would sometimes be about as impossible as to decide how much hair a man must be allowed that he may not be bald. This indeterminateness would be true even when we knew perfectly the internal nature of the creatures under discussion. But I do not see that it can prevent things from having real essences independent of the understanding, and us from know- ing them. It is true that the names and limits of species would sometimes be like the names of measures and weights, where choice is necessary in order to have fixed limits. But ordinarily there is nothing of the kind to fear, species too much alike seldom occurring together. § 28. Ph. It seems we agree here at bottom, although we differ somewhat in terms. I also admit that there is less arbitrariness in the denomination of substances than in the names of the mixed modes. For few venture to unite the bleating of a sheep with the figure of a horse, or the color of lead with the weight and fixedness of gold, and we prefer to draw copies after nature.^ Th. This is not so much because in substances regard is had only to that which exists effectively, as because there is no certainty in the case of physical ideas (which are not very thoroughly understood) that their union is possible and useful, if there is no actual existence to guarantee it. But this also takes place in the modes, not only Avhen their obscurity is impenetrable by us, as sometimes happens in physics, but also ^ That is, to follow experience in the formation of our ideas, and to conform our inner world in general to that furnished by nature. — Tr. 354 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi when it is difficult of penetration, enough examples of which occur in geometry. For in both of these sciences it is not within our power to make combinations according to our fancy, otherwise we should be right in speaking of regular decahedrons, and should seek in the semicircle-^ a centre of magnitude, as there is in it a centre of gravity. For it is in fact surprising that the first is there, and that the second cannot be. Now while in the modes the combinations are not always arbitrary, we find on the other hand that in substances they sometimes are so ; and it often depends on ourselves to make combina- tions of qualities in order further to define substantial beings in advance of experience, when we understand enough of these qualities to judge of the possibility of the combination. Thus it is that expert gardeners in the orangery can rationally and successfully propose to produce some new species and give it a name in advance. § 29. Ph. You will always agree with me that when the question arises of defining species, the number of ideas com- bined depends upon the different application, industry, or fancy of the one forming this combination, as it is the figure which regulates most frequently the determination of the species of vegetables or animals, and likewise as regards the majority of natural bodies which are not produced by seeds, it is the color which is most strongly adhered to. § 30. In truth these are often only confused conceptions, gross and inexact, and it is very essential that men agree as to the precise number of simple ideas or qualities which belong to a given species or a given name, for pains, skill, and time are needed to find simple ideas which are constantly united. However a few of the qualities composing these inexact definitions are ordinarily sufficient in conversation ; but in spite of the stir about gen- era and species, the forms, of which so much has been said in the schools, are only chimeras which avail us nothing in fur- nishing an entrance into the knowledge of specific natures. Th. Whoever makes a possible combination, is not at all mistaken therein, nor in giving it a name ; but he is mistaken 1 Such combinations of essentially self-contradictory ideas may easily be united in a complex term, and be apparently clear and possible, until analyzed and compared with reality, when their confusion and impossibility is at once made evident. — Tn. CH. VI] ON HUMAN UNDERSTANDING 355 if he thinks that his conception is altogether that which others more expert have conceived under the same name or in the same body. He perhaps conceives a genus too common instead of another more specific. There is nothing in all this contrary to the schools, and I do not see why you return here to the charge against genera, species, and forms, since it is necessary for you to recognize indeed the genera, species, and even the internal essences or forms, which we do not pretend to employ in order to know the specific nature of the thing, although we admit we are still ignorant of them. § 30. Ph. It is at least evident that the limits we assign to species are not exactly conformed to those established by nature. For in our need of general names for present use, we do not put ourselves to the trouble of discovering the qualities which would give us superior knowledge of their most essential dif- ferences and agreements, but we ourselves distinguish them into species in virtue of certain appearances which are mani- fest to everybody, that we may more easily communicate with others. Til. If we combine compatible ideas, the limits we assign to species are always exactly conformed to nature ; and if we are careful to combine ideas actually found together, our notions are also conformed to experience ; and if we consider them as provisional only for actual bodies, without excluding ex- periment made or to be made for further discovery therein, and if we have recourse to experts, when a definite question arises with reference to what is openly understood by the name, we shall not err in the matter. Thus nature may furnish ideas the most perfect and most convenient, but she will not give the lie to those we have which are good and natural, although not perhaps the best and most natural. § 32. Ph. Our generic ideas of substances, as that of metal, for example, do not follow exactly the models set them by nature, since you cannot find any body including simply malle- ability and fusibility without other qualities. Th. No 'one asks for such models and it would not be reason- able to ask for them; furthermore they do not occur in the most distinct notions. We never find a number in which there is nothing to notice but multitude in general, an extension in which there is only extension, a body in which there is only 356 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi solidity, and no other qualities ; and when the specific differ- ences are positive and contrary it is very essential that the genus share in them. Ph. If, then, any one thinks that a man, a horse, an animal, a plant, etc., are distinguished by real essences made by nature, he must think that nature is vei'y liberal with these real essences, if she produces one of them for the body, another for the animal, and still another for the horse, and that she bestows freely all these essences upon Bucephalus ; whilst genera and species are only signs more or less comprehensive. Th. If you take real essences as these substantial models, which exist as a body and nothing more, an animal and nothing more specific, a horse without individual qualities, you are right in treating them as chimeras. And no one has main- tained, I think, not even the greatest Realists of former times, that there are as many substances confining themselves to the generic as there are genera. But it does 'not follow that if general essences are not this, they are merely signs ; for I have many times remarked to you that there are possibilities in the resemblances. In like manner from the fact that colors are not always substances or extracted dyes, it does not follow that they are imaginary. For the rest you cannot think nature too liberal; she is so beyond all that we can invent, and all advau=- tageous compatible possibilities are found realized upon the grand theatre of her representations. There were formerly two axioms among philosophers : that of the Realists seemed to make nature prodigal, and that of the Nominalists seemed to declare her stingy. The one says that nature suffers no vacuum, and the other that she does nothing in vain. These two axioms are good provided you understand them ; for nature is like a good economist, who saves where it is necessary in order to be grand at times and places. She is grand in effects, and sparing in the causes she emplo3^s. § 34. Ph. Without amusing ourselves longer with this dis- cussion upon real essences, it is enough that we obtain the pur- pose of language and the usage of words which is 'to indicate our thoughts in an abridged form. If I wish to speak to any one of a species of birds three or four feet in height, whose skin is covered with something between feathers and hair, of a dark brown color, without wings, but in their place two or CH. VI] ON HUMAN UNDERSTANDING 357 three small branches, like those of the broom, which descend to the lower part of the body, with long and large legs, the feet armed only with three claws and without a tail; I am compelled to make this description whereby I can make myself understood by others. But when I am told that the name of this animal is Cassoicary, I can then use this name to designate in discourse this entire complex idea. Th. Perhaps a very exact idea of the covering of the skin or of some other part would suffice by itself alone to distin- guish this animal from every other known, as Hercules was known by his gait, and as the lion was recognized by his claw according to the Latin proverb. But the more circumstances you heap up, the less provisional is your definition. § 35. Ph. We may curtail the idea in this case without prejudice to the thing; but when nature curtails it, it is a question whether the species remains. For example: if a body existed having all the qualities of gold except mallea- bility, would it be .g-old? it depends upon men to decide. They are then the ones who determine the species of things. Th. Not at all ; they would determine only the name. But this experience would teach us that malleability has no neces- sary connection with the other qualities of gold taken together. It would teach us then a new possibility and consequently a new species. As for gold which is eager i or brittle, this comes only from additions, and is not consistent with the other tests of gold; for the cupel and antimony remove this eagerness from it. § 3Q. Ph. A portion of our doctrine follows that will appear very strange. Each abstract idea having a certain name forms a distinct species. But what of that, if nature so wills it ? I should be glad to know why a lap-dog and a greyhound are not as distinct species as a spaniel and an elephant. Th. I have distinguished above the different senses of the word species. Taking it logically, or mathematically rather, the least dissimilitude may suffice. Thus each different idea will give another species, and it makes no difference whether It has a name or not. But, physically speaking, we do not at- tend to all the varieties, and we speak either distinctly when the question concerns only appearances, or conjecturally when the 1 Cf. Locke, Philos. Works, Vol. 2, p. (35 (Bohn's ed.). — Tr. 358 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi question concerns the inner trutli of things, presuming therein some essential and immutable nature, like reason in man. We presume then, that whatever differs only by accidental changes, like water and ice, quicksilver in the liquid form and as sublimate, is of the same, species : and in organic bodies the provisional mark of the same species is usually placed in the generation or race, as in those most alike it is placed in repro- duction. It is true we cannot judge with precision, for lack of knowledge of the inner nature of things ; but, as I have said more than once, we judge provisionally and often con- jecturally. But when we wish to speak only from the external, for fear of saying nothing certain, there is some latitude ; and to dispute then whether a difference is specific or not is to dispute about the name ; and in this sense there is so great a difference between dogs, that we may very well say that the house-dogs of England and the dogs of Boulogne belong to different species. It is not impossible, however, that they belong to a remote identical or similar race, which we should find if we could go back very far, and that their ancestors were alike or identical, but that after great changes, some of the posterity have become very large and others very small. We may indeed believe also without offending reason that they have in common an inner nature, constant, specific, which is no longer subdivided thus, or which is not found here in several other such natures, and consequently is no longer varied save by accidents ; although there is also nothing to make us judge that this must necessarily be so in all that which we call the lowest species (species injima). But there is no likeli- hood that a spaniel and an elephant are of the same race, and that they have such a specific common nature. Thus in the different sorts of dogs, speaking of appearances, we may dis- tinguish species, and speaking of the inner essence we may be in suspense : but comparing the dog and the elephant there is no reason for attributing to them externally or internally that which would make us think them of one and the same species. So there is in this case no occasion for suspense in the face of the presumj)tion. In man we can also distinguish species logically speaking, and if we stopped with the external we should find also, speaking physically, differences which could pass as specific. Thus a traveller was found who thought CH. vij ON HUMAN UNDERSTANDING 359 that the Xegroes, Chinese, and finally the Americans were not of one and the same race among themselves nor with the peoples resembling us. But as we know the essential inner nature of man, i.e. the reason, which dwells in the man him- self and is found in all men, and as we notice nothing fixed and internal among us which forms a subdivision, we have no reason to judge that there is in men, according to the truth of the inner nature, an essential specific difference, while such difference is found between man and beast, supposing that the beasts are only empirical, according as I have explained above, as in fact experience gives us no reason for forming any other judgment. § 39. Ph. Let us take the example of an artificial thing whose internal structure is known to us. A time-p)iece that only indicates the hours, and one that strikes, are of one species only for those who have only one name by which to designate them ; but for him who designates the first by the name ivatch, and second clocTc, they are in relation to him dif- ferent species. It is the name and not the inner disposition which makes a new species, otherwise there would be too many species. There are watches with four wheels, and others with five ; some have strings and fusees,^ and some not ; some have a free balance, and others are regulated by a spiral spring and others by hog's bristles. Does any one of these things suffice to make a specific difference ? I say no, so long as these time-pieces agree in name. Th. And I for my part say yes, for without stopping at names, I should consider the varieties of contrivance and especially the differences of the balance ; for since a spring has been applied which governs the vibrations according to its own and consequently renders them more equal, pocket- watches have changed their character, and have become in- comparably more accurate. I have indeed mentioned before another principle of equality which might be applied to watches. Ph. If any one wishes to make divisions based upon the differences which he knows in the internal configuration he may do so ; but they would not be distinct species with rela- tion to the people who are ignorant of this construction. 1 Locke has "physies," Philos. Works, Vol. 2, p. 67 (Bohn's ed.). — Tr. 360 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi Th. I do not know why those with you always wish to make virtues, trutlis, and species depend upon our opinion or knowledge. They exist in nature, whether we know it and approve or not. To speak otherwise is to change the names of things and received language without any reason. Men up to the present time have believed that there are many kinds of clocks or watches, without informing themselves in what they consist or how they may name them. Ph. You have however recognized not long since that when men wisli to distinguish physical species by appearances, they limit them in an arbitrary way, where they find it to the pur- pose, i.e. according as they find the difference more or less considerable and according to the end they have. And you yourself have made use of the comparison of weights and measures, which are regulated and given their names accord- ing to the good pleasure of man. Th. It is since then that I have begun to understand you. Between specific differences purely logical, for which the least variation of assignable definition sufiices, however accidental it be, and between specific differences purely physical, based upon the essential or immutable, we may place a mean, which cannot be precisely determined ; it is regulated by the most important appearances, which are not altogether immutable, but which do not change easily, the one approaching the essential more than the other. And as a connoisseur too may go farther than another, the thing appears arbitrary and has some relation to men, and it appears convenient to regulate names also according to these principal differences. We can then speak thus, that there are specific civil differences and nominal spiecies which must not be confounded with what I have called above nominal definitions, and which have place in differences specifically logical as well as physical. For the rest, besides common usage, the laws themselves may give authority to the significations of words, and then the species would become legcd, as in the contracts which are called nominati, i.e., designated by a particular name. For example as the Roman Law made the age of puberty commence at the end of the fourteenth year. This entire consideration is not to be despised, but I do not see that it is of very much use here, for besides the fact that you have appeared to me to CH. VI] ON HUMAN UNDERSTANDING 361 apply it sometimes where it did not apply, we shall accom- plish nearly the same result if we consider that it rests with men to proceed in subdivisions as far as they find them to the purpose, and to abstract ulterior differences without the necessity of denying them ; and that it also rests with them to choose the certain, notwithstanding the uncertain, in order to fix some notions and measures by giving them names. Ph. I am much pleased that we are here no longer so far apart as we appeared. § 41. You agree then, sir, I see, that artificial as well as natural things are species contrary to the view of some philosophers. § 42. But before leaving the names of substances, I would add that of all the diverse ideas we have, they alone are ideas of substances which have proper or individual names ; for it rarely happens that men need to make frequent mention of any individual quality or other individual accident. Besides individual acts perish at once and the combination of circumstances which thereby comes about only subsists as in the substances. Th. There are, however, cases where it has been necessary to remember an individual accident and to give it a name ; thus your rule is ordinarily good, but there are exceptions to it. Religion furnishes us with them ; for example we cele- brate each year the memory of the birth of Jesus Christ. The Greeks call this event Theogeny, and that of the adoration of the Magi, Epiphany. And the Hebrews call the Passah par excellence the passage of the angel who caused the death of the eldest sons of the Egyptians without touching those of the Hebrews ; and this is why they were to celebrate its memory every year. As for the species of artificial things, the scholastic philosophers found difficulty in admitting them into tYioiv pre- dicaments ; but there was little necessity for their hesitation since these predicamental tables were destined for use in mak- ing a general review of our ideas. It is well however to rec- ognize the difference existing between perfect substances and between the assemblages of substances (aggregata) which are substantial entities composed either by nature or by the art of man. For nature has also such aggregates, as the bodies whose mixture is imperfect {imperfecte mixta) to use the language of our philosophers, which constitute no unum per se and do not possess in themselves a perfect unity. I believe however that 362 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi the four bodies which they call elements, and think simple, and the salts, metals, and other bodies which they think are per- fectly mixed, and to which they attribute their temperaments,^ are not unum per se either ; so much the more as we must judge that they are uniform and homogeneous only in appear- ance, and even a homogeneous body would not cease to be a mass. In a word, the perfect unity must be reserved to bodies animated, or endowed with primitive entelechies; for these entelechies are analogous to souls and are as individual and imperishable as they ; and I have elsewhere affirmed that their organic bodies are practically machines, but which surpass the artificial machines of our invention as much as the inventor of the natural machines surpasses us. For these natural machines are as imperishable as the souls themselves, and the animal with the soul subsists always : it is (the better to explain my- self by something pleasing, wholly laughable as it is,) as if a harlequin wished to strip himself in the theatre, but could not succeed because he had an indefinite number of garments one upon another ; although these infinite replications of organic bodies, which exist in an animal, are not so similar nor so applied the one to the other, as the garments, nature's art being of a wholly different subtility. All this shows that the philosophers have not been wholly in the wrong in putting so great distance between artificial things and between natural bodies endowed with a real unity. But it belonged only to our time to develop this mystery and make understood its importance and consequences in order thoroughly to establish natural theology and what is called Pneumatics,- in a manner 1 Leibnitz here alludes to the four elements of Empedocles, c. 492-c. 432, B. c, viz., fire, air, earth, water, adopted by Plato and Aristotle and called by the Peripatetics warmth, cold, dryness, humidity, a mixture of which in vary- ing proportions constituted all bodies. Cf. Zeller, Philos. d. Griec, I. 2 [Vol. 2], 758 sq., 5th ed., 1892, XL 1 [Vol. 3], 796 sq., 4th ed., 1889, 11, 2 [Vol. 4], 431, sq., 832 sq., 3d ed., 1879. The state of a body resulting from the proportional disposition of these primary constituent elements or qualities was called its temperament, the character of the temperament varying according to tlie pre- dominance of one or more of the elements. The scholastics discussed the question whether the temperament comprised these four primary qualities, or whether it did not consist in a fifth simple quality, the outcome of the recipro- cal action of the four primary qualities, which resulted in their entire destruc- tion. Cf. also Gevhsivdt, Leibniz, philos. Schrift., 4, 207. —Tr. 2 Cf. ante, p. 50, note 2. Schaarschmidt states that Pneumatics — PneumatiJc — with the meaning — Doctrine of the Spirit, Ze/i?-e vom Geiste — Psychology CH. VI] ON HUMAN UNDERSTANDING 3G3 truly natural and in agreement with our experiments and understanding, and requiring the loss of none of the important considerations they are destined to furnish, or rather enhanc- ing their value, as does the system of pre-established harmony.^ And I believe that we can best conclude this long discussion of the names of siibstances only by that means. — occurs ill Alsted's Encyclopsedie, Herbornise, 1630, cf. ante, p. 311, note 2, and that Stephen Chauvin in his Lexicon X)hiloso%ihicum, Leovardiaj, 1713, adopted it and explained it by Pneumatology and Pneumatosophy. The term is now confined to physical science, and denotes that department of hydrodynamics which treats of the properties of gases as distinguished from liquids. Cf. Kraiith-Flemming, Vocah. of the Pliilos. Sciences, p. 388, New Yorlt, Sheldon &Co., 1883. — Tr. ^ , 1 Cf. New Essays, Bk. IV., chap. 10, §§ 7 and 9, infra, pp.505, 507 ; Systeme nouveau, §§ 14-16, Gerhardt, 4, 484-86, Erdmann, 127, a-128, Jacques, 1, 475-77, trans. Duncan, Philos. Wks. of Leibnitz, 77-79; Considerations sur les principes de vie, etc., G. 6, 541, E. 430, trans. D. 165; Principes de la nature et de la grace, §§ 7-13, G. 6, 602-()04, E. 716, trans. D. 212-215; Animadversionesjn partem generalem Principlorum Cartesianorum, Ft. I. ad Art. 14, G. 4, .358, trans. D. 50; Leibniz gegen Descartes und den Cartesianismus, ,G. 4, 292-294, 401^03, 405-406, E. 17*6, trans. D. 132-138, and his note 49, p. 382 ; 3fed. de Cog. Ver. et Ideis, G. 4, 424, E. 80, a, trans. D. 30. According to Leibnitz, his doctrine of monads requires as its necessary complement the existence of God, since the single monads, expressing in their own experience all that is beyond them, yet without influence on other monads, cannot furnish a sufficient ground or reason for the harmony and connection of things in a universal world-order. This harmonious* world-order existing, its sufficient ground or reason must be found in the absolute being, God, who has given to each monad the nature which makes it capable of developing itself in its extreme individuality in accord and correspondence with every other. The pre-estab- lished harmony is thus an actual proof, in accord with experience, of the existence of God, and the suggestion of reason in the ontological argument as improved by Leibnitz, is confirmed by the comparative and comprehensive study of the phenomena of nature. For expositions and criticisms of Leibnitz's doctrine, cf. Dewey, Leibniz's Neio Essays, chaps. 11, 12; E. Zeller, Gesch. d. deutschen Philos. seit Leibniz, 2d ed., Muncheu, 1875, pp. 88-98, 124-127; F. A. Lange, Gesch. d. MateriaUsmus, 3d ed., Leipzig u. Gerlohn, 1875 sq., Bk. I., Sect. IV., chap. 4, Eng. trans, by E. C. Thomas, 3 vols., Boston, Vol. 2, pp. 124 sq. ; Kuno Fischer, Gesch. d. n. Philos., Bd. II., Leibniz, 3d ed., Heidelberg, 1889, pp. 455 sq., 539 sq.— TR. 364 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi CHAPTER VII OF PARTICLES § 1. Ph. Besides the words which are used to name ideas, we need those which signify the connection of ideas or proposi- tions. This is, this is not, are general signs of affirmation or negation. But besides the parts of propositions the mind also binds together sentences and entire propositions, § 2. availing itself of words expressing this union of different affirmations and negations and which are called particles ; in whose proper use the art of speaking well principally consists. It is in order that reasoning be consecutive and methodical that terms showing the connection, restriction, distinction, opposition, em- phasis, etc., are needed. And when they are despised the hearer is embarrassed. Til. I admit that particles are very useful ; but I am not aware that the art of speaking well consists principally in their proper use. If any one presents only aphorisms or detached theses, as they often do in the universities, or as in the case of that which they call among the jurisconsults an articulate libel, or as in the articles which are offered to the witnesses, then provided we arrange these propositions well we shall accomplish very nearly the same result in making them understood as if we had put in the connective and the particles ; for the reader supplies them. But I admit there would be trouble if you put' in the particles badly, and much more than if you omitted them. Particles seem to me also to unite not only the parts of discourse composed of proposi- tions and the parts of the proposition composed of ideas, but also the parts of the idea, composed in many ways by the combination of other ideas. And it is this last connection which is indicated by the prepositions, while the adverbs modify the affirmation or negation in the verb ; and the con- junctions modify the connection of different affirmations or negations. But I doubt not that you have noticed all this yourself, although your words seem to state otherwise. § 3. Ph. The part of grammar which treats of particles has CH. vii] ON HUMAN UNDERSTANDING 365 been cultivated less than that which represents in order the cases, genders, modes, tenses, gerimdices, and supines. It is true that in some languages they have also arranged the particles under some titles by distinct subdivisions with great appear- ance of exactness. But it is not sufficient to run through these catalogues. One must reflect upou his own thoughts in order to observe the forms which the mind takes in discours- ing, for the particles are so many indications of the action of the mind. Th. It is very true that the doctrine of the particles is important, and I wish we might enter into much greater detail thereupon. For nothing would be more suited to make known the different forms of the understanding. Genders are of no account in philosophical grammar, but the cases corre- spond to the prepositions, and often the preposition is enveloped in the noun and as it were absorbed, and other particles are concealed in the inflections of the verbs. § 4. Ph. In order properly to explain particles it is not sufficient to render them (as is usual in a dictionary) by the words of another language which approach most nearly their meaning, because it is as difficult to comprehend their precise meaning in one language as in another ; besides the significa- tions of related words in two languages are not always exactly the same and indeed they vary in one and the same language. I remember that in the Hebrew language there is one particle of a single letter^ of which there are reckoned up more than fifty significations. Th. Scholars have attempted to make special treatises upon the particles of the Latin, Greek, and Hebrew; and Strauchius,^ a celebrated jurisconsult, has published a book upon the use of particles in jurisprudence, where their signification is of no small consequence. We ordinarily find, however, that it is rather by means of examples and synonymes that they attempt to explain them, than by distinct notions. Further we can 1 I.e. the adverb b- — Tr. 2 Johann Strauch, 1612-lf)80, the maternal uncle of Leibnitz, a distinguished jurisconsult, Professor at Leipzig, .lena, and Giessen, and Syndicus in Braun- schweig; cf. Guhrauer, G. W. Freiherr v. Leibnitz, Pt. I., Bk. I., pp. 6, 35 sq., and Aumerkunf/en z. erst. Buche, pp. 6, 7. The hook here referred to by Leibnitz is entitled: Lexicon X)articularuni juris s. de usu et efficacia quor- vndam syncategorematum et particularum indeclinabilium. — Tr. 366 LEIBNITZ'S CKITIQUE OF LOCKE [bk. hi not always find a general or formal signification for tliem, as tlie late Bohlius ^ called it, which can satisfy all the examples ; but notwithstanding this we can always reduce all the uses of a word to a definite number of significations. And this is what should be done. § 5. Ph. In fact the number of significations greatly exceeds that of the particles. In English the particle hut has very differ- ent significations: (1) when I say: but to say no more, {mats pour ne rien dire de plus) as if this particle indicated that the mind stops in its course before it has reached the end. But saying : (2) Isatv hut two jjlanets (je vis seulement deux planetes), the mind restricts the sense of what it means to that which has been expressed by the exclusion of everything else. And when I say (3) : yoti pray, hut it is not that God would bring you to the true religion, hut that he loould confirm you in your oicn (vous priez Dieu mais ce n'est pas qu'il veuille vous amener a la connaissance de la vraye Religion, mais qu'il vous confirme dans la vostre), the first but (ov mais) designates a supposition in the mind which is otherwise than it should be, and the second shows that the mind puts a direct opposition betwe'en what precedes and what follows. (4) AH animals have sense, hut a dog is an animal (tons les animaux ont du sentiment, mais le chien est un animal). Here the .particle signifies the connection of the second proposition with the first. Th. The French mais (but) may be substituted in all these instances except the 'Second ; but the German allein, taken as a particle, which signifies a kind of mixture of mais (but) and seulement (only), may doubtless be substituted instead of but in all these examples except the last, where its use may be a little doubtful. Mais (but) is also rendered in German some- times by aber, sometimes by sondern, which indicates a sepa- ration or segregation and approaches the particle allein. For a proper explanation of the particles, it is not sufficient to make an abstract explication as we have just made here ; but we must proceed to a paraphrase which may be substituted in 1 Samuel Bohl, 1611-1689, Professor at Rostock, who devoted himself to the furtherance of the' study of Hebrew in Germany, and whom Leibnitz mentions because of his works on the doctrine of the Hebrew Vowel- and Accent-Signs ; c/. Dutens, Leibniz, op. om., 5, 190. He published a large number of works, among which were Scrutin. S. s. ex accentihus, 1636, and Dissertat. pro for- mali Signif. S. S. eruenda, Rostock, 1637. — Tr. CH. VII] ON HUMAN UNDERSTANDING 367 its place, as the definition may be put in the place of the thing defined. When we have striven to seek and to determine these suitable loaraphrases, in all the particles so far as they are susceptible of them, we shall have regulated their sig- nifications. Let us try to attain this result in our four ex- amples. In the first we mean: Thus far only speak we of this, and no farther {non.piu) ; in the second: I see only two planets, and no more ; in the third : You pray God, and for this only, viz. to be confirmed in your religion, and no more, etc. ; in the fourth, it is as if we said : all animals have sense ; it is sufficient to consider that only, and no more is needed. The dog is an animal, he then has sense. Thus all these examples indicate limits, and a non plus ultra, whether in things, or in discourse. Thus hut is an end, a limit of the course, as if we said : stop, we are there, we have reached our But. But, Bute, is an old Teutonic word, signifying some- thing fixed, an abode. Beuten (an obsolete word found still in some church songs) is to abide. 3Iais originates from magis, as if any one wished to say : as for the surplus we must leave it, which is the same as saying': ISTo more is needed, it is enough, let us come to something else, or this is something else. But as the use of languages varies in a strange manner, it would be necessary to enter much farther into the detail of examples in order sufficiently to regulate the significations of particles. In French we avoid the double mais by a cependant (however), and we should say: Vous priez, cependant ce n'est pas pour obtenir la verite, mais pour estre confirm^ dans vostre opinion (You pray, not however (cependant) to obtain the truth but (mais) to be confirmed in your opinion). The sed of the Latins was often expressed formerly by ains, which is the anzi of the Italians, and the French in modifying it have deprived their language of an advantageous expression. For example : There was no certainty about it, yet (cepiendant) we were persuaded of what I have informed you, because we like to believe what we wish ; but it has been found that it was not so ; but (ains) rather, etc. (II n'y avoit rien de seur, cependant on estoit persuade de ce que je vous ay mand6, parce qu'on aime a croire ce qu'on souhaite ; mais il s'est trouv^ que ce n'estoit pag cela; ains plustost, etc.). § 6. Ph. My purpose has been to touch this matter only 368 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi very slightly. I would add that particles often include either constantly or in certain constructions the sense of an entire proposition. Th. But when it is a complete sentiment, I think that it is onl}^ by means of a kind of ellipsis ; otherwise it is the intej-- jections alone which in my opinion can subsist by themselves and say all in a word, as ah! (Jwi me!). For when we say mats, adding nothing more, it is an ellipsis for : but let us tvait for the confirmation of intelligence and not flatter ourselves unduly. There is something approximating to this in the 7iisi of the Latins : si nisi non esset, if there were not but (mais). For the rest I should not be displeased, sir, had you entered a little farther into the detail of the turns of the mind which appear marvellous in the use of the particles. But since we have reason for hastening to conclude this investigation of words and to return to things, I do not wish to delay you longer, although I truly think that languages are the best mirrors of the human mind, and that an exact analysis of the signification of words would show us better than anything else the workings of the understanding. CHAPTER VIII OF ABSTRACT AND CONCRETE TERMS § 1. Ph. It is further to be remarked that terms are abstract or concrete. Each abstract idea is distinct, so that of two the one can never be the other. The mind, must perceive by its intuitive knowledge the difference between them, and consequently two of these ideas can never be affirmed one of another. Every one sees at once the falsehood of these propo- sitions : humanity is animalify or rationality : this is as evident as any of the generally received maxims. Th. There is still something to be said thereupon. We admit that justice is a virtue, a habit (habitus), a quality, an accident, etc. Thus two abstract terms may be stated one of another. I am furthermore wont to distinguish two kinds of abstracts. There are abstract logical terms, and there are also abstract real terms. The abstract real terms, or conceived CH. IX] ON HUMAN UNDERSTANDING 369 at least as real, are either essences or parts of the essence, or accidents, i.e. beings added to snbstance. The abstract logical terms are the predications reduced to terms, as if I said : to be a man, to be an animal; and in this sense the one can be stated of the other, by saying : to be a ma?), is to be an animal. But in the realities this has no place. For we cannot say that humanity or man-ness^ {Vhommeite) — (if you please), which is the essence of the whole man, is animality, whicli is only a part of this. essence; yet these abstract and incomplete beings signified by the abstract real terms have also their genera and species which are not less expressed by the abstract real terms : thus there is predication between them, as I have shown by the example of justice, and virtue. § 2. Ph. One may always say that substances have only few abstract names ; they have scarcely spoken in the schools of humanity, animality, corporality ; and they have never been authorized in the world. Th. The reason is that but few of these terms were necessary to serve as examples and to throw light upon the general no- tion, which was the reason why they were not wholly neglected. If the ancients did not use the word humanity in the sense of the schools, they said human nature, which is the same thing. It is certain also that they said divinity, or rather divine nature ; and theologians having found it needful to speak of these two natures and of real accidents, they were attached to these abstract entities in the schools of philosophy and the- ology, and perhaps to a greater extent than was proper. CHAPTER IX OF THE IMPERFECTIONS OF WORDS § 1. Ph. We have already spoken of the double use of loords. The one is to register our own thoughts in order to aid our memory which makes us talk to ourselves ; the other is to communicate our thoughts to others by means of speech. 1 1 have taken the liberty to coin the word as an equivalent of the French, which I think is also coined by Leibnitz to express the abstraction of the scholastics. — Tr. 9 R 370 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi These two uses show the perfection or imperfection of words. § 2. When we speak only to ourselves, it is a matter of indif- ference what words we employ, provided we remember their meaning and do not change it. But § 3. the use of communication is also of two kinds, civil and philosophic. The civil consists in the conversation and use of the civil life. The x>hiloso];ihic use is that made of words for the purpose of giving precise notions and to express in general propositions certain truths. Th. Very good : words are not less marks (notoe) for us (as the characters of arithmetic or algebra may be) than signs for others ; and the use of words as of signs is as much in place when the question concerns the application of general precepts to the usage of life, as when it concerns the discovery or verification of these precepts. The first use of signs is civil, and the second jyhilosojyJiic. § 5. Ph. Now it is difficult, chiefly in the following cases, to learn and retain the idea which each word signifies, (1) when these ideas are very complex ; (2) when the ideas com- posing a ncAV one have no natural bond between them, so that there is in nature no fixed measure nor any model to rectify and regulate them ; (3) when the model is not easy to be known ; (4) when the meaning of the word and the real essence are not exactly the same. The names of the modes are most lia- ble to be doubtful and imperfect for the two first reasons, and those of substances for the two second. § 6. When the idea of the modes is very complex, as that of the majority of the terms of ethics, they rarely have precisely the same significa- tion in the minds of two different persons. § 7. The defect also of the models renders these words equivocal. He who first invented the word brusquer (to be abrupt with) understood thereby what he found to the purpose, without informing those who have used it as he of his precise meaning, and without having shown them any constant model. § 8. Common use regulates sufficiently the sense of words for ordinary conversa- tion, but it has no precision ; and the signification most con- formed to the peculiar nature of the language is every day disputed. Many speak of gloiy, but few have the same under- standing of it. § 9. They are only simple sounds in the mouths of many, or at least their meanings are very indefinite. And in a discourse or conversation in which mention is made CH. IX] ON HUMAN UNDERSTANDING 371 of honor, faith, grace, religion, the church, and above all in dis- cussion, you will notice at once that men have different notions which they apply to the same terms. And if it is difficult to understand the meaning of the terms of the people of our time, it is much more difficult to understand ancient books. Fortunate is it that we may pass them by save when they contain what we should believe and do. TJi. These remarks are good: but in regard to ancient books, as we need to understand Holy Scripture above all, and as Roman laws are still of great use in a good part of Europe, we are indeed compelled to consult a great many other ancient books ; the Rabbis, the Church Fathers, even the profane his- torians. Besides the ancient physicians also deserve to be understood. The practice of medicine by the Greeks came through the Arabs to us ; the water from the fountain has been 'made turbid in the streams of the Arabs, and purified in many respects since we have begun to have recourse to the original Greeks. But these Arabs do not cease to be of use and we are as- sured that Ebenbitar,^ for example, who in his books on Simples has copied Dioscorides, often serves to throw light upon him. I find also that, next to religion and history, it is chiefly in medi- cine, as far as it is empirical, that the tradition of the ancients preserved in writing, and in general the observations of another 1 Ibn-al-Baitar, c. 1197-1248, a distinguished Arabian botanist, — according to Pouchet the most learned tliat tlie Arabian School has produced, — who wrote a general liistory of simples, or of plants alphabetically arranged, a materia mecUca, based upon and said to contain for the most part the work of the Greek physician Dioscorides, c. 100 a.d., Uepl 'yat;? 'laTptKTj?, as well as a variety of facts from other sources, including descriptions of plants not men- tioned by either Dioscorides or Pliny the Elder, 23-79. Most of Baitar's works still remain in MSS. in the libraries of Paris and the Escurial. Fr. R. Dietz published a small fragment of tiie work on Simples in his Analecta me- dica ex librls MSS., Lipsise, 1833, 8vo. There are also Grosse Zusammenstel- Iwivj il. d. Krilfte d. bekannt. einfachen Heil-inid-Nahrxmgsmittel v. . . . Ehn Baithar. Aus d. Arahischen ilhersetzt v. Dr. Joseph v. Sontheimer, 2 vols., Stuttgart, 1840^2, and Traite des simples, trans, by L. Leclerc, in Inst, de France, Notices et extraits des MSS. de la Bibl. Nationale, vol. 23, Pt. I., Paris, 1877, Ito. For some account of Baitar, cf. Leclerc in Gazette hehdom. de medi- cine et de chirurgie,:Kxu., 97, 129, Paris, 1875 ; F. A. Pouchet, Histoire des sciences naturelles au moyen age. Paris, 1853, 8vo. Schaarschmidt says that Leibnitz may have been led to the remark which he here makes upon Baitar by tlie Exercitationes de homonymis hyles iatricse, appended to Claud. Salmasius, 1588-1(!53, Plinianse exercitationes, P. 101. a. B. 110. a. A., Trajecti-ad-Rhenum, lfi89, 2 vols., fol., where different accounts of Dioscorides are amended from Ebnbitar. — Tr. 372 LEIBNITZ'S CKITIQUE OF LOCKE . [ek. hi may be of service. I have therefore always held in high esteem physicians mach versed in the knowledge of antiquity ; and I was very sorry thfrt Reinesius,^ excellent in both depart- ments (of knowledge), had turned aside to explain the rites and history of the ancients, rather than to recover a part of the knowledge they had of nature, in which it has been shown that he would have been able furthermore marvellously to suc- ceed. When the Latins, Greeks, Hebrews and Arabs shall some day be exhausted, the Chinese, supplied also with ancient books, will enter the lists and furnish matter for the curiosity of our critics. Not to speak of some old books of the Persians, Armenians, Copts and Brahmins, which will be unearthed in time so as not to neglect any light antiquity may give on doc- trines by tradition and on facts by history. And if there were no longer an ancient book to examine, languages would take the place of books and they are the most ancient monuments of mankind. In time all the languages of the world Avill be recorded and placed in the dictionaries and grammars, and compared together ; this will be of very great use both for the knowledge of things, since names often correspond to their properties (as is seen by the names of plants among different peoples), and for the knowledge of our mind and the wonder- ful variety of its operations. Xot to speak of the origin of nations, which is known by means of solid etymologies which the comparison of languages will best furnish. But of this I have already spoken. And all this shows the use and extent of criticism, little considered by some otherwise very clever philosophers who take the liberty to speak with contempt of Rabhinage - and in general of lohilology. We see also that critics will find for a long time yet matter for fruitful exercise, 1 Thomas Reinesius, 1587-1667, a physician who wrote on natural history and medicine, and afterwards devoted himself to pliilological and antiquarian studies. Among his works were, Scholn jvreconsultoriini medica relatioiuim libris aliquot convprelipnsn , qvihiis prinfipia medicinal in Jus transmuta ex professo examinant'iir , Lipsite, 1679, 12mo; Vi/nfa-nna inscriptidnen') antiqiiarvm cum primift Romse veteris, quarum omis^sa est recensio in Grvteii opere, cum comment, Lipsise, 1682, fol. Cf. B. Schuchardt, Lebensbeschreibun gen be- rilhrnter yErzte 'und Natnr for seller, 10 elche ans Thilringen stamvien. Corre- sp)ondenz-Blatter des allgemeinen arztlichen Vereins von Thilringen, Weimar, 1888, xvii., 556, 601.— Tr. " A tSrm of disparagement, meaning tlie study made of the hooks of the rabhis. — Tr. CH. IX] - ON HUMAN UNDERSTANDING 373 and they will do well not to amuse themselves too much with minutiae, since they have so many objects more pleasing for treatment ; though I well know that minutiae also are often very necessary with the critics for the discovery of more important knowledge. And as criticism turns in large measure upon the meaning of words and the interpretation of au.thors, especially the ancients, this discussion about words joined with the men- tion you made of the ancients, makes me touch upon this important point. But to return to your four defects of nomi- nation, I tell you, sir, that we can remedy them all, especially since writing has been invented and they subsist only through our negligence. For it depends upon us to fix their meanings, at least in any scholarly language, and to agree to destroy this tower of Babel. But there are two defects where the remedy is mcu'e difficult, consisting the one in the doubt which exists whether the ideas are compatible, when experience does not furnish them all combined in one and the same subject ; the other in the necessity for making provisional definitions of sensible things, when our experience with them is insufficient for more complete definitions : but I have spoken more than once of both these defects.^ Ph. [I am going to tell you some things which will serve further to clear up to some extent the defects you have just remarked, and the third of those which I have indicated makes it seem that these definitions are " provisional ; viz.: — when we have no sufficient knowledge of our sensible models, i.e. the substantial beings of corporeal nature. This defect also makes us ignorant as to whether we may combine the sensible qualities which nature has not combined, because at bottom we do not understand them.] Now if the signification of the words which serve for the mixed modes is uncertain, for lack of models which show the same composition, that of the names of the substantial beings is uncertain for a wholly contrary reason, because they must signify what is supposed to be conformed to the reality of things, and to be related to the models formed by nature. Th. I have already more than once remarked in our pre- vious conversations that this is not essential to the ideas of 1 Cf. New Essays, Bk. III., chap. 6. — Tr. 374 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi substances ; but I admit tliat ideas made after nature are the surest and most useful. § 12. Ph. When then we follow the models wholly made by nature, unless the imagination finds it necessary to retain their representations, the names of substances have in ordi- nary use a double relation, as I have already shown. The first is that they signify the internal and real constitution of things, but this model cannot be known and consequently can- not serve to regulate the significations. Th. That is not the question here, since we are speaking of ideas of which we have models ; the internal essence is in the thing, but we agree that it cannot serve as a pattern. § 13. Ph. The second relation is then that which the names of substances immediately have to the simple ideas, which exist at the same time in the substance. But as the number of these ideas united in one and the same subject is great, men speak of this same subject, forming very different ideas of it, both by the different combination of the simple ideas they make and because the greater part of the qualities of bodies are the powers which they have of producing changes in other bodies and receiving them ; witness the changes one of the basest metals is capable of undergoing through the opera- tion of fire, and it receives many more yet at the hands of a chemist, through the application of other bodies. Further, one is contented with weight and color as criteria for a knowledge of gold ; another includes ductility, fixedness ; and the third desires to make us take into consideration its solubility in aqua regia. § 14. As things likewise often resemble each other, it is sometimes difiicult to designate their precise differences. Th. As bodies are really liable to be altered, disguised, falsified, counterfeited, it is a great point to be able to dis- tinguish and recognize them. Gold is disguised in solution, but it may be drawn off, either by precipitating it or dis- tilling the water ; and counterfeit or adulterated gold is recognized or purified by the art of the assayers, which not being known to everybody, it is not strange that men do not all have the same idea of gold. And ordinarily it is only the experts who have sufiiciently just ideas of these mat- ters. CH. IX] ON HUMAN UNDERSTANDING 375 § 15. Ph. This variety does not, however, cause so much confusion in civil intercourse as in philosophic researches. Th. It would be more tolerable if it had no influence in prac- tical life where it is often important not to receive a Qui pro quo, and consequently to know the characteristics of things or to have at hand the class who know them. And it is especially important as regards drugs and materials which are costly, and of Avhich you may have need on important occasions. The philosophical confusion will manifest itself rather in the use of more general terms. § 18. Ph. The names of simple ideas are less liable to equivo- cation, and we are rarely mistaken as regards the terms white, bitter, etc. Th. It is, however, true that these terms are not wholly exempt from uncertainty ; and I have already noticed the example of neighboring colors which are within the confines of two species and whose species is doubtful. § 19. Ph. After the names of simple ideas, those of the simjjle modes are least doubtful, as for example, those of figures and numbers. But, § 20. the mixed modes and substances cause all the trouble. § 21. Men will say that instead of imputing these imperfections to the words, we should rather put them to the account of our understanding ; but I reply that words interpose themselves to such an extent between our mind and the truth of things, that we may compare them with the medium, across which pass the rays from visible objects, and Avhich often spreads a mist before our eyes ; and I have tried to think that, if the imperfections of language v^^ere more thoroughly examined, the majority of the disputes would cease of themselves, and the way to knowledge and perhaps to peace would be more open to men. Th. I think we could succeed from this time in written dis- cussions, if men would agree upon certain rules and execute them with care. But in order to proceed exactly viva voce and at once, some change in the language would be necessary. I have elsewhere ^ entered upon this enquiry. 1 In his writiiicfs in furtherance of his plan for the establishment of a General Characteristic or Philosophical Langi;affe, Sp^cieuse f/ei)irah\ a project which Leibnitz had very much at heart, as apjiears from his frequent allusion to the subject, and upon which throughout his entire life he spent much labor, chietiy 376 LEIBXITZ'S CRITIQUE OF LOCKE [bk. in § 22. Ph. While waiting for this reform which will not be ready very soon, this uncertainty regarding words should teach us to be moderate, especially when it is a question of imposing upon others the sense attributed by us to the ancient authors, since in the Greek authors it is found that nearly every one speaks a different language. Th. I have been rather surprised to see that Greek authors so distant from one another in time and place, as Homer, Herodotus, Strabo, Plutarch, Lucian, Eusebius, Procopius, Photius, approach so closely, while the Latins have changed so much, and the Germans, English, and French much more. But the fact is, the Greeks since Homer's time, and still more when Athens was in a flourishing condition, had good authors which posterity has taken as models, at least in writ- ing. Eor no doubt the common language of the Greeks must •have been much changed already under the rule of the Romans. And this same reason accounts for the fact that the Italian has not suffered so great a change as the French, because the Italians, having had earlier writers of durable reputation, imi- tated and moreover esteemed Dante, Petrarch, Boccaccio, and other authors at a time when those of the French were no longer appreciated. CHAPTER X OF THE ABUSE OF WORDS § 1. Ph. Besides the natural imperfections of language, there are some that are voluntary and arise from negligence, and it is an abuse of words to use them so badly. The first and most palpable abuse is, § 2. that we attach no clear idea to tliem. Of these words there are two classes : the first have never had any definite idea, either in their origin or ordinary use. For the most part philosophical and religious sects have introduced preparatory, and with little positive results in accomplishing his plan. Cf- Neiu Essmjs, Bk. IV. chap. 6, § 2, Th., chap. 17, § 13, Th.; Gerhardt, Leibniz. Vhilos. Schrift., 3, 216; 4, 27 sq., Erdmann, 6 sq.; G. 7, 3 sq., E. 82 sq., 6(39 sq.; Trendelenburs:, Ueber Leibniz. Entiourf einer allgemeinen Characteristik, in his Hisior. Beitrdge z. Philos., vol. 3, pp. 1 sq., Berlin, 1867; L. Neff, G. W. Leibniz als Sprachforscher unci Etymologe, Pt. II., pp. 13 sq., Heidelberg, 1870-1.— Tr. cii. X] ON HUMAN UNDERSTANDING 377 them ill order to support some strange opinion, or to conceal some weak place in their system. They are, however, distin guishing characters in the mouth of members of the party. § 3. There are other words, which in their first and common use have some clear idea, but which have since been appro- priated to very important matters without attaching to them any certain idea. In this way the words wisdom, glory, grace, are often in the mouths of men. Th. I believe that insignificant words are less in number than you think, and that with a little care and good will you can till up their void or fix their indefiniteness. Wisdom appears to be nothing else than the science of happiness. Grace is a favor done to those who do not deserve it and who find themselves in a state where they need it. And glory is the fame of the excellence of some one. § 4. Ph. I do not wish now to examine whether there is anything to be said in regard to these definitions, but rather to notice the causes of the abuse of words. In the first place, we learn the words before we learn the ideas belonging to them, and children accustomed thereto from the cradle use them in like manner during their whole life : the more as they do not cease to make themselves understood in conversation, Avithout ever having fixed their idea, by using different expressions in order to make others understand their meaning. This, however, often fills their discourses with a quantity of vain sounds, especially in matters concerning morals. Men take the words they find in use among their neighbors, and in order not to appear ignorant of their meaning employ them confidently without giving them a certain sense : and, as in this kind of discourse they are rarely in the right, they are also rarely convinced that they are wrong; and to wish to draw them from their error is to wish to dispossess a vagabond. Th. Men in fact take so rarely the necessary trouble to understand terms or words that I have more than once been astonished that children can learn languages so soon, and that men furthermore speak them so accurately ; a view to which we attach so little in instructing children in their mother tongue and which others think of so little in acquiring clear definitions ; the more so as those we learn in the schools do not ordinarily concern the words in public use. For the rest, I 378 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi admit that men frequently happen to be wrong when indeed they discuss seriously and speak in accord with their feeling; but I have also remarked often enough that in their speculative discussions upon matters within the province of their mind, they have every reason for two sides, except in the oppositions they make to each other where they misconstrue another's view. This arises from the bad use of terms and sometimes also from a spirit of contradiction and affectation of superi- ority. § 5. Ph. In the second place the use of words is sometimes inconstant, a practice only too general among scholars. It is nevertheless a plain cheat, and if voluntary, is folly or malice. If any one so conducted himself in his accounts (as to take an X for a V), who, I pray, would have anything to do with him ? Th. This abuse being so common not only among scholars but also in the world at large, I believe that it is due rather to bad custom and inadvertence than to malice. Usually the different significations of the same word have some affinity ; this makes one pass for another and does not give time to con- sider what is said with all the precision that is desirable. We are accustomed to tropes and figures, and some elegance or brilliant falsehood easily imposes upon us. For we oftener seek pleasure, amusement, and appearance, than truth ; besides, vanity mixes itself therein. § 6. Ph. The third abuse is an affected ohscurity, either by giving terms in use unusual meanings, or by introducing neio terms without explaining them. The ancient Sophists, whom Lucian ridicules so properly, pretending to speak of every- thing, covered their ignorance under the veil of the obscurity of words. Among the sects of philosophers the Peripatetic has shown itself remarkable by this defect; but the other sects, even among the moderns, are not wholly exempt from it. For example, the people who abuse the term extension, and find it necessary to confuse it with that of body. § 7. Logic or the art of discussion, which is held in such high esteem, has helped to maintain this obscurity. § 8. Those who have given themselves up to it have been useless or rather detrimental to the state; § 9. while mechanics, though de- spised by the learned, have been serviceable to human life. CH. x] ON HUMAN UNDERSTANDING 379 But these obscure doctors have been admired by the ignorant ; and they have been thought invincible because provided with briers and tliorns, into which it was no pleasure to thrust one's self, their obscurity alone serving as a defence of their absurd- ity. § 12. The evil is that this art of obscuring words has confused the great lailes of men's action, religion and justice. Til. Your complaint is largely just : it is nevertheless true that there are, though rarely, pardonable and even praiseworthy obscurities, as when we profess to be enigmatical, and the enigma is timely. Pythagoras ^ so used it, and it is frequently the manner of the Orientals. The alchemists, who are called adepts, declare that they wish to be understood only by the sons of the art. And that would be well, if these pretended sons of the art had the key to the cipher. A certain obscurity may be allowed ; but something must be concealed which is worth divining, and the enigma must be decipherable. But religion and justice demand clear ideas. It seems that the little order brought into their teaching has made the confusion in their doctrine ; and the indeterminateness of the terms is perhaps more harmful than their obscurity. Now as logic is the art which teaches the order and connection of thoughts, I do not see any reason for blaming it. On the contrary it is for want of logic that men deceive themselves.- § 14. Pli. The fourth abuse is when we take words for things, i.e. believe that the terms correspond to the real essence of the 1 Pythagoras, c. 580-570-c. 500 b.c. The reference is to his so-called Symbols, or sayings preserved in a symbolic form, in order that their meaning might be concealed from the uninitiated, and the characteristic of which is the union of an ethical prescript with an external a,ction relatively indifferent. Cf. Dioge- nes Laertius, De vitis, dogmatibus, et apophthegmatis clarorumphilosophorum, VIII, 17 sq., who gives some of these symbols with interpretations of a part of them ; Zeller, Philos. d. Griec, 5th ed., 1892, Vol. 1, p. 324, note 2, 402. Mullach, Fragmt. Philos. Grsec, Vol. 1, p. 504 sq., gives a collection of these sayings. Examples are: "Carry not the image of God in the finger-ring," "Stir not the fire with the sword," " Sacrifice and pray with bare feet." Gottliug, Gesammlt. Ahhundl., Vol. 1, p. 278 sq., 2, 280 sq., has given them a "pene- trating investigation," on which see the note of Zeller above cited. Leibnitz on Pythagoras, cf. Gerhardt, Leibniz. pjJdlos. Schri/t., 7, 147. — Tr. 2 Leibnitz, while rejecting the over-refinements of the scholastic logic, never- theless rightly values formal logic as an aid to clear thinking and correct reasoning. Cf. the letter to Gabriel Wagner, 1696, Gerhardt, Leibniz, philos. Schrift., 7, 512 sq., Erdmann, 418 sq., Guhrauer, Leibniz, deutsche Schrift., 1, 374 sg., Berlin, 1838. — Tr. 380 LEIBNITZ'S CRITIQUE OE LOCKE [bk. in substances. Who is there brought up in the Peripatetic phi- losophy who does not think that the ten names which represent the predicaments are exactly conformed to the nature of things ; that the substantial forms, vegetative souls, abhorrence of a vacuum, intentional S2)ecies, etc., are something real ? The Platonists have their soul of the loorld, and the Epicureans the tendency of their atoms towards movement at the time when they are at rest. If the aericd or etherecd vehicles ^ of Dr. More had pre- vailed in any corner of the world they would have been thought no less real. Th. Properly speaking this is not to take words for things, but to believe that true which is not so, an error too common with all men, depending not alone upon the abuse of words, but consisting in something entirely different. The design of the i:)redicaments is a very useful one, and we ought to think of rectifying rather than of rejecting them. Substances, quantities, qualities, actions or passions, and relations, i.e. five general names of things may, together with those formed by their composition, suffice, and have not you yourself, in mar- shalling ideas, been willing to grant them as the predicaments ? I have spoken above of substanticd forms.^ And I know not whether we have sufficient reason for rejecting the vegetcdive soids,^ since persons of much experience and judgment recog- 1 The aerial or ethereal vehicles are the aerial or celestial bodies of the spirits, wliich, according to More, the souls of men after sufficient purification attain, either at death, in the case of a very few of the noblest and most heroic, or at some period after death. Cf. H. More, Opera omnia, Londini, 1679, 2 vols., fol. ; Tract, de immortalitate animse, Bk. III. chap. 1, Axioma, 27, §§ 3, 28 sq., Vol. 2, p. 396 sq., chap. 11, § 2, p. 427 ; Antidotus adversus Atheis- mum, Bk. III. chap. 3, § 9, Vol. 2, p. 99. — Tr. 2 Cf. ante, p. 349 and note. — Tr. 3 The scholastic philosophy recognized three forms or kinds of souls, corre- sponding to the three orders of life, plants, animals, and men, viz.: the vege- tative, sensitive, and intellective {anima vegeiabilis or nutritiva, sensibilis or sensitiva, intellectiva or rationalis). Of these the vegetative is the lowest, the sensitive the next higher, the intellective the highest ; and the Ixigher form includes potentially in itself the lower and subordinate form and its functions. The functions of the vegetative soul are nutrition, growth, repro- duction ; of the sensitive soul, sensation, feeling, perceptional, appetitive and emotional activity ; of the intellective, those of the reason and the will. In man, these several functions are all united in the intellective or rational soul, which lie alone possesses, and which comprises within itself the sensitive and vegetative souls. Cf. Stockl, Gesch. d. Philos. d. Mittelalters, 11. 2 [Vol. 3], 592 sq., 618 sq., 633 sq. — Tr. CH. x] ON HUMAN UNDERSTANDING 381 nize a great analogy between plants and animals, and you, 'sir, have appeared to admit animal souls. Abhorrence of a vacuum may be soundly understood; i.e. supposing nature has once filled space, and that bodies are impenetrable and non-condens- able, she could not admit any vacuum ; and I consider these three suppositions well grounded. But the intentional species,^ which are to make the connection between the soul and the body, are not so, though we may excuse the sensible species,'^ 1 Cf. 5th letter of Leibnitz to Clarke, § 84, Gerliardt, 7, 410, Erdmann, 773, b, Jacques, 2, 465, Dutens, 2, Pt. I, 161, trans. Duncan, 275. Tlie doctrine of the intentional species {species intentionales) to which were opposed the real species {species reales) or the actual forms of things, arose in the attempts of the Mediaeval Schoolmen to explain the process and philosophy of sense-perception and cognition. Two views have in general been held concerning their nature: 1. That they were the forms, similitudes, or images (formse, similitudines, simulacra) of external objects, different both from the mind and from these objects, the intermediate and vicarious repre- sentatives of these objects in perception and thought, the media through which the mind infers and comes to know these external objects — a form of the doctrine of mediate perception. 2. That they were modifications of the mind itself, occasioned by the action upon the mind of the external object and the mind's responsive reaction thereto, by which the mind is likened or con- formed to the given object and so determined immediately to cognize it. The latter view is maintained by the Roman Catholic psychologists, as being the doctrine of the greatest of the schoolmen, such as Albertus Magnus, Thomas Aquinas, Duns Scotus, and as giving the real meaning of the terms they use. It is the more correct interpretation. The intentional species, according as they affected or were modifications of the sense or the intellect, were divided into sensible species {species sensih lies) and intelUc/ible or intellectual species {species intelligibiles vel intellectuales) . Both the sensible and the intelligible species were further distinguished as impressed species {species impressa) and expressed species {species expressa)'. According to the representative theory of the intentional species, the species impressa was the vicarious existence emitted by the object, impressed on the particular faculty, and concurring with it in its operation ; while the species expressa was the actual operation elicited by the faculty and the impressed species conjointly, i.e. the sensations and intellections. The direct or imme- diate theory regarded the genesis of species, whether as sensible or intelligible, as exhibiting two stages : 1. In sensuous cognition, (a) the species sensibilis impressa, or "the modification of the sensuous faculty viewed as an impres- sion wrought in the mind by the action of the object," and (b) the species sensibilis expressa, or "the reaction of the mind as an act of cognitive con- sciousness." 2. In intellectual cognition, (a) the species intelligibilis im- pressa, or the "modification effected in the recipient capacity" of the intellevtus patiens vel possibilis (the pftssiwe intellect — Aristotle's vov<; waB-q-n.- Ko?),and (b) the species intelligibilis expressa, or the "mental modification refiecting the essence of the object, and by means of which the object is ap- prehended," a modification due to the act of the intellectus agens (the active intellect — Aristotle's vov<; TroirjTixo?). 382 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi wliicli proceed from the object to the distant organ, meaning thereby the propagation of motion. I admit that there is no Platonic soul of the tvorld, for God is beyond the world, extra- mundana intelligentia, or rather supramundana} I know not whether by the tendency to movement of the Epicurean atoms you understand the weight attributed to them, no doubt with reason, since they maintain that bodies all move of them- selves in one and the same direction. The late Henry More, a theologian of the English Church, wholly clever as he was, showed himself a little too ready to invent hypotheses which were neither intelligible nor apparent ; witness his Hylarchic principle^ of matter, a cause of weight, elasticity, and other wonders which are met with. 'I have nothing to say of these ethereal vehicles, having never examined their nature. § 15. Ph. An example touching the word matter will assist you the better to enter into my thought. Matter is taken as The doctrine of the intentional species was held by the Realists, Aquinas, Duns Scotus, and others. The Nominalists, especially Durandus, Biel, and Occam, rejected it, and the doctrine was exploded in the seventeenth century, largely by the arguments of Gassendi, Hobbes, and Descartes. On the whole subject, c/'. Hamilton's Reid, 8th ed., Edinburgh, 1880, Vol. 1, p. 267 sq., and Note M., Vol. 2, p. 951 sq.; Lects. on Metaphys., Boston, 1875, p. 291 sq., and notes; Stockl, Gesch. d. Philos. d. MittelaUers, II. 1 [Vol. 2] 463 s?., II. 2 [Vol. 3] 808, 965, 978, 991 sq., III. [Vol. 4] 634 sq. ; Haureau, Histoire de la philos. scolastique, II. 1 [Vol. 2] 417 .sq., II. 2 [Vol. 3] 247 sq., 378 sq. ; Prantl, Gesch. d. Logik im Ahendlande, Vol. 3, pp. 113, 210 sq., 294, 335 sq. ; Maher, S. J., Psychology (Manuals of Catholic Philosophy — Stonyhurst Series) , pp. 49-53, 290-297, London: Longmans, Green & Co., 1890; Zigliara, Summa Philosophica, 3d ed., Lugduni, 1880, Vol. 2, pp. 243-4, 260 sq. ; Suarez, De Anima, Lib. III. cc. 2, 3; Kleutgen, Philos. d. Vorzeit, §§ 18-52; Sanseverino, Bynauulogia, Neapoli, 1862-66, Vol. 1, pp. 373-403 (of which pp. 390-400 contain " an effective refutation of the charge of representationism against St. Thomas and the leading scholastics, based on the doctrine of species"), Vol.2, pp. 586 6'g. — Tr. 1 Cf. The'odicee, Pt. II. § 217, Gerhardt, 6, 248, Erdmann, 571, a, Jacques, 2, 2)5. —Tr. ■2 Cf. Gerhardt, Leibniz, philos. Schrift., 7, 339; letter to Placcius, Sept. 8, 1690, Dutens, Leibnit. op. om., 6, 48; to T. Burnett, Aug. 24 (v.s.) 1697, G. 3, 217, D. 6, 263. More rejected the mechanical explanation of physical natiire, and adopted the principlum hylarchicum, or .fpiritus naturse as he designates it, the immaterial force in all nature, the principle of the movement and sympathy of beings, similar to the anima mundi of the Platonists and the archseus {cf. ante, p. 67, note 3) of the Alchemists. Cf. H. More, Opera omnia, Londini, 1679, Enchiridion metaphys., especially in the Scholia, to chap. 13, § 4, Vol. 1, p. 222 sq. ; also Tract, de immortalitate animse, Bk. III. chap. 12, Vol. 2, p. 430. — Tr. CH. X] ON HUMAN UNDERSTANDING - 383 an entity really existing in nature, distinct from the body ; which indeed is thoroughly self-evident ; otherwise these two ideas might be put indifferently the one in the place of the other. For we may say that one single matter composes all bodies, but not that a single body composes all matter. Neither will we say, I think, that one matter is greater than another. Matter expresses the substance and solidity of body ; thus we no more conceive different matters than differ- ent solidities. But since matter has been taken as a name of something existing under this determination, this thought has produced unintelligible discourse and confused discussion upon materia prima. Th. This example appears to me to serve rather to excuse than to blame the Peripatetic philosophy. If all silver were figured, or rather because all silver is figured by nature or art, is it less allowable to say that silver is an entity really existing in nature, distinct (taking it in its precision) from the plate or the money ? You will not on that account say that silver is nothing else than certain qualities of money. Thus it is not so useless as you suppose to reason in general physics about materia jj?'ma and to determine its nature in order to know whether it is always uniform, whether it has some other property besides impenetrability (as I in fact have shown ^ after Kepler that it also has what may be called inertia), etc., although it is never found wholly pure ; as it would be allow- able to reason about pure silver, although we had none with us nor the means of purifying it. I do not at all disapprove what Aristotle has said about materia prima ;'^ bvit one cannot 1 Cf. De ipsa natura, 1698, § 11, Gerhardt, Leihniz. philos. Schrift., 4, 510, Erdmaim, 157, a, Jacques, 1, 462 (in French), Dutens, 2, Ft. II., 54, trans. Duhcan, 119; TModicee, Pt. I., § 30, G. 6, 119, E. 512, a, J. 2, 89, Dutens, 1, 141 (in Latin) ; Specimen dynamicum, 1695, Pt. I., Gerhardt, Leihniz. math. Schrift., 6, 234 sq., Dutens, 3. 315 sq., trans. Appendix, 670 sq. ; G. Leibniz, philoii. Schrift.. i, 464-7, Dutens, 2, Pt. I., 2:34-7, two letters to the editor of the "Journal des Savans," in the numbers for June 18th, 1691, January, 1693, tlie first orio-inally a fragment from a letter to Antonio Alberti, G. 7, 447-9; 5tli letter to Clarke, § 102^ G. 7, 414, E. 775, b, J. 2, 470, Dutens, 2, 165, trans. Duncan, 280. In the letter to Jac. Thomasius, April 20-30, 1669 {cf. G. 1, 17, 18, 24), Leibnitz affirmed that matter consisted of extension and inpenetrability only. -Tr. 2 Cf. Zeller, Philos. d. Griech., 3d ed., 1879, II. 2 [Vol. 4] , p. 320, note 2 ; and Bonitz, Ind. Arist. sub voc. iiAr;, in vol. 5 of Berlin Academy, ed. of Aristotle. Cy. also Gerhardt, Leibniz, philos. Schrift., 7, 259. — Tr. 384 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi help blaming those who have stopped too soon and have con- jured up chimeras out of the ill-understood words of this philosopher, who perhaps also has given too much occasion sometimes for this misconception and nonsense. But we should not exaggerate so much the defects of this celebrated author, because we know that many of his works were not completed or published by himself. § 17. Ph. The fifth abuse is the putting of words in the place of things which they do not and cannot in any way signify. It occurs when by the names of substances we mean to say something more than this : what I call gold is malleable (although at bottom then gold signifies nothing else than what is malleable), intending to have it understood that mallea- bility depends uj^on the real essence of gold. Thus we say that it is right to define man with Aristotle as a reasonable animal ; and that it is not right to define him with Plato as a two-legged animal without feathers and with broad nails. § 18. There is scarcely any one who does not suppose that these words signify a thing having a real essence upon which these properties depend; but it is a plain abuse when the complex idea signified by this word does not include this thing. Th. For myself I should rather think that we are plainly wrong in censuring this common usage, since it is very true that in. the complex idea of gold is included the thought that it is a thing having a real essence, whose constitution is un- known to us in detail otherwise than that upon it depend such qualities as malleability. But in order to express its mallea- bility without identity and without the defect of coccysm or repetition (see chap. 8, § 18),^ we must recognize this thing by other qualities, as color and weight. And it is as if we said that a certain fusible body, yellow and very heavy, called gold, has a nature which gives it besides the quality of being very soft to the hammer and capable of iDeing made very thin. As for the definition of man attributed to Plato, which he appears to have made only for practice, and which you would not, I think, compare seriously with that which is received, it is manifestly a little too external and provisional; for if this Cassoioary, of which you recently spoke (chap. 6, § 34), had 1 The reference is incorrect. Perhaps chap. 6, § 18, is meant, or chap. 10, §18.— Tr. CH. x] ON HUMAN UNDEESTANDING 385 been found to have wide nails, it would be man; for it would not have been necessary to strip it of its feathers, as in the case of the cock which Diogenes, as they say, wished to make a Platonic man.^ § 19. Ph. In the mixed modes, as soon as an idea entering therein is changed, you at once recognize it as another thing, as plainly appears in the words, murder, which signifies in English (as Mordt in German), homicide premeditated with design ; manslaughter (a word corresponding in origin to homi- cide), a voluntary but not premeditated homicide; chance- medley (a chance melee, according to the force of the word), homicide committed without design; for what is expressed by the names and what I think to be in the thing (which I called before nominal essence and reed essence) is the same. But it is not so in the names of substances ; for if one puts into the idea of gold what another leaves out, for example fixedness and solubility in aqua regia, men do not think for that reason that its species, has been changed, but only that the one has a more perfect idea than the other of what constitutes the real con- cealed essence to which the name of gold is given, although this secret relation is useless and serves only to involve us in diffi- culties. Th. I think I have already made this statement ; but I am going also to show you clearly here, that what you, sir, have jugt said, is found in the modes, as in the substances, and that we have no ground for censuring the internal essence for this relation. Here is an example: we may define a parabola, in the sense of the geometers, as a figure in which all the lines parallel to a certain straight line are united by thought in a certain point or focus. But it is rather the exterior and the effect which is expressed by this idea or definition, than the interned essence of this figure or what can at once make known its origin. We may at the beginning even doubt if such a figure as we wish and which ought to produce this effect is a possible thing ; and it is this which with me shows whether a 1 Cf. Diogenes Laertius, c. 230-250, D,e vitis, dogmatibus et apophther/matis elarorum pfiilosophorvm lib. decern, VI. 40: nAarioi-os 6pi7}a'ii'j Ovto? eanv 6 nAartoi'o? ai'^pwrro?. oSev tw opoj 7rpo(j6Te07/ To vKaTvuivvxov. The definitions ascribed to Plato, and found in some editions of his works, are beyond doubt spurious. — Tr. 2c 386 LEIBNITZ'S CRITIQUE OF LOCKE [bk. in definition is only nominal and taken from tlie properties, or whether it is ' also real. But he who mentions the parabola and knows it only by the definition I have just spoken of, ceases not, when speaking of it, to understand a figure which has a certain construction and constitution unknown to him, but which he wishes to learn in order to be able to draw it. Another who has examined it more thoroughly will add some other property, and will discover, for example, that in the figure asked for, the portion of the axis intercepted between the ordinate and the perpendicular drawn to the same point of the curve is always constant, and equal to the distance from the vertex to the focus. He will thus have a more per- fect idea than the former, and will come more easily to the drawing of the figure, although he is not yet there. And, moreover, we shall agree that it is the same figure, the consti- tution of which is still concealed. You see then, sir, that all that you have found and partly censured in the use of words signifying substances is also found and found plainly justified in the words signifying the mixed modes. But what has made you think that there was some difference between the sub- stances and the modes,^ is merely the fact that you have not consulted here the intellectual modes difficult of discussion, which are found to resemble in all this bodies which are still more difficult to know. § 20. Ph. Thus I fear I must suppress what I wished to say to you, sir, of the cause of what I have thought an abuse, as if it were because we falsely think that nature always acts with regularity and fixes limits to each species by this specific essence or internal constitution which we there understand and which always follows the same specific name. Th. You see clearly then, sir, by the example of the geo- metrical modes, that we are not wrong in referring them to internal and specific essences, although there is great differ- ence between sensible things, whether substances, or modes, of which we have only nominal provisional definitions, and of which we do not readily hope for real ones, and between the intellectual modes, difficult of discussion since we can at last reach the internal constitution of the geometrical figures. 1 Jacques reads : " c'est que vous n'avez point consvilte," etc. Gerhardt and Erdmann read: " n'est que vous," etc. — Tr. CH. x] ON HUMAN UNDERSTANDING 367 § 21. Ph. [I see at last that I should have been wrong in laying the blame of this relation upon the essences and internal constitutions, under the pretext that this would render our words signs of nothing or of an unknown something. For what is unknown in certain respects may make itself known in another way, and the inner nature may partly reveal itself by the phenomena which spring from it. And as for the question : whether a monstrous foetus is a man or not ? I see that, if it cannot be decided at once, this fact does not prevent the species from being well fixed in itself, our ignorance nowise changing anything in the nature of things.] Th. In fact, some very clever geometers have chanced to possess insufficient knowledge as to what the figures were, many qualities of which seemingly exhaustive of the subject they knew. For example, there were some lines called pearls,^ of which there were given indeed the quadratures and the measure of their surfaces and of the solids made by their revolution, before it was known that they were only a com- position of certain cubic paraboloids. Thus in considering beforehand these pearls as a particular species, they had only provisional knowledge of them. If this may happen in geom- etry, do you wonder that it is difficult to determine the species of corporeal nature which are incomparably more complex ? § 22. FJi. Let us pass to the sixth abuse in order to con- tinue the enumeration begun, although I see clearly that some of the points must be struck from the list. This general but little noticed abuse is this : men having by long use attached certain ideas to certain words, imagine that this connection is manifest and that everybody agrees to it. Whence it comes that they feel very strange, when asked the meaning of the words they employ, when indeed the question is an absolutely necessary one. There are few people who do not take it as an 1 Cf. New Essays, Bk. IV., chap. 7, § 4, Th. infra, p. 465. Reue Fran9ois Walter de Sluse, 1622-1685, a Flemish geometer, canon of Liege cathedral, and author of the method for the construction of the roots of equations of the 3d and 4th degree, "which consists in reducing the resolution of the proposed equation to that of the system of two equations representing two conies, by introducing an unknown auxiliary wliose elimination reproduces the primitive equation." He developed this method in his Mesolahium et problemata soUda, etc., 4to, Leodii Eburonum, 1668. Leibnitz mentions this work in a letter to Hobbes, 13-22 July, 1670, Gerhardt, Leibniz, philos. Schrift., 7, 573. — Tr. 388 LEIBXITZ'S CRITIQUE OF LOCKE [bk. hi affront if asked what tliey iiieau when speaking of life. But the yague idea tliey may have of it is insufficient when the question arises as to the knowledge whetlier a plant, already formed in the seed, or a pullet in the egg not yet in process of incubation, or a man in a swoon without sense or motion, has life. And although men do not wish to appear so little intelligent or so obtrusive as to find it necessary to ask for an explanation of the terms used, nor critics so disagreeable as to censure others unceasingly for the use they make of words, nevertheless when it is a question of exact research, such explication is necessary. Often scholars of different parties in the reasonings they display the one against the other merely speak different languages and think the same thing, although perhaps their interests are different. Th. I think I have explained sufficiently my views upon the notion of life, which must always be accompanied by per- ception in the soul; otherwise it would be only an appearance, as the life which the American savages attributed to watches or clocks, or which those magistrates attributed to the mario- nettes, who believed them animated by demons, when they desired to punish as a sorcerer the one who had first pre- sented this spectacle in their city. § 23. Ph. In conclusion, words serve (1) to make our thoughts understood, (2) to do this easily, and (3) to furnish entrance into the knowledge of things. Words fail at the first point, when they have no definite and constant idea either received or understood by others. § 23. They fail in facility, when they have very complex ideas, without distinct names ; this is often the fault of the languages themselves which have no names ; often also of the man who is ignorant of them ; in that case extensive paraphrases are necessary, § 24. But when the ideas signified by the words do not agree with what is real, they fail in the third point. § 26. (1) He who has terms without ideas is like a man who has only a catalogue of books. §27. (2) He who has very complex ideas is like a man who has a quantity of books in loose sheets without titles, and who could not give the book save by giving the sheets in succession. § 28. (3) He who is not constant in the use of signs is like a merchant who sells different goods under the same name. § 29. (4) He who attaches particular CH. x] ON HUMAN UNDERSTANDING 389 ideas to received words cannot enlighten others by the light he may have. § 30. (5) He who has in his head ideas of sub- stances which never had existence, cannot advance in real knowledge. § 33. The first will speak in vain of the taran- tula or of charity. The second will see new animals without being able easily to show them to others. The third will take body sometimes as a solid, sometimes as a mere exten- sion ; and by frugality he will designate sometimes the virtue, sometimes the kindred vice. The fourth will call a mule by the name horse, and what everybody calls prodigal will be to him generous ; and the fifth will seek in Tartary on the authority of Herodotus ^ a nation composed of men having only one eye. I remark that the first four defects are common to the names of substances and modes, but that the last is pecu- liar to substances. Th. Your remarks are very instructive. I will only add that you seem to have something chimerical still in your ideas of the accidents or forms of being ; and so the fifth defect is also common to substances and to accidents. The extravagant shepherd was not so, only because he believed there were, nymphs concealed in the trees, bnt also because he always expected romantic adventures. § 34. Ph. I had thought to conclude, bnt I remember the seventh and last abuse, which is that of figurative terms or allusions. But there will be difficulty in thinking it an abuse, because what is called wit and imagination is better received than truth wholly dry. It goes well in discourse where you only seek to please; but at bottom, order and clearness ex- cepted, all the art of rhetoric, all these artificial and figura- tive applications of words, serve only to insinuate false ideas, to excite the passions and seduce the judgment, so that they are nothing but pure frauds. jSTevertheless this fallacious art is given the first rank and rewards. It is evident that men care but little for truth and much prefer to deceive and to be deceived. This is so true that I doubt not that what I have ■ just said against this art is regarded as the result of an extreme audacity. For eloquence, like the fair sex, has charms too powerful to allow itself to be opposed. 1 Book III., chap. 116 : IV., chaps. 13, 27 : of., also .Eschylus, Prometheus, 823 (SOi, Dindorf), 3d ed., F. A. Paley, London, 1870; Pausanius, 1, 24, 6. — Tr. 390 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi Th. Very far from censuring your zeal for the truth, I find it just. And woukl that it might be effective. I do not wholly despair of it, because you seem to me, sir, to combat eloquence with its own Aveapons, and to have an eloquence of another species superior to this deceptive kind, as there was a Venus Urania, mother of divine love, before whom this other bastard Venus, mother of a blind love, dared not appear with her child with eyes blinded.^ But that indeed proves that your thesis needs some moderation, and that certain adorn- ments of eloquence are like the Egyptian vases which you could use in the worship of the true Grod. It is as in painting and music, which are abused, one of which often represents grotesque and even hurtful imaginations, and the other softens the heart, and the two amuse in vain ; but they can be usefully employed, the one to render the truth clear, the other to make it effective, and this last result must be also that of poetry which contains rhetoric and music. CHAPTER XI OF THE REMEDIES WHICH MAY BE APPLIED TO THE IMPER- FECTION'S AND ABUSES JUST SPOKEN OF § 1. Ph. This is not the place to plunge into this discussion upon the use of a true eloquence, and still less to reply to your obliging compliment, since we ought to think of bringing this matter of words to an end, by seeking the remedies for the imperfections we have noticed therein. § 2. It would be ridic- ulous to attempt to reform the languages, and to desire to com- pel men to speak only according to the measure of their knowl- edge. § 3. But it is not too much to desire that philosophers speak exactly, when the question concerns a serious search for the truth : without this all will be full of error, opiniativeness, and vain disputes. § 8. The first remedy is to use no word 1 For the myth here referred to by Leibnitz, cf. Plato, Symposium, 180, D, Jowett's trans. Vol. 2, p. 32, 2d ed., 1875, Vol. 1, p. 550, 3d ed., 1892; Pausa- nias, 9, 16, 3; also Harrison- Verrall, Mythology and Monum.ents of Ancient Athens, 212 sq., London, Macmillan & Co., 1890; Preller, Griech. My thoL, 2d ed., 1860, Vol. 1, p. 265. — Tr. CH. XI] ON HUxMAN UNDERSTANDING 391 without attaching thereto an idea, instead of frequently em- ploying words like instinct, sympathy, antipathy, without attaching any sense to them. Th. The rule is good ; but I know not whether the examples are pertinent. Everybody seems to understand by instinct an inclination of an animal to what is proper for it, without on that account apprehending its reason ; and men indeed ought less to neglect these instincts, which they discover moreover in themselves, although their artificial method of living has for the most part nearly effaced them ; the physician of his own accord, indeed, has carefully observed it. SynnKdliy or antipathy signifies that which in bodies destitute of feeling corresponds to the instinct for union or separation found in animals. And although we have no such knowledge of the cause of these inclinations or tendencies, as is to be desired, we nevertheless have a notion of them sufficient to discourse of them intelligibly. § 9. Ph. The second remedy is that the ideas of the names of the modes at least be determined and, § 10. that the ideas of the names of substances be more conformed to what exists. If any one says that justice is conduct conformed to the. law relating to the good of another, this idea is not sufficiently determined, so long as we have no distinct idea of that which is called law. Th. We might say here that the laiv is a precept of wisdom or of the science of happiness. § 11. Ph. The third remedy is to employ terms so far as possible in conformity with received usage. § 12. The fourth is to declare in what sense we take the words, whether we coin new ones or employ the old in a new sense, (or) whether we find that use has not sufficiently fixed their mean- ing. § 13. But there is some difference. § 14. The words for simple ideas which cannot be defined, are explained by synony- mous words, when they are better known, or by showing the thing. It is by these means that we can make a peasant un- derstand what the color feuille morte is, by telling him that it is that of dry leaves which fall in the autumn. § 15. The names of the mixed modes should be explained by definition, for that is possible. § 16. It is upon this ground that ethics is suscepti- ble of demonstration. We shall take man as a corporeal i,^^ i.i.iu.NiiZ'S CRITIQUE OF LOCKE [bk. iii rational being without troubling ourselves about his external figure, § 17. for it is by means of definitions that the matters of morality may be clearly treated. AVe shall rather define justice according to the idea we have in our miud tlian seek a model therefor outside of us, as Aristides, and form it thereupon. § 18. And as the majority of the mixed modes nowhere exist together, we can fix them in defining them only by the enumeration of that Avhich is scattered. § 19. In substances there are ordinarily some directing or characteristic qualities which we consider as the most distinc- tive idea of the species, to which we suppose the other ideas forming the complex idea of the species are attached. It is form in vegetables and animals, and color in animate bodies, and in some color and form together. This is why, § 20. the definition of man given by Plato is more cliaracteristic than that of Aristotle ; or why we should not cause the death of monstrous productions, § 21. and often sight avails as much as any other test ; for persons accustomed to test gold often distinguish by sight the true from the false, the pure from that which has been adulterated. Th. Everything doubtless returns to the definitions which may extend even to primitive ideas. One and the same sub- ject may have several definitions, but the knowledge that they agree with themselves, must be learned by reason, by demon- strating one definition by another, or by experience, by proving that they constantly go together. As for morality, one part is wholly grounded in reason ; but there is another depending upon experience and related to the disposition. Por a knowl- edge of substances, form and color, i.e. the visible, gives us the first ideas, because it is by these that we know things at a distance ; but they are ordinarily too provisional, and in • things of importance to us we try to know substance more closely. I am astonished, moreover, that you return again to the definition of man, attributed to Plato, since you have just yourself stated, § 16. that in morals man must be taken as a corporeal rational being without troubling ourselves about the external form. Por the rest it is true that a large practice does much for discerning at sight what another may scarcely know through arduous experiments. And physicians of large experi- ence, with very good sight and memory, often know at the first CH. XI] UN HUMAN UNDERSTANDING 393 appearance the disease which another will draw out for himself Avith difficulty by force of questioning and trying the pulse. But it is well to unite all the indications we may have. § 22. Ph. I admit that he to whom a good assayer makes known all the qualities of gold, will have a better knowledge of them than sight could give. But if we could learn its in- ternal constitution, the meaning of the word gold would be as easily determined as that of the triangle. Til. It would be wholly as determined, and it would have in it no provisional element ; but it would not be so easily deter- mined. For I think a distinction a little prolix would be necessary in order to explain the contexture of gold, as is the case indeed in geometry with figures whose definition is long.^ § 23. Ph. Spirits separated from bodies have doubtless knowledge more perfect than ours, although we have no notion of the manner in which they may acquire it. But they may have as clear ideas of the radical constitution of bodies, as we have of a triangle. Th. I have already remarked, sir, that I have reasons for thinking that no created spirits exist entirely separate from bodies ; but there are no doubt some whose organs and under- standing are incomparably more perfect than ours, and which surpass us in every kind of conception, as much and more than Mr. Frenicle,^ or that Swedish boy of whom I have spoken to you, surpassed the common run of men in the calculation of numbers, made by imagination. § 24. Ph. We have already noticed that the definitions of substances which may serve in explaining names are imperfect in relation to the knowledge of things. For usually we put 1 Cf. Gerhardt, Leibniz, philos. Schri/t., 4, 319. Bernard Frenicle de Bessy, c. 1605-1675, brother of the poet Nicolas Fre'niele, 1600-l(i61, " conseiller a la cour des monnaies," member of the Paris Academy of Sciences, who acquired the reputation of being the first arithmetician of his age by the rapidity with ^yhich he solved the most complicated numerical problems, and by his ingen- ious researches upon the solution in whole numbers of indeterminate equations. His method, known as the method of exclusionK, appears to have been an inge- nious groping, but based on some general propositions which greatly restricted this groping, and which have since been rigorously demonstrated by Le'onard Euler, 1707-1783 and Jos. Louis Lagrange, 1736-1813. Pierre de Fermat, 1601- 16()5, and Descartes, 1596-1()50, greatly admired his work, astonished that he could go so far without the aid of algebra and that his arithmetic could con- duct him wliere analysis finds so much difficulty in going. His principal work M'as, Traite des trianglen, reciconjles en noinbre, Paris, 1(J76. — Tr. 394 LEIBNITZ'S CRITIQUE OF LOCKE [bk. hi the name in the place of the thing ; then the name says more than the definitions ; thus to give a good definition of sub- stances, we must study natural history. Th. You see then, sir, that the name gold, for example, signifies not only that which he who pronounces it knows of it, — for example, something yellow, very heavy, — but also what he does not know, and which another may know, i.e. a body endowed with an internal constitution from which pro- ceed color and weight, and from which spring still other prop- erties admitted to be better known by experts. § 25. Ph. It were now to be wished that those practised in physical researches would set down the simple ideas in which they observe that the individuals of each species constantly agree. But the composition of a dictionary of this kind which would contain, so to speak, a natural history, would re- quire too many persons, too much time, trouble, and sagacity for such a work ever to be hoped for. It would be well, how- ever, to accompany words with small copper-plate engravings of things known by their external form. Such a dictionary would be of much service to posterity and would spare future critics much trouble. Small figures as of the celery-plant {apium), of a Bouquetin (ibex, a kind of wild goat), would be more valuable than long descriptions of this plant or of this animal. And in order to know what the Latins called strigiles and sistrum, tunica and pallium, figures in the margin would be incomparably more valuable than the pretended synonymes, currycomb, cymbal, dress, cloak, mantle, Avhich show but little of them. For the rest I shall not stop upon the seventh remedy of the abuse of words which is to employ constantly the same term in the same sense, or to give notice when you change it. For we have spoken sufiiciently of this subject. TJi. Rev. Father Grimaldi,^ President of the INIathematical 1 Claudius Philip Grimaldi, with whom Leibnitz became acquainted during his stay in Rome in 1689, and with whom he corresponded, receiving from him after his return to Pekin much interesting information. Cf. Guhrauer, G. W. Freiherr v. Leibniz, 2, 95 sq. ; Kuno Fischer, Gesch. d. h. Philos., Vol. 2, p. 201, 3d ed., Heidelberg, 1889; Dutens, Leibniz, op. om., 4, Pt. I. 81, 83 s^., 88: 6, 106, 128, 227, Gerhardt, Leibniz. jMlos. Sehrift. 3, 166, 174. Schaarschmidt states that such dictionaries as Leibnitz here mentions on the authority of Grimaldi exist in fact among the Chinese, and have been brought to Europe, that the Bonn University library possesses a couple of parts of one such dictionary, and that it must be regarded as an alphabetically arranged orbis pictus. — Tr. CH. XI] ON HUMAN UNDERSTANDING 395 Society at li'ekin, tells me that the Chinese have illustrated dictionaries. There is a small nomenclator printed at Nurem- berg in which there are such figures for each word which are good enough. Such an illustrated universal dictionary were to be desired, and would not be very difficult to make. As for the description of sjjecies, it is properly natural history, and we are working at it by degrees. Were it not for the wars (which have troubled Europe since the first foundation of the Societies or Royal Academies) it would be farther advanced, and already in a condition to profit from our labors ; but the great for the most part do not recognize its importance, nor what good they deprive themselves of by neglecting the ad- vancement of solid knowledge ; and besides they are ordinarily too much indisposed by the pleasures of peace or by the cares of war to weigh things which do not strike them at once. ESSAY ON UNDERSTANDING Book IV. — Of Knowledge CHAPTER I OF KNOWLEDGE IX GENERAL § 1. Pli. Hitherto we have spoken of ideas and of words Avhich represent them ; let us come now to the knoivledge, which the ideas furnish, for it rests only upon our ideas. § 2. Knowledge is simply the perception of the connection and agreement, or of the opposition and disagreement, which we find between two of our ideas. Whether we imagine, con- jecture, or believe, it is always that. We perceive, for exam- ple, by this means, that white is not black, and that the angles of a triangle and their equality to two right angles have a necessary connection. Th. Knowledge has a still more general signification, so that we find it also in ideas or terms, before we reach proposi- tions or truths. And it may be said that he who has atten- tively looked at more pictures of plants and animals, more diagrams of machines, more descriptions or representations of houses or fortresses, who has read more ingenious romances, heard more curious narratives, this one, I say, will have more knowledge than another, even though there should not be a word of truth in all that which was portrayed or related to him ; for the custom he has of representing in his mind many express and actual conceptions or ideas, renders him more fit to conceive what is placed before him ; and it is certain that he will be better instructed and more capable than another who has neither seen nor read nor heard anything, provided .".97 398 LEIBNITZ'S CRITIQUE OF LOCKE [bk. it that in these stories and representations he takes nothing as true which is not so and that these impressions do not prevent ) him elsewhere from distinguishing the real from the imagi- yiary, or the existent from the possible. This is why certain logicians of the period of the Reformation who were in some measure of the party of the Ramists/ were not wrong in say- ing that the topics or orders of invention (argumenta, as they call them) serve as much for the explication or very detailed description of an incomplex theme, i.e. of a thing or idea, as for the proof of a complex theme, i.e. of a thesis, proposition, or truth. And indeed a thesis may be explained, in order that its sense and force may be well known, without raising the question of its truth or proof, as is seen in sermons and homi- lies explaining certain passages of Holy Scripture, or in instruction or lectures upon certain texts of civil or canon law whose truth is presupposed. We can even say that there are some themes which are means between an idea and a proposi- tion. These are the questions, some of which demand only yes or no ; and they are the nearest to propositions. But there are some also which demand the how, the circumstances, etc., where there is more to be supplied in order to make proposi- tions. It is true, it maybe said, that in descriptions^ (even of things purely ideal) there is a tacit affirmation of possibility. But it is also true that, as we may undertake the explanation and proof of a falsehood, a method which sometimes serves as its best refutation, the art of description may fall upon the impossible also. Something like this is found in the novelle of the Count of Scandiano followed by Ariosto,^ and in the 1 The Ramists were disciples of Peter Ramus {of. infra p. 408, note 1) . Schaarsclimidt states that Leibnitz probably has in mind chiefly J. H. Alsted, whom he has previously (o/. ante, pp. 311, note 2, 362) cited, and whom he greatly prized and studied, in whose Sy sterna logicse harmonicmn, Her- borniae, 1614, p. 69, the argumentum is divided into argumentum simplex (which Leibnitz calls theme inromplexe) and into argumentum compJexitm. The former, according to Alsted, is a "terminus extra omnem dispositionem dirigens materiam " (Leibnitz says: "une chose ou idee"), the latter is a " definitio et distributio " (Leibnitz says : " une these, proposition ou verite ") . C;/'. Alsted, p. 261. — Tr. 2 I.e. in the sense of nominal definitions, which allow the really impossible. Cf. ante, p. 317, note 3. — Tr. 3 Leibnitz here refers to Matteo Maria Boiardo, c. 1434-1494, Count of Scandiano, and the author of Orlando Innamorato, which a recent writer calls "the most chivalrous poem of the Renaissance," and "a masterpiece of en. I] ON HUMAN UNDERSTANDING 399 ''Amadis of Gaul " ^ or other old romances, in the fairy-stories which were again in fashion some years since, in the "True History"^ of Lucian and in the "Voyages" of Cyrano de Bergeracj^to say nothing -of the grotesque figures of the painters. So we know stories with the rhetoricians belono- in the number of progymnasmata or preliminary exercises. But taking knowledge in a narrower sense, i.e. as knowledge of inventive genius," and which furnished Ludovico Ariosto, 1474-1533, with the theme of his Orlando F arioso. For an account of the two writers and their works, vf.'J. A. Symouds, Renaissance in Italy, Pt. IV., Italian Literature, Vol. 1, pp. 455 sq., Vol. 2, pp. 1 sq. New York, H. Holt & Co., 1885. Through a misunderstanding of Leibnitz's reference to the Count of Scan- diauo, Schaarschmidt, in his note to the passage, has wrongly identified him with Tito Giovanni Ganzarini, 1518-1582, Professor of Literature at Modena, called il Scandianese, from his birthplace, Sqandiano. Ariosto published his Orlando Furioso in 1516, two years before Ganzarini was born, and could scarcely be said to have "followed" an author who was only fifteen years old when the poet himself died. — Tr. 1 The Amadis de Gaula, the best of all the old romances of chivalry, was originally written, it is supposed, about 1390, by Vasco de Lobeira, a Portu- guese knight attached to the court of John I. of Portugal, and who died in 1403. The oldest text now extant is in Spanish prose, a version from the Portuguese original, now lost, made by Garcia Ordonez de Montalvo, between 1492 and 1504. Editions of the Spanish version are numerous, the earliest accessible being that of 1519; and there are translations in English, French, German, Italian, and other lan.guages. The best and at present the only readable edition in English is the abridged translation (with a Preface giving an account, not, however, without error, of the work), made from the Spanish, by Robert Southey, London, 1803, 4 vols., 12mo, new ed., London, 1872, 3 vols., IGmo. Cf. also, V. de Lobeira, Amadis de Gaula, Barcelona, 1847-8, 4 vols., 16rao; George Ticknor, Hist, of Spanish Lit., 3d ed., Boston, 18G3, Vol. 1, pp. 198-207; L. Braunfels, iTriiisc/ier Versuch iiber Amadis, Leipzig, 1876. It may be added that the writer of the article, "Amadis of Gaul," in the EncyrJop. Brit., 9th ed., argues for the Anglo-Norman origin of the romance, on the ground that all its ideas and materials, its design and machinery, belong to the Anglo-Norman romance-cycle in vogue before Lobeira was born. — Tr. 2 The 'AA)j8oO? io-Topi'a? A670? ( Verse Historix) of Lucian is one of the witty satirist's cleverest works, written in easy and elegant Greek, and exhibiting great fertility of invention. It was purposely composed, says Lucian, as a satire on the poets and logographers who have written so many marvellous tales, and contains things which neither he nor any one else has ever seen, M'hich not only do not, but cannot, exi.st, and descriptions of experiences and adventures which are absurd and impossible, chief among which is a voyage to the moon. Lucian himself says that the only true statement in his History is that it contains nothing but lies from beginning to end. It has witliont doubt supplied hints to, or served as a model for, writers like Rabelais, Swift, and Cyrano de Bergerac. — Tr. ^ Cf. ante, p. 228, note 2. Amid many imaginative extravagances, these Voyages contain a pretty exact knowledge of the philosophy of Descartes. — Tr. 400 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv truth, as you, sir, do here, I say it is quite true that truth is always grounded in the agreement or disagreement of ideas, but it is not true in general that our knowledge of truth is a perception of this agreement or disagreement. For when we know truth only empirically, from having experienced it, without knowing the connection of things and the reason there is in what we have experienced, we have no perception of this agreement or disagreement, unless we mean that we feel it in a confused way without being conscious of it. But your examples, it seems, show that you always demand ^knowl- edge in which one is conscious of connection or opposition, and this is what cannot be granted you. Further, we can treat a complex theme not alone by seeking the proofs of its truth, but also in explicating and otherwise illustrating it, according to the topical order, as I have already observed. Finally, I have a further remark to make upon our definition : viz. that it appears only suited to categorical truths, in which there are tico ideas, the subject and the predicate ; but there is besides a knowledge of hypothetical truths or what may be reduced thereto (as disjunctives and others) in which there is connection between the antecedent and the consequent propo- sition ; thus more than two ideas may enter therein. § 3. Fh. [Let us limit ourselves here to the knowledge of truth and then apply what will be said of the connection of ideas to the connection of propositions, in order to include in one whole the categorical and hypothetical truths.] Now I believe that this agreement or disagreement may be reduced ^/<5'"^'' [ to four kin,ds : (1) Identity or diversity, (2) Relation, (3) Co- i existence or necessary connection, (4) Real 'existence. § 4. For the mind perceives immediately that one idea is not an- other, that white is not black ; § 5. then it perceives their relation by comparing them with each other ; for example, that two triangles whose bases are equal and which are found between two parallels are equal. § 6. Next there is coexist- ence (or rather connection), as fixedness always accompanies the other ideas of gold. § 7. Finally there is real exist- ence beyond the mind, as when it is said : God is. Th. I believe it may be said that the connection is nothing else than the agreement or the relation taken generally. And I have remarked above that every relation is either of com- CH. I] ON HUMAN UNDEESTANDING 401 parison or concurrence. That of coinparison gives diversity and identity, either complete or j)artial ; whereby are consti- tuted the concepts of the same or tlie diverse, the like or unlike. Concurrence contains what you call coexistence, i.e. connection of existence. But when we say that a thing exists or that it has real existence, this existence itself is the predicate, i.e. it has a notion joined with the idea in question, and there is connection between these two notions. The existence of the object of an idea may also be conceived, as the concurrence of this object with the Ego. Thus I believe it may be said that there is only comparison or concurrence ; but that the com- parison which marks identity or diversity, and the concurrence of the thing with the Ego, are the relations which deserve to be distinguished among others. ■* More exact and more pro- found researches might perhaps be made ; but I content myself here with making remarks. § 8. Ph. There is actual Jcnoivledge, which is the present perception of the relation of ideas ; and there is habitual hioivledge, when the mind has so evidently perceived the agreement or disagreement of ideas, and so placed it in its memory, that every time it comes to reflect upon the proposi- tion, it is at once certain of the truth it contains without the least doubt. For being capable of thinking clearly and dis- tinctly of but one thing at once, men would all be very igno- rant if they knew only the actual object of their thoughts ; and he who knew most would know but one truth. Th. It is true that our science, the most demonstrative in- deed, being very often obliged to acquire its existence by a long chain of inferences, must involve the memory of a past demonstration which is no longer distinctly in view, when the conclusion is made ; otherwise it would always be repeating this demonstration. And even while it lasts it cannot be understood as a complete whole at once ; for all its parts can- not be i^resent in the mind at the same time ; thus always re- calling the preceding part to mind, we should never advance to the last which achieves the conclusion. This is the reason also 1 Leibnitz reduces Locke's four kinds of agreement or disagreement to t\yo, and thus generalizes the relation and considers the existence as the concur- rence of the object with the Ego. This concurrence Leibnitz explains by his doctrine of pre-established harmony. — Tr. 2d 402 LEIBNITZ'S CKITIQUE OE LOCKE [bk. if that without writing it would be difficult properly to establish the sciences, the memory not being sufficiently reliable. But having put in writing a long demonstration, like, for example, those of Apollonius,^ and having gone over again all its parts, as if they were examining a chain, link by link, men can assure themselves regarding their reasonings ; for which pur- pose proofs are also of use, and the result at last justifies the whole. But we see by this that as all belief consists in the memory of past life, of proofs or reasons, it is not within our power or choice to believe or disbelieve, since memory is not a thing depending on our will. § 9. Ph. It is true that our habitual knowledge is of two sorts or degrees. Sometimes, truths laid up as it were in the memory no sooner present themselves to the mind, than it sees the relation between the ideas entering therein ; but, some- times, the mind contents itself with the memory of the convic- tion, without retaining the proofs, and often, indeed, without the power to recall them if it wished. It may be thought that this is rather to believe one's memory than really to know the truth in question, and this formerly appeared to me to be a mean between opinion and knowledge, a kind of assurance superior to simple belief based upon the testimony of another. But upon due reflection I find that this knowledge contains perfect certainty. I remember, i.e. I know (memory being only the reviving of something past), that I was once certain of the truth of this proposition, that the three angles of a tri- angle are equal to two right angles. Now, the immutability of the same relations between the same immutable things is at present the mediate idea which shows me that, if they were once equal, they will be so still. It is upon this ground that in mathematics particular demonstrations furnish general knowledge ; otherwise a geometer's knowledge would not ex- tend beyond this particular figure which he had drawn while demonstrating it. Th. The mediate idea of which you, sir, speak, presupposes the fidelity of our memory ; but it sometimes happens that our memory deceives us, and that we have not made every neces- sary effort, although we now believe we have. This is clearly seen in the examination of accounts. Sometimes there are 1 Cf. ante, p. 108, note 1. — Tr. CH. ij ON HUMAN UNDERSTANDING 403 examiners officially appointed, as at our mines in the Harz, and to make the receivers of the particular mines more atten- tive, they have imposed a money penalty upon every error in calculation ; nevertheless they find them in spite of this pen- alty. But the more care we employ, the more reliance we can place upon past reasonings. I have devised a method of keep- ing accounts, by which he who collects the sums of the col- umns leaves upon the paper traces of the progress of his reasoning, so that he does not reason in vain. He can always revise and correct the last errors without affecting the first : the examination, also, which another desires to make costs, in this way, almost no trouble, because he can examine the very same traces at a glance. There are, besides, means of verifying the accounts of each article, by a very convenient kind of proof, without increasing to any considerable extent the labor of the computation. And all this easily shows that men may have rigorous demonstrations on paper, and have an infinite number of them. But unless we remember that we have been abso- lutely accurate, we cannot have this certainty in the mind. And this accuracy consists in an orderly procedure, the observ- ance of which in each part is an assurance as regards the whole ; as in the examination of a chain by links, in which inspecting each to see if it is strong, and measuring with the hand so as not to skip any, assurance is obtained of the good quality of the chain. And by this means we have all the certitude of which human things are capable. But I do not agree that in mathematics particular demonstrations upon the figure which is drawn furnish this general certitude, as you seem to take it. For you must know that it is not the figures which furnish the proof with geometers, although the style of the exposition may make you think so. The force of the dem- onstration is independent of the figure drawn, which is drawn only to facilitate the knowledge of our meaning, and to fix the attention ; it is the universal propositions, i.e. the definitions, axioms, and theorems already demonstrated, which make the reasoning, and which would sustain it though the figure were not there. Hence it is that a learned geometer, like Scheube- lius,^ has given Euclid's figures without the letters which might 1 Johann Scheybl ^ Latin, Scheubelius — 1494-1570, was, according to Joclier, AUgemeines Gelehrten-LexKon, Leipzig, 1750-51, VoL 4, p. 257, a professor 404 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv ))ind them to the demonstration he has put with them ; and anotlier, like Herlinus/ has reduced the same demonstrations to syllogisms and prosyllogisms. CHAPTER II OF THE DEGREES OF OUR KJfOWLEDGE § 1, Ph. Knowledge is then intuitive when the mind per- ceives the agreement of two ideas immediately by themselves without the intervention of any other. In this case, the mind takes no pains to prove or examine the truth. As the eye sees the light, the mind sees that white is not black, that a circle is not a triangle, that three is two and one. This knowl- edge is the clearest and most certain of which human weak- ness is capable ; it acts in an irresistible manner without allowing the mind to hesitate. It is knowledge that the idea is in the mind as perceived. Whoever asks for greater certi- tude, knows not what he asks. Th. Primitive truths, which are known by intuition, are of two kinds, like the derivative. They are truths of reason or truths of fact. Truths of reason are necessary, and those of fact are contingent. The primitive truths of reason are those which I call by the general name of identical, because they seem only to repeat the same thing without giving us any information. They are affirmative or negative. The affirma- tive are such as the following : Ectch thing is ivhat it is, and in of mathematics in the University at Tiibingen. His Euclidis sex libri prhni de c/eometricis principiis qr. et kit. cum commentario appeared at Basle, 1590. — Tr. 1 Christian Herlinus, whom Leibnitz also mentions toward the end of his Meditationes de Cog., Verit., et Ideis, as co-editor witli Conrad Dasypodius (1532-1600, professor of mathematics in Strassburg- University, and Canon of St. Thomas' Church) of Euclid, appears to be otherwise unknown. Their joint work, of which Herlinus did the first and fifth books, and Dasypodius the other four, appeared under the title Analysis c/eometriai sex lihrorvm Eudidis, etc., Strassburg, 1566, fol. It is, says Michaud, Biog. UniverseUr, Vol. 10, p. 560, a pedantic work in which the demonstrations of tiie Greek geometer are reduced to syllogistic form, so that a proposition of fifteen or twenty lines is spun out into -several pages, and is often more involved or at least more difficult to follow. — Tr. CH. II] ON HUxMAN UNDERSTANDING 405 as many examples as you please, A is A, B is B. I shall be what I shall be. I have written what I have written. And tiothiiig in verse as in prose, is to be nothing or a trifle. The equilateral rectangle is a rectangle} The rational animal is al- ways an animal. And in the hypothetical: If the regular figure of four sides is an equilateral rectangle, this figure is a rectangle. Copidatives, disjunctives, and other propositions are also sus- ceptible of this identicism, and I reckon indeed among the attirmatives : non-A is non-A. And this hypothetical : if A is non-B, it follows that A is non-B. Again, if non-A is BC, it follows that non-A is BC. If a figure having no obtuse angle mail be a regular triangle, a figure having no obtuse angle may be regular. I come now to the identical negatives which belong either to the principle of contradiction or to the disparates. The principle of contradiction is in general : a proposition is either true or false : this contains tw^o true statements, one that the true and the false are not compatible in one and the same proposition, or thcd a pro2:)Osition cannot be true and false at once; the other that the opposition or the negation of the true and the false are not compatible, or that there is no mean be- tween the true and the false, or rather : it is impossible for a proposition to be neither true nor fcdse. Now all this is also true in all imaginable propositions in particular, as what is A cannot be non-A. Again,- AB cannot be non-A. An equilat- eral rectangle cannot be non-rectangle. Again, it is true that every man is an animal, then it is false that any man is found u-ho is not an animal. We may vary these statements in many Avays, and apply them to copulatives, disjunctives, and others. As for the disparates, they are the propositions whicli state tliat the object of one idea is not the object of another idea ; as, that heat is. not the same thing as color ; again, man and animal are not the same, although every man is an animal. All this may be asserted independently of all proof or of re- duction to opposition, or to the principle of contradiction. ^ Enlmann and Jacques omit: "Est un rectangle. L'animal raisonnable est tonjours un animal. Et dans les hypothetiques : Si la figure regnliere de quatre costes est un rectangle equilateral." — Tr. - Erdmann and Jacques omit: "Item AB ne sauroit estre non-A. Un rectangle equilateral ne sauroit estre non-rectangle. Item il est vray que tout homme est un animal, done il est faux," and instead of the last foiu- words, read : " Item il est vray," etc. — Tr. 406 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv when these ideas are sufficiently understood not to require here analysis ; otherwise they a,re liable to be misunderstood : for in saying, the triangle and the trilateral are not the same, we should be mistaken, since upon proper consideration we find that three sides and three angles always go together. In say- ing, the quadrilateral rectangle and the rectangle are not the same, we should also be mistaken. For it is found that the four- sided figure alone can have all the angles right angles. But we may also say in the abstract that the triangle is not the tri- lateral, or that the formal causes of the triangle and of the tri- lateral are not the same, as the philosophers express it. They are different relations of one and the same thing. Some one after having heard with patience what we have just said up to this point, will lose it after all and will say that we are amusing ourselves with frivolous statements, and that all identical truths are useless. But he will make this judgment for want of having thought sufficiently upon these matters. The deductions of logic, for example, are demon- strated by identical principles ; and geometers require the principle of contradiction in their demonstrations which re- duce to the impossible.^ Let us be content here to show the use of identicals in the demonstrations of rational deduction. I say, then, that the principle of contradiction alone suffices to demonstrate the second and the third figures of the syllogism by means of the first. For example, we may conclude in the first figure, in Barbara : All B is C, All A is B, Then All A is C. Suppose that the conclusion is false (or that it is true that some A is not C), then one or the other of the premises will be false also. Suppose that the second is true, the first must then be false, which maintains that all B is C. Then its con- tradictory will be true, i.e. some B will not be C. And this will be the conclusion of a new argument, drawn from the 1 I.e. the so-called indirect proof, which provisionally assumes the truth of the contradictory opposite of the proposition to be jDroved, and then, having discovered tlie impossibility of this assumption, concludes, by the aid of the principle of contradiction, that the original proposition is correct. — Tr. CH. II] ON HUMAN UNDERSTANDING 407 falsity of the conclusion and the truth of one of the premises of the preceding argument. Here is this new argument : Some A is not C. This is opposed to the preceding conclusion supposed false. All A is B. This is the preceding premise supposed true. Then some B is not C. This is the present true conclusion, opposed to the preced- ing false premise. This argument is in the mode Disamis of the third figure, which is thus plainly demonstrated and at once from the mode Barbara of the first figure by employing simply the prin- ciple of contradiction. And I noticed in my yOuth, when I examined minutely these things, that all the modes of the second and third figure may be drawn from the first by this method alone, by supposing that the mode of the first is valid, and consequently that the conclusion being false, or its contra- dictory being taken as true, and one of the premises being taken as true also, the contradictory of the other premise is true. It is true that in the schools of logic they prefer to make use of conversions to draw the less princiiKil figures from the first Avhich is the iyrinci2:)al, because this method appears better suited to the scholars. But for those who seek demon- strative reasons, in which the least possible suppositions must be employed, we shall not demonstrate by the supposition of conversion what may be demonstrated by the primitive princi- ple alone, which is that of contradiction and which assumes nothing. I have also made this apparently remarkable obser- vation, that only the less principal figures which are called direct, viz. the second and the third, can be demonstrated by the principle of contradiction by itself : but the less original indirect figure, the fourth, whose invention the Arabs attribute to Galen,^ although we found nothing concerning it in the 1 Claudius Galeuus, c. 130-e. 201, a very celebrated physician and medical writer, who also wrote a large number of philosophical and logical works, the greater part of which are now lost. His medical and scientific treatises contain considerable philosophical and logical discussion, and his De nsu partium 403 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv works of his remaining to us, nor in the other Greek authors, the fourth, I say, has this disadvantage, that it cannot be derived from the first or principal figure by this method alone, and it is necessary besides to employ another supposi- tion, viz. conversions, so that it is farther removed by one degree than the second and the third, which are on a level and equally removed from the first ; while the fourth needs also the second and the third for its demonstration. For it is found very opportunely that the conversions required are demonstrated by the second or third figure, demonstrable independently of the conversions, as I have just shown. It is Peter Ramus ^ who already made this remark concerning the demonstrability of conversion by these figures ; and (if I am not mistaken) he reproached the logicians, who make use of conversion to demonstrate these figures, with arguing in a circle, although it was not so much the circle that he found it necessary to reproach them with (for they did not use these cor}'), hum. is, says Janet, " an apology for and a continual application of the principle of final causes." The most complete ed. of his works containing the Greek text and a Latin version is the Opera Omnia, cur. C. G. Kiihn, Leipzig, 1821-33, 20 vols., 8vo. For his philosophical views, ef. K. Sprengel, Beitr. z. Gesch. d. Medicin, 1, 117-195, Halle, 1794-6; on his logic, cf. Prantl, Gesch. d. Logik, 1, 559-577. A brief account of his philosophy is given by Zeller, Fhilos. d. Griech., III., 1 [Vol. 5], 823 sq., 3d ed., Leipzig, 1880. The invention of the fourth syllogistic figure was ascribed to Galen by Averroes, 1105-1198, but without adequate foundation. Galen was led through the additions to the first figure already made by Theophrastus, c. 373-c. 288 B.C., to transpose the premises in the same, and only by this means indirectly to the fourth arrangement of the middle term. Cf. Prantl, Gesch. d. Logik im Ahendlande, 1, 570-574 ; also Sir W. Hamilton, Lects. on Logic, Boston, 1873, Lect. XX., TT LXXIII., pp. 285-6; Lect. XXI., T[ LXXIV., p. 302-3, and notes. — Tr. 1 Petrus Ramus — Pierre de la Rame'e— 1515-1572, murdered during St. Bartholomew's Night, was a determined opponent of Aristotelian scholasticism, and especially of its logic or dialectic, in the place of which he attempted to set up a new, simpler, and better grounded dialectic. For this purpose he wrote and published his two works, Animadversionea Aristotelicie, Paris, 1534, etc., and Listitutiones dialectics, Paris, 1543. Following Cicero and Quintilian, his scheme was a blending of logic and rhetoric. For a long time after him, logicians were divided into Ramists and Anti-Ramists, while the Semi-Ramists, among whom were Alsted and Goclen {cf. ante, p. 311, note 2), sought to mediate between the Aristotelic dialectic, as set forth by JMelanch- thon, and that of Ramus. The remarks to which Leibnitz here refers are found, according to Schaarschmidt, in Animacl. Aristotel., Lutetise, 1548, pp. 388 sq. For a good account of Ramus, cf. Stockl, Gesch. d. Philos. d. MittelaUers,lll. [Vol. 4], pp. 296 sq.; also Ueberweg-Heiuze, Gesch. d. Philos., 7th ed., 3, 24. 26. — Tr. CH. II] ON HUMAN UNDERSTANDING 409 figures in their turn to justify the conversions) as the hysteron proteron or the reversal {le rebours); because conversions need rather to be demonstrated by these figures, than these figures by the conversions. But as this demonstration of conversions shows also the use of the identical affirmatives, v^^hich many take as altogether frivolous, it will be so much more to the purpose to introduce them here. I wish to speak only of con- versions without contraposition, which suffice me here, and which are simple or per accidens, as they are called. Simple conversions are of two kinds : that of the universal negative, as : no square is obtuse-angled, then no obtuse-angled Jigm-e is a square; and that of the particular affirmative, as : some tri- angles are obtuse-angled, then some obtuse-angled figures are triangles. V>wt conversion per accidens, as it is called, concerns the universal affirmative, as : every square is a rectangle, then some rectangles are squares. A rectangle is here always under- stood to be a figure all- of whose angles are right angles, and b}^ the square is understood a regular quadrilateral. Now the question is to demonstrate these three kinds of conversion, which are : (1) No A is B, then no B is A. (2) Some A is B, tlien some B is A. (3) All A is B, then some B is A. Demonstration of the first conversion in Cesare, which belongs to the second figure. No A is B. All B is B. Then no B is A. Demonstration of the second conversion in Datisi, which be- longs to the third figure. All A is A. Some A is B. Then some B is A. Demonstration of the third conversion in Darapti, which belongs to the third figure. All A is A. All A is B. Then some B is A. 410 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv This sliows that the purest and apparently most useless identical propositions are of considerable use in the abstract and general; and that may teach us that we should not despise any truth. As for this proposition, that three is as much as two and one, which you, sir, still adduce as an example of intuitive knowledge, I have to say that it is only the defini- tion of the term three, for the simplest definitions of numbers are formed in this way : Tivo is one plus one, three is two plus one, foiir is three plus one, etc. It is true that there is therein a concealed statement, which I have already spoken of, viz. that these ideas are possible : and this is here known intuitively, so that it may be said, that an intuitive knowledge is comprised in definitions when their possibility appears at once. And in this way all adequate definitions contain primitive truths of reason and consequently intuitive knowledge. In short, you can say in general that all primitive truths of reason are imme- diate with respect to 'an immediateness of ideas. As for the primitive truths of fact, they are the immediate in- ternal experiences of an immedictteness of feeling. And here it is that the first truth of the Cartesians or of St. Augustine : / think, therefore I am, i.e. / am a thing lohich thinks, holds good.^ But we must know, that as the identicals are general or par- ticular, and as one is as clear as the other (since the statement that A is A is as clear as the statement that a thing is what it is), so is it also with the first truths of fact. For not only is it immediately clear to me that I think, but it is wholly as clear to me that I have different thoughts, that sometimes I think of A, and sometimes of B, etc. Thus the Cartesian principle is valid, but it is not the only one of its kind. You see by this that all jsrimiYtve truths of reason or of fact have this in common, that they cannot be proved by anything more cer- tain. § 2. Ph. 1 am very glad, sir, that you have carried forward 1 Cf. Augustine, Solil. II., 1: "Tu qui scis te nosse, scis te esse? Scio! Undescis? Nescio! Simplicem te sentis an multiplicem? Nescio! Cogitare te scis? Scio!" in Opera, Vol. 1, p. 369, Benedictine ed., Paris, Franciscus Muguet, 1679; Vol. 1, p. 885, ed. Migne, Paris, 18Jtl. Augustine, 354-430, thus anticipated the principle of Descartes, 1596-1650, " Cogito ergo sura," a fact iinknown however to Descartes, who was not one of the class of reading philosophers, until hrought to liis knowledge hy Arnauld, 1612-1694, and Mersenne, 1588-1648, in their criticism of bis philosophy. — Tr. CH. II] ON HUMAN UNDERSTANDING 411 farther than I had done that which relates to intuitive knowl- edge. Now demonstrative Jcnoivledge is only a concatenation of intuitive knowledge in all the connections of mediate ideas. For often the mind cannot nnite, compare, or apply immedi- ately the ideas one to the other, and this compels it to make use of other ideas (one or more) as means to the discovery of the agreement or disagreement it seeks, and this is what we call reasoning. As in demonstrating the three angles of a tri- angle to be equal to two right angles, it finds some other angles which are seen to be equal both to the three angles of the triangle and to two right angles. § 3. These intervening ideas are called proofs, and the disposition of the mind to dis- cover them is called sagacity. § 4. And even when found, this knowledge cannot be acquired without pains and atten- tion and by more than a single passing view ; for the mind must enter upon a progression of ideas, made gradually and by degrees, § 5. and there is doubt before the demonstra- tion. § 6. It is not so clear as the intuitive knowledge, as the image reflected by several mirrors from one to another grows more and more faint with each reflection, and is no longer at once so recognizable especially by weak eyes. It is the same with knowledge produced by a long train of proof. § 7. And although each step taken by reason in the demon- stration is intuitive knowledge or simple sight, nevertheless as in this long train of proofs the memory does not so exactly preserve this connection of ideas, men often take fallacies for demonstrations. Th. Besides natural sagacity or that acquired by exercise, there is an art of finding mediate ideas (the medium), and this art is analysis. Now it is well to consider here, that the ques- tion is sometimes to find the truth or falsehood of a given proposition, which is nothing else than an answer to the ques- tion An? i.e. whether it is or is not. Sometimes it concerns an answer to a more difficult {coiter is paribus) question, where it is asked for example hy ivkom and hoio 9 and where there is more to be supplied. And it is these questions alone, which leave a part of the proposition blank, which the mathemati- cians call p?'o&/e?7is. As, when we are asked to find a mirror which collects all the rays of the sun in one point, we are asked for its form, or how it is made. As for the first ques- 412 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv tions in which the point at stake is only truth and falsehood and where there is nothing to be supplied in the subject or predicate, there is less invention, yet there is some, and the judgment alone is not sufficient. It is true that a man of judg- ment, i.e. one who is capable of attention and reserve, and who has the leisure, the patience, and the necessary freedom of mind, may understand the most difficult demonstration if properly set before him. But the most judicious man in the world, without other aid, will not always be capable of discov- ering this demonstration. Thus there is still some invention therein ; and with geometers there was more of it formerly than now. For when analysis was less cultivated, more sagac- ity was necessary to attain it, and it is on this account that some geometers still of the old school,^ or others who have not yet sufficient aptness in the new methods, think they have done something wonderful when they discover the demonstra- tion of some theorem that others have invented. But those who are versed in the art of invention know when this is esti- mable or not ; for example, if some one sets forth the quadra- ture of a space comprised within a curved and a straight line, which is successful in all its segments and which I call general, it is always within our power according to our methods to dis- cover its demonstration, provided we are willing to take the trouble. But there are some particular quadratures of certain portions, where the thing may be so involved, that it will not always be possible {in potestate) thus far to develop it. It happens also that induction presents us with truths in num- bers and in figures whose general reason is not yet discovered. For much is needed in order to attain perfection of analysis in geometry and in numbers, as many are becoming conceited upon the basis of the boasts of some men otherwise excellent, but a little too hasty or too ambitious. But it is much more difficiilt to discover important truths, and still more to discover means of producing what is sought, when it is justly sought, than to discover the demonstration of truths which another has discovered. Beautiful truths are often attained by synthesis, by passing from the simple to the complex ; but when it is a question of discovering exactlj'' the means of producing what is proposed, synthesis is ordinarily 1 Gerhardt reads : " roclie " ; Erdmann and Jacques : "race." — Tr. CH. II] OX HLTMAN UNDERSTANDING 413 not sufficient, and often to be willing to make all the requisite combinations would be an endless task, although one might often be aided therein by the method of exclusion,^ which cuts off a good portion of useless combinations, and often nature does not admit any other method. But the means are not al- ways at hand for the proper pursuit of this method. Analysis then must give us a thread in this labyrinth, when it is possi- ble, for t^ere are cases Avhere the nature itself of the question demands that we grope about, short cuts not being always possible. § 8. Ph. Now as in demonstration intuitive knowledge is always supposed, it has, I think, given occasion for this maxim : that all reasoning springs from things already Jcnoion and agreed to {ex pnecognitis et proiconcessis) r But we shall have occasion to speak of the falsity of this axiom when we speak of the maxims which are improperly taken as the foundation of our reasoning. Th. I am curious to learn what falsehood you can find in an axiom apparently so reasonable. If it were always necessary to reduce everything to intuitive knowledge, demonstration would often be insufferably prolix. This is why mathema- ticians have had the cleverness to divide the difficulties and to demonstrate separately the intervening propositions. And there is art also in this ; for as the mediate truths (which are called lemmas, since they appear to be a digression) may be assigned in many ways, it is well, in order to aid the under- standing and the memory, to choose those of them which greatly shorten the process, and appear memorable and worthy in themselves of being demonstrated. But there is another 1 The "method of exclusion " or elimination, says Schaarschmidt, proceeds from a disjunctive judgment, the predicate of which embraces in the sum of its divisional members all possible determinations of the subject. After it has been shown that individual divisional members cannot be united with the subject in a categorical judgment, that one alone of the divisional members which cannot be separated from the subject remains as the actual ijredicate tor tlie valid determination of the subject. For example: A is B, or C, or D, or E. In this formula, B, C, D, E must include all thinkable predicate- determinations of A. In the question : Is A, B, or C. or D, or E, it is then proved that A is not C, D, E, in which case A must be B; or that A is not B, D, E, in which case A must be C, and so on. — Tb. - Cf. Aristotle, Analyt. Post., I., 1, p. 71", 1: 77ao-a SiSaaxaMa Kal i-aa-a. |U.aOr)cris itai'orjTLKj) i< wpovirapxovcrris ytVerai yvJxr^hi';. — Tr. 414 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv obstacle, viz. : that it is not easy to demonstrate all the axioms, and to reduce demonstration wliolly to intuitive knowledge. And if we had chosen to wait for that, perhaps we should not yet have the science of geometry. But we have already spoken of this in our former conversations, and we shall have occasion to speak of it again. § 9. Ph. We shall come to that presently ; now I shall re- mark again what I have already touched upon more than once, that it is a common opinion that only the mathematical sciences are capable of a demonstrative certainty ; but as the agreement and disagreement which may be known intuitively is not a privilege belonging only to the ideas of numbers and figures, it is perhaps for want of application' on our part that mathematics alone have attained to demonstrations. § 10. Many reasons conspired to this end. The mathematical sciences are very generally useful ; the least difference therein is very easily recognized. § 11.^ These other simple ideas, which are appearances or situations produced in us, have no exact measure of their different degrees. § 12.- But when the difference of these visible qualities, for example, is sufficiently great to excite in the mind clearly distinct ideas, as those of blue or red, they are as capable of demonstration as those of number and extension. Th. There are notable examples enough of demonstration outside of mathematics, and it may be said that Aristotle has already given some in his " Prior Analytics." In fact logic is as susceptible of demonstrations as geometry, and it may be said that the logic of the geometers, or the methods of argu- mentation explained and established by Euclid in reasoning upon propositions, are a particular extension or promotion of general logic. Archimedes ^ is the first, whose works we have, who has practised the art of demonstration upon an occasion where he is treating of physics, as he has done in his book on 1 § 11, as also § 12, is § 17 in the texts of Erdraann and Jacques. — Tr. 2 § 12 is § 13 in Loclve, PMlos. Works, Vol. 2, p. 140 (Bolm's ed.).— Tr. 3 Archimedes, 287-212 B.C., the greatest naathematician among the Greeks, distinguished also for his discoveries in hydrostatics and hydraulics, and for his ingenious inventions. He fii'st placed the science of engineering upon a sound mathematical basis. The most complete and magnificent edition of his extant works is that edited by Torelli and published at Oxford, at the Claren- don Press, 1792, fol. — Tr. CH. II] ON HUMAN UNDERSTANDING 415 Equilibrium. Furthermore, jurists may be said to have many good, demonstrations ; especially the ancient Roman jurists, whose fragments have been preserved to us in the Pandects. I am wholly of the opinion of Laurentius Valla,^ who cannot enough admire these authors among others, because they all speak in a manner so. just and so clear and in fact reason in a way closely approaching the demonstrative, and often it is wholly demonstrative.^ Indeed, I do not know any science outside that of law and that of arms, in which the Eomans have made any considerable addition to Avhat they received from the Greeks. Tu regere imperio populos Romane memento : Hse tibi erunt artes pacique imponere morem, Parcere subjectis, et debellare superbos.* This precise manner of expressing themselves is the reason that all the jurists of the Pandects, though sometimes quite 1 Laurentius Valla — Lorenzo della Valle — c. 1407-1457, a humanist and philolog'ian of the earlier Italian Renaissance, was an earnest opponent of the scholastic dialectic, a determined foe of tradition and authority, and the initi- ator and champion of a bold and unbiassed criticism which he applied to language, historical documents, and ethical opinions. He was eminent as a Latinist, and his treatise Elegantix latinse lincjux, c. 1431, in six books, — the Preface to the third book of which Schaarschmidt thinks Leibnitz probably had in mind in referring to Valla's admiration for the style of the Roman jurists, therein very highly praised, — subjected the forms of Latin grammar and rhetoric to critical investigation and analysis, and established upon a scientific foundation the principles of Latin style. His De /also crecUta et ementita Constantini Donatione, 1440, destroyed the claims of the Papacy to temporal power based upon this alleged "Donation," by proving its docu- mentary foundations to be forgeries. His principal philosophical writings are : De voluptaie et vero bono, 1431, in which he boldly defended the Epicurean doctrine of pleasure as the true and only good; De libera arbitrio ; and the Dlrdecticx disputationes contra AristoteVwox, 1499, of which Prantl, Gesch. d. Logik im Abendlande, 4, 161-167, gives some account with citations. Valla's Opera Omnia, Basiliaj, 1465 and 1540-1543. Leibnitz refers to him and his De lib. arbit. and De voluptaie in the Theodicee, Pt. HI., §§ 405 .s^. For accounts of his life and works, rf. G. Tiraboschi. Storia della Leiteratura Itidiana, Vol. 6, Pt. II., pp. .339-340, Rome, 1784; Symonds, Renaiftftance in Itahj, Pt. II., The Revival of Learning, p. 258 sq., New York, H. Holt & Co., 1881. For his philosophy, cf. Stockl, GeRch. d. Philos. d. Mittelalfers, HI. [Vol. 4] , 279-283. Mancini published at Florence, 1891, a brilliant and exhaus- tive monograph investigating and settling disputed points in Valla's life. — Tr. - Cf. Leibnitz's letter to Kestner, No. 15, in Ch. Kortholt, Leibnit. epist. nd dirersof!, Lipsise, 17-34-1742, Vol. 3, p. 256, Dutens, Leibnit. opera omnia, Vol.4, Pt. HI., p. 267, where he expresses himself similarly as here. Also, Guhrauer, T^eibniz, eine Biographie, Pt. I., pp. 36, 37. — Til. 3 Verg. ^n. 6, 851-853. — Tr. 416 LEIBNITZ'S CRITIQUE OF LOCKE [bk. w distant from one another in time, seem to be a single author, and there would be much difficulty in distinguishing them, if the names of the writers were not at the beginning of the ex- tracts ; as it would be difficult to distinguish Euclid,^ Archi- medes and Apollonius ^ in reading their demonstrations upon matters which the one as well as the other has totiched upon. It must be admitted that the Greeks have reasoned with all possible accuracy in mathematics, and that they have left the human race models in the art of demonstration : for if the Babylonians and the Egyptians had anything more than an empirical geometry, nothing of it at least remains ; but it is astonishing that these same Greeks lost it to such an extent ^ at once as soon as they turned aside ever so little from num- bers and figures in order to proceed to philosophy. For it is strange that we do not see a shadow of demonstration in Plato and in Aristotle (his ''Prior Analytics" excepted) and in all the other ancient philosophers. Proclus * was an excellent geometer, but he seems another man when he speaks on phi- losophy. What has made it easier to reason demonstrably in mathematics is largely the fact that experience can there guar- antee the reasoning at every moment, as is also the case in the syllogistic figures. But in metaphysics and ethics this par- allelism of reason and experience is no longer found ; and in 1 Cf. ante, p. 93, note 1. — Tr. 2 Qf. ante, p. 108, note 1. — Tr. 3 A strange remark for Leibnitz to make, wlio had so tliorouglily studied Aristotle in his youth, and in later years Plato, whose works contain demon- strations inferior in no respect certainly to the precision of the Pandects. The only explanations that seem to touch the case are that Leibnitz had in mind the stringency and completeness of mathematical demonstration, which in form, and sometimes in content also, is apparently, and sometimes really, superior, though not necessarily so merely because mathematical, to the demonstrations of philosophy ; or, as he seems to suggest in the immediately following con- text, that metaphysics being a matter of pure thought and ethics largely an ideal not as yet realized in the actual, their demonstrations cannot, like those of mathematics, be experim.entally verified, and must thus be regarded as, in a sense, lacking in completeness as demonstrations. — Tb. * Cf. ante, p. 108, note 2. Leibnitz's remark concerning Proclus has its justification in the fact that his philosophical system, while embracing the entire philosophy and theology of his predecessors methodically elaborated with great dialectic art and skill, is yet purely formal in its completeness, its thought exhibiting little freedom or creative power, and wholly lacking in any real scientific basis and character. Though presenting here and there evidence of deep speculative ability on the part of its author, his philosophy is never- theless wholly wanting in such demonstration as is found in his mathematical work. — Tr. CH. II] ON HUMAN UNDERSTANDING 417 physics experiments demand labor and expense. Now men at once relaxed their attention, and as a consequence were led astray when they were destitute of this faithful guide, experience, who aided and sustained thein in their walk, as that little revolving machine does, which prevents children from falling when walking. There was a succeclaneum,^ but it is something that has not been and is not yet sufficiently con- sidered. And I shall speak of it in its place. For the rest, blue and red are scarcely capable of furnishing matter for demonstration by means of the ideas we have of them, because these ideas are confused. And these colors do not supply matter for reasoning so long as in experience they are found accompanied by some distinct ideas, but in which the con- nection with their own ideas does not appear.] § 14. Ph. Besides intuition and demonstration, which are the two degrees of our knowledge, all the rest is faith or opinion, and not knowledge, at least as regards all general truths. But the mind has also another perception, regarding the particular existence of finite beings outside of us, and this is sensitive knoioledge.^ Th. [Oj:>mioft, based on probability, deserves perhaps the name knowledge also ; otherwise nearly all historic knowledge and many other kinds will fall. But without disputing about terms, I hold that the investigation of the degrees of probahility is very important, that we are still lacking in it, and that this lack is a great defect of our logics.^ For if the question can- not always be decided absolutely, the degree of resemblance ex datis can always be determined, and conseqvientl}^ one can reasonably judge what view is the most likely. And when 1 I.e., a substitute. The expression was much used by the later Roman jurists. — Tr. '■^ Locke's word is " sensitive," Philos. Wks. (Bohn's ed.), Vol. 2, p. Ill, udfin. His three degrees of knowledge are intuitive, demonstrative, and sensitive, cf. infra, p. 420. — Tr. 3 Cf. Leibnitz's letter to Kestner, No. 11, Jan. 30, 1711, § .3 (Dutens, Leibnit. op. om.4:, Pt. III., 2t)4, and Kortholt, Leibnit. epist. ad diversos, 3, 251) : " Ea vero pars Logicre, qua so. gradus verisimilitudinum et argumentorum pondera constituerentur, nuspiam hactenus reperitnr traditur. Ego juvenis aliquamlo aggressns sum, sed per varia dissipatus, fere intra voluntatem steti. Topica Aristotelis scopo meo nou respondet. Congerit regnlas, quae occasionem aliquam prfebere possnnt de argumentis cogitandi, sed qune non possnnt docere, quantum cuique argumento aut judieio ponderis insit." — Tr. 418 LEIBNITZ'S CRITIQUE OE LOCKE [bk. iv our moralists (I mean the wisest of tliem, such as the present {moderne) General of the Jesuits)^ unite the safest and the most probable, and prefer even the safe to the probable,- they are not far in fact from the most probable ; for the question of safety is here that of the little probability of an evil to be feared. The fault of the moralists lax upon this article ® has largely been, that they have had a too limited and too inade- quate notion of the probable, which they have confounded with Iho, Endoxon^ ov the probable {opinahle) of Aristotle; for Aris- totle in his " Topics " did not mean to accommodate himself to the opinion of others, as did the orators and sophists. Eiidoxon is with him what has been received from the greatest number or the most authoritative : he is wrong in having restricted his '* Topics " to this, and this view caused him to adhere only to received maxims, for the most part vague, as if he wished 1 Leibnitz probably refers to Tirso Gonzalez, General of the Jesuits from 1687-1705, and author of a work on probabilism, opposing the doctrine and maintaining that the Jesuits did not originate it, entitled Fundamentum theologise moralis, id est tractatus theologicus de recto usu opinionum proba- bilium, 4to, Dillingen, 1689, Naples, 1694. An abridgment with the title tSynop- sis tract, tlieol. de recto usu opinionum prohahilium, concinnata a theologo quodam Soc.Jesu: cui accessit logistica prohabilitatum, 3d ed., appeared at Venice, 1696, 8vo. Cf. Michaud, Biog. Univ. 18, 111-112, Du Pin, Bihlioih. des aut. eccles. du XVII. siecle, and, for the De recto usu opin. prob., Migue, Theol. cur. compl. Vol. 11, p. 1397. — Tr. 2 The theory of moral probabilism is, perhaps the most celebrated question discussed in Moral Theology, and formed one of the chief subjects of contro- versy between the Jansenists and the Jesuits of the seventeenth century. The aim of moral probabilism is to find some rule by which action may tie determined in that portion of the moral realm in which certainty is impossible, and probability only can be attained. The probable opinion being that which has a certain number of arguments in its favor, either intrinsic, i.e., grounded in reason, judgment in regard to whicli was restricted to men of considerable education and especially to those versed in moral theology, or extrinsic, i.e., resting on some external authority, such as that of some theologian of repute ; and the safe opinion, that which conforms to the moral law, casuists distinguish the following doctrines: 1. Probabilism, whicli permits action in accoi-d with the opinion which is least probable and least safe ; 2. Probabilorism, or the preference of the most probable opinion, regardless of its relative safety ; 3. Tutiorism, or the choice of the safest opinion, without regard to its rela- tive probability. On the whole subject, cf. the dissertation of Pierre Nicole annexed to his Latin trans, of Pascal's Lettres 'provincinles, and Janet, La Morale, Bk. III., Chap. 3, Paris, 1874, Eng. trans., The Theory of Morals, pp. 292-308, New York, Chas. Scribner's Sons,' 1883. — Tr. 3 According to Janet, the casuists refuted by Pascal. — Tr. C/. Topics, I., 1, 100'' 21 : ei'SofaSeTaSoKoGi'TaTrao'ii' ij toT? TrAet'trTOisi) rot? trot/jOis, Ka\ TOiirots Tj TTa.(Tiv 17 TOis jrAeicTTOis ij Tois /naAtcrTa yvoipiti.oi'; Ka.\ ev66^oi!. — TR. CH. II] ON HUMAN UNDERSTANDING 419 to reason only by means of quodlibets ^ or proverbs. But the probable or the likely is more extended : it must be drawn from the nature of things ; and the opinion of persons whose authority has weight is one of the things which may contribute to render an opinion probable, but not what completes the en- tire verisimilitude. At the time when Copernicus- was almost alone in his opinion, it was still incomparably more probable than that of all the rest of the human race. Now T do not know but that the establishment of the art of estimating ])robabilities ^ would be more useful than a majority of our demonstrative sciences, and I have thought of this more than once.] Ph. Sensitive hnoivledge, or that which establishes the exist- ence of particular beings without us, goes beyond bare proba- bility ; but it has not all the certainty of the two degrees of knowledge of which we have just spoken. Nothing is more certain than that the idea we receive of an external object is in our mind, and this is intuitive knowledge : but the knowl- edge whether from this we can certainly infer the existence of anything without us corresponding to this idea, this it is which certain persons think may be questioned, because men may have such ideas in their minds, when no such thing actu- ally exists. For myself I believe, however, that there is a degree of evidence which elevates us beyond doubt. One is unalterably convinced that there is a great difference between the perceptions which he has when by day he looks at the sun, and when by night he thinks about it ; and the idea which is 1 The Medifeval Latin " quodlibetum " was a very elaborate and subtle scholastic argumentation upon a question chosen at pleasure — " quod libet " — but almost always of a theological or philosophical character. Such ques- tions were called " quodlibetarise qusestiones " ; they were proposed chiefly for the exercise of students, and their discussion was carried on to satisfy curiosity or for entertainment, and, for the most part, served rather to exhibit the skill and dexterity of the dialectician than to establish truth. The French word " quolibet," starting from the scholastic use of the term in the sense of an argumentative subtlety, came by a debasing extension of this meaning to signify a witty, but not always appropriate commonplace, a bad joke, a pun, an epigram ; and it is in this sense that Leibnitz, coupling the word with " proverbs," uses the term. — Tr. 2 Nicolas Copernicus, 1473-1543, published his theory of the planetary system in his De orbium cwlestium revolutionibus lit. VI., Nuremberg, 1543, 2d ed., Basle, 1568, both fol. 3d ed., with notes by Nicolas Muler in his Astronomia Instaurata, Amsterdam, 1617 and 1640, 4to. — Tr. 3 Cf. ante, p. 213, note 2, p. 214, note 1 ; also Erdmann, Leibiiit. opera philos., 84. — Tr. 420 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv renewed by recourse to the memory is very different from that which actually comes to us by means of the senses. Some one will say that a dream may produce the same effect. I reply in the first place that it matters little that I remove this doubt, because if all is but a dream, reasoning is useless, truth and knowledge nothing at all. In the second place, he will ac- knowledge, in my opinion, the difference between dreaming of being in a fire, and being actually in it. And if he persists in appearing sceptical, I shall tell him that it is enough that we certainly find pleasure or pain following the application to ourselves of certain objects, true or dreamt of, and that this certitude is as great as our happiness or misery ; two things beyond which we have no interest. Thus I think we may count three sorts of knowledge : intuitive, demonstrative and sensitive. Th. [I think you are right, sir, and I also think that to these species of certitude or certain knowledge you can add the knoidedge of the probable; thus there will be two sorts of knowledge, as there are two sorts of proofs, the first of which produce certitude, and the second end only in probability. But let us come to this dispute of the Sceptics and the Dogmatists upon the existence of things without us. We have already touched upon it, but we must return to it here. I formerly discussed the subject a great deal viva voce and in writing with the late Abbe Foucher,^ Canon of Dijon, a learned and 1 Simon Foucher, 1644-1696, a devoted student of the Platonic philosophy, in consequence of which he was called " the restorer of the philosophy of the Academy." His Critique de la Recherche cle la Ve'rite, here mentioned by Leibnitz, appeared at Paris, 1675. It was based upon the sceptical principles of the Middle Academy, and was subjected to a very sharp criticism by Male- branche in the Preface to the next edition of the Recherche de la Ve'rite'. Foucher also wrote Dissertation sur la recherche de la verite ou stir la philo- sophie des academiciens, Paris, 1673, said to be his best work, and De la Sagesse des anciens, Paris, 1683. For Foucher's " objections " (published in the "Journal des Savans " of Sept. 12, 1695) to Leibnitz's doctrine of pre- established harmony as set forth in the Stjsteme nouveau (" Jour, des Savans," June 27, 1695), cf. Gerhardt, 1,424, and 4, 487, Erdmann, 129, Dutens, 2, Pt. I., 102, trans. Duncan, 81 ; and for Leibnitz's reply (" Jour, des Savans," April 2 and 9, 1696), cf. G. 4, 493, E. 131, Dutens, 2, Pt. I., 67, trans. Duncan, 85. The corresj)ondence of Foucher with Leibnitz was first published by Foucher de Careil in his Lettres et opuscules inedits de Leibniz, Favis, 1854, pp. 27-131 (>■/. Introd. pp. 22-41, where the controversy over Malebranche is thoroughly con- sidered), and more recently, 1875, after a new comparison with the originals in the Royal Library at Hannover, by Gerhardt, Leibniz, philos. Schrift., 1, 363sg. — Tr. i CH. ii] ON HUMAN UNDERSTANDING 421 subtile man, but a little too prepossessed in favor of liis Acad- emicians, which sect he was very desirous of reviving, as Gas- sendi^ had brought upon the stage that of Epicurus.^ His critique upon " The Search after Truth," ^ and the other minor treatises which he afterwards published, have made their author quite well known. He published also in the "Journal des Savans " some objections to my System of Pre-established Harmony, when I gave it to the public after having digested it for many years ; but death prevented him from replying to my answer. He always preached the necessity of guarding against prejudice and of using great accuracy, but besides the fact that he himself did not make it his duty to carry out his counsel to others, in which he was perhaps excusable, it seems to me that he was not careful whether another did it, antici- pating doubtless that no one would ever do it. ISTow I showed him that the truth of sensible things consisted only in the connection of phenomena, which must have its reason and is that which distinguishes them from dreams ; but that the 1 Cf. ante, pp. 64, note 2, 65, n. 3. Gassendi published on the life and phi- losophy of Epicurus: De vita, moribus et doctrina Ejncuri, Lugd. Bat., 1647; Animadversiones in lib}'. X. Biog. Laert. de Epicuro, Lugd. Bat. 1649; Syn- tacjma philos. Epicuri, The Hague, 1655. For his philosophy, cf. his Syntagma philosojMcum, Vols. 1 and 2 of his Opera omnia; also Stockl, Gesch. d. Phi- los. d. Mittelalters, III. [Vol. 4], 316-327; Lange, Gesch. d. Materialismus, Vol. 1, Eng. trans. Vol. 1, pp. 253-269; R. Adamson, article "Gassendi," in Encyclop. Brit., 9th ed. — Tr. " Cf. ante, p. 126, note 1. On his life and philosophy, cf. Zeller, Philos. d. Griech., III., 1 [Vol. 5] , 363 sq., 3d ed., Leijizig, 1880; Lange, Gesch. d. Materi- alismus, Vol. 1, Eng. trans., Vol. 1, i^p. 98 sq. ; Benn, The Greek Philosophers, Vol. 2, pp. 53 sq. ; Wm. Wallace, Epicureanism, in the series of " Chief Ancient Philosophies," pub. by the Society for promoting Christian Knowl- edge, London, 1880. — Tr. 3 The Be la Recherche de la Verity, the principal work of Malebranche, 1638-1715, appeared in 1674-1679. The most recent edition is that of F. Bouil- lier, with an introduction and notes, 2 vols., Paris, 1880. On Malebranche's philosophy, cf. Bouillier, Histoire de la Philos. Cartesienne, Paris, 1854; Olle- Lapruue, La Philos. de Malebranche, 2 vols., Paris, 1870-1872; Kuno Fischer, Gesch. d. n. Philos., 3d ed., I., 1, Eng. trans, by J. P. Gordy, New York, Scrib- ners, 1887; Martineau, Types of Ethical Theory, 2d ed.. Vol. 1, p. 159 sq. For a critical account of Malebranche's place in the history of i^hilosophy, cf. Edward Caird, article " Cartesianism," in Encyclop. Brit., 9tli ed. For Leib- nitz's correspondence with Malebranche, cf. Gerhardt, Leibniz, philos. Schrift., 1, 315-361 ; for his discussion of Malebranche's philosophy, cf. Gerhardt, 3, 656-660, Erdmann, 735-737, Dutens, 2, Pt. I., 213, trans. Duncan, 233-237; G. 6, 579-594 {cf. also 481-483), E. 690-697, D. 2, Pt. I., 201 ; G. 6, 574-578 {cf. also 480-483; Locke's examination of Malebranche is in his Philos. Works, Vol. 2, 413-458, Bohu's ed.), E. 450-452, trans. Duncan, 185-189.— Tr. 422 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv truth of our existence- and the cause of phenomena is of a different nature, because it establishes substances, and that the Sceptics spoiled what they rightly say by carrying it too farj and by wishing indeed to extend their doubts even to immediate experience, and to the geometrical truths, a thing which Toucher did not do however, and to the other truths of reason, which he did a little too much. But to return to . you, sir, you are right in saying that there is ordinarily some difference between feelings and imaginations ; but the Sceptics will say that the more or less does not alter the species. Be- sides, although feelings are wont to be more vivid than im- aginations, it is nevertheless a fact that there are cases where imaginative persons are impressed as much or perhaps more by their imaginations than another is by the truth of things ; so that I think the true criterion concerning the objects of the senses is the connection of the phenomena, i.e. the connection of that which takes place in different places and times, and in the experience of different men who are themselves, each to the others, very important phenomena in this respect. And the connection of the phenomena which guarantees the truths of fact in respect to sensible things outside of us, is verified by means of the truths of reason ; as the phenomena of optics are explained by geometry. It must, however, be admitted that none of this certitude is of the highest degree, as you have well recognized. For it is not impossible, metaphysically speaking, that there may be a dream continuous and lasting like the life of a man ; but it is a thing as contrary to reason as Would be the fiction of a book which should be formed by chance by throwing together the type pell-mell. For the rest, it is also true that, provided the phenomena are connected, it does not matter whether they are called dreams or not, since experience shows that we are not deceived in the measures we take concerning phenomena when they are understood accord- ing to the truths of reason.^] 1 Cf. New Essays, Bk. III., chap. 4, § 2, Th., ante, pp. 318, 319, notes 1 and 2, and Bk. IV., chap. 11, § 10, Th., infra, p. 512. The principle of the " con- nection of the phenomena," tlieir constant occurrence in the same order and relations, giving them a certain measure of objectivity in our consciousness and enabling us to predict the appearance of other members of the series when one member presents itself, is for Leibnitz the guarantee of the truth of our sense-knowledge and the ground of our greatest possible certainty therein ; CH. Ill] ON HUMAN UNDERSTANDING 423 §15. Ph. For the rest, knowledge is no.t always clear, though ideas may be. A man who has as clear ideas as any mathe- matician in the world of the angles of a triangle and of equality to two right angles, may yet have a very obscure perception of their agreement. Th. [Ordinarily when ideas are thoroughly understood their agreements and disagreements appear. I admit, however, that at times some of them are so complex, that much care is needed to develop what they conceal ; and in this respect certain agreements or disagreements may still remain obscure. As to your example, I remark that if we have in the imag- ination the angles of a triangle we do not on that account' have clear ideas of them. The imagination cannot furnish us an image common to acute-angled and obtuse-angled triangles, and yet the idea of triangle is common to them : thus this idea does not consist in images and it is not as easy as you may think thoroughly to understand the angles of a triangle.] CHAPTER III , OF THE EXTENT OK HUMAN KNOWLEDGE § 1. Pli. Our knowledge does not extend beyond our ideas, § 2. nor beyond the perception of their agreement or dis- agreement. § 3. It cannot always be intuitive, because Ave cannot always compare things immediately, for example, the size of two triangles upon one and the same base, equal, but very different. § 4. Our knowledge, also, cannot always be demonstrative, for we cannot always find mediate ideas. § 5. Finally, our sensitive knowledge regards only the existence of things which actually strike our senses. § 6. Thus not only our ideas are limited, but also our knowledge is more limited than our ideas. I do not doubt however that human knowl- edge can be carried much farther if men will devote the,m- but he holds that this guarantee is " verified," and the consecutions of experi- ence supplemented, "by means of the truths of reason," and particularly by the use of the principles of logic. The position here taken is also that of the modern scientist, who keeps strictly within the scientific realm and does not pass on to consider the ultimate metaphysical nature and ground of the phenomena he investigates. — Tr. 424 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv selves sincerely to discovering the means of perfecting truth, with, entire freedom of mind and with all the application and industry they employ in coloring or maintaining falsehood, in defending a system in favor of which they have declared themselves, or else a certain party and certain interests, with, which they find themselves united. But after all our knowledge can never embrace all we may wish to know concerning the ideas we have. For example, we shall never perhaps be able to find a circle equal to a square, and know certainly that it is so. Th. [There are confused ideas in which we cannot promise ourselves a complete knowledge, like those of certain sensible qualities. But when they are distinct, there is room to hope for all. As for the square equal to the circle, Archimedes has already shown that there is one. For it is the one whose side is the mean proportional between the semi-diameter and the semi-circumference. He has also determined a straight line equal to the circumference of the circle by means of a straight line tangent to the spiral, as others by the tangent to the quadratrix ; a method of quadrature with which Clavius ^ was wholly content ; not to speak of a thread applied to the cir- cumference and then stretched out, or of the circumference which revolves to describe the cycloid and is changed to a straight line. Some demand that the construction be made by employing only the ruler and the compasses ; but the majority of geometrical problems cannot be constructed by this means. The question then is rather that of finding the proportion between the square and the circle. But this pro- portion not being capable of expression in finite rational num- bers, it has been necessary, in order to employ only rational numbers, to express this same proportion in an infinite series ^ 1 Christopher Clavius, 1537-1612, a Jesuit and distinguished mathematician, Professor of Mathematics at Rome, and called " the Euclid of the sixteenth century," was employed hy Pope Gregory XIII. in the reformation of the calendar, for which he made the principal calculations. Among his works are: Euclid^s elementorum , Rome, 1574; Sinus linese tangentes, etc., Rome, 1586, 4to; Romani Calendarii a Gregorio XIII. P.M. restituti Expllcatio, Rome, 1603. His Opera mathematica, containing these and several other works, appeared at Mayence, 1612, 5 vols., fol. — Tr. ^ Leibnitz's infinite series, which, according to Schaarschmidt, he had dis- covered before he became acquainted with Huygeus, and also before his discovery of the infinitesimal calculus, Js~ = l — - + - — -+Q~i3 + r^"-) ^^^ CH. Ill] ON HUMAN UNDERSTANDING 425 of these numbers, which I have assigned in a manner quite simple. ISTow we should like to know whether there is not some finite quantity, although it be irrational only, or more than irrational, which can express this infinite series, that is to say, whether we can find exactly an abbreviated expression for this series. But finite, especially irrational, expressions, if we proceed to the most irrational of all, may vary in too many ways for us to be able to make an enumeration of them or to determine easily all that they are capable of. There might be perhaps a means of doing it if this irrationality should be ex- plained by an ordinary, or even more, an extraordinary equa- as related to unity it expresses the proportion obtaining between the circle and the circumscribed square. Cf. De vera proportione circuli ad quadratum circumscriptum in numeris rationalibus, "Acta Erud. Lips.," February, 1682, p. 41 sq., Gerhardt, Leibniz, math. Schrift., II., 1 [Vol. 5], 118, Dutens, Leih- nit. op. om., 3, 140 sq.; Quadratura aritJwietica, " Acta Erud. Lip.," April, 1691, p. 180, Gerhardt, Leibniz. matJi. Schrift., II., 1 [Vol. 5], 130, Dutens, 3, 242; also letter to Conring, Jan. 3, 1678, Gerhardt, Leibniz, philos. Schrift., 1, 187. The problem of which Leibnitz here speaks is the modern form of the prob- lems of the rectification and quadrature of the circle or the calculation and construction of w and of a square mathematically exactly equal in area to a given circle. In referring to it he distinguishes between an "ordinary," or algebraic, and an "extraordinary," or, as it is now termed, transcendental equation. The problem is to prove that w cannot be the root of any equation having whole numbers for coefficients, or that tt is not algebraical. The quad- rature of the circle has long been known to be an unsolvable problem, — Leib- nitz knew this, — but the impossibility of its solution has only recently been demonstrated. Not until mathematicians jDossessed the methods furnished by the theory of definite integrals and the departments of higher algebra devel- oped in the last few decades was this demonstration possible. With the aid of these methods Prof. Lindemann of Konigsberg succeeded, in June, 1882, in demonstrating with exactness the non-algebraic character of tt, and thus proved for the first time that the rectification and the squaring of the circle with ruler and compasses is impossible. For his jjroof , cf. Vber die Ludolph'sche Zo/i^. iuthe " Sitzungsberichte d. kongl. Pr. Akad. d.Wiss., zu Berlin," June 22, 1882, PI). 679-6S2; the " Comptes Rendus " of the French Academy, Vol. 115, pp. 72-74, " Math. Annalen," Vol. 20, pp. 213-225. For an historical sketch of the problem of circle-quadrature, cf. Holtzen- dorff and Virchow, Sammlung (/emeinrerstandlicher loissenschaftiicher Vor- triif/e. Heft 67 ; an article from this by H. Schubert, in " The Monist," Janunry, 1891, Vol. 1, No. 2, pp. 197-228, repriiited in Smithsonian Report, 1890, pp. 97- 120; and the article " Squaring of tlie Circle," in the Enci/clop. Brit., 9th ed.. Vol. 22, pp. 450-454 (American Reprint). On Leibnitz's relation to the prob- lem, (f. Kummer, Festrede am Leibniztage, in the " Mouatsberichte d. Pr. Akad. d. Wiss.," July, 1867, p. 387 sq., an article which, while not directly taking into consideration the present interesting passage for the history of mathematics, is admirable in its understanding of the peculiarities of Leib- nitz's method of thought. — Te. 426 LEIBNITZ'S CRITIQUE OF LOCKE [bk. it tion, which would introduce the irrational or even the unknown quantity into the exponent/ for which, however, an extended calculation would be required, and in which the difficulty will not easily be solved unless we some day find a short method for its solution. But to exclude all the finite expressions is impos- sible, as I myself know, and to determine exactly the best is an immense task. And all this shows us that the human mind proposes questions so strange, especially when the infinite enters therein, that we must not be astonished if there is some difficulty in making them out, so nuich the more as all depends often on a short method in these geometrical matters, which cannot always be determined on, just as fractions cannot always be reduced to the lowest terms or the divisors of a number be found. It is true that we may always have these divisors if they are possible, because their number is finite ; but when what we have to examine is infinitely variable and ascends by degrees, we are not its master though we wish to be, and it is too laborious to do all that is necessary in order to attempt methodically to reach the short method or the rule of progression exempting us from going farther. And as its usefulness does not correspond to the labor, its success is left to posterity, which will be able to enjoy it when this labor or prolixity is diminished by the new preparations and means which time may furnish. Unless the persons who devote themselves from time to time to these studies determine to do properly what is necessary in order to further progress, we cannot hope to advance much in a short time. And we must not think that all is done, since indeed in ordinary geometry, we still have no method for. determining the best constructions when the problems are a little complex. A certain progres- sion of synthesis should be mixed with our analysis in order the better to succeed. And I remember to have heard it said that the Pensionary De Witt ^ had some thoughts on this subject.] 1 Cf. Letter to Arnauld, Gerhardt, Leibniz, xthilos. Schrift., 2, 61, 62, Janet, (Euvres pMlos. de Leibniz, 1, 622. — Tr. ^ Johu De Witt, 1625-1672, an illustrious Dutch statesman, was a steadfast opponent of the House of Orange, whose re-elevation to power in the United Provinces he labored earnestly and for many years successfully to prevent. His plans for his country were finally defeated by the diplomacy of Lonis XIV., the opposition of the Calvinist clergy, and the change in the popular CH. Ill] ON HUMAN UNDERSTANDING 427 Ph. There is, indeed, another difficulty, to know whether a purely material being thinks or not,^ and perhaps we shall never be capable of knowing this, although we have ideas of matter and of thought, for the reason that it is impossible for us to discover by contemplation of our own ideas without revelation, whether God has not given to some masses of matter, htly dis- posed, the power to perceive and to think, or whether he has not united and joined to matter so disposed an immaterial substance that thinks. For as regards our notions, it is no more difficult for us to conceive that God, if he pleases, can add to our idea of matter the faculty of thinking, than to under- stand that he joins to it another substance with the faculty of thinking, since we know not ivherein thinking consists, nor to what kind of substance this all powerful Being has been pleased to give that poiver, which cannot exist in any created being save by virtue of the good pleasure and the bounty of • the Creator. Th. [This question is without doubt incomparably more important than the preceding ; but I venture to say to you, sir, that I wish it were as easy to touch souls in order to influence them for their good, and to heal bodies of their diseases, as I think it is in our power to determine this ques- tion. I hope you Avill admit at least that I can advance icith- out offending against modesty and without speaking as a master in default of good reasons ; for besides speaking only accord- ing to received and common opinion, I think I have brought thereto an attention not common. In the first place, I grant you, sir, that when Ave have only confused ideas of thought and of matter, as is ordinarily the case, we must not be astonished if we do not see the means of solving such questions. As I remarked a little before, one who has only the ideas of the angles of a triangle commonly held will never think of finding feeling towards the Prince of Orange, occasioned by the recollection of their country's obligations to his ancestors. He was massacred, with his brother Cornelius, in the revolution which put the Prince William (afterwards "William in. of England) at the head of the United Provinces. He published Elementa liiieannn curvanim, Leyden, IGoO; The Hague, 1709. — Tr. ^ Cf. ante, p. 56 .s^., where Leibnitz shows that Locke afterwards gave up the opinion which he once advanced as possible that matter can think. For Leib- nitz, who regards matter as a mere pheuomenon and not a reality, the question does not exist. — Tk. 428 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv them always equal to two right angles. We must consider that matter taken as a complete being {i.e. secondary matter in distinction from i\e primary, which is something purely passive and consequently incomplete) is only a mass, or that which results therefrom, and that every real mctss supposes simple substances or real unities, and when we further consider what belongs to the nature of these real unities, i.e. perception and its consequences, we are transferred so to speak into another world, that is to say into the intelligible world of substances while before we have been only among the phenomena of the senses. And this knowledge of the interior of matter shows us sufficiently its natural capability, and that whenever God shall give it organs suitable for rational expression, the imma- terial substance which reasons will not fail to be given it also, in virtue of that harmony which is also a natural consequence •of substances. Matter cannot subsist without immaterial substances, i.e. without the unities ; after which the question should no longer be asked whether God is free to give them to it or not ; and if these substances had not in themselves this correspondence or harmony of which I have just spoken, God Avould not act in accordance with the natural order. To speak in an entirely simple manner of giving or according powers is to return to the naked faculties of the schoolmen and to im- agine minute self-subsisting entities, which may go in and out like pigeons from a pigeon-house. It is making substances of them without being aware of it. The primitive p>owers con- stitute substances themselves, and the derivative powers, or, if you prefer, the faculties, are only modes of being, which must be derived from substances, and are not derived from matter so long as it is only a machine, i.e. so long as it is abstractly considered only as the incomplete essence of primary matter, or passivity pure and simple. As to which I think you will agree, sir, that it is not within the power of mere mechanism to produce perception, sensation, reason. They must then spring from some other substantial thing. To desire God to act otherwise and to give to things accidents which are not modes of being or modifications derived from substances, is to have recourse to miracles and to what the schoolmen called the obediential power, by a kind of supernatural exaltation, as when certain theologians claim that the fire of hell burns up sepa- CH. Ill] ON HUMAN UNDERSTANDING 4:i9 rated souls. In which case it may indeed be doubted whether it Avas the fire that acted or whether God did not himself produce the effect, acting in place of the fire.] Ph. You surprise me somewhat by your eli;cidations, and you anticipate me in many of the things I was going to say to you upon the limits of our knowledge. I should have said to you that we are not in a state of vision, as the theologians call it, that faith and probability must suffice us as regards many things, and particularly as regards the immateriality of the sold ; that all the great ends of morality and religion are established upon sufficiently good foundations without the aid of the proofs of this immateriality drawn from philosophy ; and that it is evident that he who has begun to make us sub- sist here as sensible and intelligent beings, and who has pre- served us many years in this state, can and will make us enjoy also a similar state of sensibility in the other life, and make us capable of receiving there the retribution he has designed for men according as they shall have conducted themselves in this life ; in fine that we may judge by this that the necessity to determine for or against the immateriality of the soul is not so great as some people too zealous for their own views have wished to persuade us. [I was going to say all this to you, and more besides to the same effect, but I see now how differ- ent is the statement that we are sensible, thinking, immortal beings by nature and the statement that we are so only by mir- acle. It is a miracle, in fact, which I know I must admit if the soul is not immaterial ; but this view of miracle, besides being without foundation, will not produce a sufficiently good effect in the minds of most people. I see clearly also from the way you understand the matter, that we can decide rationally as regards the present question, without finding it needful to depart to the enjoyment of the state of vision and to find ourselves in the company of those superior spirits who penetrate very deeply into the internal constitution of things and Avhose living and penetrating sight and vast field of knowledge may make us imagine by conjecture what happiness they must enjoy.] I had supposed it entirely beyond our knowledge to combine sen- sation ivith extended matter, and existence ivith a thing which has absolutely no extension. I had therefore become convinced that those who took sides here followed the unreasonable method 430 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv of certain persons, who, seeing that things considered from a certain side are incomprehensible, tlirow themselves headlong upon the opposite side, although it is no less unintelligible ; a procedure which arose in my opinion from the fact that some having their mind too deeply buried so to speak in matter, could not accord any existence to that which is not material ; and others not finding that thought is included in the natural faculties of matter, concluded that God himself could not give life and perception to a solid substance without putting therein an immaterial substance ; while I now see that if He had done so it would be by a miracle, and that this incomprehensibility of the union of the soul and the body or of the union of sensa- tion ivith matter seems to cease through your hypothesis of pre- established harmony between different substances.] Th. [In fact there is nothing unintelligible in this new hypothesis, since it attributes to the soul and to bodies only the modifications which we experience in ourselves and in them ; and only makes them appear more regular and more connected than has been thought hitherto. The difficulty which remains exists only as regards those who wish to imagine what is only intelligible,^ as if they wished to see sounds or hear colors, and these are they who refuse existence to everything which is net extended, a view which will compel them to refuse it to God himself, i.e. to renounce the causes and reasons of changes and of such changes : these reasons being incapable of arising from extension and from natures purely passive, and not indeed wholly from particular and inferior active natures without the pure and universal act of the supreme substance.] Ph. One objection remains for me with reference to things whose matter is naturally susceptible of feeling. The body so far as we can conceive it, is capable only of striking and effecting a body, and motion can produce nothing but motion : so that when we agree that the body produces pleasure or pain or the idea of a color or sound, we seem compelled to abandon our reason, to go beyond our own ideas, and to at- tribute this production solely to the good pleasure of our Creator. What reason have we then to conclude that it is not the same with perception in matter ? I almost see what 1 Cf. ante, p. 274, note 2-— Tr. CH. Ill] ON HUMAN UNDERSTANDING 431 reply you can make, and although you have already said some- thing regarding it more than once, I understand you better now, sir, than I have done. But I shall be very glad to hear further what reply you will make regarding it upon this important occasion. Til. [You rightly judge, sir, that I shall say that matter cannot produce pleasure, pain, or thought in us. It is the soul itself which produces them iu conformity to what takes place in matter. And some clever people among the moderns begin to declare that they understand occasional causes only as I. iSTow this being posited, there occurs nothing unintelligible, except that we cannot distinguish all that enters into our con- fused perceptions, which contain even the infinite, and which are the detailed expression of what occurs in bodies. As for the good pleasure of the Creator, it must be said that he is ruled by the natures of things, so that he produces and con- serves therein only what suits them and can be explained, at least in general, by their natures; for the detail often sur- passes us as much as the care and power of arranging the grains of a mountain of sand according to the order of the ligures, although there is here nothing difficult to understand Vnit the multitude. Otherwise if this knowledge were in itself beyond us, and if we could not indeed conceive the rea- son of the relations of the soul and body in general, in fine, if God gave to things accidental poivers detached from their natures, and consequently removed from reason in general, there would be a back door for calling back the too occult quali- ties which no mind can understand, and these little goblins of faculties incapable of reason, Et quidquid Schola finxit otiosa : [helpful goblins who proceed to appear like the gods of the theatre, or like the fairies of the Amadis, and who will do at need all that a philosopher wishes, without ceremony and witho^it Itools. But to attribute the origin of these powers to the good Ipleasure of God appears to me a thing not quite congruous with Ihim who is the supreme reason, Avith whom everything is Iregular, everything consistent. This good pleasure would not [indeed be good, nor pleasure, if there were not a perpetual parallelism between the power and the wisdom of God.] 432 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv § 8. Ph. Our knowledge of identity and diversity goes as far as our ideas, but that of the connection of our ideas, §§9, 10. as regards their coexistence in one and the same subject is very imperfect and almost nothing § 11. especially as regards secondary qualities as colors, sounds, and tastes § 12. because we do not know their connection with the primary qualities, i.e. § 13. how they depend upon size, figure, or motion. § 15. We know a little more of the incompatibility of the secondary qualities ; for a subject cannot have, for example, two colors at the same time, and when they seem to be seen in an opal or in an infusion of lignum nephriticum, it is in different parts of the object. § 16. It is the same with the active and passive powers of bodies. Our researches in this direction must depend on experience. Th. [The ideas of sensible qualities are confused, and the powers which should produce them furnish in consequence only ideas into which some confusion enters : thus the connections of these ideas can be known otherwise than by experience only as they are reduced to the distinct ideas which accom- pany them, as has been done (for example) in regard to the colors of the rainbow and of prisms. And this method pre- sents a beginning in analysis which is of great use in physics ; and by following it I doubt not that medicine in time will find itself considerably more advanced, especially if the public is a little better interested tiian hitherto.] § 18. Ph. As for the knowledge of relations it is the largest field of our knowledge aiid it is difficult to determine how far it may extend. Progress depends on our sagacity in finding intermediate ideas. Those. who are ignorant of algebra cannot imagine the wonderful things that may be done in this field by means of this science. And I do not see that it is easy to determine what new means of perfecting other parts of our knowledge may yet be found out by a penetrating mind. At least the ideas regarding quantity are not the only ones capable of demonstration ; there are others, perhaps the most important part of our contemplation, from which we might deduce certain knowledge, if vices, passions, and domineering did not directly oppose the execution of such enterprise. Th. [Nothing is truer than what you, sir, here say. What I is there more important, supposing it is true, than what I be- CH. Ill] ON HUMAN UNDERSTANDING 433 lieve Ave have determined upon the nature of substance, upon unity and multiplicity, upon identity and diversity, upon the constitution of individuals, upon the impossibilities of void and atoms, upon the origin of cohesion, upon the law of con tmuity, and the other laws of nature ; but chiefly upon the harmony of thmgs, the immateriality of souls, the union of the soul and the body, the conservation of souls, and even of the animal after death. And there is nothing in all this which I do not think demonstrated or demonstrable.] _ Ph. [It is true that your hypothesis appears extremely con- sistent and of great simplicity: a clever man in France who desired to refute it, admits publicly that he was impressed by It. And It is a simplicity very different from that which I see It will be well to show this doctrine more and more in its true light. But m speaking of things whicli are of most importance to us, I thought of morality to which I admit your metaphysic gives wonderful foundations : but without diggino- so deep it has sufficiently firm foundations, although perhaps%hey do iiot extend as far (as I remember that you remarked) when a nat- ural theology like yours is not their base. Yet the considera- tion 01 the goods of this life alone already serves to establish important consequences for regulating human society We can estimate justice and injustice as incontestably as in math- ematics ; for example this proposition : There cannot be injustice ^vliere there is no property, is as certain as any demonstration which IS m Euclid ; property being the right to a certain thino- and wjnstice the violation of a right. It is the same with thS proposition: Bo government allows absolute liberty. Vox qov- ernvient is the establishment of certain laws, whose execution It demands, and absolute liberty is the power each one has of doing whatever he pleases. Th. [You use the word prop>erty a little differently from its ordinary use, for you mean by it the right of one person to a thing to the exclusion of the right of another. Thus if there ^vere no property, as if all were common, there nevertheless might be injustice. By thing in the definition of property vou Hiust also further understand action ; for otherwise, if 'there were therein no right to things, it would be always an injustice to prevent men from acting where they find it needful. But nceordmg to this explanation it is impossible that there be no 2 F 434 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv property. As for the proposition concerning the incompati- bility of government with absohite liberty, it belongs to the number of the corollaries, i.e. the propositions, which it is sufficient to point out. There are some in jurisprudence which are more complex, as for example, those concerning what is called jus accrescendi,^ concerning the conditions and many other matters ; and I indicated them when I published in my youth some theses upon the conditions, in which I demon- strated some of them. And if I had leisure, I would retouch them.^] Ph. [That would afford pleasure to the curious, and serve to anticipate any one who might reprint them without re- vision.] Th. [That is what happened to my " Ars Combinatoria," ^ as I have already complained. It was a fruit of my early youth, and yet it was reprinted a long time after without consulting me and without indicating even that it was a second edition, g,nd this made some think to my prejudice that I was capable 1 Cf. Poste, Gains, Elements of Roman Laio, Bk. II., 199 (p. 262, 3d ed., Oxford, 1890) : " Illud constat si duobus pluribusve per vindicatiouem eadeiu res legata sit, sive conjuuctim, sive disjunctim, si omnes veniant ad legatum, partes ad singulos pertinere, et deficientis portionem collegatario adcrescere." Also Saudars, Inst, of Justinian, Lib. II., Tit. XX., 8 (p. 226, 8th ed., London, 1888): "Si eadem res duobus legata sit, sive conjunctim sive disjunctim: si ambo perveniant ad legatum, scinditur inter eos legatum ; si alter deficiat, quia aut spreverit legatum, aut vivo testatore decesserit, vel alio quolibet modo defecerit, totum ad collegatarium jjertinet." In reference to the ^ms accrescencli — the law of increase — Sandars says, p. 198: " If any one instituted heir died before the testator, or refused to take his share of the inheritance, his share was, in fact, undisposed of. But as the testator was always supposed to have disposed of his whole estate, if he dis- posed of any part, this share was divided among all those who entered on the inheritance in proportions corresponding to the share given them by the will. Their claim was called the 'jus accrescencli.' " — Tr. - Leibnitz here refers to his thesis De conditionibus, which he defended under the presidency of Prof. Leonhard Schwendendiirfer, at Leipzig, in 1665. Guhrauer states {cf. Leibniz, eine Biographie, Pt. I., pp. 36-37) that we do not know the treatise in its original form, but in the revision and rearrange- ment of its material made by Leibnitz in 1672, in a collection of his juristic treatises under the title Specifinina juris, and which is found in Duteus, Leib- nit. op. om., 4, Pt. III., 92 sq. — Tr. 3 The Dissertatio de Arte Combinatoria, cf. Gprhardt, 4, 27 sq., Erdmann, 6 SCI., Dutens, 2, Pt. I., 341 sq., appeared at Leipzig in 1666. The pirated edi- tion here referred to by Leibnitz was published at Frankfort, 1690, and re- viewed by him in the " Acta Erud.," February, 1691. Cf. Guhrauer, Leibniz, eine Biog., Pt. I., pp. 37-38, and Anmerkunyen z. erst. Buche, pp. 7, 8; Dutens, 6, 295. — Tr. CH. Ill] ON HUMAN UNDERSTANDING 435 of publishing such a piece in my mature years ; for although it contains thoughts of some consequence, which I still ap- prove, it also contains some which could become only a young student.] § 19. Ph. I find that diagrams are a great remedy for the uncertainty of words, but they cannot have place in moral ideas. Most moral ideas are more complex than the diagrams ordinarily considered in mathematics ; thus the mind finds it difiicult to retain the precise combinations of what enters into moral ideas, in a manner as perfect as is necessary in long de- ductions. And if in arithmetic the different stages are not designated by marks whose precise meaning is known, and which last and remain in sight, it is well-nigh impossible to make extended computations. § 20. Definitions furnish some remedy provided they are constantly employed in ethics. And for the rest, it is not easy to foresee what methods may be suggested by algebra or by some other means of this nature to remove other difticulties. Th. [The late Erhard Weigel,^ a mathematician of Jena in Thuringia, ingeniously invented diagrams to represent moral things ; and when the late Samuel Puffendorf,- his disciple, pub- 1 Erhard Weigel, 1625-1699, a distinguished German mathematician and astronomer, was professor of mathematics in Jena from 1653 on, where he was Leibnitz's first teacher in the subject, when he studied there in 1663, cf. Guhrauer Leibniz, eine Biographie, Pt. I., pp. 26, 32. The Diet of Ratisbon appointed him to organize a commission for the correction of the calendar. He also labored earnestly for the reform of the school system in Germany, travelling through the country in 1696 for this purpose, cf. Guhrauer, op. cit., Pt. II., pp. 211-214, and the correspondence of Leibnitz and Placcius, from Feb. 12, 1696 on, Dutens, Leibnit. op. om., 6, 61 sq. Weigel, who was a philosopher, moralist, and an original investigator of the law of nature (Naturrecht) as well as a mathematician, published many works, among them the Expose arithmetique cle la morale, or, as the German title runs, Arithmetische Beschreibung der Morahveisheit von Personen und Sachen, woraus das gemeine Wesen besteht, nach der pythagorisehen Kreutz- zahl in lauter tetraktische Glieder eingetheilt, Jena, 1674, 4to, in which he attempted a mathematical exposition of moral philosophy, based upon the Pythagorean principle that the essence of things consists in numbers. Leibnitz thus speaks of this book in the Miscellanea, No. CLIII., Dutens, 6, 325: "M. Weigelius a fait un excellent livre en Allemand sur la morale eclairee par les noml)res, et je ne crois pas que les Pythagoriciens ayent rien dit de plus beau sur ce chapitre." For further remarks of Leilinitz on Weigel, cf. Guhrauer, Leibnitz's deutsche Schriften, 2, 473 sq. — Tr. - Samuel Pufendorf , 1632-1694, was one of the greatest German publicists and historians, and one of the founders of the science of public law. He studied at Jena under Weigel, with wliom he formed an intimate friendship. 436 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv lished his " Elements of universal Jurisprudence " sufficiently conformed to the thoughts of Weigel, there was added thereto in the Jena edition the " Moral Sphere "of this mathematician. But these diagrams are a kind of allegory nearly like the table of Cebes/ but less pojjular and serving the memory in the re- tention and arrangement of its ideas rather than the judgment in the acquisition of demonstrative knowledge. They do not cease to have their use in arousing the mind. Geometrical diagrams appear simpler than moral things ; but they are not so, because continuity includes the nrfinite from which it must be chosen. For example, to cut a triangle into four equal parts by two straight lines perpendicular to each other is a question apparently simple but really quite difficult. It is not the same in questions of morality since they are determinable and to whose teacliing and influence he largely owes the orderly method and mathematical precision and dryness which characterize his style, and that independence of character which never yielded to the " ipsedixitism " of other writers, however high their position and authority.' Among his works are: Elementa jurisprudentise universalis, cum appenclice cle Sphsera morali (of Weigel), Hag. Com., 1(360, 12mo— also Jena, 1'660, "bei Meyer"; the ed. here meant by Leibnitz, according to Schaarschmidt, who states that in the 2d Jena ed., 1669, the tiphsera moralis occurs, p. 313 sq., — the book which obtained for him from the elector Charles Louis, to whom it was dedicated, the newly created chair of the law of nature and of nations at Heidelberg; De statu imperii germanici, Geneva, 1667, — the book which first called forth Leibnitz's aversion and criticism, — small in bulk, but great in significance, in which he criticised the political organization of the empire, suggested a remedy for the evils therein, and revealed himself as a consummate statesman, subsequent events proving the justness of his conclusions ; and the work on which his fame chiefly rests, De jure naturse et gentium, 1672, trans, into French, with notes, by Barbeyrac, Amsterdam, 1712, and into English by Basil Kenuett, London, 1729, and re'sume of the same, De officio hominis et civis, 1675. For Leibnitz's criticism of Pufendorf and his work, — the severest, perhaps, he ever made ou any one, and through which he is, to a considerable extent, responsible for the failure of posterity justly to estimate and acknowledge its debt to him, — cf. letter to Kestner, No. 7, § 2, Dutens, 4, Ft. III., 261; Monita qusedam ad avra(TtJ.a, and the Scholastic "phantasma," — signifies here a mental modification given or produced through the agency of the senses, but having no corresponding external object, i.e. an entirely siibjective plienomenon, real as such, but which, since it corresponds to no objective external reality, has, to a certain extent, the character of a mere appearance. — Tr. 2 Qf. JSieiv Essays, Bk. IV., chap. 2, § 14, Th. (2), ante, p. 422, note 1. Leibnitz felt, says Schaarschmidt, that we could not be satisfied from a philo- sophical point of view with the old definition of truth as consisting in the agreement of thought with reality. — Tr. 446 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv should be made, while that which you here make between simple and complex ideas, and ideas complex belonging to sub- stances and to accidents, does not appear to me well founded, since all intelligible ideas have their archetypes in the eternal possibility of things.] § 5. Pli. It is true that our coinplex ideas need archetypes outside the mind only when the question concerns an existing substance which must effectively unite outside us these com- plex ideas, and the simple ideas of which they are composed. The knowledge of mathematical truths is real, although it re- volves only upon our ideas, and finds nowhere exact circles. But Ave are assured that existing things will agree with our archetypes according as what we suppose therein is found existing. § 7. This serves to justify the reality of moral things. § 8. jSTor are Cicero's "Offices" less conformed to truth, because no one in the world rules his life exactly according to the pattern of a virtuous man such as Cicero has painted for us. § 9. But (it will be said) if moral ideas be of our invention, what a strange notion shall we have of justice and temperance? § 10. I reply that the uncertainty will be only in the lan- guage, because what is said is not always understood, or always understood in the same way. Th. [You might reply also, sir, and much better in my opinion, that the ideas of justice and temperance are not of our invention, any more than those of the circle or the square. I think I have sufficiently shown this.] § 11. Ph. As for the ideas of substances existing outside us, our knowledge is real so long as it is conformed to these archetypes; and in this respect the mind must not combine ideas arbitrarily, so much the more as there are ver}^ few sim- ple ideas of which we can be certain that they can or cannot exist together in nature beyond what appears by sensible observations. Th. It is, as I have more than once said,, because these ideas, when reason cannot judge of their compatibility or con- nection, are confused, like those of the particular qualities of the senses. § 13. Ph. It is well also as regards existing substances not to limit ourselves to names or to species supposed to be estab- CH. IV] ON HUMAN UNDERSTANDING 447 lished by names. This makes me return to discussions we have often enough had regarding the definition of man. For speaking of an innocent ^ who has lived forty years without giv- ing the least sign of reason, could we not say that he holds the middle place between man and beast? It would possibly be thought a very bold paradox, or even a falsehood with very dangerous consequences. But it seemed to me formerly and it seems still to some of my friends whom I cannot disabuse as yet (of the idea) that it is only in virtue of a prejudice based upon this false supposition that these two names maw and beast signify distinct species, so well marked by real essences in nature that no other species can intervene between them, as if all things were thrown into the mould according to the precise number of these essences. § 14. When these friends are asked what species of animals these innocents are, if they are neither men nor beasts, they reply they are innocents, and that is sufficient. If asked further what they will become in the next world, our friends reply they are not concerned to know or inquire. Let them fall or stand to their oimi master (Rom. 14 : 4), who is good and faithful and disposes of his creatures not according to the narrow limits of our particular' thoughts or opinions, nor does he distinguish them conformably to the names and species it has pleased us to invent; let it suffice us that those who are capable of instruction will be called to render an account of their conduct and will receive their re- ward according to the deeds done in their bodies (2 Cor. 5:10). § 15. I shall exhibit to you the rest of their reasonings. The question (say they) lohether imbeciles must be deprived of a future state rests upon two equally false suppositions : first that every being having the form and external appearance of man is destined to an immortal state after this life ; and second that everything having a human birth must enjoy this privilege. Remove these imaginative ideas, and you will see that such questions are ridiculous and groundless. In fact I think we shall disallow the first supposition and shall not have the mind so buried in matter as to believe that eternal life is due to any form of material mass, so that the mass must have feeling eternally because moulded upon such a figui'e. § 16. But the 1 Locke's word is " changeling," Philos. Works (Bobu's ed.), Vol. 2, p. 176 sq., and note. — Tr. 448 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv second supposition comes to the rescue. We shall say that this innocent comes from rational parents and that consequently it must have a rational soul. I know not by what rule of logic we can establish such a consequence, nor how after that we should dare to destroy these ill-formed and disfigured produc- tions. Oh, they are monsters, it will be said. Very well, so be it. But what will this always intractable innocent be? Shall a defect in the body make a monster, and not a defect in the mind? This is to return to the first supposition, already refuted, that the external sulfices. A well-formed innocent is a man, as we believe; he has a rational soul, although it does not appear; but make the ears a little longer and more pointed, and the nose a little Hatter than usual, then you begin to hesitate. Make the face narrower, flatter, and longer; there you are all at once decided. And if the head is per- fectly that of any animal, it is no doubt a monster; and this is for you a demonstration that it has no rational soul and that it should be destroyed. 1 ask you now where to find the just measure and the final limits bearing with them a rational soul. There are human /ceiwses, half beast, half man, others- ■ three parts of which belong to the one, and one part to the other. How determine precisely the li:ieaments which indicate reason? Further, will not this monster be a species midway between man and beast? And such is the innocent in question. Th. [I am astonished that you return to this question suffi- ciently examined by us, and that more than once, and that you have not better catechized your friends. If we distin- guish the man from the beast by the faculty of reason, there is no middle ground, the animal in question must have it or not have it; but as this faculty sometimes does not appear, we -judge of it by indices which are not demonstrative of the truth till this reason manifests itself : for we know by the experience of those who have lost it and who at last have re- covered its exercise, that its function may be suspended. Birth and form furnish presumptions of that which is concealed. But the presumption of birth is effaced (eliditur) by a figure very different from the human, such as that of the animal was, born of a woman of Zealand according to Levinus Lemnius ^ ^ Livin Lemmens — Latin, Levinus Lemnii^s — 1505-1568, a Dutch physician, who was very successful in practice, and had in his time a very great reputa- CH. T] ON HUMAN UNDERSTANDING 449 (Book I., Cliap. 8), wliicli had a hooked beak, a long and round neck, flashing eyes, a pointed tail, and great agility at first in running about the room. But you will say that there are some monsters or hrothers of the Lombards (as the physicians formerly called them because it was said that the women of Lombardy were subject to this kind of childbirth) who approach more and more the human figure. Very well; so be it. How then (say you) can the proper limits of the figure which is to pass as human be determined? I reply that in a conjectural matter there is no precision. And there the affair ends. You object that the innocent does not exhibit reason, and yet passes as a man, but if it had a monstrous figure, it would not be man, and thus you have more regard for figure than for reason. But, does this monster exhibit reason? Certainly not. You see, then, that it lacks more than the innocent. The defect of the exercise of reason is often temporal, but it does not cease in those in whom it is accompanied by a dog's head. For the rest, if this animal with a human figure is not a man, there is no great harm in guarding it during the uncertainty as to its fate. And whether it has a rational soul or not, God will not have made it for nothing, and we may say of the souls of men who live in a state always similar to that of early infancy that their fate may be the same as that of the souls of those infants who die in the cradle. CHAPTEE V OF TRUTH IN GENERAL § 1. Ph. For many centuries the question has been asked. What is truth? § 2. Our friends think it is the joining or separating of signs according as the things themselves agree or disagree among themselves. By the joining or separating of signs must be understood what is otherwise called o, propo- sition. tion. Lemnius relates this marvellous occurrence, which he states was reported to him by the woman herself, as soon as she had barely recovered, but in which there must have been some deception, in his De mirarulis occultis naturw, Bk. I., chap. 8, p. 37, Francofurti, 1628, Eng. trans., p. 24, London, 1658. — Tr. 2g 450 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv Til. But an e2ntliet does not make a proposition; for example, the loise man. But there is a union of two terms. Negation also is different from separation; for saying man, and after an interval saying ivise, is not a denial. Agreement also, or dis- agreement is not properly speaking what is expressed by the proposition. Two eggs have agreement and two enemies have disagreement. The question here concerns an entirely par- ticular mode of agreement or disagreement. Thus I think this detinition fails wholly to explain the point in question. But what I find least to my taste in your definition of truth is that you seek truth in words. Thus the same sense ex- pressed in Latin, German, English, French, will not be the same truth, and it will be necessary to say with Hobbes,^ that 1 Cf. Leibnitz, Be stilo philos. Nizolii, § 28, ad fin., Gerhardt, 4, 158, Erd- mann, 69 b, Dutens, 4, Pt. I., 60, wliere, after expressing his belief that " Occam himself was not more of a Nominalist than Thomas Hobbes now is, who, in truth, seems to me more than a Nominalist," Leibnitz continues: " Non cou- tentus enim cum Nomiualibus viuiversalia ad nomina reducere, ipsam rerum vevitatem ait in nominalibus consistere, ac, quod majus est, pendere ab arbitrio hnmano, quia Veritas pendeat a definitionibus terminorum, definitiones autem terminorum ab arbitrio humano." Hobbes in liis Leviathan (Morley's Uni- versal Library, No. 21), 3d ed., London: Geo. Routledge & Sous, 1887, Pt. 1., chap. 4, p. 24, after speaking of " the imposing of ' names,' and the 'connec- tion of tliem,' " says: " When two names are joined together into a conse- quence, or affirmation, as thus, ' a man is a living creature ' ... if the latter name 'living creature,' signify all that the former name 'man' signiiieth, then the affirmation, or consequence, is ' true ' ; otherwise ' false.' For ' true ' and 'false' are attributes of speech, and not of things. . . ." And in the next paragraph : " Seeing then that truth consisteth in the right ordering of names in our affirmations, a man that seeketh precise truth had need to remember what every name he uses stands for, and to place it accordingly." Leibnitz, probably, had this or some similar passage in mind, in his references to Hobbes' doctrine, and his statement is a possible and seemingly fair interpretation of many passages in Hobbes' writings, which passages, however, might be offset by others of a different character. Hobbes, nevertheless, seems never to have gone beyond his nominalistic position, never, at least, so far as consciously to connect his doctrine of truth with the facts of experience and the reality of things; while Leibnitz's doctrine of truth has to a certain extent at least an objective reference in affirming an actual or at least 'possible existence of the objects of ideas, cf. ante, pp. 422, note 1, 445, note 2, infra, p, 452, note 1. For further exposition of Hobbes' doctrine, cf. G. Croom Robertson, HohheK, pp. 83-90, espec. p. 87 (Philos. Classics), Edinburgh: Wm. Blackwood & Sons, 1886. On the relation of Leibnitz to Hobbes, cf. F. Tiinnies, Leibniz unci Hobbes, inthe " Philos. Monatshefte," vol.23, 1887, 557-573; see also, "Mind," No. 50, April, 1888, pp. 312-314. For two letters of Leibnitz to Hobbes, cf. Gerhardt, Leibniz, philos. Schrift., 1, 82-87, also, 7, 572-574, where the first letter is given with an amended text. Leibnitz appended to his The'odicee a short piece entitled Reflexions sur Vouvrage que M. Hobbes a publi6 en CH. v} ON HUMAN UNDERSTANDING 451 truth depends on the good pleasure of men ; which is to speak in a very strange manner. You attribute, indeed, truth to God, who, you will agree with me (I think), has no need of signs. Finally, I have been astonished already more than once at the disposition of your friends who are pleased to make essences, species, and truths nomhial. Ph. Do not advance too fast. Under signs they include ideas. Thus, truths will be either mental or nominal, accord- ing to the species of signs. Th. [We shall then have also literal truths, which may be distinguished as truths upon paper or parchment, of ordinary black ink or of printer's ink, if truths must be distinguished by signs. It were then better to place truths in the relation between the objects of ideas which causes the one to be or not to be included in the other. That does not depend upon languages, and is common to us with God and the angels; and when God manifests a truth to us we shall acquire that which is in his understanding, for although there is an infi- nite difference between his ideas and ours, as regards perfec- tion and extent, it is always true that they agree in the 'same relation. It is, then, in this relation that truth must be placed, and we can distinguish between the truths which are inde- pendent of our good pleasure, and between the exjrressions which we invent as seems good to us.] § 3. Ph. It is only too true that men, even in their minds, put words 'in the place of things, especially when the ideas are complex and indeterminate. But it is also true as you have observ^ed, that then the mind contents itself with the indication only of the truth, without for the present under- standing it, in the persuasion that it depends upon itself to understand it when it will. For the rest, the act Avhich takes place in affirming or denying is more easily conceived by re- flecting upon what goes on in us, than explained in words. Therefore, you do not take it ill that in default of some- thing better we have spoken of joining together or of sepa- rating. § 8. You will also agree that propositioiis at least may be called verbal, and that, when they are true, they are Aiifjlois, cle la liberie, cle la necessity et du hasard, cf. Gerhardt, 6, 388-309, Erdmann, 629-()34, Janet, CEuvres philos. de Leibniz, 2, 424-437, Duteus, 1, 415-429 (in Latin). — Tr. 452 LEIBNITZ'S CRITIQUE OE LOCKE [bk. iv both verbal aiid also real, for, § 9. falsehood consists in joining names otherwise than as their ideas agree or disagree. § 10. Words are at least great vehicles of truth. § 11. There is also a moral truth, which consists in sj)eaking of things according to the persuasion of our mind; there is finally metaphysical truth which is the real existence of things in conformity to the ideas we have of them. Th.. [Moral truth is by some called veracity, and metaphysi- cal truth is commonly taken by the metaphysicians as an attribute of being, but it is an attribute very useless and almost void of meaning. Let us content ourselves with seek- ing truth in the correspondence of the propositions in the mind with the things in question. It is true that I have also attributed truth to ideas in saying that ideas are true or false ; but then I mean, in reality, the truth of propositions affirming the possibility of the object of the idea. In the same sense we can say also that a heing is true, that is to say, the propo- sition affirming its actual, or at least, possible existence.] ^ CHAPTER VI OF UNIVERSAL PROPOSITIONS, THEIR TRUTH AND CERTITUDE § 2. Ph. All our knowledge is of general or .particular truths. We can never make the former, which are the most important, well understood, and can ourselves, indeed, very rarely comprehend them save as they are conceived and ex- pressed by words. Th. [I think that other marks also can produce this effect; we see it in the characters of the Chinese. A universal char- 1 Cf. New Essays, Bk. II., chap. 32, ante, p. 281, and notes; also Bk. III., chap. 3, ante, p. 317, note 3 ; and Bk. IV., chap. 1, ante, pp. 397-8. Locke in the first of these passages agrees with the view of Aristotle, De Interpret., 1, 16'^, 12, that truth or falsity is predicable not of single ideas, but only of their union in judgments' or propositions; and Leibnitz in the present passage maintains essentially the same doctrine in saying that by the truth he attributes to ideas he means the truth of the propositions affirming the possibility of the objects of the ideas. Such " true " or " false " ideas must, then, be regarded simply as abbreviated propositions, or as tacitly involving propositions. The idea of the decahedron {cf. ante, p. 315, and note 1) is false, although we have its nominal definition, because the figure is impossible. — Tr. CH. VI] ON HUMAN UNDERSTANDING 453 acleristic ^ very popular and better than theirs might be intro- duced if small figures were employed in the place of words, which would represent visible things by their lines, and the invisible by the visible which accompany them, adding thereto certain additional marks suitable to make understood the flex- ions and the particles. This would be of service at first for easy communication with distant nations; but if introduced also among us without, however, renouncing ordinary writing, the employment of this mode of writing would be very useful in enriching the imagination, and in giving thoughts less surd and verbal than we now have. It is true that the art of draw- ing not being known by all, it follows that, excepting the books printed in this way (which everybody would soon learn to read), everybody could not avail themselves of it otherwise than by a method of printing, i.e. having the figures all en- graved ready for printing upon paper, and adding thereto afterwards with the pen the marks of the flexions or particles. But in time everybody would learn the plan in youth, so as not to be deprived of the convenience of this figured character, which would speak in truth to the eyes, and would be very agreeable to the people, just as in fact the peasants already have certain almanacs, telling them without words much that they ask; and I remember to have seen some satirical impres- sions in copper-plate which possessed a somewhat enigmatical character in which there were figures significant of themselves, mingled with words, ^ while our letters and the Chinese char- acters are significant only by the will of men {ex instituto). § 3. Ph. [I think your thoughts will some day be carried out, so agreeable and natural appears to me this ivriting, and it seems to be of no little consequence for increasing the per- fection of our mind, and rendering our conceptions more real.] But to return to general knowledge and its certainty, it will be proper to remark that there is a certainty of truth and also a certainty of knowledge. When words are so joined in propo- sitions tiiat they express exactly the agreement or disagree- 1 Cf. ante, p. 375, notel. 2 Probably somethino; similar to what is now known by the term " Rebus." For a brief statement of the development of writing from the picture stage, its earliest form, to the alphabetic as we now have it, cf. E. Benj. Andrews, Institutes of Gen. Hist., chap. 2, § 13, p. 49. 2d ed. Boston: Silver, Burdett & Co., 1888. — Tr. 454 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv iiient as it really is, it is a certainty of truth; and the cer- tainty of Jcnoivledge consists in perceiving the agreement or disagreement of ideas so far as it is expressed in propositions. This is what we ordinarily call being certain of a proposition. Th. [In fact this lastkiiid of certainty ^i\\ also suffice with- out the iTse of words, and is. nothing else than a perfect knowl- edge of the truth ; while the first kind of certainty appears to be nothing else than the truth itself.] § 4. Ph. Now as we cannot be assured of the truth of any general proposition, unless we know the precise limits of the signification of the terms of which it is composed, it will be necessary for us to know the essence of each species, which is not difficult as regards the simple ideas and the modes. But in substances wherein a real essence distinct from the nominal is supposed to determine the species, the extent of the gene- ral term is very uncertain, because we do not know this real essence; and consequently in this sense we cannot be assured of any general jnoposition made upon the basis of these sub- stances. But when we suppose the species of substances to be nothing else than the reduction of substantial individuals into certain sorts, arranged under different general names according as they agree with the different abstract ideas which we designate by these names, we cannot doubt whether a prop- osition, well known as it sliou.ld be, is true or not. Th. [I do not know why you, sir, return again to a point sufficiently discussed by us, and which I believe an empty one. But, after all, I am very glad of it, because you give me an op- portunity very suitable (it seems to me) to disabuse you anew. I say then to you that we can be assured, for example, of a thousand truths regarding gold, or that body whose internal essence makes itself known by the greatest weight known here below, or by the greatest ductility, or by other marks. For we say 'that the body of the greatest known ductility is also the heaviest of all known bodies. It is true that it is not impossible that all which has hitherto been noticed in gold will some day be found in two bodies distinguishable by other new qualities, and that thus gold would no longer be the low- est species, as it has hitherto been regarded provisionally. We might also, if the one kind remained rare, and the other became common, think it proper to reserve the name of CH. VI] ON HUMAN UNDERSTANDING 455 true gold to the single rare species, in order to retain it in use as money by means of new assays which would be suited to it. After which we shall not doubt, also, that the internal essence of these two species is different; and if indeed the definition of an actually existing substance should not be fully determined in all respects (as in fact, that of men is not as regards the external figure), we should not cease to have an infinite number of general propositions upon its subject, which would follow from reason and the other qualities which we recognize in it. All that we can say regarding these gen- eral propositions is, that in case man is taken as the lowest species and restricted to the race of Adam, we shall have no properties of man such as are named in quarto modo,^ ov may 1 The terra in quarto modo, here used by Leibnitz, refers to a classification oi propria — iSia, properties — existent in the time of Porpliyry, 233-304, though not accepted by him, — cf. 'Eldayiay-fj, chap. 4, 4"=, 14 (in Aristotle, ed. Berl. Acad., Vol. 4, p. 4) : to 6e i5tov Biaipovcn. TeTpa;(U>S . . . (18.) TeVapTor &k iria-ii', oTi kol avTLrTTpe^iei. — and due, perhaps, to some one of the old Peripatetics, and prevalent in different forms in the Middle Age, according to which classification as given by Porphyry there were four classes : 1. Propria belonging to one species only, but not to every individual thereof, as gram- matical to man ; 2. Propria belonging to every individual of the species, but not to this species alone, as biped to man ; 3. Propria belonging to one species only and to every individual thereof, but not always, as hoary to man ; 4. Pro- pria belonging to one species only, to every individual thereof, always, as riKihility or risible to man. The propria of this fourth class — quartus modus — are, each, of equal breadth with its subject, and, though no part of the essence of the species of which they are predicated, — man, for example, without the proprium risible, still being man, — as a matter of fact belong to every individual of the species on all occasions, and to no individual of any other species. Propositions predi- cating such propria are judgments in A, according to Arclibishop Thomson's terminology, of the type "Common Salt is Chloride of Sodium," and are of course convertible. Propria of this fourth class alone, i.e. propria each of which would be coinci- dent with its subject so as to be enouneible in a judgment in A — recii^rocal — con- stitute the fourth predicable, and answer to the 'i&iov of Aristotle and Porphyry, and the proprium of Appuleius, Marcianus Capella and Boethius. These writers, with the exception of Aristotle, to whom probably the four-fold divis- ion of propria was unknown, regard the other three classes, which were pro- pria according to the Middle Age schoolmen, as accidents, — accidentia, avp.0e~ /Stjkoto, — a fact which explains the somewhat peculiar language of Leibnitz: "We shall have no properties of man such as (of the sort that) are named in quarto modo," etc. Leibnitz's thought is this : " In the case of ' man ' " taken as the lowest species — .tpecies inflma — and " limited to Adam's race, there is, except provisionally, no such proprium. ' Sole-rational-animal ' would be,, provisionally, such a proprium, because up till now we know no men whom it 456 LEIBNITZ'S CRITIQUE OE LOCKE [bk. iv be enounced concerning him by a reciprocal or simply conver- tible proposition, unless provisionally, as in saying: man is the only rational animal. Taking man as those of our race, the provisional consists in the assumption that he is the only rational animal of those known to us; for we might some day find other animals who would have in common with the posterity of men of the present time all that which we have hitherto observed in them, but who would have another origin. It is as if the so-called Australians should overrun our coun- tries : in all likelihood we should then discover some means of distinguishing them from ourselves. But in case this should not happen, and supposing that God had forbidden this mixt- ure of these races, and that Jesus Christ had redeemed ours only, it would be necessary to try to make some artificial marks in order to distinguish between them. There would doubtless be an internal difference, but as it would not make itself recog- nizable, we should be reduced to the extrinsic denomination of birth alone which we should try to accompany with a durable artificial mark that would give an intrinsic denomination, and a constant means of distinguishing our race from the others. These are all fictions, for we have no need to recur to these distinctions, being the only rational animals of this globe. Yet these fictions are useful in knowing the natures of ideas, substances, and truths general in their character. But if man were not taken as the loivest species nor as that of the rational animals of the race of Adam, and if, instead of that, he signified a genus common to several species, which belonged now to a single known race, but which might belong also to others distinguishable either by birth or even by their natural marks, as, for example, in the case of the supposed Australians; then, I say, this genus would have reciprocal propositions, and the present definition of man would not be provisional. It is would not fit, and know of no other species any of whose individuals it would fit. Only provisionally, however, for future discoveries may shoM', in either of these respects, that ' sole-rational-animal,' and ' man ' are not exactly coinci- dent concepts." On the whole subject, cf. Prantl, Gesch. d. Logik, Vol. 1, pp. 343, 395, 425, 581, 584, 630, 674, 676, 696, Vol. 2, pp. 342-343, Vol. 3, p. 102, Vol. 4, p. 241, note 383; Aldrich, Artis Logical Rudimenta, ed. Mansel, Oxford, 1856, pp. 32-34. I would add that for much of the material as well as of the language of the above note, I am indebted to the kindness of Pres. E. B. Andrews of Brown UniA'ersity. — Tr. J CH. VI] ON HUMAN UNDERSTANDING 457 tlie same with gold; for suppose that some day there were two kinds of it distinguishable, the one rare and hitherto unknown, the other common and perhaps artificial, discovered in the course of time; then suppose that the name gold should continue for the present species, i.e. for the natural and rare gold, in order to preserve by its means the commodity of gold money, based upon the rarity of this substance, its definition known hitherto by intrinsic denominations would have been provisional only, and should be augmented by new marks which will be discovered, to distinguish the rare gold or the ancient species from the new artificial gold. But if the name gold should then remain common to the two species, i.e. if by gold you mean a genus of which up to the present time we know no subdivision, and which we now take as the lowest species (but only provisionally until the subdivision is known) and if some day a new species were found, i.e. an artificial gold, easy to make, and which might become common; I say that in this sense the definition of this genus should not be judged provisional, but perpetual. And indeed, without troubling ourselves with the names man or gold, whatever name is given to the genus or to the lowest known species, and even if none should be given them, what has just been said would be always true of ideas, genera or species, and species will be defined provisionally only by the definitions of genera. But it will always be allowable and reasonable to assume, by means of a reciprocal proposition, that there is a real internal essence belonging either to the genus or the species, which makes itself known ordinarily by external marks. I have assumed hitherto that the race does not degenerate or change; but if the same race passed into another species, we should be so much the more obliged to recur to other marks and denominations intrinsic or extrinsic, without confining ourselves to the race. § 7. Ph. Complex ideas, which the names we give to the species of substances justify, are collections of ideas of certain qualities which we have observed coexisting in an unknown sab- stratum which we call substance. But we cannot know cer- tainly what other qualities coexist necessarily with such com- binations, unless we can discover their dependence as regards their primary qualities, - 458 LEIBNITZ'S CEITIQUE OF LOCKE [bk. iv Th. I have already remarked before that the same (diffi- culty) is found in the ideas of accidents, whose nature is a little abstruse, as, for example, are the figures in geometry- for when the question concerns, for example, the figure of a mirror which collects all the parallel rays into one point as a focus, many properties of this mirror may be found before its construction is known, but we shall be uncertain about many other relations it may have, until we find in it that which corresponds to the internal constitution of substances, i.e. the construction of this figure of the mirror, which will constitute as it were the key to ulterior knowledge.] Ph. But if we had known the internal constitution of this body, we should have found therein only the dependence which the primary, or what you call manifest, qualities may have, i.e. you would know what size, figure, and moving force depend thereupon; but we should never know the connection which they may have with the secondary or confused qucdities, i.e. with the sensible qualities, as colors, tastes, etc. Th. The fact is, you still assume that these sensible quali- ties, or rather the ideas we have of them, do not depend upon figure and movement in a natural way, but only upon the good pleasure of God, who gives us these ideas. You appear to have forgotten, sir, the remonstrance I have more than once made to you against this opinion, in order to make you think rather that these sensitive ideas depend in detail upon the fig- ures and movements, and express them exactly, although we cannot distinguish therein this detail in the confusion of too great a multitude and minuteness of mechanical actions which strike our senses. But if we had reached the internal constitution of some bodies, we 'should see also how they must have these qualities, which would themselves be reduced to their intelligible reasons ; although it would never be in our power to recognize them sensibly in these sensitive i.deas which are a confused resultant of the actions of bodies upon us, as, now that we have the perfect analysis of green into blue and yellow, ^ and have scarcely anything more to ask in regard to it save as related to these ingredients, we are, however, incapable of analyzing the ideas of blue and yellow in pur 1 Cf. ante, p. 320, note 1 ; also Leibnitz's letter to Th. Burnett, without date, but written, according to Gerhardt, in 1699, G., Leibniz, philos. Schrift., 3, 256. — Tr. CH. VI] ON HUMAN UNDERSTANDING 459 sensitive idea of green, for tlie yevy reason that it is a con- fused idea. It is much tlie same as we cannot analyze the idea of the teeth of the wheel, i.e. of the cause, in the percep- tion of an artificial transparency, which I have noticed among the clock-makers, made by the rapid rotation of a cog-wheel, which makes the teeth disappear, and an imaginary continu- ous transparency appear in their place, composed of the suc- cessive appearances of the teeth and their intervals, but in which the succession is so rapid that our phantasy cannot dis- tinguish it. We find then, indeed, these teeth in the distinct notion of this transparency, but not in this confused sensitive percej^tion, whose nature is to be and to remain confused; otherwise if the confusion ceased (as if the motion were so slow that we could observe its parts and their succession) this notion, i.e. this phantasm^ of a transparency would no longer exist. And as there is no need of imagining that God for his good pleasure gives us this phantasm, and that it is independent of the movement of the teeth of the wheel and their intervals, and as, on the' contrary, we conceive it to be only a confused expression of what takes place in this movement, aii expression, I say, that consists in the fact that these successive things are confounded in an apparent simul- taneity: it is thus easy to think that it will be the same as regards other sensitive phantasms, of which we have not as yet so perfect an analysis, as of colors, tastes, etc. For, to speak the truth, they deserve this name phantasms rather than that of qualities or even of ideas. And it would suffice us in all respects to understand them as well as this artificial trans- parency, without its being reasonable or possible to claim a further knowledge of them; for to desire these confused phantasms to abide, and yet to distinguish therein their in- gredients by the phantasy itself, is a contradiction, is a desire to have the pleasure of being deceived by an agreeable per- spective, and to desire that at the same time the eye see the de- ception, which would destroy it. It is a case, in short, where — , nihilo plus agas Quam si des operam, ut cum ratione insaiiias.^ ^ Cf. ante, p. 445, note 1. Schaarschmidt here translates: " Phautasie- Erscheinuna; "'; in line 17 of this page. " Phantasievorstellung " ; in lines 24, 2G, 31, " Erscheinungen." — Tr. 2 Terence, Eiin., 1. 1. 17, 18. — Tr. 460 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv But it often happens that men seek nodum in scirpo ^ and make difficulties where there are none, by demanding the impossible, and afterwards complaining of their impotence and of the limits of their light. § 8. Ph. All gold is fixed is a proposition, the truth of which we cannot certainly know. For if gold signities a species of things, distinguished by a real essence, which nature has given it, we are ignorant what particular substances are of this species. Thus, although this maybe gold, we cannot affirm it with certainty. If we take gold as a body endoAved with a cer- tain yellow color, malleable, fusible, heavier than any known body, it is not difficult to know what is or is not gold; but with all that, no other quality can be affirmed or denied with certainty of gold, than that which has a connection with this idea, according to a connection or incompatibility which may be discovered.^ Now fixity having no known connection with color, weight, and the other simple ideas which I have sup- posed to constitute the complex idea we have of gold, it is impossible that we can know with certainty the truth of this proposition, that all gold is fixed. Th. We know almost as certainly that the heaviest of all bodies known here below is fixed, as we know certainly that it will be light to-morrow. This is because we have tried it a hundred thousand times; it is an experimental certainty, and of fact, although we do not know the bond which unites the fixity with the other qualities of this body. Moreover, it is unnecessary to oppose two things which agree and amount to the same thing. When I think of a body, which is at the same time yellow, fusible, and which resists the cupel, I think of a body whose specific essence, although unknown in its interior, makes these qualities emanate from its depths, and makes itself known confusedly at least by means of them. I see nothing wrong in that, nor anything which requires you to return so often to the charge in order to attack it. § 10. PJi. It is enough for me now that this knowledge of the fixity of the heaviest of bodies is not known to us by the 1 Of. ante, p. 22G, note 1. — Tr. 2 According to the texts of Gerhardt and Erdmann. JacquSs and Janet read: "Que ce qui a avec cette idee une connexion ou une incompatibilite qu'on pent decouvrir"; i.e. than that which has a discoverable connection or incompatibility with this idea. — Tr. CH. vij ON HUMAN UNDERSTANDING 461 agreement or disagreement of ideas. And I for myself think that among the secondary qualities of bodies and the powers relating to them there cannot any two be named whose neces- sary coexistence or incompatibility can be known with cer- tainty, except the qualities which belong to the same sense and necessarily exclude one another, as when you can say that what is white is not black. Th. I believe, however, that you might perhaps find them ; for example, every palpable body (or that which may be felt by toiTch) is visible. Every hard body makes a noise when struck in the air. The tones of strings or wires are semi-pro- portional to the weights which cause their tension. It is true that what you ask succeeds only as far as you conceive distinct, ideas united with confused sensitive ideas. § 11. Pli. It is not always necessary to think that bodies have their qualities by themselves independently of anything else. A piece of gold, separated from the impression and influence of every other body, would immediately lose its yellow color and weight; perhaps, also, it would become friable and lose its malleability. You know how vegetables and animals depend upon the earth, air, and sun ; how do you know whether the very distant fixed stars have not also an influence upon us? Th. This is a very excellent remark; and if the contexture of certain bodies were known to us, we could not judge wholly of their effects without knowing the interior of those which touch and traverse them. § 13. Ph. Our judgment, however, may go further than our knowledge. For people sedulous in making observations can penetrate farther, and by means of certain probabilities resulting from an exact observation and by certain hints pur- posely put together, often make just conjectures regarding that which experience has not yet discovered to them ; but it is always only conjecture. Th. But if experience justifies these consequences in a con- stant manner, do you not find that you can acquire certain propositions by this means? Certain, I say, at least as those which assert, for example, that the heaviest of our bodies is fixed and that the one which is after it the heaviest is volatile, for it seems to me that the certainty (understanding it as moral 462 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv or physical), but not the necessity (or metaphysical certainty) of these propositions which are learned by experience alone and not by analysis and the bond of ideas, is established among us and with reason.^ CHAPTER VII OF PROPOSITIONS CALLED MAXIMS OR AXIOMS § 1. Ph. There is one species of propositions which under the name of maxims or axioms pass as principles of science, and because they are self-evident, we have been contented to call them innate, although no one that I know of has ever tried to show the reason and ground of their extreme clearness, which forces us, so to speak, to give them our consent. It is not, however, useless to enter into this investigation and to see whether this great evidence is peculiar to these proposi- tions alone, as also to examine how far they contribute to our knowledge. Th. This investigation is very useful and very important. But you must not suppose, sir, that it has been entirely neglected. You will find in a hundred places that the Scho- lastics have said that these propositions are evident ex ter- minis, as soon as the terms are understood, so that they were persuaded that the force of conviction was grounded in the knowledge of the terms, i.e. in the connection of their ideas. But geometers have done very much more: that is 1 Metaphysical and moral or physical certainty differ as the certainty of the truths of reason and the truths of fact. The truths of reason ground them- selves in the necessities of thought, and their certainty is accordingly absolute. The truths of fact, in Leibnitz's view, rest upon the divine choice of the best, and have an evidence merely relative and established with the aid of experi- ence ; their necessity is accordingly only hypothetical. Cf. New Essays, Bk. II., chap. 21, § 8, Th., ante, pp. 179-180, and § 13, Th., ante, p. 183. The prin- ciple upon which the whole matter depends is the famous distinction of the medifeval scholastics between the understanding and the will of God, a prin- ciple to which Leibnitz very often recurs, especially in oi'der to maintain the contingency of the world, and to escape from the universal fatalism of Spinoza. According to this principle, the imderstanding of God is the source of the necessary truths, and the will of God the source of the contingent truths. The distinction, however, does not solve the problem either of the contingency of the physical universe or of the moral freedom of man. — Tr. CH. vii] ON HUMAN UNDERSTANDING 463 they have undertaken very often to demonstrate them.^ Pro- clus already attributes to Thales of Miletus, one of the oldest known geometers, the wish to demonstrate the proposi- tions which Euclid has since assumed as evident.^ It is said that Apollonius has demonstrated other axioms, and Proclus lias also done so. The late Mr. Roberval, already eighty years old or thereabouts, intended to publish the new ele- ments of geometry of which I think I have already spoken to 3'ou.^ Perhaps the "New Elements" of Arnauld, which at that time made some stir, had contributed thereto.* He exhibited specimens of them in the Royal Academy of Sciences, and some found fault that assuming this axiom, if equal mag- 1 Leibnitz frequently refers, both in the New Essays and elsewhere, to- the demonstrability of the axioms, and the thought was evidently a favorite one with him. It is a weighty thought, too; for all real advance in specula- tive and truly and lastingly constructive thinking rests upon just this " work- ing-over of the notions," as Herbart expresses it, this deeper penetration into their real meaning and content, and its exposition in the simplest possible intelligible forms. — Tr. - Proclus cites Thales of Miletus in prop. XV., theor. VIII., of his In primum Euclidis Elementorum lib. Commentarii, ex recog. G. Friedlein, p. 299. Thales, c.624-c. 550 B.C., was the founder of the Greek geometry, astron- omy, and philosophy. For his geometry, cf. G. J. Allman, Greek Geometry from Thales to Euclid, Dublin, 1889 ; for his philosophy, cf. Zeller, PMlos. d. 'Grierh., I., 1 [Vol. 1], 180-196, 5th ed., Leipzig, 1892. — Tr". 3 Cf. ante, p. 107, note 1. — Tr. * The work of Antoine Arnauld, 1612-1694, here referred to is the Nouveawx Elemens de Geometrie, Paris, 1661, mentioned among the most prominent books of that time by Ch. Wolf in his Kurzer Unterricht v. d. vornehmsten math. Schrift., Wien, 1763. Arnauld was an excellent mathematician, an able philosopher and theologian, a celebrated controversialist, and the indefatigable champion and mouthpiece of the Jansenists against the Jesuits. A zealous Catholic, lie repeatedly tried to convert Leibnitz to that faith. Leibnitz's correspondence with him contains important matter regarding his own philos- ophy. It was originally edited and published by C. L. Grotefend, Briefioechsel z. Leibniz, Arnauld u. d. Landf/rafen Ernst v. Hessen-Rheinfels aus d. Hand- schriften der Konigl. Bibliothek z. Hannover, Hanover, 1846, and was re- printed conformably to Grotefend's text by Janet, (Euvres philos. de Leibniz, Vol. 1, pp. 577-691, and, with a new comparison of the original Mss., by Ger- hardt, Leibniz, philos. Schrift., Vol. 2, pp. 11-138; cf. also his Einleitung, ib. p. 5 sq., and Vol. 1, p. 65, and for Leibnitz's first letter, unanswered, to Ar- nauld, ib. 68-82 (Grotefend, op. cit. 137 sq.). Arnauld's (Euvres completes, with a life by Larriere, appeared at Paris and Lausanne, 1775-1783, 45 vols., Vols. 38-40 containing the philosophical works. Of these the most important are : Des vrales et des fausses idees, 1683, directed against Malebranche, in which Arnauld develops his doctrine of perception and attacks the theory of representative ideas, on which cf. Hamilton's Reid, 8th ed.. Vol. 1, pp. 295-298, Vol. 2, pp. 823 b, 963; Reflexions philos. et theolQ(/. sur le nouveau systeme de la nature et de la grace du P. Malebranche, 1685- 464 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv nitiides are added to equals, equals arise tJierefrovt, he demon- strated this other which is considered equally evident : if equals are talcen from equal magnitudes, equals rema;in. It was said he should have assumed both or demonstrated both. But I was not of that opinion, and I believed that it was always so much gained to have diminished the number of the axioms. Addition is no doubt anterior to subtraction and more simple, because the two terms are employed in addition in the same way, which is not the case in subtraction. Arnauld did the opposite of Roberval. He assumed still more than Euclid. As for the maxims, they are sometimes taken as established propositions whether evident or not. That may be well for beginners whom scrupulousness holds back; but w'hen the establishment of science is the question, it is a dif- ferent matter. Thus it is that they are often taken in ethics and even among the logicians in their topics, in some of which there is a good supply, but a part of which contain enough of them vague and obscure. For the rest, I said a long time since publicly and privately that it is important to demon- strate all our secondary axioms, which we ordinarily use, by reducing them to the primitive or immediate and indemon- strable axioms, which I recently and elsewhere called the identicals. § 2. Ph. Knowledge is self-evident when the agreement or disagreement of ideas is immediately perceived. § 3. But there are truths, not recognized as axioms, which are none the less self-evident. Let us see if the four species of agree- ment of which we spoke not long since (chap. 1, § 3, and chap. 3, § 7), viz. : identity, connection, relation, and real ex- istence, furnish us with them. § 4. As for identity or diver- sity, we have as many evident propositions, as we have dis- tinct ideas, for we can deny both, as in saying man is not a horse, red is not blue. Further the statement tohat is, is, is as evident as the statement a man is a man. Th. It is true, and I have already remarked that it is as evident to say ecthetically in particular A is A, as to say in 1686 ; Objections contre Descartes ; and La Logiqve ou I'Art de Penser, or the celebrated Port Royal Logic, 1662, written in conjunction with Nicole (c/. infra, p. 530, note 1) , the best specimen of the logic of the Cartesian school. It has been translated into English most admirably by Prof. Thos. Spencer Baynes. — Tk. CH. VII] ON HUMAN UNDERSTANDING 465 general : it is ivhat it is. But to deny the subjects of different ideas one of another is not always certain, as I have already remarked; as if any one wished to say, the trilateral (or that which has three sides) is not a triangle, because, in fact, tri- laterality is not triangularity ; again, if any one had said : the jyearls of Slusius'^ (oi which I spoke to you not long since) are not the lines of the %ubic parabola, he would have been mis- taken, and yet that would have appeared evident to many people. The late Mr, Hardy, ^ Conseiller au Chatelet de Paris, an excellent geometer and orientalist and well versed in the ancient geometers, who has published the commentary of Marinus on the Data of Euclid, was so prepossessed with the fact that the oblique section of the cone called an ellipse is different from the oblique section of the cylinder, that the demonstration of Serenus ^ appeared to him paralogistic, and I could gain nothing against him by my remonstrances : as he was nearly as old as Roberval, when I saw him, and I was a very young man, a difference which could give me very little persuasive power as regards him, although in other respects I was on very good terms with him. This example may show in passing what prepossession may do even in the case of clever people, for he was truly prepossessed, and Hardy is spoken of 1 Cf. ante, p. 387, note 1. — Tr. 2 Claude Hardy, born near the close of the sixteenth century, died in 1678, was a barrister by profession, and became in 1626 " Conseiller au Chatelet de Paris." He was acquainted with not less than thirty-six ancient and modern languages, and made a profound study of mathematics. Descartes chose him as one of his judges in his controversy with Fermat, in 1698, over Fermat's De maximls et minimis. Hardy published the Data Euclidis, Greek text, with Latin trans., together with the commentary of Marinus, the Neo-Platonist {cf. Zeller, Philos. d. Griech., HI., 2 [Vol. 6], 833, 3d ed., 1881), who lived in the fifth century, and was a disciple and the successor of Proclus (cf. ante, p. 108, note 2), at Paris, 1625, ito. Leibnitz speaks of Hardy as an "homme de me'rite, grand geometre, et grand orientaliste," cf. Dutens, 5, 610.— Tr. 3 Serenus of Antissa, in the island of Lesbos, a Greek geometer, who lived in the fourth century, was the author of two treatises, De Sectione Cylindri et Coni, lihri duo, which, according to Brunet, appeared, together with the Conies of Apollonius of Perga, the Lemmas of Pappus of Alexandria, and the commentaries of Eutocius of Ascalonita, at Bonn, 1566, foL, reprinted at Pis- toja, 1696, fol., and afterwards edited and published by Halley, Oxford, 1710, fol. Hardy could not have seen either of the last two editions, since he died in 1678, but possibly he may have been acquainted with that of 1566; and, if not, then, as Schaarschmidt says, he must refer to Mersenne's Synopsis, Paris, 1644, which contains, pp. 276-312, an abridgment of Apollonius and Serenus. — Tr. 2h 466 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv with esteem in the letters of Descartes.^ But I brought him forward only to show how we may be mistaken in denying one idea of another, if we have not thoroughly enough examined them where it is necessary. § 5. Ph. As regards connection or coexistence, we have very few self-evident propositions; there are, however, some, and it appears to me that this is a self-evident proposition : hm bodies cannot he in the same place. Th. Many Christians contest the point with you, as I have already remarked, and even Aristotle and those who after him admit real and exact condensations, reducing one and the same entire body into a smaller place than it before filled, and those who, as the late Mr. Comenius ^ has done in a little book writ- ten expressly for the purpose, claim to overthrow ^ modern natural philosophy by the experiment of the air-gun, cannot be expected to agree therewith. If you take the body as the impenetrable mass, your statement will be true, because it Avill be identical or nearly so; but that the real body is such will be denied you. At least it Avill be said that God could 1 Schaai'schniidt thinks that Leibnitz here confounded Hardy with Roberval, whom he had mentioned just before. Descartes frequently mentions Hardy in his letters, cf., for example, Pt. I., epist. Ill, Pt. II., epist. 61, 98, 101, 108, Pt. III., epist. 34, 60, 63, etc.; he also corresponded with him, and doubtless valued him highly, as witness his choice of him as arbiter in his conti'oversy with Fermat, but he nowhere in his letters appears expi-essly to praise him : while he speaks thus of Roberval in Lib. III., epist. 56, ad Fermatium: " qui procul dubio inter primarios seculi nostri geonietras censeri debet." — Tr. 2 John Amos Comenius, 1592-1671, the last bishop of the old Moravian and Bohemian Brethren, devoted himself chiefly to the refoi'm and regulation of public education and instruction, and wi'ote many works on pedagogy, which he collected and published under the title Opera didactica omnia, Amsterdam, 1657, 4 vols., fol. He also did some work in physical science, publishing his Dlsquisltio de caloris et frigoris natxira, Amsterdam, 1659, 12rao, which the Avriter in Midland, Biog. Univ., 9, 345, says is the only one of his phj'sical works deserving to be in demand, and his Phi/sicas ad lumen divinum refor- niatse synopsis, Leipsig, 1633, and Amsterdam, 1643, Eng. trans., London, 1651, which is, perhaps, the book to which Leibnitz here refers. For Leibnitz's esti- mate of a portion of the writings of Comenius, cf. Dutens, 5, 181. For an account of his life and work, cf. S. S. Laurie, Comenius. His Life and Edacft- tioncd Works, 4th ed. (Pitt Press Series), Cambridge, Univ. Press, 1893: also a reprint of the same, with five portraits, a somewhat extended and annotated bibliography, and photographic reproductions of pages from early editions of Comenius' works, published by C. W. Bardeen, Syracuse, N. Y., 1893. — Tr. - 3 Gerhardt reads " reserver," probably a Ms. or typographical error: Erd- uiann. Jacques, and Janet read " renverser," which, as the context requires, ihe ti'aiislation follows. — Tr. CH. VII] ON HUMAN UNDERSTANDING 467 make it otherwise, so that this impenetrability will be ad- mitted only as conformed to the natural order of things which God has established and of which experiment assures us, although elsewhere it would be necessary to admit that it is also very conformable to reason. § 6. Ph. As for the relations of the modes, mathematicians have formed many axioms upon the one relation of equality, like that of which you have just spoken, that if equals be taken from equals the remainders are equal. But it is not less evident, I think, that one and one are equal to two, and that if from the five fingers of one hand you take away two and then two others from the five fingers of the other hand, the number of the fingers remaining will be equal. Th. That one and one make two, is not properly a truth, but it is the definition of two ; although it is true and evident that it is the definition'of a possible thing. As for the axiom of Euclid applied to the fingers of the hand, I willingly admit that it is as easy to conceive what you say of the fingers as to see it in the case of A and B ; but in order not to do often the same thing, you observe it generally, and afterwards it is sufficient to make subsumptions. Otherwise, it is as if you preferred calculation by particular numbers to universal rules, which would be obtaining less than is possible. For it is of more account to solve the general problem : to find two num- bers whose sum makes a given number, and whose difference also makes a given number, than merely to seek two numbers Avhose sum makes ten, and whose difference makes six. For if I proceed in this second problem according to the method of numerical algebra, mixed with the literal {specieuse), the calculation will be as follows: a -f 6 = 10, and a — & = G; of which by adding together the right side to the right, and the left side to the left, I produce the result, a-\-h-{-a — h = 10 -f- 6, i.e. (since + h and — 6 cancel each other) 2 a. = 10 or a = 8. Subtracting the right side from the right, and the left from the left (since to take away a — 6 is to add — a + h) I produce the result a + 6 — a + 6 = 10 — 6, i.e. 2 & = 1 or h = 2. Thvis, I shall in truth have the a and 6 , 1 ask for, which are 8 and 2, which satisfy the problem, i.e. whose sum is 10 and whose difference is 6 ; but I have not thereby the general method for any other numbers, Avhich we might wish 468 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv or be able to put in the place of 10 or 6, a method which J. n-ould, however, find with the same facility as these two num- •lers 8 and 2, by putting x and v in the place of the numbers 10 and 6. Por proceeding the same as before we shall have a -{- b + a — b = X + V, i.e. 2 a =: X -\- V or a = ^ X -\- V, and we •shall also have a -\- b — a -\- b = x — v, i.e. 2b = x — v or b = ^x— V. This calculation gives this theorem or general ccmon, that when two numbers are required whose sum and differ- •ence are given, you have only to take as the greater of the required nu.mbers, half of the sum made from the given sum and difference ; and for the less of the required numbers, half of the difference between the given sum and difference. You see also that I might have dispensed with the letters, if I had treated the numbers as letters, i.e. if instead of putting 2 a = 16 and 2 6 = 4, 1 had written 2 a = 10 + 6 and 2 6 = 10 - 6, which would have given me a = ^ (10 + 6) and b = ^ (10 — 6). Thus, in the particular calculation itself I should have had the general calculation, taking these symbols 10 and 6 as general numbers, as if they were the letters x and v\ in order to have a truth or method more general, and taking these same charac- ters 10 and 6 also for the numbers they ordinarily signify, I shall have a sensible example which may serve, indeed, as a proof. And as Vieta ^ has substituted letters for numbers for the sake of greater generality, I have desired to reintroduce the numerical characters, since they are more serviceable in algebra (specieuse) even than the letters. I have found this of much use in large calculations for avoiding errors and even 1 Fran9ois Viete, 1540-1603, better known by tbe Latin form of his name, Vieta, was a distinguished French matliematician, who is often regarded as the founder of modern algebra, because of his introduction of the general use of letters as symbols of undetermined, and therefore general, quantities, thus opening up the way for the higher mathematical analysis, afterwai-ds carried on by Descartes and others. To him is also due the invention of the different simple transformations now used in the solution of equations, such as adding to or subtracting from the members of an equation the same quantity, or mul- tiplying or dividing them by the same quantity. He first enounced the princi- ple of homogeneity or the principle that all the quantities in an equation should be of one kind, — lines, surfaces, solids, or supersolids, — a principle which, after three centuries of controversy, has now been adopted generally by mathemati- cians. His various mathematical writings, which, being a man of wealth, he printed at his own expense and distributed among the scholars of Europe, were collected and edited by F. van Schooten, Professor of Mathematics at Leyden, aided by J. Golius and Mersenne, and published under the title of Opera mathematica, Leyden, 1646, 1 vol., fol. — Tr. CH. VII] ON HUMAN UNDERSTANDING 4G9 in the application of proofs, such as the casting away of tlie nines in the midst of tlie computation without waiting for the result, when there are only numbers instead of letters; which may often be when you employ skill in the positions, so that the suppositions are found true in the particular case, besides the use there is of seeing the connections and orders which the letters alone cannot always make the mind discern so well, as I have elsewhere shown, after I found that the good char- acteristic is one of the greatest aids of the human mind. § 7. Ph. As for real existence which I had counted as the fourth species of existence which may be noticed in ideas, it can furnish us no axiom, for we have not indeed a demonstra- tive knowledge of beings outside us, God alone excepted. Th. We can always say that this proposition / exist, is of the highest evidence, being a proposition which cannot be proved by any other, or rather an immediate truth. And to say I think, therefore I am, is not properly to prove existence by thought, since to think and to be thinking is the same thing; and to say, I am thinking, is already to say, / ayn. You can, however, exclude this proposition from the number of the axi- oms with some reason, for it is a proposition of fact, based upon an immediate experience, and it is not a necessary prop- osition, whose necessity is seen in the immediate agreement of ideas. On the contrary, it is only God who sees how these two terms, /and existence are united, i.e. why I exist. But if the axiom is taken more generally as an immediate or non- provaMe truth, we may say that this proposition, I am, is an axiom, and in every case we may be assured that it is a primi- tive truth, or rather unum ex 23>*i/??js cognitis inter terminos com- jilexos, i.e. that it is one of the first known statements which is understood in the natural order of our knowledge, for it may be that a man has never thought expressly of forming this proposition, which, however, is innate to him. § 8. Ph. [I have always believed that the axioms have little influence upon the other parts of our knowledge. But you have disabused me, since you have indeed shown an important use of identical propositions. Suffer me, however, sir, to set before you still what I have in mind upon this article, for your explanations may also serve to make others return from their error.] § 8, It is a celebrated rule in the schools that 470 LEIBNITZ'S CUlTIQL'i: OF LOCKE [bk. iv all reasoning comes from things already known and admitted, ex praecoguitis et praeconcessis. This rule seems to cause these maxims to be regarded as truths known to the mind before the others, and the other parts of our knowledge as truths dependent upon the axioms. § 9. [I think I have shown (Book I., chap. 1) that these axioms are not the first known, the child knowing much sooner that the rod which I show him is not the sugar he has tasted, than all the axioms you please. But you have distinguished between particular knowledge or experiences of facts and the principles of a universal and necessary knowledge (and herein I admit that it is necessary to recur to axioms) as also between the natural and accidental order]. Th. I have also added that in the natural order the state- ment, that a thing is what it is, is prior to the statement that it is not another; for the question here does not concern the history of our discoveries, which is different in different men, but the connection and natural order of truths, which is always the same.-^ But your remark, viz. : that what the child sees is only a fact, deserves still more reflection; for the expe- riences of the senses do not give truths absolutely certain (as you have often yourself, sir, observed not long since), nor are they exempt from all danger of illusion. For if it is allow- able to make fictions metaphysically possible, sugar might imperceptibly be changed into a rod, in order to punish the child who has been naughty, as water is changed into wine with us on Christmas eve, if it has been well prepared (mori- gene).^ But in all cases the pain (you will say) that the rod inflicts will never be the pleasure the sugar gives. I reply that the child will take it into his head as late to make an express proposition about this, as to notice this axiom, that you can- 1 Leibnitz here calls attention to a very important distinction, viz. : the dis- tinction between the historical and the natural or logical order of our knowl- edge. The genesis of our knowledge, its gradual rise in the course of our lives, is always a matter of individual experience, the experience of no two indi- viduals being precisely alike ; while the natural or logical order and connec- tion of truths, being grounded in reason, is always the same for all. Leibnitz's remark further suggests that the origin of a principle or truth is not its justification, a common fallacy in much of the investigation of the present (lay, and that the ultimate criteria of truth are philosophical, not historical. Cf. Bnwne, Metaphysics, pp. l.S sq.. New York : Harper and Bros., 1882. — Tr. '•^ Duncan, Philos. \VJ.:<. 54, translates: "rectified." — Tr. CH. VII] ON HUMAN UNDERSTANDING 471 not truly say that what is is not at the same time, although he can very Avell perceive the difference of the pleasure and the pain, as well as the difference between perceiving and not perceiving. § 10. Ph. There are, however, a number of other truths as self-evident as these maxims. For example, that one and tioo are equal to three, is as evident a proposition as that axiom which states: that the lohole is equal to the sum of all its parts. Th. You appear to have forgotten, sir, that I have shoAvn you more than once that the statement one and tivo is three is only the definition of the term three, so that to say that one and two is equal to three, is to say that a thing is equal to itself. As for this axiom, that the vjhole is equal to the svm of all itsjMrts, Euclid makes no express use of it. This axiom also needs limitation, for it must be added that these parts must not themselves have a common part, for seven and eight are parts of twelve, but they make more than twelve. The bust and the trunk taken together are more than the man, in that the thorax is common to them both. But Euclid says, that the whole is greater than its part, a statement which is Avholly trustAvorthy. And the statement that the body is greater than the trunk, differs from the axiom of Euclid only in this, that this axiom is limited to what is exactly necessary : but in exemplifying it and clothing the body you make the intelligible become also sensible, for the statement that a given whole is larger than a given part, is in fact the proposition that a whole is larger than its part, but the features of which are embellished with some coloring or addition : it is as if he Avho says A B says A. Thus it is not necessary here to oppose the axiom and the example as different truths in this regard, but to consider the axiom as embodied in the example and rendering it true. It is a different matter, if the evidence is not observed in the example itself, and wlien the affirmation of the example is a consequence, and not merely a subsnnip- tion of the universal proposition, as may occur indeed in the case of the axioms. Ph. Our clever author says here: I should like to ask these gentlemen who maintain that all other knowledge (not of fact) depends upon general principles innate and self-evident, Avliat principle they need to prove that two and, two are four? for 472 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv we know (according to him) the truth of this kind of proposi- tions without recourse to any proof. What do you say about it, sir? Th. I say that I was awaiting you there well prepared. That two and two are four is not a truth at once immediate, supposing that four signifies three and one. We can then demonstrate it, and in this way : — Definitions. — (1) Tvjo is one and one. (2) Three is two and one. (3) Four is three and one. Axiom. — Putting equal things in tlieir place, the equality remains. Demonstration. — 2 and 2 is 2 and 1 and 1 (by del 1) 2 + 2 2 and 1 and 1 is 3 and 1 (by def. 2) 2 + 1 + 1 3 and 1 is 4 (by def. 3) 3 + 1 4 Then (by the axiom) 2 and 2 is 4. Which was to be demonstrated. I might, instead of saying that 2 and 2 is 2 and 1 and 1, say that 2 and 2 is equal to 2 and 1 and 1, and thus with the others. But it may be understood throughout in order to shorten the process; and that, in virtue of another axiom which states that a thing is equal to itself, or that what is the same, is equal. Ph. [This demonstration, as little necessary as it is in rela- tion to its too well known conclusion, serves to show how truths depend on definitions and axioms. Thus I foresee what reply you will make to many objections that are made against the use of axioms. You object that there will be an innu- merable multitude of principles ; but this is when you reckon among the principles the corollaries which follow from the definitions by the aid of some axiom. And since the defini- tions or ideas are innumerable, so also will the principles be in this sense, supposing also with you that the undemonstra- ble principles are the identical axioms. They become innu- merable also by exemplification, but at bottom you can reckon A is A and B is B as one and the same principle differently clothed. Th. Further, this difference of degrees in the evidence makes me disagree with your distinguished author that all CH. VII] ON HUMAN UNDERSTANDING 473 these truths called principles and which pass as self-evident, because they are so near the indemonstrable primitive ax- ioms, are entirely independent and incapable of receiving the one from the other any light or proof. For they may always be reduced either to axioms, themselves, or to other truths nearer the axioms, as this truth, that two and two make four, has shown you. And I just told you how Roberval diminished the number of Euclid's axioms, by sometimes reducing one to another. § 11. Ph. This judicious writer, who has furnished an occa- sion for our conferences, agrees that maxims have their use, but he believes that it is rather that of closing the mouth of the obstinate, than of establishing the sciences. I should be very glad, said he, if you would show me some one of these sciences built upon these general axioms which cannot be shown to be sustained as well without axioms. Th. Geometry is, Avithout doubt, one of these sciences. Euclid expressly employs axioms in demonstration, and this axiom : that tiuo homogeneous magnitudes are equal tvhen one is neither larger nor smaller than the other, is the basis of the demonstrations of Euclid and Archimedes respecting the size of curvilinears. Archimedes employed axioms of which Euclid had no need; for example, of two lines, each of which is con- cave always on the same side, that which encloses the other is the greater. We cannot also dispense with the identical ax- ioms in geometry, as, for example, the principle of contradic- tion, or the demonstrations which lead to the impossible. And as for the other axioms, which are demonstrable, we may dispense with them, absolutely speaking, and draw conclu- sions immediately from the identicals and from the defini- tions; but the prolixity of the demonstrations, and the end- less repetitions into which you would then fall, would cause a horrible confusion, if it were always necessary to begin ah ovo; while by assuming the mean propositions, already proved, we easily pass much farther. This assumption of truths already known is useful, especially as regards the ax- ioms, for they recur so often that geometers are compelled to make use of them constantly without citing them; so that we should be mistaken in thinking that they are not there, because we do not perhaps always see them quoted in the margin. 474 LEIBNITZ'S CKITIQUE OF LOCKE [bk. it Ph. But he objects to the example from theology. For the knowledge of this holy religion came to us from revelation (says our author), and without this aid the maxims would never have been able to make us know it. The light comes to us then from the things themselves, or immediately from the infallible veracity of God, Th. It is as if I said, medicine is based upon experience, reason then is of no use therein. Christian theology, which is the true medicine for souls, is based upon revelation which corresponds to experience ; but to make of it a perfect body, we must unite therewith natural theology, which is drawn from the axioms of eternal reason. Is not this principle indeed that veracity is an attribute of God, upon which you acknowledge that the certainty of revelation is based, a maxim taken from natural theology?^ Ph. Our author wishes to distinguish between the means of acquiring knowledge and of teaching it, or rather between teaching and communicating. After schools had been erected and professors established to teach the sciences that others had found out, these professors availed themselves of these max- ims in order to impress the sciences upon the minds of their scholars, and to convince them by means of the axioms of cer- tain particular truths; while the particular truths have served the first discoverers in finding the truth without the general maxims. Th. I wish that this pretended procedure had been justified for us by examples of some particular truths. Bvit rightly considering things, we shall not find it practised in the estab- lishment of the sciences. And if the discoverer finds only a particular truth, he is only half a discoverer. If Pythagoras ^ 1 Locke, without discussing its possibility or its method, assumes a special source of religion in an immediate revelation of God to the soul of man, and rests the truth of this revelation upon the " unerring veracity" of God. Cf. Philos. Wks., Vol. 2, p. 209, Bohn's ed. Leibnitz, who elsewliere discusses to a certain extent both the possibility and the method of revelation, and admits its possibility, and also its actuality, especially as regards those things which are beyond the limits of our finite experience, emphasizes the rational element in theology by calling attention to the fact that revelation presupposes a nat- ural idea of God, philosophically derived and including the attribute of verac- ity, to which it may appeal and by which its character and claims to authority must be judged. — Tr. 2 Cf. ante, p. 379, note 1. On his life and philosophy, cf. Zeller, Philoi^. d. Griech., 5th ed.. Vol. 1, pp. 296 sq. For his mathematical work, cf. G. J. GH. viij ON HUMAN UNDERSTANDING 475 had only observed that the triangle whose sides are 3, 4, 5, has the property of the equality of the square on the hypothenuse with those on the sides (i.e. that 9 + 16 = 25), would he on that account have been the discoverer of this great truth which includes all right-angled triangles, and which has passed into a maxim with the geometers? It is true that often an exam- ple, seen by chance, serves as the occasion which suggests to a clever man the search for general truth, but it is still very often no easy matter to find it; besides, this path of discover}^ is not the best nor the most employed by those who proceed in an orderly and methodical way, and they make use of it only upon the occasions when better methods fall short. In the same way, some have thought that Archimedes found the quadrature of the parabola by weighing a piece of wood cut parabolically, and that this particular experiment caused him to discover the general truth; but those who know the pene- tration of this great man see clearly that he had no need of such an aid. Moreover, if this empirical way of particular truths had been the occasion of all the discoveries, it would not have been sufficient to give them; and the discoverers themselves have been delighted with observing the maxims and the general truths if they have been able to attain them, otherwise their discoveries would have been very imperfect. All that maj' then be attributed to the schools and to the pro- fessors, is that they have collected and arranged the maxims and other general truths: and Avould God they had done so still more and with more care and choice, the sciences would not be found so scattered and so confused. For the rest I admit, that there is often some difference between the method we use in teaching the sciences and that which has produced their discovery : but this is not the point in question. Some- times, as I have already observed, chance has given occasion for discovery. If we had noticed these occasions, and had preserved the memory of them for posterity (which would have been very useful), this detail would have been a very con- siderable part of the history of the arts, but it would not have Allnian, Greek Geometry from Thalea to Euclid, Dublin, 1889, and, by the same author, Pitthafiorecm Geometry, being the mathematical part of the article " Pythagoras "' iu the Encyclop. Brit., 0th ed., Vol. 20, pp. 146-140 (Amer. ed.). — Tk. 476 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv been proper to make systems of them. Sometimes also dis- coverers have proceeded rationally to the truth, but by ex- tended circuits. I find that in matters of importance authors would have rendered service to the public, if they had been willing sincerely to indicate in their writings the traces of their experiments ; but if the system of science should be built upon that foundation, it would be as if in a finished house you wished to preserve all the apparatus which ^ the architect re- quired in building it. Good methods of teaching are all such that by their means science could certainly have been discov- ered; and then if they are not empirical, i.e. if the truths are taught by reasons or by proofs drawn from ideas, it will always be by axioms, theorems, canons, and such other general propo- sitions. The case is different when the truths are aphorisms like those of Hippocrates,^ i.e. truths of fact either general, or 1 Gerhardt reads " done," manifestly a manuscript or a typographical error. Erdmann, Jacques, and Janet read "dont," which the translation follows. — Tr. 2 Hippocrates of Cos, 460-375 B.C., the " Father of Medicine," was the first to base the practice of medicine on the observation of nature and the principles of an inductive philosophy. Though descended from a family of priest-physi- cians, he put aside all its traditions and prejudices, gave himself up to the study of the natural history of disease in the living subject, and treated it always as subject to natural laws. He placed especial emphasis on sympto- mology and dietetics. The two chief modern critical editions of his writings, or those ascribed to him, are E. Littre, CEuvres completes d'Hippocrate, 10 vols., Paris, 1839-61, and F. Z. Ermerins, Hippocratis et aliorum medicorum veterum reliquix, 3 vols., Utrecht, 1859-64. The 'A(i)opiug and continued opposition from those who thought it useless. He dispute CEITIQUE O-F LQCKE [bk. iv three sides, and the consequent: the said figure has three angles. Although, again, the hypothetical may often be transformed into the categorical, merely by changing a little the terms, as if instead of the preceding hypothetical, I said: the angles of every figure with three sides are equal to two right angles. The Scholastics have hotly disputed de constantia subjecti, as they called it, i.e. how the proposition made upon a subject can have a real truth, if this subject does not exi^t. The fact is that the truth is only conditional, and says, that in case the- subject ever exists, it will be found such. But it will be further demanded, in what is this connection founded, since tliere is in it some reality which does not deceive. The reply will be, that it is in the connection of ideas. But it will be asked in reply, where would these ideas be if no mind existed, and what then would become of the real ground of this cer- tainty of the eternal truths? This leads us finally to the ulti- mate ground of truths, viz. : to that Supreme and Universal Mind, which cannot fail to exist, whose understanding, to speak truly, is the region of eternal truths, as St. Augustine has recognized and expresses in a sufficiently vivid way. ^ jAnd in order not to think that it is unnecessary to recur to this, we must consider that these necessary truths contain the de- termining reason and the regulating principle of existences themselves, and, in a word, the laws of the universe. Thus these necessary truths being anterior to the existence of contingent beings, must be grounded in the existence of a ^ Aurelius Augustinus, 354-430, grounded his philosophy in the principle of the absolute and immediate certainty of consciousness or inner experii^ce. Cf. De Beata Vita, chap. 7 ; Solil. II., 1 {ante, p. 410, note 1) ; De Vera Relig., 39, 72 sq. : De Trin., X., 14, XIV., 7. In this certainty of the individual conscious- ness, i.e. in thought itself, is immediately involved the idea of God in whom exist the universal truths as the ideas or norms of all reality. Cf. De Ideis, 2 : " Sunt namque idese principales formae quaedam, vel rationes rerum stabiles et incommutabiles, quae ipsae formatse non sunt atque per hoc seternse ac semper eodem modo se habentes, quae in divina intelligentia continentur, et quum ipsae neque oriantur neque intereant, secundum eas tamen formari dicitur omne, quod interire potest et omne, quod oritur et interit." For a good account of Augustine's philosophy, cf. Ueberweg-Heinze, 7th ed., Berlin, 1888, 2, 97-115, especially 106-7, Eng. trans, from 4th Germ, ed.. New York, 1871, 1, 333 sq., especially 339-40; Windelband, Hist, of Phllos., trans, by Tufts, 276 sq. Augustine's works form Vols. 32-47 of the Latin Fathers in Migne, Patrol, cur. compl., Paris, 1835 sq.; Eng. trans, by Dods, 15 vols., Edinburgh, 1871-77, and in Schaff's lib. Nicene and Post-Nicene Fathers, Vols. 1-8, Buffalo, 1886-88. — Tr. CH. xii] ON HUMAN UNDERSTANDING 517 necessary substance. Here it is that I find, the original of the ideas and truths which are graven in our souls, not in the form of propositions, but as the sources out of Avhich applica- tion and occasion will cause actual judgments to arise. -^ CHAPTER XII OF THE IMPROVEMENT OF OUR KNOWLEDGE § 1. Ph. We have spoken of the kinds of knowledge we have. Now let us come to the means of improving the knowl- edge or of finding the truth. It is the received opinion among scholars, that the maxims are the bases of all knowledge, and that each particular science is based upon certain things already known (prcecognita). § 2. I admit that mathematics seem to favor this method by their good success, and you have given considerable support to this view. But it is still doubtful whether it is not rather the ideas which were of service therein through their connection than two or three general maxims which were posited at the beginning. A young lad knows that his body is greater than his little finger, but not by vir- tue of this axiom, that the whole is greater than its part.. Knowledge commenced by particular propositions ; but after- wards it was desired to relieve the memory by means of gen- eral notions from a cumbersome load of particular ideas. If language were so imperfect that there were no relative terms, ivhole and part, could he not know that his body is larger than his little finger? I at least give you the reasons of my author, although I think I foresee what you will say thereto in con- formity with what you have already said. Th. I know not why you bear the maxims such ill will as to attack them yet again ; if they serve to relieve the memory of a multitude of particular ideas, as you admit, they must be very useful, although they had no other use. But I add that 1 For Leibnitz God is the source of all truths as well as of all beings. The idea of God contains in itself potentially all truth, and is the regulative (but not in the Kantian sense of the term), or better, the constitutive, principle of all thought, just as his actuality contains potentially within itself all exist- ences, and is the regulative, i.e., constitutive, principle of all being. C'f. also, ante, p. 496, note 1. — Tr. 518 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv they do not spring from particular ideas, for they are not found by induction from examples. He who knows that ten is more than nine, that the body is larger than the finger, and that the house is too large to be able to run away with the door, knows each one of these particular propositions, by one and the same general reason which is, as it were, incorpo- rated therein and illuminated, just as we see designs adorned with colors in which the proportion and configuration con- sists properly in the outlines, whatever the color may be. Now this common reason is the axiom itself which is known, so to speak, implicitly, although it does not exist at first in an abstract and separate manner. The examples derive their truth from the incorporated axiom, and the axiom has not its ground in the examples. And as this common reason of these particular truths exists in the minds of all men, you see clearly that it is not necessary that the words ivhole and part be found in the language of him who is imbiied therewith. § 4. Fh. But is it not dangerous to authorize assumptions under the pretext of axioms? One will assume, with some of the ancients, that all is matter; another, with Polemo,^ that the world is God; a third will assert that the sun is the prin- cipal divinity. Judge what a religion we should have, if that ^vere allowed. So true is it that it is dangerous to receive principles without questioning them, especially if they con- cern morality. For some one will expect another life, like that of Aristippus,^ who placed happiness in the pleasures of the body, rather than like that of Antisthenes,^ who main- 1 Polemo, the successor of Xenocrates, 396-314 B.C., as scholarcli, or head, 314-270 B.C., of the school of the Old Academy, and the third iu that office from Plato (Speusippus holding it from Plato's death in 347 to 339, and Xeno- crates from 339-314), devoted himself chiefly to ethics. The statement that he declared the universe to be God — UoKiii.ov tov k6(xij.ov Behv aTre<^T)va.To — rests on the authority of Stobseus, Eclogas. phys., Bk. I., chap. 2, 5, § 62, p. 15, ed. A. Meineke, Leipzig, 1855-64. For his philosophy, c/. Zeller, Philos.d. Griech., II., 1 [Vol. 3], 993-4, 1045-6, 4th ed., Leipzig, 1889. — Tr. 2 Aristippus, c. 435-c. 366 B.C., the founder of the Cyrenaic school, made pleasure, which, according to Diog. Laertius, II., 85, 86, he defined as the feeling of a gentle motion — t€\o^ S' aire(l>aive rriv A^iav KCvri(Tiv eis ala-Oria-LV ava&iSo- fieVrji/ . . . TTjv jaer \eiav Kivricrtv Tr/v rjSovrjv — the end of life, the wisc man aiming to enjoy pleasure without being controlled by it. For his writings, cf. Mul- lach, Fragt. philos. Gr., II., 397 sq. On his life and philosophy, cf. Zeller, Philos. d. Griech., II., 1 [Vol. 3], 336 sq., ethical doctrine, ;352 .sq. — Tk. 3 Antisthenes, c. 440-c. 369 B.C., a pupil of Gorgias and Socrates, was the founder of the Cynic school, and taught, according to Diog. Laertius, VI., IL CH. xii] ON HUMAN UNDERSTANDING 519 tained. that virtue suffices to produce happiness. And Arche- laus,^ who will lay it down as a principle that justice and injustice, honesty and dishonesty, are defined only by the laws and not by nature, will no doubt have other measures of moral good and evil than those who admit obligations anterior to human constitutions. § 5. It must be, then, that principles are certain. § 6. But this certainty comes only from the com- parison of ideas : thus we have no need of other principles, and according to this rule alone we shall advance much farther than by putting our minds at the disposal of another. Th. I am astonished, sir, that you turn against maxims, i.e. against evident principles, that which can and must be said against principles assumed gratis. When one demands proe- cognita in the sciences, or anterior knowledge, which serves to ground science, he demands known jJ^'incijyles and not arbi- trary positions, whose truth is not known; and even Aristotle understands that the inferior and subaltern borrow their prin- ciples from other superior sciences in which they have been demonstrated, except the first of the sciences, which we call metaphysics, which, according to him, asks nothing from the others, and furnishes them the principles they need; and when he says: 8a ma-Teveiv t6v ixavOdvovTa,"^ the apprentice must that virtue only is a good, aud that it is sufficient for happiness — aurapKi) yap T'-riv dperr/i' i'lvai ■npo'; evSaifj^ovCau. For his Writings, cf. Mullach, Fragt. phllos. Gr., II., 261 sq. On his life and philosophy, cf. Zeller, Phllos. d. Griech., II., 1 [Vol. 3], 281 sq., ethical doctrine, 303 sq. — Tn. 1 Archelaus, the dates of whose birth and death are unknown, was a physi- cist, and the disciple of Anaxagoras, c. .500-428 B.C., whose physical doctrine he seems to have modified in the direction of the Ionic school as represented by Anaximines, c. 588-c. J)24 B.C., and Diogenes of Apollonia. Zeller says that the statement, as given by Diog. Laertius, II., 16, that he derived the distinc- tion of good and bad from custom rather than nature — t6 SUawv etc ai Kal to aitrxpov ov (fiuo-et aWa vofiiu — appears to be duc to a mistake in interpreting his language, and that he merely said that men at the beginning were without custom and law, and first attained thereto in the course of time. On his philosophy, cf. Zeller, Philos. d. Griech., I., 2 [Vol. 2J, 1031-10.38, 5th ed., Leipzig, 1892. — Tr. ^ Cf. Aristotle, Sophist. Elenck., chap. 2, 161, b, 1-3: SiSao-KaAiicol p^ev oi « TOiV ot/ceitui' ap\(af eKatTTOV paBrip.a.TO'; Kal ovk €k tuiv toO aTTOKptvopevov So^wf avK\oyi^6- pevoi. {Sel yap TTKTT^vei.i' Tov pai'edi'ovTa), i.e. discussions for the purpose of teach- ing proceed from the special principles of each science, and do not draw their conclusions from the opinions of the participating pupil ; Aristotle's thought being that the pupil will receive a confirmation of the mere faith in the prin- ciples demanded of him at the outset, in the course of the explanation and demonstration of these principles in his presence, and in the agreement of the scientific results with the facts and his further knowledge. Leibnitz here 520 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv believe his master, his thougkt is that he must do it only while waiting, while he is not yet instructed in the higher sciences, so that it is only provisionally. Thus we are very far from receiving gratuitous pTinciples. To this it must be added that even principles whose certainty is not complete may have their use if we build upon them only by demonstration; for although all the conclusions in this case are conditional only, and are valid only upon the supposition that this principle is true, nevertheless this connection itself and these conditional enunciations would at least be demonstrated; so that it were much to be desired that we had many books written in this way, where there would be no danger of error, the reader or disciple being warned of the condition. And practice will be regulated by these conclusions only as the supposition shall be found verified elsewhere. This method also serves very often itself to verify suppositions or hypotheses, when many conclusions arise from them, the truth of which is otherwise known, and sometimes this gives a perfect proof (retour) sufficient to demonstrate the truth of the hypothesis. Mr. Conring,^ a physician by profession, but a clever man in every kind of learning, except perhaps mathematics, wrote a letter to a friend engaged in reprinting at Helmstadt the book of Viottus,'^ an esteemed Peripatetic philosopher who tried to expresses a similar thought, in premising the provisional character of that faith which the beginner should have in his teacher. — Tr. 1 Hermann Conring, 1606-1*181, one of the most learned men of his age, possessed of vast erudition, and thoroughly informed on medicine, law, the- ology, history, physics, philology, etc., taught at Helmstadt, and wrote an immense number of works, which have been united in part and published under the title of Opera omnia, Brunswick, 1730, 7 vols., fol. For an account of him, cf. Michaud, Biog. Univ., Vol. 9, pp. 447-452. For his correspondence with Leibnitz, cf. Gerhardt, Leibniz, philos. Schrift., 1, 153-206. — Tr. 2 Bartolommeo Viotto, or Viotti, surnamed a Clivolo, son of a distin- guished surgeon, Tommaso Viotto, who was the first in the University of Turin to i-eceive the laurel crown in surgery from the Decurions of Trino, was a philosopher and physician of Turin, and, in the five years preceding 1552, public professor of logic in that city. He died in 1568. He was author of De balneorum naturalium viribus lib. IV., Lugduni, 1552, reprinted in De balneis omnia quse extant apud Grsecos, Latinos, et Arab as, fol. Venetiis, 1553, pp. 2A1-1\; and of the work here and elsewhere referred to by Leibnitz, Demonstrationum in methodum medendi lib. V., Svo, Parisiis, 1560, and under the editorship of A. Frolingius, Helmstadt, 1661, Braunschweig, 1684. Cf. Correspondence of Leibnitz and Conring, Gerhardt, Leibniz, philos. Schrift., 1, 184, 187 ; of Leibnitz and Placcius, Dutens, Leibnit. op. om., 6, 45. Conring, Introd. in univ. art. med., Halse et Lipsiae, 1726, p. 23, says of CH. XII] ON HUMAN UNDERSTANDING 621 explain the demonstration and "Posterior Analytics" of Aristotle. This letter was appended to the book, and in it Conring criticised Pappus Avhen he said that analysis proposes to discover the unknown by assuming it, and by reaching therefrom, by inference, known truths ; ^ a method which is contrary to logic (he said) which teaches that from falsehood we cannot infer truths. But I made known to him afterwards that analysis makes use of definitions and other reciprocal propositions which furnish means of making the proof (retour), and of discovering synthetic demonstrations.^ And even when this proof is not demonstrative, as in physics, it is nevertheless sometimes highly probable, when the hy- pothesis explains easily many phenomena, diflB.cult without it and very independent of one another, I hold to the truth, sir, that the principle of principles is in a way the good use of ideas and of experience; but by examining it thoroughly we shall find that, as regards ideas, it is nothing else than the union of definitions by means of identical axi- oms. Nevertheless, it is not always an easy thing to come to this ultimate analysis, and whatever desire the geometers, at least the ancient geometers, have shown to succeed therein, they have not yet been able to do so. The celebrated author him : " Certe qui necessitatem ejus in medicina simul et ipsam artem demon- strandi post Galenuni ostenderit, hactenus nemo inventus est, si excipias unum Bartholomseum Viottum hominem longe doctissimum ; cujus de demon- stratione prseclarum opus ante centum annos prodiit." Cf., also, G. Pasch, De novis inventis, 2d ed., 4to, Lipsise, 1700, p. 26; J. A. van der Linden, De scriptis medlcis, 8vo, Amstelredami, 1637, p. 82, Linden, renovat., 4to, Norim- bergae, 1686, pp. 114, 119; Kestner, Medicinisches-Gelehrten-Lexicon, 4to, Jena, 1740, p. 897 ; G. G. Bonino, Biografia medica piemontese, 8vo, Torino, 1824, Vol. l,pp. 199-201. — Tk. 1 Pappus of Alexandria was a Greek geometer " of a very high order," who flourished, according to the best recent opinion, in the reign of Diocletian, 284-;30o, and whose twayi^yy-ff, or Collection, is of very great value in the his- tory of mathematics. From Bk. VII. of this work is derived a large part of our knowledge of Greek geometry. The best ed. of the whole work is F. Hultsch, Pappi Alexandrini Collectionis qiise supe>-siint, 3 vols., Berlin, 1876-78. Pappus' explanation of the nature of analysis and synthesis, Avhich Con- ring erroneously criticised, is found in the preface of Bk. VII. of the "S.wayuyri, cf. Hultsch, op. cit., Vol. 2, pp. 634-6; C. I. Gerhardt, Der Sammlung des Pappus V071 Alexandrien, siehentes u. achtes Buck, Halle, 1871, pp. 2-4. Ac- cording to Schaarschniidt, this explanation is perhaps the clearest and best concise statement that has been made of the nature of the aualj'tic and syn- thetic method. — Te. 2 Cf. Correspondence of Leibnitz and Conring, Letter of Jan. 3d, 1G78, Gerhardt, Leibniz, philos. Schrift., 1, 187-8; also, ibid., 185, 190, 193 sq. — Tr. 522 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv of "The Essay on Human Understanding," would give them much pleasure if he would complete this investigation, a little more difficult than we think. Euclid, for example, has put among the axioms one which amounts to saying: that two straight lines can meet only once. The image derived from the experience of the senses, does not permit us to picture to ourselves more than one meeting of the two lines; but it is not upon this that science must be founded. And if any one believes that this image gives the connection of distinct ideas, he is not sufficiently instructed concerning the source of truths, and a multitude of propositions, demonstrable by others ante- rior, would pass with him as immediate. Many of those who have criticised Euclid, have not sufficiently considered this: these kinds of images are only confused ideas, and he who knows the straight lines only by this means will not be capable of demonstrating anything. Euclid, therefore, for want of a distinctly expressed idea, i.e. a definition of a straight line (for that which he gives meanwhile is obscure and of no use to him in his demonstrations), was obliged to return to two axioms which for him took the place of definitions and which he em- ployed in his demonstrations : the one that two straight lines have no common part, the other that they enclose no space. Archimedes has given a kind of definition of the straight line, in saying that it is the shortest line between two points. But he tacitly assumes (by employing in his demonstrations ele- ments like those of Euclid, based upon the two axioms I have just mentioned) that the properties (affections) of which these axioms speak, accord with the line Avhich he defines.^ Thus if you believe, with your friends, under the pretext of the agree- ment or disagreement of ideas, that what these images tell us was allowed and is still to be received in geometry, without seeking that strictness of demonstration by means of defini- tions and axioms which the ancients demanded in this science (as I believe many people will believe for lack of information), I will admit, sir, that you may be contented as regards those who trouble themselves only about practical geometry such as it is, but not as regards those who desire to have the science which serves indeed to perfect the practical. And if the ancients had been of this opinion and had relaxed their efforts 1 Gerhardt and Erdmann read " definit " ; Jacques " decrit." — Tr. CH. xii] ON HUMAN UNDERSTANDING 523 on this point, I think they would have made but little advance, and would have left us only an empirical geometry such as that of the Egyptians apparently was, and such as that of the Chinese seems still to be; this would have deprived us of the most worthful physical and mechanical knowledge which geometry has caused us to discover, and which is unknown wherever our geometry is unknown. It is also apparent that in following the senses and their images we should fall into errors; much the same as we see that all those who are not instructed in exact geometry receive as an indubitable truth upon trust in their imagination, that two lines continually approaching each other, must finally meet; while geometers give contrary instances in the case of certain lines called asymptotes. But besides this we should be deprived of what I value most highly in geometry as related to reflection, viz. : permitting us to catch a glimpse of the true source of eternal truths and of the means of making us comprehend their neces- sity, a matter which the confused ideas of the sense-images could not show us distinctly. You will say to me that Euclid was obliged, however, to confine himself to certain axioms whose evidence is seen only confusedly by means of the images. I agree with you that he has limited himself to these axioms, but it was better for him to limit himself to a small number of truths of this nature which appeared to him the simplest and to deduce from them the others which another less exact would also have taken as certain without demonstra- tion, than to leave many of them undemonstrated, and what is worse, to allow people the liberty of extending their laxity according to their fancy. You see then, sir, that what you and your friends have said regarding the connection of ideas as the true source of truths needs explication. If you are willing to content yourself with the confused sight of this connection, you weaken the exactness of demonstrations, and Euclid has done incomparably better in reducing all to defini- tions and to a small number of axioms. Yet if you wish this connection of ideas to be distinctly seen and expressed, you will be obliged to recur to definitions and identical axioms, as I claim; and sometimes you will be obliged to content yourself with some axioms less primitive, as Euclid and Archimedes have done, when you find difficulty in attaining a 524 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv perfect analysis, and you will do better in that way than to neglect or defer some fortunate discoveries which you can already make by their means : as in fact I have already said to you at another time, sir, that I believe we should not have a geometry (I mean a demonstrative science), if the ancients had not been willing to advance until they had demonstrated the axioms they were obliged to employ. § 7. Ph. I begin to understand what a distinctly known con- nection of ideas is, and I see clearly that in this sense axioms are necessary. I see clearly also how necessary it is that the method we follow in our researches, when the question is that of the examination of ideas, be regulated by the example of the mathematicians who from certain very clear and easy beginnings (which are nothing else than the axioms and defi- nitions) proceed by small degrees and a continual chain of reasoning to the discovery and demonstration of truths that appear at first beyond human capacity. The art of finding proofs, and these admirable methods they have invented for separating and putting in order mediate ideas is what has produced such wonderful and unexpected discoveries. But whether with time a similar method may not be found out useful in respect to other ideas as well as those belonging to magnitude is a question I will not determine. At least, if other ideas were examined according to the ordinary method of the mathematicians, they would lead our thoughts farther than we are perhaps led to imagine. § 8. And this might be done particularly in the case of morality, as I have more than once said. Th. I believe you are right, sir, and I have been disposed for a long time to make it my business to accomplish your predictions. § 9. Ph. In regard to the knowledge of bodies we are com- pelled to take a directly contrary path; for having no ideas of their real essences, we are obliged to recur to experience. § 10. But I do not deny that a man accustomed to making rational and regular experiments is capable of forming juster conjectures regarding their still unknown properties than another not so accustomed, but it is judgment and opinion, not knowledge and certainty. This makes me think that physics is incapable of becoming a science in our hands. But experi- CH. XII] ON HUMAN UNDERSTANDING 525 ments and historical observations may be of use to us as regards the health of our bodies and the conveniences of life. Th. I admit that physics as a whole will never be a per- fect science among us, but we shall not cease to be able to have some physical science, and indeed we have already some specimens of it. For example, magnetology may pass for such a science, for, making a few suppositions based upon experience, we can demonstrate from them by a certain infer- ence a number of phenomena which really occur as we see that reason declares. We ought not to hope to give a reason for all experiments, as indeed the geometers have not yet proved all their axioms; but just as they are satisfied to deduce a large number of theorems from a small number of principles of the reason, so is it sufficient that the physicists by means of certain principles of experience give a reason for a multi- tude of phenomena and can indeed prove them in practice. § 11. Ph. Since then our faculties are not fitted to make us discern the internal fabric of bodies, we must consider that it is enough that they discover to us the existence of God, and a sufficiently extended knowledge of ourselves to instruct us in our duties and in our greatest interests, particularly as related to eternity. And I think I am right in inferring therefrom that morality is the proper science and the imjyortaiit busiyiess of mankind in general, as, on the other hand, the different arts which are conversant about different parts of nature are the lot of par- ticular men. It may be said, for example, that ignorance of the use of iron is a reason in the countries of America, where nature has spread abroad abundantly all kinds of goods, for the lack of the greatest part of the conveniences of life. Thus very far from despising the science of nature, § 12. I hold, that if this study is directed, as it ought to be, it may be of greater use to the human race than all that has been done up to this time; and he who invented printing, who discovered the use of the compass, and who made known the virtue of quinquina, has contributed more to the propagation of knowl- edge and to the advancement of the useful conveniences of life, and has saved more people from the grave, than the founders of colleges and hospitals and other monuments of the most exemplary charity, which have been built at great expense. 526 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv Th. You could say nothing, sir, more to my liking. True morality or piety, very far from favoring the inactivity of cer- tain idle quietists, must impel us to cultivate the arts. And as I said not long since, a better police would be able to bring us some day a much better medical science than that we have at present. We cannot preach this doctrine enough, next to the care for virtue. § 13. Ph. Although I recommend experiments, I do not despise probable hypotheses. They may lead us to new dis- coveries, and are, at least, a great aid to the memory. But our mind has a great tendency to go too fast and to be satis- fied with certain superficial appearances, for lack of taking the necessary time and trouble to apply them to a multitude of phenomena. Th. The art of discovering the causes of phenomena, or true hypotheses, is like the art of deciphering, in which an ingenious conjecture often greatly shortens the road. Lord Bacon began to put the art of experimenting into precepts, and Chevalier Boyle ^ had a ' great talent for practising it. But if the art of employing experiments and of drawing con- sequences therefrom is not joined with it, we shall never with the utmost cost attain to what a man of great penetration might discover at first sight. Descartes, assuredly such a man, has made a similar remark in one of his letters ^ regarding the method of the Chancellor of England; and Spinoza (whom I do not hesitate to quote when he says a good thing) in one of his letters '^ to the late Mr. Oldenburg, Secretary of the Eoyal Society of England, printed among the posthumous works of this subtle Jew, makes a similar reflection upon a work of Boyle, who, to speak the truth, stops a little too much to draw from a great number of fine experiments no other con- 1 Cf. ante, p. 324, note 2. — Tr. 2 The remark here referred to by Leibnitz as occurring in one of Descartes' letters has not as yet been found in any of those now extant ; and, as mention is made of Bacon ,in Spinoza's remark cited immediately after, it is possible that Leibnitz confounded the two authors, a thing which might readily happen, especially as Leibnitz was often out of the reach of books when composing his works, as probably in this case, cf. ante, p. 8, note 1. — Te. 3 Cf. Spinoza, Opera, ed. Van Vloten and Land, 2, 19 : " Sed interim nescio, cur clarissimus vir hoc" {i.e. universal mechanism) " adeo sollicite conetur colligere ex hoc suo experiraento ; cum jam hoc a Verulamio, et postea a Cartesio satis superque demonstratum sit." — Tr. CH. XII] ON HUMAN UNDERSTANDING .527 elusion than this which he might take as a principle, viz. : that everything in nature takes place mechanically, a principle Avhich can be rendered certain by reason alone, and never by experiments, whatever their number. § 14. Ph. After having established clear and distinct ideas with fixed names, the great means of extending our knowl- edge is the art of finding mediate ideas which can show us the connection or incompatibility of the extreme ideas. The max- ims at least are of no avail in furnishing them. Suppose a man has not an exact idea of a right angle, he will vainly tor- ment himself in demonstrating something about the right- angled triangle : and whatever maxims he employs, he Avill have difficulty in attaining by their aid the proof that the first squares of the sides enclosing the right angle are equal to the square on the hypothenuse. A man might ruminate upon these axioms a long time without ever seeing more clearly into mathematics. Th. It is of no avail to ruminate upon the axioms without having something to which to apply them. Axioms often serve to connect ideas, as, for example, this maxim, that similar extensions of the second and third dimensions are in reason double and triple the corresponding extensions of the first dimension, is of very great use ; and the quadrature, for ex- ample, of the lune of Hippocrates ^ springs from it at once in the case of the circles by uniting therewith the application of these two figures the one to the other, when their given posi- tion furnishes the opportunity for so doing, as their known comparison promises light thereupon. 1 Hippocrates of Chios, c. 440 B.C., a contemporary of Hippocrates of Cos, the physician (c/. ante, p. 476, note 2), was a celebrated Greek geometer, whose most noted achievement was the discovery of the quadrature of the lune, or the crescent-shaped plane figure produced by drawing two perpendicular radii in a circle and describing upon the line joining their extremities a semicircle. This lune is famous as the first curvilinear space whose area was exactly de- termined, and its area is exactly equal to that of the triangle formed by the two radii and the line joining their extremities. For the demonstration of this, c/. Larousse, Grande Diet. Univ. cle XIX^ Steele, Vol. 10, p. 791, a, b. On Hippocrates and his services to mathematics, cf. Allman, Greek Geom. from Thales to Euclid, 64 sq.; Gow, A Short Hist, of Greek Math., 1(34 sq.: H. Suter, Gesch. d. math. Wissenschaften, 2d ed.. Vol. 1, pp. 33-36, Ziirich, 1873. — Tr. 528 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv CHAPTER XIII OTHER CONSIDERATIONS CONCERNING OUR KNOWLEDGE § 1. Ph. It will be perhaps further appropriate to add, that our knowledge has a close relation to our sight in this, as well as in other things, that it is neither wholly necessary nor wholly voluntary. We cannot fail to see when our eyes are open to the light, but we can turn them towards certain objects, § 2. and consider them with more or less application. Thus when the faculty is once applied, it does not depend upon the will to determine the knowledge; no more than a man can prevent himself from seeing what he sees. But he must employ his faculties, as it is necessary in order to inform himself. Th. We have spoken before of this point, and established the fact that it does not depend upon man to have this or that opinion in the present state, but it depends upon him to pre- pare himself to have it or not to have it eventually, and that thus opinions are voluntary only in an indirect manner. CHAPTER XIV • OF JUDGMENT §]. Ph. Man would be found without direction in the greater part of the arts of his life, if he had nothing to con- duct him from the point where certain knowledge fails him. § 2. He must often be contented with a simple ttviUght of prob- ability. § 3. The faculty of using this is judgment. One is contented with it often of necessity, but often through want of diligence, patience, and skill. § 4. It is called assent or dissent, and is employed when anything is presumed, i.e. when it is taken as true before it is proved. When this is done con- formably to the reality of things, it is a right judgment. Th. Others call judgment the act which is performed every time a statement is made after some knowledge of a cause; and there will be some also who will distinguish judgment CHS. xiii-xv] ON HUMAN UNDERSTANDING 529 from opinion, as not of necessity being so uncertain. But I do not wish to criticise any one regarding the use of words, and it is allowed you, sir, to take judgment as a probable opinion. As for presumption, which is a term of the juris- consults, good use with them distinguishes it from conjecture. It is something more, something which must pass for truth provisionally until there is proof of the contrary, while a sign, a coiijecture, must often be weighed against another con- jecture. Thus it is that he who admits having borrowed money from another, is presumed to pay the debt, unless he shows that he had done so already, or that the debt ceases by some other principle. Presumption is not then in this sense taking before proof, which is not allowed, but taking in advance but with foundation, while awaiting a contrary proof. CHAPTEE XV OF PROBABILITY § 1. Ph. If demonstration shows the connection of ideas, probability is nothing else than the appearance of this connec- tion based upon proofs in which immutable connection is not seen. § 2. There are several degrees of assent from assurance down to conjecture, doubt, distrust. § 3. When there is cer- tainty, there is intuition in all parts of the reasoning which show its connection; but what makes me believe is some- thing extraneous. § 4. Now probability is grounded in its conformity v/ith what we know, or in the testimony of those who know. Th. I prefer to maintain that it is always grounded in like- lihood (vraisemblance) or in conformity with the truth; and the testimony of another is also a thing which the truth has been wont to have for itself as regards the facts that are within reach. It may be said then that the similarity of the probable and the truth is taken either from the thing itself, or from some extraneous thing. The rhetoricians employ two kinds of arguments: the artificial, drawn from things by rea- soning, and the non- artificial, based only upon the express testimony either of man or perhaps also of the thing itself. 2 M 530 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv But there are mixed arguments also, for testimony may itself- furnish a fact which serves to form an artificial argument. § 5. Ph. It is for lack of similarity to truth that we do not readily believe that which has nothing like that which we know. Thus when an ambassador told the king of Siam that Avith us the water was so hardened in winter that an elephant might walk thereon without breaking through, the king said to him : Hitherto I have believed you as a man of good faith ; now I see that you lie. § 6. But if the testimony of others can render a fact probable, the opinion of others should not pass of itself as a true ground of probability. For there is more error than knowledge among men, and if the belief of those whom we know and esteem is a legitimate ground of assent, men have reason to be Heathen in Japan, Mahometans in Turkey, Papists in Spain, Calvinists in Holland, and Luther- ans in Sweden. Til. The testimony of men is no doubt of more weight than their opinion, and in reason it is also the result of more reflection. But you know that the judge sometimes makes them take the oath de credtditate, as it is called ; that in the examinations, we often ask witnesses not only what they have seen but also what they think, demanding of them at the same time the reasons of their judgment, and whether they have reflected thereupon to such an extent as behooves them. Judges also defer much to the views and opinions of ex- perts in each profession; private individuals, in proportion as it is inconvenient for them to present themselves at the appropriate examination, are not less compelled to do this. Thus a child, or other human being whose condition is but little better in this respect, is obliged, whenever he finds him- self in a certain situation, to follow the religion of the coun- try, so long as he sees nothing bad therein, and so long as he is not in a condition to find out whether there is a better. A tutor of pages, whatever his sect, will compel them each to go to the church where those who profess the same belief as this young man go. The discussions between Nicole ^ and others on the argument from the great number in a matter of 1 Pierre Nicole, 1625-1695, one of the most distinguished of the Port-Royal- ists, and, with the exception of Arnauld {cf. ante, p. 463, note 4) and Pascal, the most accomplished memher of the school, was author with Arnauld of the fa- CH. XV] ON HUMAN UNDERSTANDING 531 faith may be consulted, in which sometimes one defers to it too much and another does not consider it enough. There are other similar prejudgments by which men would very easily exempt themselves from discussion. These are what Tertul- lian, in a special treatise, calls Prescriptiones,'^ availing him- self of a term which the ancient jurisconsults (whose lan- guage was not unknown to him) intended for many kinds of exceptions or foreign and predisposing allegations, but which now means merely the temporal prescription when it is in- tended to repel the demand of another because not made with- in the time fixed by law. Thus there was reason for mak- ing known the legitimate prejudgments both on the side of the Roman Church and on that of the Protestants. It has been found that there are means of opposing novelty, for example, on the part of both in certain respects ; as, for example, when the Protestants for the most part abandoned the ancient form of ordination of clergymen, and the Eomanists changed the ancient canon of the Old Testament books of Holy Scrij)ture, as I have clearly enough shown in a discussion I had in writing, and from time to time, with the bishop of Meavix, whom we have just lost, according to the news which came some days since. ^ Thus these censures being mutual, the novelty, although it presents a suspicion of error in these matters, is not a certain proof thereof. mous L'Art de Penser or the Port Royal Logic. His most important work is his Essais de Morcde, Paris, 1671-74. It was about his De I'unite de Veglise ou rtfutatio7i du nouveau systeme de Junen, Paris, 1687, tliat tlie theological controversies here alluded to byljcibnitz centred, and " in which the question was considered, whether Roman Catholicism allows itself to engage in the — undoubtedly questionable — argument of the ' majority of professors.'" An account of Nicole's De Vunit^ de Veglise will be found in Bayle's Diet., Eng. transL, Vol. 4, p. 363, London, 1737. — Tr. 1 Tertullian, 150-160 — 220-240, sought in his De Prsescriptione HsRveticorum to produce a formal general argument against all heresies — " adversus hrere- ses omnes " — his object being to prevent heretics, in accordance with certain just and necessary rules {prsescriptiones) , from appealing to Scripture in sup- port of their views. For an account of the work, cf. Smith and Wace, Diet, of Christ. Biog., Vol. 4, p. 837 a, sq.—Tvi. 2 Leibnitz here refers to his correspondence with Jacques Benigne Bossuet, 1627-1704, Bishop of Meaux from 1681 till his death. This correspondence was irenic in character, and extended, with some interruptions, over a period of about 25 years, but was without result, because Leibnitz would not suffer the freedom of scientific inquiry to be taken away, while Bossuet desired sub- jection to the infallible authority of the church. The entire correspondence has been published by Foucher de Careil, QSnvres de Leibniz, Vols. 1, 2, 532 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv CHAPTER XVI OF THE DEGREES OF ASSENT § 1. Ph. As for the degrees of assent, we must take care that the grounds of probability we have do not operate beyond the degree of likelihood found therein or which has been found therein when they are examined. For we must admit that assent cannot always be based upon an actual view of the rea- sons which have prevailed with the mind, and it would be very difficult even for those ^ who have an admirable memory Paris, 1859-60. A portion of the same is found in Dutens, Leihyiit. op. om., 1, 507 sg. The letters especially referred to are (1) of Leibnitz: Dec. 11, 1099, (Foucher de Careil, (Muvres de Leibniz, 2, 274-277 ; Dutens, Leibnit. op. om., 1, 594-596), May 14 and 24, 1700 (F. 2, 314-3G9 ; D. 1, 612-642) ; (2) of Bossuet : Jan. 9 and 30, 1700 (F. 2, 278-30(3; D. 1, 596-611), Aug. 17, 1701 (F. 2, 396-426; D. 1, 657-(J7.3). For an account of the controversy, cf. Pichler, Die Theologie des Leibniz, Vol. 2, pp. 206-215. The present passage is important, as it enables us to determine the date of the composition of the Neio Essays, or at least of this portion of them. Bos- suet died April 12, 1704. This passage must then have been written in the second half of April, 1704; and from other data (for which cf. Guhrauer, Leibniz. Eine Biographie, Bk. II., p. 282 and Anmerkungen z. zweiten Buche, pp. 38-39; and Gerhardt's Introduction to the New Essays, ante, pp. 8, 9, and notes) it is evident that the entire work was substantially completed in 1704, though the revision of the French style, and possibly some minor additions or alterations, occupied Leibnitz to a certain extent after this date. In this connection it is to be noted that the date given, ante, p. 9, line 15, 1709, should be 1704 {cf. Gerhardt, Leibniz, philos. Schrift., 3, 297, note *), and that Gerhardt's remark, ante, p. 9: "On the other hand, he remarks, well- nigh it seems in the opposite sense," etc., as well as that by the Translator, ante, -p. 101, note i,pr ope. fn.: " As Leibnitz was occupied . . . with the com- position and revision of his New Essays, from 1700 ... to 1709 and perhaps later . . . possibly even as late as 1714 or 1716," should be modified accord- ingly. -Tr. 1 Gerhardt's text reads: " Sur une veue actuelle des raisons, qui ont prevalu sur I'esprit, et il seroit tres difficile, meme a ceitx, qui ont une memoire ad- mirable," etc. The words italicised above are not found in the t]exts of Raspe, Erdmann, Jacques and Janet; and Janet restores the sense of " this incorrect phrase "thus: "... Sur une vue actuelle des raisons, co?)ime i^amwe chez ceux qui ont une memoire admirable, capable de toujours retenir. ..." Gerhardt's reading agrees with Locke's text, cf. Philos. Wks., Vol. 2, p. 271, Bohn's ed., and is therefore to be preferred. — Tr. CH. xvi] ON HUMAN UNDERSTANDING 633 always to retain all the proofs which have compelled them to a certain assent, and which sometimes might fill a volume on a single question. It suffices that they have once examined the matter minutely with sincerity and with care, and that they have, so to speak, cast np the account. § 2. Without this men must be very sceptical, or change their view at every moment, in order to yield themselves to every man who, having exam- ined the question of late, offers them arguments which they cannot at once wholly answer, for lack of memory or of appli- cation at leisure. § 3. It must be admitted that this often makes men obstinate in error : but the fault is, not tliat they rely upon their memory, but that they have badly judged be- fore. For often the remark that they have never thought otherwise takes the place of an examination and of reason with men. But ordinarily those who have least examined their opinions hold them most tenaciously. Holding to what one has seen is praiseworthy, but not always to what one has believed, because some consideration may have been left behind capable of overturning all. There is perhaps no one in the world who has the leisure, patience, and means of assembling all the proofs on both sides of the question upon which he has his opinions in order to compare these proofs and safely to conclude that nothing more remains for him to know for his more ample instruction. But the care of our life and of our more important interests cannot bear the delay, and it is abso- lutely necessary that our judgment be determined upon the points when we are incapable of attaining to a certain knowl- edge. Th. There is nothing but what is good and solid in what you, sir, have just said. It would be desirable, however, for men to have at certain junctures written abstracts (in form of memoranda) of the reasons which have led them to an impor- tant opinion, which they are obliged often to justify after- wards to themselves or others. Besides, although in a matter of justice it is not usually allowable to retract the judgments which have been passed, and to revise the verdicts agreed upon (otherwise there would necessarily be perpetual unrest, which would be so much the more intolerable as the accounts of things past cannot always be preserved), yet one is some- times allowed upon new light to sue for justice, and also to 534 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv obtain what is called restitutio in integrum ^ contrary to the decision that has been given. And likewise in onr own affairs, especially in matters very important, where it is still allowable to embark or to put back, and where it is not preju- dicial to suspend their execution and to proceed bridle in hand, the decisions of our minds based upon probabilities shojild never so pass in rem judicatam, "^ as the jurisconsults call it, i.e. to a settlement, that we may not be disposed to the revision of the reasoning when new counter reasons of weight present themselves. But when there is no more time for delib- eration, we must follow the judgment we made with as much firmness as if it were infallible, but not always with so much strictness.^ § 4. Ph. Since, then, men cannot avoid exposing themselves to error in judgment and having different opinions, since they cannot look at things from the same points of view, they must maintain peace between themselves and the duties of humanity amid this diversity of opinions without claiming that another should promptly change a rooted opinion upon our objec- tions, especially if there is room for supposing that his adversary acts from interest or ambition or from some other private motive. Most frequently those who would impose upon others the necessity of yielding to their opinions have examined things with but little thoroughness. For those who have entered beforehand sufficiently into the discussion to extricate themselves from doubt are so few in number, and find so little reason to condemn others, that nothing violent is to be expected on their part. Th. Really that which one has the most right to censure in men is not their opinion, but their rash judgment in censuring 1 Cf. Paulus, Sententiarnm, Lib. I., Tit. VII. 1.: "Integri restitutio est re- dintegrandfe rei vel causae actio. 2. Integri restitutionem praetor tribuit ex his causis, quae per metum, dolum et status permutationem, et justum errorem, et abseiitiam necessariam, et infirmitatem aetatis gesta esse dicuntur ; " also Digest, Lib. XLII., Tit. I. 33. ^ Cf. Dic/est, Lib. XLII., Tit. I. 1 : " Res jvdicata dicitur, quae finem con- troversiam pronunciatione judicis accipit : quod vel condemnatione vel abso- lutione contingit." — Tr. 3 Janet cites as a parallel jaassage Descartes, Discours de la Methode, Pt. III. : " Ma seconde niaxime etait d'etre le plus ferme et le plus resolu en mes actions que je pourrais, et de ne suivre pas moins constaniment les opinions les plus douteuses lorsque je m'y serais une fois determine que si elles eussent ete tres-assurees." — Tr. CH. XVI] ON HUMAN UNDERSTANDING 535 that of others, as if it were necessary to be stupid or wicked to judge differently from themselves; a condition of things Avhich, in the authors of these passions and hatreds Avho spread them among the public, is the effect of a mind haughty and unfair, Avhich loves .to rule and cannot suffer contradiction. JSTot that there is not, in truth, reason very often for censuring the opinions of others, but it must be done in a spirit of fair- ness, and sympathy with human weakness. It is true that we are right in taking precautions against bad doctrines, which are influential upon manners and upon practical piety : but we must not attribute them to people to their prejudice without having good proofs of the same. If fairness wishes to spare persons, piety demands the representation, where it is fitting, of the bad effects of their dogmas when they are in- jurious, as those are which are contrary to the providence of a perfectly wise, good, and just God, and contrary to that immortality of souls which renders them susceptible of the effects of his justice, not to speak of other opinions dangerous as regards morality and the police. I know that excellent and well-meaning men maintain that these theoretic opinions have less influence upon practice than is thought, and I also know that there are persons of an excellent disposition whom these opinions will never make do anything unworthy of themselves : as also those who have reached these errors by speculation, are by nature wont to be farther removed from the vices to which men in general are susceptible, besides the fact that they are careful of the dignity of the sect in which they are, as it were, chiefs; and it may be said that Epicurus and Spinoza, for example, have led a life wholly exemplary. But these reasons cease most frequently in their disciples or imitators, who, believing themselves released from the trouble- some fear of an overseeing Providence and of a menacing future, give loose reins to their brutish passions, and turn their mind to the seduction and corruption of others ; and if they are ambitious and of a disposition somewhat harsh, they will be capable, for their pleasure or advancement, of setting on fire the four corners of the earth, as I have knoAvn from the character of some Avhom death has swept away. I find also that similar opinions insinuating themselves little by little into the minds of men of high life who rule others and upon 536 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv "whom affairs depend, and slipping into the books in fashion, dispose all things to the general revolution with which Europe is threatened, and accomplish the destruction of what still remains in the world of the generous sentiments of the ancient Greeks and Romans, who preferred love of country and of the public good, and regard for posterity to fortune, and even to life. These public spirits, as the English call them, are fast diminishing, and are no longer in fashion; and they will diminish still faster when they are no longer sus- tained by the good morality and true religion which even natural reason teaches us. The best of the opposite character who are beginning to rule have no other principle than that they call honor. But the mark of the honest man and of the man of honor with them is only to do no baseness as they understand it. And if for the sake of power or through caprice anyone poured forth a deluge of blood, if he turned every sense upside down, that would be counted as nothing, and a Herostratus ^ of the ancients or a Don Juan in the " Festin de Pierre " ^ would pass for a hero. Boldly they scoff at the love of country, they ridicule those who care for the public, and when any well-mean- ing man speaks of what will become of posterity, they reply: we shall see when the time comes. But these persons will pos- sibly experience themselves the evils they think reserved for others. If, however, this disease of an epidemic mind whose bad effects begin to be visible is corrected, these evils will perhaps be prevented; but if it goes on increasing. Providence will correct men by the revolution itself which must spring there- from : for whatever may happen, everything will always turn out for the better in general at the end of the account, although that ought not and cannot happen without the punishment of those who have contributed even to the good by their bad acts. But I return from a digression into which the consideration of truthful opinions and of the right of censuring them has led me. 1 Herostratus, an Ephesian, who, for the sake of making his name famous, as he himself confessed on being put to torture, set fire to the temple of Ar- temis at Ephesus, on the night in which Alexander the Great was born, 356 B.C. — Tr. 2 The Don Jrian ou le Festin de Pierre, 1665, a comedy of Moliere, 1622- 1673, the principal character of which is Don Juan. The play, written in prose, was versified in 1677, at the request of Moliere's widow, by Thomas Corneille, 1625-1709. — Tr. CH. XVI] ON HUMAN UNDERSTANDING 537 Now as in theology censures go very much farther than else- where, and as those who lay great stress upon their orthodoxy, often condemn their adversaries, to whom those in the same party who are called syncretists by their adversaries are opposed, this opinion has caused civil wars to spring up between the rigid and condescending in one and the same party. But, as to refuse eternal salvation to those who are of another opinion is to encroach upon the rights of God, the wisest of those who condemn, only indicate the peril in which they think they see erring souls, and leave to the peculiar mercy of God those whose wickedness does not render them incapable of profiting therefrom, and on their part believe themselves obliged to make all imaginable efforts to withdraw them from a condition so dangerous. If these persons who thus judge of the perils of others have come to this opinion after a suitable examination and there are no means of dis- abusing them of it, their conduct cannot be censured so long as they use only fair means. But as soon as they go farther, they violate the laws of equity. For they should consider that others persuaded like themselves have an equal right to maintain their views, and even to spread them if they think them important. Opinions must be excepted Avhich teach crimes that should not be allowed, and which it is right to suppress by stringent means, if it should be true, indeed, that he who maintains thetn cannot be rid of them; ^ as it is right to destroy even a poisonous animal, wholly innocent as it is. But I speak of suppressing the sect and not men, since we can prevent them from doing harm and dogmatising. § 5. Ph. To return to the ground and degrees of assent, it is proper to remark tliat propositions are of two kinds. Some are of fact, and, depending upon observation, may be based upon human testimony ; others are speculative, and, regarding things which our senses could not discover, are incapable of similar testimony. § 6. When a particular fact is in conformit}^ with our constant observations, and with the uniform report of others, we rest upon it as firmly as if it were certain knowl- 1 Gerhai'dt reads: " ne peut point s'en defaire." Erdmann, Jacques and Janf.t read: " ne peut point s'en faire," and Janet in his note says : "supply 'd'autres.' " With this reading the meaning is: " cannot procure for himself others." — Tr. 538 LEIBNITZ'S CRITIQUE OF LOCKE [bk.iv edge, and where it is in conformity with the testimony of all men, in all ages, so far as can be known, it is the first and highest degree of probability; for example, that fire warms, that iron sinks to the bottom of the water. Our belief built upon such foundations rises to assurance. § 7. In the second place, all historians relate that such an one has preferred his individual interest to that of the public, and as it has always been observed that this is the custom of the majority of men, the assent I give to these histories is confidence. § 8. Thirdly, when there is nothing either for or against it in the nature of things, a fact, vouched for by the testimony of unsuspected people, for example, that Julius Caesar lived, is received with 2i firm belief. § 9. But when the testimony is found contrary to the ordinary course of nature or the witnesses vary among themselves, the degrees of probability may vary infinitely, whence arise these degrees which we call belief, conjecture, doubt, uncertainty, distrust; and there it is that exactness is necessary to form a right judgment and to proportion our assent to the degrees of probability. Til. Jurisconsults in treating of proofs, presumptions, con- jectures, and indices, have said a number of good things on this subject, and have gone into some considerable detail. They begin with notoriety, in which there is no need of proof. Afterwards they come to complete proofs, or those which pass as such, upon which they pronounce sentence, at least, in a civil process, but upon which in some places they are more reserved in a criminal process; and they are not wrong in demanding in such case proofs more than complete, and espe- cially as regards what is called corpus delicti, according to the nature of the act. There are then proofs more than complete, and there are also ordinary complete p)roofs. Then there are presumptions, which pass provisionally as complete proofs, i.'e. so long as the contrary is not proved. There are proofs more than half complete (to speak precisely), in which the one who relies upon them is allowed to swear to make them good (the juramentum suppletorium) ; there are others less than half complete, where wholly to the contrary the oath is adminis- tered to him who denies the act, to purge himself (the jura- mentum purgationis) . Beyond this there are many degrees of conjectures and indices. Particularly in a criminal process CH. xvi] ON HUMAN UNDERSTANDING 539 there are indices {ad torhiram) to proceed to the torture, which itself has its degrees indicated by the formulas of arrest; there are indices (ad terrendum) sufficient to show the instru- ments of torture and to prepare things as if they intended to come to it. There are some (ad capturam) to make sure of a suspected man; and (ad inquireyidum) to make inquiries secretly and without noise. And these differences may be of use also on other similar occasions. The entire form of judi- cial procedure is nothing else in fact than a species of logic aioplied to questions of law. Physicians also have a number of degrees and differences in their signs and indications which may be seen among them. The mathematicians of our times have begun to calculate chances upon the occasion of games. Chevalier de Mere/ whose "Agremens" and other works have been printed, a man of penetrating mind who was both a player and a philosopher, gave them an opportunity by form- ing questions regarding the profits in order to know how much the game would be worth, if interrupted at such or such a stage. In this way he induced Pascal, his friend, to examine these things a little. The question made a stir and gave Huygens the opportunity to produce his treatise *'de Alea."^ 1 Cf. ante, p. 213, note 2; also Response {Repliqiie) aux reflexions confenues dans la seconde Edition du Dictiojinaire Critique de M. Bayle, Gerhardt, 4, 570, Erdmann, 190, Janet, 2, 593, Dutens, 2, Ft. I., 92. Antoine Gombault, chevalier de Mere, c. IGlO-KiSl, was erroneonsly confounded with a Georges Brossin, chevalier de Mere, belonging to another family, by all biographers since Moreri, until the special researches of M. de Bremont d'Ars proved the error and assigned him his right name. He had an inordinately exalted idea of his own importance and attainments, especially in mathematics. His Agrements, discours de M. le chevalier de Mere a iV™« **, appeared in 1677, 12mo, and in the collected edition of all his works, entitled (Euvres du chevalier de Mere, Amsterdam, 1692, 2 vols., 12mo. A volume of QSuvres posthumes, 12mo, appeared at Paris, 1700, and again at The Hague, 1701. For further account of him, cf. Larousse, Grande Diet. Univ. de A'/A"™" Siecle, Vol. 11, p. 72. — Tr. ■^ Of. ante, p. 150, note 3. Huygens' Be ratiociniis in alese ludo, dated The Hague, 1657, is found in F. van Scliooten, Exercitat. math. lib.V., pp. 514-539, Lugd. Bat. 1657, 4to. It was written by Huygens in Dutch and translated into Latin by Schooten. There are two English translations, one attributed to Motte, but probably by Arbuthnot ; the other by W. Brown. Cf. I. Todhunter, Hist, of the Math. Theo7^ of Probability, pp. 22-23, Cambridge and Loudon, Macmillan & Co., 1865. Leibnitz, Miscellan. Leibnit., No. CXIII., cf. Dutens, 6, Pt. I., 318, says of it: " Christiani Hugenii ratiocinia r?e lusu alese, Franc. Schotenii script is mathematicis adjecta, sunt elegans specimen ratiocinationis de gradibus probabilitatis." Spinoza also discussed the calculation of probabilities in games of chance. 640 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv Other learned men entered into the subject. Some principles were established of which the Pensioner De Witt also availed himself in a brief discourse printed in Dutch on annuities.-^ The foundation on which they have built goes back to the prosthaphceresis,- i.e. the taking of an arithmetical mean be- tween several equally receivable suppositions. Our peasants also have made use of it for a long time according to their natural mathematics. For example, when some inheritance or land is to be sold, they form three bodies of appraisers ; these bodies are called Schurzen in Low Saxon, and each body makes an estimate of the property in question. Suppose, then, that the first estimates its value to be 1000 crowns, the second 1400, the third 1500; the sum of these three estimates is taken, viz. 3900, and because there were three bodies, the third, i.e. 1300, is taken as the mean value asked for; or rather, they take the sum of the third part of each estimate which is the same thing. This is the axiom: oiqualihus cequalia, equal suppositions must have equal consideration. But when the suppositions are unequal they compare them with each other. Suppose,- for example, tliat with two dice, the one ought to win if it makes 7 points, the other if it makes 9, the question is asked v/hat j^roportion obtains between their probabilities of winning? I reply that the probability of the last is worth only two-thirds of the in a letter to Jan van der Meer. Cf. Epistola No. 38 (formerly 43) , Spinoza, Opera, ed. Van Vloten and Land, 2, 145-149 (in Latin and Dutch) : Spinoza's Bi-iefwechtel, in J. H. v. Kirchmann's Philos. Bibliothek, Vol. 46, pp. 145- 147. — Tr. 1 Cf. ante, p. 426, note 2. John De Witt appears to have been " the first to apply scientific principles to the calculations connected with annuities, which are analogous to those connected with assurances." His report on this sub- ject was presented to the States General, July 30, KiTl. It was entitled De vardye van de Uf-renteji na propnrtie van de los-renten, and appeared at La Haye, KiTl. An abstract of it, showing- exa.-tly how De Witt reasoned on the subject, will be found in M. Nicolas Struyck, Inlelding tot liet algeniHne geo- graphy, etc., p. 34."), Amsterdam, 1740, 4to, and an English translation of the tract is printed in Contributions to the Hist, of Insurance by Frederick Hendriks in the "Assurance Magazine," Vol. 2 (18.52), p. 231. For some remarks on De Witt's hypothesis as to the rate of mortality, cf. the same vol., p. 393. — Tr. 2 Prosthaphaeresis — 7rpoo-ea<|>aipea-i; — = a previous subtraction. The term here signifies " the fundamental principle for the ascertainment of the degree of probability which requires us to take the arithmetical mean of the existing suppositions estimated according to their relative value." — Tr. CH. XVI] ON HUMAN UNDERSTANDING 541 probability of the first, for the first can make 7 in three ways with two dice, viz. : by 1 and 6, or 2 and 5, or 3 and 4; and the other can make 9 in two ways only, by throwing 3 and 6, or 4 and 5; and all these methods are equally possible. Then the probabilities, which are as the numbers of equal possibilities, will be as 3 to 2, or as 1 to -1. I have more than once said that a new kind of logic would be required which would treat of the degrees of probabilit}', since Aristotle in his " Topics " has done nothing less than this, and has con- tented himself with putting in a certain order certain popular rules distributed according to the common topics, which may be of use on some occasion where the question concerns the amplification of the discourse and the giving to it probability without putting it to the trouble of furnishing iis a necessary balance for weighing probabilities and forming thereupon a solid judgment.^ It would be well for him who should treat of this matter to pursue the examination of games of chance; and in general I Avish that some skilful mathematician would produce an ample work with full details and thoroughly reasoned upon all sorts of games, which would be very useful in perfecting the art of invention, the human mind appearing to better advantage in games than in the most serious matters. § 10. Ph. The law of England observes this rule, that the copy of an act received as authentic by witnesses is a good proof, but the copy of a copy, however attested, and by wit- nesses the most credible, is never admitted as a proof in a trial. I have never yet heard any one censure this wise pre- caution. This observation at least may be drawn from it, that testimony has less force in proportion as it is farther removed from the original truth which is in the thing itself; while among certain peoples use is made of it in a directly contrary manner, opinions acquiring force as they grow older, and what would not at all have appeared probable a thousahd years ago to a reasonable man a contemporary of the one who first certified it, passes at present as certain because many h^ve related it upon his testimony. Th. Historical critics have great regard for contemporary witnesses of things : but a contemporary even merits belief chiefly as regards public events only ; but when he speaks of 1 Cf. ante, p. 417, note 3. — Tr. 542 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv motives, secrets, hidden forces, and things Avhich may be dis- puted, as, for example, poisonings, assassinations, we acquaint ourselves with what many have believed. Procopius is very credible when he speaks of the war of Belisarius against the Vandals and the Goths, but when he retails horrible scandals against the Empress Theodora in his " Anecdotes," he may believe them who will.^ Generally, we should be very re- served in believing satires ; we see some published in our times which, although wholly improbable, have nevertheless been greedily swallowed by the ignorant. And some day perhaps it will be said : Is it possible that one would have dared to publish these things at that time, if there had been any appar- ent foundation for them ? But if this statement is some day made, the judgment will be a very erroneous one. The world, however, is inclined to indulge in satire ; and, to quote but one example, the late Mr. Maurier, the son,^ having published, from some caprice, in his memoirs printed some years since, certain things wholly without foundation against the incom- parable Hugo Grotius, ambassador from Sweden to France, stirred apparently by some unknown circumstance against the memory of this illustrious friend of his father, I have noticed that many authors have repeated them from envy, although the negotiations and letters of this great man sufficiently make known the contrary. We have emancipated ourselves indeed from writing romances in history, and he who produced the last life of Cromwell thought that in order to enliven the subject he was allowed, in speaking of the life, still private, of this clever usurper, to make him travel in France, where he follows him into the public houses of Paris as if he had 1 For critical discussion of the authorship of the Ta 'AvexSoTa — Anecdota or Historia Arcana — of Procopius, and of the credibility of its contents, cf. J. H. Reiukens, Anecdota sintne scrij^ta a Procopio Csesariensi inq^iiritur, Breslau, 1858, who denies, and F. Dahn, Prokojylus von CUsarea, Berlin, 18(J5, who affirms, that Procopius is the author. Prof. James Bryce gives a brief account and estimate of the work in his article on "Procopius," in the Encyclop. Brit. 9th ed. Cf. also M. Debidour, Thesis, 1877, who tries to make out the best case he can for Theodora, and Prof. Bryce in the " Contemporary Review," Feb. 1885. — Tr. 2 Louis Aubery du Maurier, the historian, died 1687, was the son of Benjamin Aubery, an ambassador from France to Holland, and published Memoires pour servir a I'Histoire de Hollande, 1680, Menioi7^es de Hamburg, de Lubeck, de Holstein, etc. Leibnitz refers to him in his letter to Bierling, Oct. 24, 1709, Gerhardt, 7, 487. —Tb. CH. xvi] ON HUMAN UNDERSTANDING 54c! been his master.^ But it appears by tlie history of Crouiwel] written by Carrington, a well-informed man, and dedicated to his son Kichard when he acted the part of the Pro> tector, that Cromwell never went out of the British Isles. Detail especially is uncertain. There are almost no good accounts of battles ; the majority of those of Titus Livius appear to be imaginary, as well as those of Quintus Curtius. It would be necessary to have on both sides the accounts of exact and capable men, who indeed would draw up plans of them like those which the Count of Dahlberg, who had already served with distinction under the King of Sweden, Charles Gustavus, and who, being Governor-General of Livonia, re- cently defended Kiga, has had engraved touching the actions and battles of this prince. We must not, however, at once decry a good historian at a word from some prince or minister who has exclaimed against him on some occasion, or in regard to some subject not to his taste or wherein there really is per- haps some fault. The story is told that Charles the Fifth, wishing to have something of Sleidan^ read, said: "Bring me ni}' story-teller {menteur),'" and that Carlowitz, a Saxon gentle- man, of good repute at that time, said that the history of Slei- dan destroyed in his mind all the good opinion he had had of the ancient histories. That statement, I say, will have no force in the minds of well-informed persons in overthrowing the authority of the history of Sleidan, the best part of which is a series of the public acts of the Diets and Assemblies, and of the writings authorized by the princes. And if there re- mained the least scruple regarding it, it has just been removed by the excellent history of my distinguished friend, the late Mr. Von Seckendorf^ (in which I cannot, however, refrain 1 Leibuitz here refers, according to Schaarschmidt, to Jas. Heath's Flaqel- lum; or the Life and Death, Birth and Burial of Oliver, the late Usurper, London, 1663, 8vo. In this book the Protector is generously slandered and abused. S. Carrington's The Hist, of the Life and Death of Oliver Croimvell, London, 1659, 8vo, is a panegyric, in which Cromwell is compared, among others, with Alexander the Great. An abridgment of Heath's book may be found in the " Harleian Miscellany," 1,279, ed. Park. It may be added that " the earliest lives of Cromwell were either brief chronicles of the chief events of his life or were panegyrics." — Tr. 2 Of. ante, p. 114, note 1. — Tr. 3 Veit Ludwig yon Seckendorf, 1626-1692, a distinguished German scholar and statesman, whose Cornmentarins historicus et apologeticus de Lutheran- ■544 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv from disapproving the term '' Ltitlieranism " on the title-page, which a bad custom has authorized in Saxony), wherein the majority of the statements are justified by extracts from an immense number of yjieces, drawn from the Saxon archives which he had at his disposal, although the Bishop of Meaux, who contested their validity, and to whom I sent it, merely replied to me that this book is horribly prolix ; but I could wish that it were twice as large on the same scale. The more ample it is, the more hold it must give, since one has only to choose his passages ; besides, there are some esteemed histori- cal works which are much greater. For the rest, we do not always despise authors posterior to times of which they speak when what they relate is apparently otherwise. Some- times, .also, it happens that they preserve some most ancient pieces. For example, there has been doubt as to what family Suibert, Bishop of Bamberg, since Pope under the name of Clement II., belonged. An anonymous author of the history of Brunswick, who lived in the fourteenth century, named his family, and some persons lea-rned in our history desired to pay no regard whatever to it; but I have had a chronicle much more ancient, not yet printed, in \vhich the same statement is made with more details, from which it appears that he be- longed to the family of the ancient allodial seigniors of Horn- bourg (not faV from Wolfenbuttel), the territory of which was given by the last owner to the cathedral church of Halber- stadt. § 11. Ph. I do not wish you to think that I desired to lessen the authority and use of history by my remark. It is from this source that we receive with a convincing evidence a large iftmo sive de Ecformationp, Leipzig, 1692, 3 vols., fol., occasioned by and directed against tlie L' Histoire du Lutheranisine, Paris, KJSO, of tlie Jesuit Maimbourg, is his most important work, and a rich storeliouse of authentic materials for the history of the reformation from 1517-1547, drawn from tocuments contained in the Saxon archives, the writings of the reformers and 1 lieir contemporaries, accompanied by a polemical and historical commentary. ft is the work of an able, philosophic mind, with scarcely a trace of the secta- rian spirit. Leibnitz gives a brief account and estimate of the book in his letters to Bossuet, Jan. 8-18, and April 8-18, 1692 [cf. Foucher de Careil, (Eavi-fs de Leibniz, 1, 228, 275, Dntens, Leihnit. op. 07)i.', 1. 523-4, 530-531). It is also referred to in Bossuet's letters to Leibnitz, Jan. 10, 1692 (F. 1, 22(5, D. 1, 522), March 26 or May 26, 1692 (F. 1, 253), and Leibnitz to Bossuet, without dates (F. 1, 223, 254-255). For further remarks of Leibnitz concerning it, cf. Dutens, 5, 90, 93, 566. — Tr. J CH. xvi] ON HUMAN UNDERSTANDING 545 part of our useful truths. I see nothing more valuable than the records of antiquity remaining to us, and I wish we had more of them, and less corrupted. But it is always true that no copy raises itself higher than the certainty of its first original. Th. It is certain, that Avhen we have a single ancient author as the authority for a fact, all those who have copied him add no weight thereto, or rather should be reckoned as nothing. It should be wholly as if what they said belonged to the number, Toiv aTTtt^ Aeyo/xeVwv, of things which have been said only once, a collection of which Menage^ wished to make. Moreover, to- day, if a hundred thousand petty writers should repeat the slanders of Bolsec ^ (for example), a man of judgment would value it no more than the noise of goslings. Jurisconsults have written de fide historica; but the subject merits a more exact research, and some of these gentlemen have been too indulgent. As for tliat which is of great antiquity, some of the most noted facts are doubtful. Clever people have doubted, with reason, whether Romulus was the first founder of the city of Rome. There is dispute about the death of Cyrus, and besides, the discrepancy between Herodotus and Ctesias has spread doubt upon the history of the Assyrians, Babylonians, and Persians. That of Nebuchadnezzar, of Judith, and even of the Ahasuerus of Esther suffer from great difficulties. The Romans, when speaking of the gold of Toulouse, contradict the story of the defeat of the Gauls by Camillus. Above all, the particular and private history of peoples is without credit, unless it is taken from very ancient originals, and is suf- ficiently in conformity with public history. This is why the 1 Cf. ante, p. .350, note 1. — Tr. ' Jerome Hermes Bolsec, born at Paris, died 1685, at Lyons, was a Carmel- ite of Paris, who forsook his order, became a Protestant, fled to Italy and thence to Geneva, where he set up as a pliysieian, but not meeting witli tlie success he desired, gave himself up to theology, discoursed publicly on the doctrine of Predestination, advocating the views of Pelagius, and thus incur- ring the censure of Calvin, was imprisoned and then banished by the Senate of Geneva, Dec. 29, 1551. He went thence to Bern, whither Calvin pursued him. These persecutions developed in him a violent liatred towards Calvin, which, after his return to the Catholic faith, he vented in his L'Histoire de la vie, maeurs, actrs, doctrine et niort de Jean Calvin, Paris, 1577, 8vo. He also pub- lished a similar work, L'Histoire de la vie, nKjiiirs, doctrine et deportements de Theodore de Beze, Paris, 1580, Svo. Both works are merely pamphlets, with no historical authority. — Tk. 2 N 546 LEIBNITZ'S CRITIQUE OF LOCKE [bk iv stories told us of the ancient German, Gallic, British, Scotch, Polish, and other kings pass with reason as fabulous and made up. Trebeta, son of Ninus, founder of Treves, Bru- tus, ancestor of the Britons, or Britains, are as real as the Amadis. The tales taken from certain story-tellers, which Trithemius,^ Aventin,^ and even Albinus^ and Sifrid Petri* have taken the liberty to tell of the ancient princes of the Franks, Boii, Saxons, Frisians ; and what Saxo Gramaticus and the Edda tell us of the remote antiquities of the north, cannot have more authority than what Kadlubko,^ the first Polish historian, says of one of their kings, a son-in-law of Julius CaBsar. But when the histories of different peoples agree in instances where there is no appearance that one has copied another, it is a great sign of their truth. Such is the 1 .Johann Tritliemius, 1462-1516, abbot of Spanheim, whose Compendium, sive breviariumprimi voluminis annaliwni, sive historianim, cle oriffine reimm et gentis Franeorum appeared at Mainz, 1515, reprinted, Paris, 1539. Leib- nitz speaks of him in his Introd. in collectionem Sci'iptorum Histor. Bruns- vieensi inservientium, Dutens, 4, Pt. II., 4, 5. For an account of him, cf. Midland, Biog. Univ. Vol. 46, pp. 551-559. —Tr. 2 Johann Thurmayr Aventinus, 1466-1534, autlior of Annales Boiorum. His history, the materials of which were drawn from authentic sources, was finished in 1528, and published " with some important omissions " of passages adverse to the Roman Catholics by Zeigler in 1554. The omitted passages were afterwards restored by Nicolas Cisner in the Basle ed., 1580. Leibnitz mentions him \nh\s Introd. in col. Script. Histor. Brunsvic, Dutens, 4, Pt. II., 4. — Tr. 3 Alcuin, — Latin, Alcuinus or Albinus Flaccus, — c. 735-804, the instructor of Charlemagne, whose collected works, containing among other things some historical treatises, were first published by And. Duchesne, Paris, 1617, 1 vol., fol., and afterwards by Froben, Alcuini opera, post editionem ab And. Qverce- tano curatuin, de novo collata, emendata, aucta et illustrata, 2 vols., fol., Ratisbon, 1777. Migne, Patrol., Vols. 100, 101, is a reprint of this ed. — Tr. * Sifrid or Suffrid Petri, 1527-1597, a Dutch philologist of great learning, but deficient in critical ability and taste, was Professor of Latin and Greek in the University of Erfurt, 1557, of Law at Cologne, 1577, and of Canon Law at Louvain and Cologne, 1585. He was the historiographer of the States of Fries- land, and published De Frisiorum antiqvitate et ongine lib. III., Cologne, 15!:K); Be Scriptoribus Frisise decades XVI. et semis, Cologne, 1593. His Historia veterum episcoporum Ultrajectinse sedis et comitum HoUandix, appeared at Francker, 1612. — Tr. 5 Vincent Kadlubek or Kodlubko, 1161-1223, bishop of Cracow, a Latin chronicler of the early history of Poland, whose Historia Polonica, Do- bromiel, 1612, 12mo, written with spirit, but in a barbarous style, throws much light on the events of his own time, but must be received with caution, as regards the early period, since he treated the early legendary stories, many of which closely resemble the Scandinavian sagas, as genuine history. The work is in four books and extends to the year 1202, and is true and faithful in relating events in Poland in the 11th and 12th centuries. — Tr. CH, XVI] ON HUMAN UNDERSTANDING 547 accord of Herodotus with the history of the Old Testament in many things, for example, when he speaks ^ of the battle of Megiddo between the king of Egypt, and the Syrians of Pales- tine, i.e. the Jews, in which, according to the testimony of the sacred history we have of the Hebrews, King Josias was mortally wounded. The consent of the Arabic, Persian, and Turkish historians with the Greeks, Romans, and other occi- dentals gives pleasure to those who seek for facts ; as also the testimony which the medals and superscriptions, remain- ing from antiquity, render to the books which have come down from the ancients to us and which are, in reality, copies of copies. We must wait for what we shall yet learn of the history of China, until we are in a better condition to judge of it, and until it shall bear its credibility with itself. The use of history consists principally in the pleasure there is in knowing origins, in the justice rendered to the men who have deserved well of other men, in the establishment of historical criticism, and especially of sacred history, which supports the foundations of revelation, and (putting also aside the geneal- ogies and laws of princes and powers) in the useful teachings which the examples furnish us. I do not despise the thorough examination of antiquities, even to the smallest trifles ; for sometimes the knowledge which the critics draw from them may be of use in more important matters. I consent, for ex- ample, to the writing even of the entire history of clothing and of the tailor's art, from the garments of the Hebrew priests, or, if you please, from the peltries which God gave to the first bride and bridegroom at their departure from Paradise, to the top-knots and furbelows of our time, and to the union there- with of all that can be drawn from ancient sculptures and from paintings also made some centuries after. I will furnish indeed, if any one desires it, the memoirs of a man of Augs- burg of the past century, who is described with all the clothes which he wore from his infancy up to the age of 63 years. I do not know who told me that the late Duke of Aumont,- a 1 Cf. Herodotus H. 159, and notes of Bahr and Rawlinson on the passage. — Tr. 2 Louis-Marie-Victor d'Aumont, 1632-1704, a French scholar, numismatist, and " brigadier du roi" under Louis XIV. in the Low Countries, contributed much to the progress of the knowledge of medals, and was a member of the " Ac.idemic des inscriptions et Belles-Lettres." — Tr. 548 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv great connoisseur of fine antiquities, had a similar curiosity. This may perhaps be of use in distinguishing the legitimate monuments from those which are not so, not to speak of other uses. And since men are allowed to play, they will still further be allowed to divert themselves with these kinds of work, if their essential duties do not suffer thereby. But I wish there might be some persons who would devote them- selves preferably to drawing from history that which is more useful, as the extraordinary examples of virtue, remarks upon the conveniences of life, stratagems of politics and of war. And I wish that a kind of universal history were written which should indicate only such things, and some few others of more consequence ; for sometimes one reads an extensive historical work, learned, well-written, suited also to the end of the author, and excellent of its kind, but which contains little useful instruction, by which I do not mean here simple morality, with which the " Theatrum vitse humange " ^ and other such florileges are filled, but skill and knowledge of which everybody would not think in case of need. I wish also that an infinite number of things of this nature, by which we might profit, might be drawn from books of travel, and be arranged according to the order of the subjects. But it is astonishing that while so many useful things remain to be done, men amuse themselves almost always with what is already done, or with purely useless things, or at least Avith what is the least important, and I see little remedy therefor until the public is more concerned about them in more tranquil times. § 12. Ph. Your digressions give pleasure and profit. But from the probabilities of facts, let us come to those of opinions concerning things which do not fall under the senses. Such things are incapable of any testimony, for example, the exist- ence and- nature of spirits, angels, demons, etc., the material substances which are in the planets and other mansions''^ of 1 Theodore Zwinger, 1533-1588, a celebrated Swiss physician, whose Thea- trum vitas hunianse, " a vast compilation of historical facts and anecdotes, and of curious and piquant observations," iu preparing which he availed himself of the materials which his father-in-law, Lycostlienes [Conrad Wolffhart], 1518-1561, had collected and asked him to set in order, appeared at Basle, 1565-1601, 5 vols., fol. — Tr. 2 Gerhardt reads: " de," a Ms. or typographical error; Erdmann, Jacques, and Janet have " et." — Tr. 8 Locke's word, Philos. Works, Vol. 2, p. 279 (Bohn's ed.). — Tr. CH. xvi] ON HUMAN UNDERSTANDING 549 this vast universe ; tinally, upon the mode of operation of the majority of the works of nature, and of all these things we can have merely conjectures, wherein analogy^ is the great rule of probability. For being incapable of attestation, they can appear probable only so far as they agree more or less with established trnths. As violent friction of two bodies produces heat and even tire, as the refractions of transparent bodies produce the appearance of colors, we think that fire consists in a violent agitation of the imperceptible parts, and that colors also, whose origin we do not see, come from a simi- lar ref laction ; and finding that there is a gradual connection in all the parts of the creation that may be subject to human oosc^rvatiun, without any considerable gap between any two, we have every reason to think that things rise also towards perfection gradually and by insensible degrees.^ It is difficult to say where the sensible and the rational begin, and Avhat is the lowest degree of living things ; it is like the increase or diminution of quantity in a regular cone. The difference is exceeding great between certain men and certain animals; but if we wish to compare the understanding and capacity of certain men and certain brutes, we shall find so little differ- ence, that it will be very difficult to assert that the under- standing of these men is clearer or more extended than that of these brutes. When, therefore, we observe such an insensi- ble gradation between the parts of creation from man to the lowest parts l)eneath him, the rule of analogy makes us regard it as probable that there is a parallel gradation in the things above us and beyond the sphere of our observation, and this kind of probability is the broad foundation of rational hypotheses.^ 1 In the case of natural phenomena beyond the reach of the senses, analogy- is the great rule of probability, the reasoning in general being hypothetical only, and the force and certainty of the conclusion therefrom being directly proportional to the reality and degree of the resemblance or similarity of the phenomena. Since Locke's and Leibnitz's day, great advance has been made in our knowledge of the nature of the mateiials existing in the various heav- enly bodies, chiefly through the aid of the spectroscope and spectral analysis, not only strengthening and increasing the measure of probability in the appli- cation of the conclusion from analogy to the conjectured conditions of other worlds, but in some cases and to a certain extent giving us well accredited positive knowledge in regard to their constitution. — Tr. - Cf. A. C. Fraser, Locke's Essai/ Concerning Human Understanding, Vol. 2, p. 380, note 2. Oxford, Clarendon Press, 1894. —Tr. 2 The probable conclusion from analogy is a rational hypothesis, whose 550 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv Th. It is upon the ground of this analogy that Huygens, in his " Cosmotheoros," ^ judges that the condition of the other principal planets is quite similar to ours, excepting the differ- ence which their different distance from the sun must cause : and Fontenelle,^ who had already before published his conver- sations full of wit and knowledge on the plurality of worlds, hypothetical character consists in the fact that it is not a completely exhaus- tive induction or a mathematical demonstration from the given data, therefore still problematical, and whose rationality consists in the fact that no known reason exists against the assumed instance, but on the contrary the analogy itself directly furnishes occasion for a provisional consideration of, if not a belief in, the hypothesis. — Tr. 1 Cf. ante, p. 150, note 3. Huygen's Cosmotheoros, sive de teiTis aelestibus earumque ornatu conjecture — a speculation concerning the inhabitants of the planets, and the last work of the great physicist and mathematician — appeared posthumously, at the Hague, 1698, and in a German trans., Leipzig, 1703, just before Leibnitz wrote Bk. IV. of the Neio Essays, and in an English trans., entitled, The Celestial World discovered; or Conjectw^es concerning the Inhabitants, Plants, and Productions of the Worlds in the Planets, Lon- don, 1699, 8vo; Conjectures concerning the Planetanj Worlds, Glasgow, 1727, r2mo. The work is found in Huygens, Opera Omnia, Leyden, 182i, 2 vols., Vol. 1, pp. 641-722. — Tr. 2 Bernard le Bovier de Fontenelle, 1657-1757, a litterateur rather than a philosopher, who, nevertheless, according to Janet, " belongs to the history of philosophy, through the spirit of inquiry and criticism which animates his works," attempted, and successfully, in his Entretiens sur la pluralite des viondes, Paris, 1686, 12mo (a sixth Entretien was added in the Paris ed. of 1687, according to Brunet) to popularize the astronomical theories and doc- trines of Copernicus and Descartes. The work is a fine iUustration of the possibility of making science, without ceasing to be scientific, intelligible and interesting to the men of the world. Fontenelle became a member of the " Academie Fran^aise " in 1691, and, on the revival of the "Academic des Sci- ences de Paris " in 1699, was nominated its perpetual secretary, and continued in that office for fifty-eight years, publishing each year a volume of the Histoire of this Acad4niie, containing clear and orderly arranged extracts from or anal- yses of the papers read before the ^ca(Ze'»u'e, often accompanied with new and profound views of his own, together with Eloges of the members dying in each year, among which is the Eloge de Leibniz, "a masterpiece," found in L' Histoire de l' Academie Roy ale des Sciences de Paris, annie 1716; in Vol. 3, 1722, of the collection of these Eloges, 69 in number, entitled Histoire dw renouvellement de V Academic Roy ale des Sciences en 1699, et Eloges histonques d''s Acade'miciens marts depuis ce temps-la, 3 vols., Paris, 1708-1722; in (Euvres de Fontenelle, 3 vols.. La Haye, 1728-29, Vol. 3, pp. 232-259; new ed., 11 vols., Paris, 1766, Vol. 5, pp. 447-506; and in F. Bouillier, Eloges de Fon- tenelle avec une Inti-od. et des Notes, Paris, 1883, pp. 103-134; cf. also Jacques, (Euvres de Leibniz, Yo\. 2, pp. i-xxiv, Dutens, Leibnit. op. om., Vol. 1, pp. xix-liii. The Entretiens sur la pluralite des mondes is found in (Euvres de Fon- tenelle, La Haye, 1728-1729, Vol. 1, pp. 149-234; new ed., Paris, 1766, Vol.2, pp. 1-190; there is a German trans, by Gottsched, 1751, Eng. trans, by Glan- vill, London, 1688, 1768, by A. Behn and others, London, 1801, and from the ] CH. XV]] ON HUMAN UNDERSTANDING 551 has said some pretty things thereupon, and has discovered the art of enlivening a difficult^ subject. He would say, as it were, that a harlequin in the empire of the moon is altogether what it is here. It is true that we judge in a wholly different way of moons (which are satellites merely) than of the princi- pal planets. Kepler^ has left a little book which contains an ingenious story upon the condition of the moon, and an Eng- lishman,'' an hoiiwie d'esjyrit, has published the humorous de- scription of a Spaniard (of his own invention) whom some birds of passage transported to the moon, not to mention Cyrano,* who since went to find this Spaniard. Some clever men, wish- ing to present a beautiful picture of the other life, conduct very happy souls from world to world ; and our imagination finds therein a part of the agreeable occupations which may be ascribed to genii. But however it may strive, I doubt if it can attain its object, because of the great interval between us and these genii, and the great variety found therein. And until we find telescopes like those Descartes made us hope for in order to discern parts of the moon's sphere no larger than our houses, we cannot determine what there is in a globe different from ours. Our conjectures will be more useful and " last and best " ed., with notes and a critical account of the author's writing by the astronomer Jerome de la Lande, Paris, 1800, by Miss E. Gunning, 1803. Fontenelle was author also of Dialogues des morts, Paris, 1683; L'Histoire des Oracles, Paris, 1687 ; Doutes sur le systeme physique des causes oecasio- nelles, against Malebranche, Paris, 1686. — Tr. 1 Jacques reads : " fort difficile." — Tr. 2 Cf. ante, p. 123, note 2. The book of Kepler here referred to by Leibnitz is his Somnium seu de astronomia lunari, Francofurti, 1634, 4to, published after his death by his son, and found in Frisch, J. KeyAeri opera omnia. Vol. 8, Pt. I., pp. 21-39. The concluding paragraphs, pp. 38-39, are of a zoological and ethnological character. Michaud (Biog. Univ. 22, 313) says it is a philo- sophical and allegorical romance, in which the author exposes the astronomical phenomena as they would appear to the inhabitants of the moon, who like ourselves think that they are at the centre of the universe, but who are not so well situated as we to raise themselves to the " idea " of the true system. Schaarschmidt states that Kepler had occupied himself with Plutarch's De facie in orbe lunse (Eug. trans, in Plutarch's Morals, ed. Goodwin, 5, 234- 292 — the Moon-Dfemons, 289) and from the tales about the moon-d?emons therein contained related by Sylla, had derived his idea of a lunar geography. — Tr. 3 Franc. Godwin. Cf. ante, p. 342, note 2.— Tr. ■* Cf. ante, pp. 228, note 2 ; 399, note 3. The reference is to his Voyage dans la lune. Cf. Theodicee, Pt. III., § 343; Gerhardt, 6, 318; Erdmann, ()03 b; Jacques, 2, 268; Janet, 2, 359, 360; Dutens, 1, 364. — Tr. 552 LEIBNITZ-S CRITIQUE OF LOCKE [bk. iv more tru^ upon the internal parts of our bodies. I hope that we shall go beyond conjecture on many occasions, aud I already now believe that at least the violent agitation of the parts of the fire of which-you just spoke should not be reckoned among the things Avhich are only probable. It is a pity that the hypothesis of Descartes regarding the constitution {contexture) of the parts of the visible universe has been so little conlirmed by the re- searches and discoveries since made, or that Descartes did not live fifty years later to give us an hypothesis upon the basis of present knowledge as ingenious as the one he gave upon the basis of the knowledge of his time.^ As for the gradual con- nection of species, we have said something concerning it in a preceding conference; in which I remarked that philosophers had already reasoned upon the vacuum in the forms or species. - Everything goes by deg'rees in nature, and nothing by leaps, and this rule regarding changes is a part of my law of continuity.^ But the beauty of nature, which desires distinct perceptions, demands the appearance of leaps, and so to speak musical ca- dences in phenomena, and takes pleasure in mixing the species. Thus although there may be in some other world mediate spe- cies between man and beast (according as we understand these words), and although there may be somewhere rational animals surpassing us, nature has found it good to keep them away from us, in order to give us without contradiction the supe- riority we have in our globe. I speak of mediate speciesj and I should not wish to regulate myself here by human individ- uals, who approach the brutes, because apparently this is not a defect of faculty, but a hindrance to its exercise ; so that I think that the most stupid of men (who is not in a condition contrary to nature by reason of some disease or some other per- manent defect taking the place of the disease) is incomparably more rational and more docile than the most spiritual of all 1 Leibnitz here refers to Descartes' theory of vortices, which he elaborated in his Priacipla Philosophise, Pts. III. and IV. A brief account of it will be found in the Encyclop. Brit., 9th ed., article "Descartes," Vol. 7, pp. 107-108 (American Reprint). Cf. also J. H. v. Kirchmann's German translation, with notes, of the Prin. Philos. (Vol. 26, Ft. I., of his Philos. Bihliothek.), 2d ed. Heidelberg, 1887. For other references of Leibnitz to the theory, cf. Ger- hardt, Leibniz, philos. Schnft., 4, 283, 288-289, 340 (Dutens, Leibnit. op. om., 3, 252-253) , 348. — Tr. 2 (7/. anr)|U.a or attempted proof, and the <7vAAoyicr|U.b? o.TTO&iLKHKO'; a (i>iAoo-d(f)7);aa or demonstration. On the whole subjec^t, cf. Zeller, Philos. d. Griech., II., 2 [Vol. 4], 242 .sg., 3d ed., 1879; Prantl, Gesch. d. Lof/ik, 1, a'l sq.; Wallace, Outlines of the Philos. of Aristotle, § 23, pp. 47-48. Cf. also, JVew Essays, Bk. II., chap. 21, § 66, Th."(2), ante, p. 214, note 1; Bk. IV., chap. 2, § 14, Th., ante, p. 418, note 4. — Tr» 566 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv false, but it is not always probable, especially when a simple hypothesis gives a reason for many truths, a thing which is rare and difficult to find. We might say with Cardan,^ that the logic of -the probable has other consequences than the logic of the necessary truths. But the probability itself of these con- clusions must be demonstrated by the conclusions of the logic of the necessary truths. § 7. Ph. You appear to apologize for common logic, but I see clearly that what you bring forward belongs to a more sublime logic, to which the common is only what the alphabet is to scholarship : a fact which makes me remember a passage of the judicious Hooker, who in his book entitled "Ecclesiasti- cal Polity," Book I., § 6, thinks that if we could furnish the true JieljJS of Jcnoivledge and of the art of reasoning, Avhich in this age passing as enlightened are not much known and for which people put themselves to very little trouble, there would be as much difference as regards maturity of judgment between men Avho would make use of them and what men now are, as between the men of the present and imbeciles.'^ I wish that our con- ference may give occasion to some to make a discovery of these true helps of the art of which this great man who had so pene- trating a mind speaks. They will not be the imitators who like the cattle follow the beaten track {imitatorum servum pecus).^ 1 Girolamo Cardano, 1501-1576, an Italian physician, mathematician, and philosopher, whose complete works appeared at Lyons, 1663, 10 vols., fol., and an account of whose philosophy will be found in Stockl, Gesch. d. Philos. d. Mittelalters, III. [Vol. 4] , 452^58. — Tr. 2 Richard Hooker, 1553-1600, attempted, in his Laios of Ecclesiastical Polity, to defend the Episcopal form of government of the Church of Eng- land, as established by the Protestant sovereign and Parliaments, against the attacks of the Presbyterians. To this end he gives in the two tirst books of his work an exposition of the fundamental principles by which the disputed question should be decided, especially of the nature of law in general, as a philosoiDhical basis for the rest of his discussion. It is this portion of his work that gives it its permanent place and value in English literature and philosophy. The passage here referred to by Locke and Leibnitz runs thus, Eccles. Pol., Bk. I., chap. 6, § 3, Workfi, ed. Isaac Walton, Oxford, Univ. Press, 1841, 2 vols., Svo, Vol. 1, p. 164 : " Wherefore if afterwards there might be added the right helps of true art and learning (which helps, I must plainly confess, this age of the world, carrjing the name of a learned age, doth neither much know nor greatly regard) , there would undoubtedly be almost as great dif- ference in maturity of judgment between men thereAVith inured, and that which men now are, as between men that are now and innocents." — Tr. 3 Cf. Horace, Einst., 1, 19, 19. — Tr. CH. XVII] ON HUMAN UNDERSTANDING 567 Yet I dare say there are in this age some persons of such strength of judgment and of such large extent of mind, that they could discover new paths for the advance of knowledge, if they would take the trouble to turn their thoughts in that direction. Th. You have well remarked, sir, with the late Mr. Hooker, that the world troubles itself but little about this; otherwise I think there are and have been persons capable of succeed- ing therein. We must admit, however, that now we have great helps both on the side of mathematics and of philoso- phy, in which, the Essay concerning Human Understanding of your excellent friend is not the least. We shall see if we may not be able to profit therefrom. § 8. Ph. I must further tell you, sir, that I have believed that there was a visible mistake in the rules of the syllogism ; but since we have conferred together you have made me hesitate. I will, however, set before you my difficulty. It is stated that no syllogistic reasoning can he conclusive unless it contains at least one universal proioosition.^ But it seems that there are in the syllogism only particular things, which are the immediate object of our reasonings and knowledge; they revolve only about the agreement or disagreement of ideas, each of which ■ has only a particular existence and represents only an individ- ual thing. Th. As far as you conceive the similarity of things you con- ceive something more, and the universality consists only in that. Yet you will never propose to me any one of our argu- ments without therein employing the universal truths. It is, however, well to remark that (as far as form is concerned) the particular propositions are comprised within the universals. For although it is true that there is only a single St, Peter the 1 Locke's sensistic realism appears in sharp outlines in the present passage and its immediate context; cf. further, Locke, Philos. Wks., Vol. 2, pp. 295- 296. He maintains the existence, and consequently the knowledge, of the par- ticular and individual only, and that our reasoning, which relates to the agreement or disagreement of things, must accordingly, in order to hit the mark, confine itself to the particular. Leibnitz argues, on the other hand, that our knowledge of things, while beginning with the particular in the sense-act, does not rest there, but through thought, especially through the medium of the linguistic form of our mental creation, gives to the individual and particular at once the character of universality. With Locke the ele- ment of universality is accidental ; with Leibnitz it is essential. — Tr. 568 LEIBNll'Z'S CRITIQUE OF LOCKE [bk. iv apostle, we may nevertheless say that whoever was St. Peter the apostle denied his master. Thus this syllogism : St. Peter denied his master, St. Peter was a disciple, therefore some disciple denied his master (although it has only particular propositions), is considered to have them as universal affirma- tives, and the mood will be Darapti of the third figure.^ Ph. I wished also to say to you that it appeared to me better to transpose the premises of the syllogisms and to say : All A is B, All B is C, therefore All A is C, than to say : All B is C, All A is B, therefore All A is G. But it seems from what you have said that they do not differ, and that both are counted as one and the same mood. It is always true, as you have remarked, that the disposition different from the common is better adapted to making a chain of several syllogisms. Th. 1 am wholly of your opinion. It seems, however, that the belief has been that it was more didactic to begin with universal propositions like the majors in the first and second figures; and there are indeed orators who have this custom. But the connection appears better as you propose. I have before remarked that Aristotle may have had a particular reason for the common disposition. For instead of sayjng A is B, he was wont to say B is in A. And with this method of statement, the connection itself which you demand will arise for him in the received disposition. For, instead of saying B is C, A is B, therefore A is C, he will state it thus : C is in B, B is in A, therefore C is in A. For example, instead of saying : The rectangle is isogon (or has equal angles), the square is a rectangle, therefore the square is isogon, Aristotle, without trans- posing the propositions, will preserve the middle place to the middle term by this method of stating the propositions, which reverses the terms, and will say: The isogon is in the rectangle, the rectangle is in the square, therefore the isogon is in the square. And this mode of statement is not to be despised, for in reality 1 Peter being the middle term, and disciple the subject of the conclusiou, the minor premise must be converted, by which process the universal affirma- tive, "St. I'eter was a disciple," becomes the particular affirmative, "Some disciple was St. Peter," from which the particular conclusion, " Some disciple denied his master," immediately follows. The mood Darapti of the third figure thus becomes the mood Darii of the first. The universality of the premises consists in the fact that Peter constitutes the entire class to which he belongs. Cf. Hamilton, Logic, Boston, 1873, pp. 314-315. — Tr. I CH. XVII] ON HUMAN UNDERSTANDING * 569 the predicate is in the subject, or rather the idea of the predi- cate is included in the idea of the subject. For example, the isogon is in the rectangle, for the rectangle is the figure all of whose right angles are equal to each other, therefore in the idea of the rectangle is the idea of a figure all of whose angles are equals, which is the idea of the isogon. The common mode of statement regards rather individuals, but that of Aristotle ideas or universals. For in saying, evei'y man is an animal, I mean to say that all men are included in all animals; but I mean at the same time that the idea of animal is included in the idea of man. Animal includes more individuals than man, but man includes more ideas or more formalities ; ' the one has more examples, the other more degrees of reality ; the one more extension, the other more intension. It may also be truly said that the entire syllogistic doctrine may be demonstrated by that de continente et contento, the containing and the contained, which is different from that of the whole and the part; for the whole always exceeds the part, but the containing and the contained are sometimes equal, as is the case in reciprocal propositions.^ § 9. Ph. I begin to form for myself a wholly different idea of logic from that I formerly had. I regarded it as a scholar's diversion, but I now see that, in the way you understand it, it is like a universal mathematics. Would to God that it might push on to something more than it yet is, in order that we ^ I.e. essences. " The formality of the vow lies in the promise made to God." — Stillingdeet. — Tr. 2 Leibnitz's thought, as Schaarschmidt says, is that sometimes tlie princi- ple, what is predicable of the whole is predicable of the parts — ab universali ad particiilare conspquentia valet — is not applicable, as in cases where the concepts found in the conclusion are coordinate rather than subordinate, i.e. coincident or identical in extension. In such cases the coordination or coincidence of the concepts — principiam iclpntitatis — -might be adduced as a fundamental logical principle. To avoid this, Leibnitz proposes the principle De cont(nente et coyitento, in which in a certain sense is given the higher unity of subordination and identity, i.e. the subject may always be thought of as contained in the predicate, although coincident with it in extension. The principle, however, necessarily considers "the containing" as more ex- tended than the "contained." Gases such as Leibnitz here refers to, in which tlie coordination or agreement of terms is such as to make them identical — "important cases" "for the most part strangely overlooked" by logicians (.Tevons, Lessons in Logic, p. 124, new ed., 1880) — are discussed by Jevons in bis little work entitled The Substitution of Similars, London, Macmillau & Co., 181)9.— Tr. 570 LEIBNITZ'S CRITIQUE OF LOCKE [bk. it might be able to find thereby these true helps of reason of which Hooker spoke, which would raise men far above their present condition. Reason is a faculty which so much the more needs it, as its extent is quite limited and as it fails us in many instances. (1) Because often ideas themselves fail us. § 10. Then (2) they are often obscure and imperfect; whilst where they are clear (and distinct), as in mimhers, we find no insurmountable diffi- culties, and fall into no contradiction. § 11. (3) Often also the difficulty comes from the fact that mediate ideas are want- ing. You know that before algebra, that great instrument and noteworthy proof of human sagacity, was discovered, men regarded with amazement many demonstrations of the ancient mathematicians. § 12. It also happens (4) that the mind builds upon false principles, which may entangle it in difficulties where the reason is more involved and very far from clearing them up. § 13. Finally (5), terms whose meaning is uncertain embarrass the reason. Th. I do not know whether we so much lack ideas as you think, that is to say, distinct ideas. As for confused ideas, or rather images, or, if you prefer, impressions, as colors, tastes, etc., which are a resultant of many little ideas distinct in themselves, but of Avhich we are not distinctly conscious, we lack an infinite number of them suitable to other creatures rather than to ourselves. But these impressions also serve rather to give rise to the instincts and to establish the observa- tions of experience than to furnish matter to the reason, except so far as they are accompanied by distinct perceptions. It is then principally the defect of the knowledge we have of these distinct ideas, concealed within the confused, that stops us, and even when all is distinctly exposed to our senses or to our mind, the multitude of things that must be considered some- times perplexes us. For example, when there is a pile of one thousand cannon-balls before our eyes, it is plain that in order properly to conceive the number and properties of this multi- tude, it is very useful to arrange them in figures as is done in the magazines in order to have distinct ideas of them and to fix them, indeed, so that we may be spared the trouble of counting them more than once. It is the multitude of consid- erations also which causes some very great difficulties in the science of numbers themselves; for short methods are sought CH. xvii] ON HUMAN UNDERSTANDING 571 and sometimes we do not knoAv whether nature has them within its fokls for the case in question. For example, what is apparently simpler than the notion of the prime number? i.e. a whole number indivisible by every other except unity and itself. Yet we seek also a positive and easy sign in order to recognize them certainly without trying all the prime divisors less than the square root of the given prime. There are a number of signs which make known without much calculation that a given number is not prime, but we ask for one which is easy and which makes known certainly that it is prime when it is so. This it is which also makes algebra as yet so imper- fect, although nothing is better known than the ideas of which it makes use, since they signify only numbers in general ; for the public has not yet the means of extracting the irrational roots of any equation beyond the fourth degree ^ (excepting in a very limited case), and the methods which Diophant,- Scipio Ferreus,^ 1 In Leibnitz's day, as the text states, equations of the 2d, 3d, and 4th degrees were reduced to pure equations, but the reduction of equations of higher degrees than the 4th remained an unsolved problem, on -which mathe- maticians spent much labor, until Niels Henrik Abel, 1802-1829, a Noi-wegian mathematician of great ability and acuteness, demonstrated (1824) that the quintic equation and a fortiori the general equation of any order higher than tive, is incapable of solution by radicals. Cf. Abel, Bemonstration de Fim- possibiUte cle la resolution algebrique cles equations generates qui passent le quatrieine degre, in CEuvres completes, ed. by Holmboe, 2 vols., Christiania, 1839, Vol. 1, pp. 5-24, and in Crelle, "Journ. f. Math.," 1826, Vol. 1, pp. 65-84. — Tr. 2 Diophantus, c. 325-c. 409, a celebrated Greek mathematician of the Alexandrian school, gave, in his Anthmeticorum lib. VI., a method for the solution of equations of the 1st and 2d degrees. The Ms. of his Arithmetic was discovered in 1460 in the Vatican Library by the astronomer Regiomon- tanus, 1436-1476, and was published in a Latin trans., without the original, by Xylander, in 1575. The Greek text, with a more complete trans., and a com- mentary by Bachet de Merzeriac, whose skill in indeterminate analysis especially fitted him for the task, appeared in 1621. The best ed., based upon that of Bachet, including the Greek text with Latin trans., is that by Pierre Fermat, 1601-1665, the celebrated French mathematician, who supplemented the commentary of Bachet by valuable notes of his own. It is found in Vol. 1, pp. 65-341 of Fermat, Opera Mathematica, 2 vols., fol., Tolosae, 1670, 1679. -Tr. 3 Scipione del Ferro orFerri, c. 1465-1525, an Italian mathematician, taught arithmetic and geometry at Bologna from 1496 till his death. About 1505 he discovered the solution of a particular case of cubic equati(uis, which he did not publish, but communicated to his favorite pupil Antonio del Fiore, who in 1635 challenged Tartaglia to a trial of skill in resolving algebraical problems requiring a knowledge of this rule. Tartaglia in 1630 had already solved two cases of cubic equations, and before the time for the contest came solved two 572 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv and Lewis Ferrari ^ used respectively for the second, third, and fourth degrees in order to reduce them to the first, or in order to reduce an affected equation to a pure, are wholly- different from each other, i.e. that which is used for one degree differs a degree from that used for another. For the second degree, or the quadratic equation, is reduced to the first by merely eliminating the second term. The third degree, or the cubic equation, has been solved, because in separating the unknown quantity into parts there happily arises from these an equation of the second degree. And in the fourth degree, or the biquadratics, something is added to the two sides of the equation to render it capable of extraction on both sides, and then it is happily found that to obtain this result an equation of the third degree only is needed. But all this is only a mix- ture of good luck or chance with art or method. And in trying it on these last two degrees we knew not whether it would be successful. Further still, another artifice is necessary to suc- cess in the fifth or sixth degree, which are the sursolids or bicubes. And although Descartes believed that the method he used in the fourth, conceiving the equation as produced by two other quadratic equations (but which cannot at bottom give more than that of Lewis Ferrari), would succeed also in the sixth, it is not found to be so. This difficulty shows that even the clearest and most distinct ideas do not always give us all we ask for and all that may be drawn from them. And this makes us also judge that algebra is very far from being the art more. He thus easily won the victory, as his problems could be solved only by one or the other of his own three rules which were unknown to Fiore, and not by the remaining rule whicli was the only one known to Fiore. Tartaglia's discoveries were improved and published by Cardan in connection with his own in l.j-15, as a supplement to a treatise on arithmetic and algebra pub- lished in 15;'.9. Cf. Cardan, Opera omnia, Vol. 4, pp. 249-2(14. On Ferro, cf. Libri, Hist, des Sciences Math. en. Italic, Vol. 3, pp. 14S-151 ; Montucla, Hist, des Math., Vol. 1, p. 479, ed. 1758, Vol. 1, p. 591, ed. 1799-1802. — Tr. 1 Lndovico or Luigi Ferrari, l.")22-]562, or 15()5, an Italian mathematician, a pupil of Cardano (cf. ante, p. odtt, note 1), and Professor of Mathematics at Milan and at the University of Bnlogna, discovered the demonstration of the formula for the resolution of equations of the ?>(\ degree, sentby Tartaglia, c. 1500-1557, to Cardan under the form of an enigma, and shortly after this discovery solved equations of the 4th degree. For an account of his demonstration, c/'. Cardan, Ars magna, 1515, cliap. 15. De cubo et quadratis a;qualibus numero, § 3, Opera omnia, 10 vols., Lugduni, 16(i3, Vol. 4, p. 254. On Ferrari, cf. Libri, Hist, des Sciences Math, en Itcdie, Vol. 3, pp. 180, 181; Montucla, Hist, des Math., Vol. 1, pp. 484, 485, ed. 1758, Vol. 1, pp. 59(3, 597, ed. 1799-1802. — Tr. CH. xvii] ON HUMAN UNDERSTANDING 573 of invention, since it needs a more general art; and we may say, indeed, that the art of signs {Sj)ecieuse) in general, i.e. the art of characters, is a marvellous means of assistance, since it aids the imagination. It will not be doubted in view of the arithmetic of Diophant and the geometrical books of Apollonius and Pappus that the ancients possessed it to a certain extent. Vieta ^ has given it more extension by expressing not only what is asked for, but also the given numbers, by general characters, doing in calculating what Euclid already did in reasoning, and Descartes has extended the application of this calculus to geometry, indicating lines by equations. Nevertheless, even after the discovery of our modern algebra, Bouillaud ^ (Ismael Bullialdus), no doubt aa excellent geometer, whom, moreover, I knew in Paris, regarded only with wonder the demonstrations of Archimedes upon the spiral, and could not understand how this great man had thought of employing the tangent of this line as the dimension of the circle. Father Gregory of St. Vincent ^ appears to have divined it, thinking that it was at- tained by the parallelism of the spiral and the parabola. But this method is only a particular one, whilst the ncAv calculus of infinitesimals* which proceeds by the method of the differ- ences which I have thought of and successfully shared with the public, gives a general one, wherein this discovery concerning 1 Cf. ante, p. 468, note 1. — Tr. 2 Ismael Boulliau, 1(;05-16:)4, a French mathematician and astronomer, uho was the first to give, in his Ad astronomos monita duo, 11)57, a plausible ex- planation of the change in the light of some stars by attributing to tliem an axial revolution which shows successively their obscure and luminous parts. He was the author of several works, aniong which is the Be lineis apiruUuUS deDiotixtratioiiPS, 1()57, which Leibnitz, perhaps, had in mind here. — Tr. 3 Gregoire de Saint-Vincent, 1584-l()(i7, a Flemish geometer who was much occupied with the jjroblem of the quadrature of the circle, and whose prin- cipal work is the Oi'jus geonietricum quadraiurse circuit et stctiunuiii coni, 1G47. — Tr. 4 For Leibnitz's account of his discovery of the " calculus of infinitesimals," cf. his Historia et oric/o calculi dlfferentialis, Gerhardt, Leibniz, rnatli. Sc/iri/t., II., 1 [Vol. 5], 392-410; also his letter, April IS, ITKi, to the Countess Kiel- mannsegge, Dutens, Lr-ibint. op. 0)n., 3, 45()-4(Jl. For Leibnitz's various writ- ings on the subject, cf. Gerhardt, op. rit., II., 1 [Vol. 5] , 141-418 ; Dutens, op. cit., Vol. 3, passim. Dutens, Vol. 3, contains also much material concerning the controversy between Leibnitz and Newton regarding the disco\ery of the calculus. Further accounts are given in Guhrauer, Leibnitz, Fine Biof/raphie, 1, 280-320, Jaucourt, Historia vitse Lelbnitii, and Montucla, Tlist. d. Math., Vol. 2 (both in Dutens, op. cit. Vol. 3, pp. xii-xl, xli-lv), and in Encyclop. Brit,, 9th ed., Vol. 13, Article, " Infinitesimal Calculus." — Tr. 574 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv the spiral is mere play and a sample of the easiest, like nearly- all we have before discovered in the matter of the dimensions of curves. The reason of the advantage of this new calculus is, moreover, that it relieves the imagination in the problems, which Descartes excluded from his geometry under the pre- text that they most frequently lead to mechanics, but at bottom because they did not agree with his calculus. As for errors arising from ambiguous terms, it is our business to avoid them. Ph. There is also a case in which reasoning cannot be applied, but in which also there is no need of it and in which sight is worth more than reasoning. It is in iyituitive knowl- edge, where the connection of ideas and truths is immediately seen. Such is the knowledge of indubitable maxims, and I am tempted to believe that this is the degree of evidence which the angels have at present, and which the spirits of just men made perfect will have in a future state regarding a thousand things Avhich now escape our knowledge. § 15. But demon- stration, based upon mediate ideas, gives a reasoned knowledge. This is because the connection of the mediate idea with the extremes is necessary and is seen by Sijuxtajjosition of evidence, similar to that of a yard-stick applied now to one cloth and now to another to show that they are equal. § 16. But if the con- nection is only probable, the judgment gives only an opinion. Th. God alone has the advantage of having only intuitive knowledge. But very happy souls, however detached they are from these material bodies, and the genii themselves, however exalted they are, although they have a knowledge without com- parison more intuitive than ours, and often see at a glance what we discover only by the force of consequences after having em- ployed time and labor, must likewise find difficulties in their path without which they would not have the pleasure of making dis- coveries, which pleasure is one of the greatest. And we must always admit that there will be an infinite number of truths concealed from them either wholly or for a time, whereto they must attain by force of consequences and by demonstration or even frequently by conjecture. Ph. [These genii then are only animals more perfect than we ; it is just as if you said with the emperor of the moon : it is all as Jiere.^ CH. XVII] ON HUMAN UNDERSTANDING 575 Th. I will say so, not entirely, but in regard to the ground of things, for the modes and degrees of perfection vary infinitely. Meanwhile the ground is everywhere the same, a maxim which \s> fundamental with me and reigns in all my philosophy. I con- ceive things unknown orconfusedly knownonly after the manner of those which are distinctly known to us ; a procedure which makes philosopliy very easy, and I believe indeed that it must do so. But if this philosophy is simplest in its ground, it is also the richest in its modes, because nature may vary them infinitely, as indeed she has done with as much abundance, order, and ornateness as it is possible to imagine. This is the reason why I believe there is no genius however sublime who has not an infinite number of them above him. Yet although we are very inferior to so many intelligent beings, we have the advantage of not being visibly controlled upon this globe where we hold indisputably the first rank ; and with all the ignorance in which we are immersed we have always the pleasure of seeing nothing which surpasses us. And if we were vain we might judge as Caesar, who preferred to be first in a country town rather than second in Kome. For the rest, I speak here only of the natural knowledge of these spirits and not of the beatific vision,^ or of the supernatural light that God is pleased to give them. 1 The term "beatific vision" (visio beatifica) denotes in theological and religious thought the direct and immediate or intuitive vision of God enjoyed by the saints and angels in heaven and supposed to constitute their essential bliss. The philosophical significance of the idea as historically developed, with respect both to its speculative and practical uses, lies in the fact that the visio beatifica was regarded as the sole means of obtaining absolute truth and of realizing absolute blessedness. The idea thus involved more or less ex- plicitly a species of knowledge supernaturally mediated in some unknown and unexplained way, but considered, because of the method of its mediation, as far superior in certainty and completeness to any knowledge that finite beings could attain through the unaided action of their own intellectual powers — in brief, as the very perfection of knowledge attainable by such beings. The idea originated in Plato's conception of an immediate intuition, going beyond rational thought, of the pure forms of reality or the Ideas. Trans- formed by Philo and Plotinus into their ecstatic intuition, or that identifica- tion of the human with the Divine in which all consciousness of individual personality is lost; combined by Clement and Origen, in view of certain ex- pressions in the Pauline epistles, with the thought of a personality in union with whom the self-consciousness of the individual is preserved ; and still further developed by Augustine, as the principle of the absolute and imme- diate certainty of inner experience or consciousness invohing within itself the idea of God as the absolute personality and the sum and essence of all 57'6 LEili.\IiZ'8 CiUTIQUE OF LOCKE [bk. iv § 19. Ph. As each one makes use of reasoning either with regard to himself or with reference to another, it will not be useless to make some reflections upon foxir sorts of arguments which men are wont to use in order to draw others to their opinions or at least so to keep them in awe as to prevent them from contradicting. The first argument may be called argu- mentum ad vercundlam, when we cite the opinion of those who have acquired authority by their knowledge, rank, power, or otherwise ; for when another does not yield to it promptly, he is liable to be censured as full of vanity and even to be charged with insolence. § 20. There is also 2) argumentum ad ig tiorantiam, i. e. to demand that the opponent admit the proof or assign a better. § 21. There is 3) argumentum ad hominem, when we press a man by Avhat he has himself said. § 22. Finally, there is 4) argumentum ad judicium, which con- sists in employing proofs drawn from some one of the sources of knowledge or probability. This is the only one of all which advances and instructs us ; for if from respect I dare not con- tradict, or if I have nothing better to say, or if I contradict myself, it does not follow that you are right. I may be modest, ignorant, deceived, and you prove yourself to be mistaken also. Th. It is doubtless necessary to make a difference between what is proper to be said and what is truly to be believed. Yet as the majority of truths may be boldly maintained, there is some prejudice against an opinion that it is necessary to con- ceal. The argument ad ignorantiam is valid in cases of pre- sumption where it is reasonable to hold to an opinion till the contrary is proved. The argument ad Jiominem has this effect, that it shows that one or the other assertion is false and that truth, this conception passed into the philosophical and religious thinking and life of the Christian Church, and became especially prominent in the teachings of the Mediaeval Mystics. On this historical development cf. Win- delband, Hist, of Philos., trans, by Tufts, pp. 119 .s^., 227 nq., 249 .sg., 27(i5g.; Zeller, Philos. d. Griech., III., 2 [Vol. H], 413 «g., 611 sq., 854, note 4, 3d ed., 1881 ; Benn, Greek Philosophers, 2, 311 sq. In a modified form this intuition of divine things became what the Church fathers and the theological and philosophical writers of the Middle Age termed the lumen gratix, " the light of grace," the supernatural light given through divine inspiration, in opposition to the lumen naturale or " natural light," the rational knowledge given by nature to all men as such. Cf. Neiv Essays, Bk. I., chap. 1, § 21, Th., o>2i^e[fach"n Wahr- hp.lt, Berlin, 1871; Windelband, Hist, of Pliilos., trans, by Tnfts, pp. 318 sg., 3'S9sq., 359 ; Piinjer, Gesch. d. cJwist. Religion-tphiloa., 1, 28-29. 37, Eug. trans., 1, .39 sq., 50-52 ; Stockl, Gesch. d. Philos. d. Mittelalters. HI [Vol. 4] ,202-207, and for an account of Pomponazzi and his philosopliy, ibid. 21.3-241; cf. also L. Ferri, La Psicolngia di P. Pomponazzi, Rome, 1877. For the decree "Apostolici Regiminis," cf. Acta Concil. Reg., Vol. 'M, p. 333, Paris, 1044, 37 vols., fol.; Labbe', Concil., torn. 19, col. 842; Stockl, op. cit., Ill [Vol. 4], 20es in a method- ical and systematic form. His Opera omnia appeared at Geneva. lOl-l, 2 vols., fol. Leibnitz refers to him in the same connection in the Theodicee, Discours prelim., § 59. For further account of him, <■/. W. Gass, GcscJi. c7. ^^ruti'Stxtrntischeii Logmatik in ihr-pm Zu-'^ammenhanf/e niit ci. T/ieoIor/i", Vol. 1, pp.408 sq. Piinjer, Gesch. d. christ. Bdigionsphilos., 1, 118, 127, 128, Eng. trans., 1, 1.58, 170, 172, briefly refers to him. According to Schaarschmidt, Keckermann's proof of the Trinity from reason, which is quite closely connected with that of Lully, as Lully"s with the thoughts of Augustine, is found in his Si/^tema .s.s. theolor/im (1st ed., Ifj02; 2(:red., Hanovia-, 1607), chap. 3, pp. 20 sq., 3d ed., Hanovire, Kil."). In the introduction Keckermann expresses himself very decidedly. " Fateor 690 LEIBNITZ'S CRITIQUE OE LOCKE [bk. iv who wished to demonstrate the Trinity by reason, as Raymond Lully ^ had also tried to do formerly. But Museeus acknowl- edged with sufficient fairness that if the demonstration of the Reformed author had been valid and just, he would have had nothing to say on the subject ; that he would have been right in maintaining as regards this article that the light of the Holy Spirit might be illumined by philosophy. They have also discussed the famous question, whether those who, without any knowledge of the revelation of the Old or New Testament, died in the opinions of a natural piety, could have been saved by this means and obtained the remission of their sins ? We equidem ultro, circa mysterium de ss. Triade, ad id esse omnem intellectum humanum, quod est oculus vespertilionis ad solem," etc. Keckermanu's de- monstration was refuted by Musaeus in tlie " Dissertatio altera," appended to his De usu priiicip. rationis et philos. in conti^oversiis theologicis, 2d ed., Jense, 1665. — Tr. 1 Raymond Lully, 1234 or 1235-1315, best known as the inventor of the "Great Art," attempted to demonstrate against the assertions of the Aver- roists, the inherent rationality of the doctrines of Christianity. His Opera omnia, 10 vols. (Vols. 7 and 8 probably never printed), foL, appeared at Mainz, 1721-1742. For an account of his life and philosophy, cf. Stockl, Gesch. d. Philos. d. Mittelalters, II., 2 [Vol. 3], 924-9.52; Erdmann, Grund. d. Gesch. d. Philos., § 206, Vol. 1, pp. 375-393, Eng. trans., 1, 447-468; Neander, Hist, of the Christ. Relig. and Church, 4, 65-71, 426, 435 sq. ; for his Logic, cf. Prantl, Gesch. d. Logik im Ahendlande, 3, 145-177. Cf. also an article by Delecluse in the " Revue de Deux Mondes," 1840. Lully occupied himself much with the proof of the Trinity, discussing it, according to Schaarschmidt, in his Qusestiones [Disputatio Erimitse et Ray- rrmndi — Erdmann] super lib. Sententiarum, Lib. I., qusest. 6 ; Disputatio fidelis {catholici) et infidelis, pp. 2, 3; and especially in the Disputatio Jidei et intel- lectus, Pt. I., where the question of the demonsti-ability of the Trinity is con- sidered in detail, and Pt. II., where the proof is attempted. Schaarschmidt thinks that Leibnitz i^robably has in mind this last work. All three works are found in Opera, Vol. 4, ed. Mainz, 1729. Stockl, op. cit., 11., 2 [Vol 3], 942- 944, gives an account of Lully's argument on the Trinity, based chiefly on the Articuli fidei sacrosanctse, found in the collection of Lully's works entitled Opera ea qiise, ad inventam a Lullo artem imiversalem. pertinent, Argentorati, 1598, 1607, and 1617, and also in Opera, Vol. 2, ed. Mainz, 1722. In his list of Lully's works, Stockl cites the following which discuss the Trinity : Liber con- tradictionis inter Raymiindum et Averroistam de centum syllogismis circa mysterium Trinitatis ; Liber de substantia et accidente in quo probatur Trinitas. Cf. also Neander, op. cit., 4, 465. For Leibnitz's own views on the Trinity, cf. his Defensio Trinitatis per nova reperta logica, contra Epistolam Ariani, Dutens, Leibnit. op. om., 1, IC- 16; Duse Epist. ad Lwflerum de Trinitate et Definitionibus Mathemativis circa Deum, Spiritus, etc., Dutens, op. cit., 1, 17-23; Remarques sur le livre d'un Antitrinitaire Anglais, etc., Dutens, op. cit., 1, 24-27, and Feller, Leibnit. Miscellanea, No. IV., pp. 8-15; Theodicee , Disconrs prelim., § 22; Letter to M. B., 1696, Feller, op. cit., No. VIII., pp. 26 sq. — Tn. CH. xviii] ON HUMAN UNDERSTANDING 591 know that Clement of Alexandria, Justin Martyr, and St. Chrj'Sostom to a certain extent were inclined thereto,^ and indeed I once showed Pelisson ^ that a number of excellent doctors of the Koman church, far from condemning non-opin- ionative Protestants, even desired to save the heatlien and to maintain that the persons of whom I have just spoken could have been saved by an act of contrition, i.e. penitence grounded in the love of benevolence, in virtue of which we love God above everything, because his perfections render him supremely lovable. This brings it about that afterwards we are led with all our hearts to conform to His will and to imitate His per- fection in order the better to unite ourselves with Him, since it appears right for God not to refuse his grace to those who hold such views. ISTot to speak of Erasmus and of Ludovicus Vives,^ 1 Clement of Alexandi-ia, born c. 150-160, date and place of death unknown. Cf. Stromata (or Miscellanies), Bk. VI., chaps. 5 and 6. — Justin Martyr, c. 114-c. 1G3. Cf. First Apology, chap. 41!; Second Apology, chaps. 8 and 13. — .John Chrysostom, c. 347-407. Clement and .Justin entered the Christian church as thinkers trained in Greek philosophy, which they regarded as the gift of God in preparation for the fuller light and life of Christianity — Justin in particular thi'ough his view of the "spermatic logos," " the seed of reason implanted in every race of men " ; while Chrysostom, trained in Greek rheto- ric and oratory, took a similar view of Greek culture as from God and not from the evil one. All three would naturally look upon those who lived up to the light they had as likely to receive more in due time, and to accept it and live in it when it came. — Tr. 2 Paul Fqntauier-Pellisson, 1621-1693, born and educated a Protestant, fol- lowed at first the profession of the law, but afterwards abandoned it for that of literature. He held several public offices, among others that of histori- ographer to Louis XIV. To obtain this position he was obliged to become a Catholic. He published a large number of works, among which was a Latin paraphrase of the first book of the Institutes of Justinian, 1615; Histoire de l'Acadei)iiefrav<;aisejusqH'en 16o2, 1653, 8vo ; Tral/e de I'Evcharistie, 1{)94, 12mo, and other religious works. He corresponded extensively with Leibnitz on religious and theological subjects. The correspondence is contained in his Eefle.rAons sur les diffe're7ids en inatiere de religion, 1686, and following years, 4 vols., 12mo. Portions of the same in Dutens, Leibiiitz op. oni., 1, 678 sq. ; most complete in Foucher de Careil, CEuvres de Leibniz, Vol. 1. For the letter here referred to by Leibnitz, cf. Dutens, op. cit., 1, 681-684, Foucher de Careil, op. cit. 1, 55-66; for Pellisson's i-eplies, rf. Dutens, op. cit., 1, 697, 700- 702, Foucher de Careil, op. cjY., 1, 90-92, 96-100. For account of the controversy, cf. Guhrauer, Leibnitz, Eine Biog., Pt. II., 35 sq. — Tr. 3 Juan Luis Vives, 1492-1540, a Spanish scholar and philosopher, a younger contemporary and friend of Ei-asmus, 1467-1536, and for a time the instructor of the Princess Mary, daughter of Henry VIII., was a persistent and success- ful opponent of scholastic Aristotelianism, and, as an advocate of the direct study of Nature by the way of experiment, the precursor of Descartes and Bacon. His Opera omnia appeared at Basle, 1555, 2 vols., fol., and at Valencia, 592 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv I bring forward the view of Jaques Payva Andradius,^ a Portuguese doctor very celebrated in his time, who was one of the theologians of the Council of Trent, and who said indeed that those who did not agree with this view made God supremely cruel (neque enim, inquit, immanitas deter ior ulla esse potest). Pelisson found difficulty in finding this book in Paris, an indi- cation that authors esteemed in their time are often neglected afterwards. This is what made Bayle think that many cite Andradius only upon the testimony of Chemnitius,^ his antag- onist. This may indeed be so, but for myself I had read him before quoting him; and his disputes with Chemnitius made him celebrated in Germany, for he had written in behalf of the Jesuits against this author, and we find in his book some par- 1782-1790, 8 vols., fol. On his life and philosophy, cf. Stcickl, Gesch. d. PhiJos. cl. Mlttelalters, III. [Vol. 4], 285-287 ; Ueberweg-Heinze, Gesch. d. Philos., 7th ed., 1888, Vol. 3, pp. 24, 25 ; Lange, Gesch. d. Materia lis nius, Vol. 1, p. 106, Iserlohn, 18()H, Eng. trans., 1, 228, 2d ed., Boston, 1879; and Lange's article on " Vives," in Encykl. d. r/es. Erzieh.- u. Unterrichtswesen, Vol. 9, pp. 737-814. — Tr. 1 Diego Payva d'Andrada, 1528-1575, a celebrated theologian of one of the most noble Portuguese families, who, after completing his studies chiefly in the Scriptures and the Fathers, devoted himself with zeal to missions for instructing the ignorant, and was sent at the age of thirty-three by King Sebastian of Portugal to the Council of Trent to assist as a theologian. There he composed his Orthodoxarum explicationum de reiiglonis Christianse capi- tib.is lib. X. udversus hsereticos, contra Chemnicium, Venetiis, 1564, 8vo; and his Defensio Trldentinse fidei catholicae et integerrimx V. lib. conipre- he7isa adversus hasreticorum detestabiles calumnias et prac^ertlm Martini C'lemnicii Genuaiii, Olyssipone, 1578, 4to, Ingolstadt, 1580, 8vo. In the lat- ter book he maintained the opinions of Zwingli and Erasmus on the salvation of the heathen, in consequence of which the book was much quoted by Prot- estants. Leibnitz refers to him in this same connection in the Th eodicie , Pt. I., § 96; in an excerpt from a letter to a friend written Nov. 1697, cf. Dutens, Leihnit. op. om., 1, .33; in his letters to Pellisson, Dutens, op. cit., 1, 683, Foucher de Careil, (Eiivres de Leibniz, 1, 65-66; and in his letters to Ant. Magliabechius, No. 28, 26 Nov., (i — Dec, 1697, Dutens, op. cit., 5, 121, and to Job. Fabricius, Prof, at Helmstadt, No. 16, Sept. 20, 1698, Dutens, op. cit., 5, 235. — Tr. 2 Martin Chemnitz, 1522-1586, a German Lutheran theologian, a disciple of Melancthon, 14'.I7-1560, and said to be the ablest theologian of the period imme- diately succeeding Luther, was Professor of Theology at Wittemberg, 1551-1554, and then for thirty years pastor at Brunswick. To him more than to any other the Lutheran church owes its jiurity of doctrine and compact organization. His Loci Theologici, Frankfort, 15!!1, is one of the best expositions of Lutheran theology as modified by Melancthon. His greatest work, the Uramen Con- cilii Tridentini, appeared at Frankfort in four parts, 15(15-1573, again in 1585, 4 vols., fol., and in later eds. For further account of Chemnitz, of. Schenkel's article in Herzog, Rpalencyclop., 2d ed., Leipzig, 1878, Vol. .3, pp. 184-192. Leibnitz refers to him also in the Theodicee, Discours prelim. § 67. — Tr. CH. xviii] ON HUMAN UNDERSTANDING 593 ticulars touching the origin of this famous society. I have remarked that some Protestants called those Andradians, who were of his opinion upon the subject of which I have just spoken. There have been authors who have written expressly upon the salvation of Aristotle upon the basis of these same principles with the approbation of the Censors. The books also of Collins ^ in Latin and La Mothe le Vayer ^ in French on the salvation of the heathen are well known. But a certain Eranciscus Puccius ^ 1 Francesco CoUio — Latin, Collins ("Collins" being a misprint for " Col- lins " in all the editions of Leibnitz's text) — was an Italian theologian of great learning, a doctor of the Ainbrosian College at Milan, and Grand Peni- tentiary of the diocese of Milan from 1631 till his death in 1G40. In his Ve ani- inab us paganorum, 2 vols., 4to, Mediol. 1622-1623, 2d ed. , 1738-1740, he discnssed the question of the eternal salvation of the pagans, deciding as to the fate of individuals on the gronnd of their knowledge of divine things, their moral life, sentiments and writings, and the testimony regarding them given by eccle- siastical and profane writers. He considers Aristotle as unsaved. Dupin, Bihl. (Its Aut. eccles., 1711, tom. 17, pp. 10i)-ll() sq., gives a long abstract from this work, and an estimate of its character and value. Cf. also Tiraboschi, Storia della Letteratura Italiuna, Vol. 14 [Tomo VIII, Parte Prima, ed. Rome, 1782-1784], pp. 167-1(18, Milan, 1824. — Tr. 2 Fran9ois de La Mothe le Vayer, 1588-1672, a French writer and philos- opher, was from 1()52-1660 the instructor of Louis XIV. of France, for whom he composed many elementary treatises on various subjects of study. The book here referred to by Leibnitz is his I)e la vertu des pa'iens, Paris, 1(,'42, 4to., 3d ed., 1647. The subject is treated in the conclusion of Pt. I., cf. CEuvres, Vol. 1, p. 582, Paris, A. Courbe, 1662. The best ed. is that published at Dres- den, 1756-1759, 7 vols, in 14, 8vo. The Dela vertu des pa'iens — avec les preuves des citations mises sous le texte — is found in Vol. 5, pp. 1 iSchuler u.'Schulthess, Zurich, 1828-1842, 8 vols.. Vol. 4, pp. 42-78. In his treatise De Providentki {ihkJ.,Yo\. 4, pp. 7'.)-144) he advanced the principle that pagans who have acknowledged the true God and have led a good, life, such as Socrates and Seneca, are capable of being saved without faith : and he extended this principle to all who have no knowledge of the gospel. — Tr. 2 Claude Pajon, 162fi-1685, a French Protestant theologian, Professor of Theology- at Saumer, Ifififi, and later pastor at Orleans. Pajon taught that in conversion the Holy Spirit did not act immediately or irresistibly upon the heart, but that the soul was irself active in the work of salvation, allowing itself to be convinced by the efficacious word of truth found in Scripture with which the Spirit's influence was intimately united. His views were opposed by both Lutherans and Reformed. For further account of him, cf. Alex. Schweizer, Central-Dolmen d. Reform. Kirche, 2 vols., 1854-185fi, Vol. 2, pp. 564-663, and in Herzog, Realencyclop. 2d ed., Leipzig, 1883, Vol. 11, pp. 161- 163: W. Gass, Ge.se/i. d.prot. Doqmatik, 2, a59.s7. — Tr. 3 Cf. Feller, Otium Hanoveranum, No. LXXXVIIL, pp. 181-183 (Dutens. fi, 311, 312). — Tr. 596 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv CHAPTER XIX OF ENTHUSIASM § 1. Ph. [Would to God that all theologians and St. Augus- tine himself had always practised the maxim expressed in this passage.] But men think that the dogmatic spirit is an indication of their zeal for the truth, while it is wholly the contrary. We love the truth in reality only in proportion as we love to examine the proofs which make it what it is. And when we judge hastily we are always pressed by less sincere motives. § 2. The spirit of authority is not one of the less common motives, and a certain satisfaction it has in its own reveries is another motive which causes enthusiasm to s^jring up. § 3. This is the name which is given to the failing of those who believe an immediate revelation when it is not grounded in reason. § 4. And as we may say that reason is a natural revelation of which God is the author, just as he is the author of nature, we may also say that revelation is a super- natural reason, i.e. a reason extended upon the basis of new discoveries emanating directly from God. But these discov- eries suppose that we have the means of discerning them, which is reason itself; and to desire to proscribe reason in order to make way for revelation would be to pluck out the eyes the better to see the satellites of Jupiter through a tele- scope. § 5. The source of enthusiasm is that an immediate revelation is more convenient and shorter than the long and difficult process of reasoning which is not always followed by a happy result. Men have been seen in all ages whose melan- choly mingled with devotion, united with the good opinion they have had of themselves, has made them believe that they had an altogether different intercourse with God from other men. They suppose he has promised it to them and believe themselves his people preferably to others. § 6. Their fancy becomes an illumination and a divine authority, and their plans are an infallible direction from heaven, which they are obliged to follow. § 7. This view has produced great results and caused great evils, for a man acts more vigorously when CH. XIX] ON HUMAN UNDERSTANDING 597 he follows his own impulses and when the opinion of a divine authority is sustained by his inclinations. § 8. It is difficult to draw him therefrom, because this pretended certainty with- out proof flatters his vanity and love for that which is extraor- dinary. Fanatics compare their opinions to sight and feeling. They see the divine light as Ave see that of the sun at noon without needing the twilight of their reason to show it to them. § 9. They are certain because they are certain, and their per- suasion is right because it is strong, for this is the result to which their figurative language reduces itself. § 10. But as there are two perceptions, that of the proposition and that of the revelation, we may ask them where is clearness. If it is in the sight of the proposition, what good is revelation ? It must then be in the feeling of revelation. But how can they see that it is God who reveals and not a will-of-the-wisp which leads them around this circle : this is a revelation because I believe it strongly, and I believe it because it is a revelation. § 11. Is there anything more sxiited to throw one into error than to take the imagination for a guide ? § 12. St. Paul had great zeal when he persecuted the Christians and did not allow himself to be mistaken. We know that the devil has had martyrs, and if it is sufficient to be well persuaded we shall not be able to distinguish the delusions of Satan from the inspira- tions of the Holy Spirit. § 14. It is then the reason which makes known the truth of revelation. § 15, And if our belief proved it, it would be the circle of which I just spoke. The holy men who received the revelations of God had external signs which persuaded them of the truth of the inner light. Moses saw a bush Avhich burned without being consumed, and heard a voice from the midst of the bush, and God, in order to give him more assurance concerning his mission when he sent him to Egypt to deliver his brethren, made use of the miracle of the rod changed into a serpent. Gideon was sent by an angel to deliver the people of Israel from the yoke of the Mid- ianites ; yet he demanded a sign in order to be convinced that this commission was given him on the part of God. § 16. I do not, however, deny that God sometimes illumines the minds of men, in order to make them understand certain important truths or to lead them to good acts, by the immediate influence and assistance of the Holy Spirit without any extraordinary 598 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv sign accompanying this influence. But in these cases also we have reason and Scripture, two infallible rules for judging of these illuminations ; for if they agree with these rules Ave run at least no risk in regarding them as inspired of God, although it is not perhaps an immediate revelation. Th. Enthusiasm was at the beginning a good term. And as the sophism properly indicates an exercise of wisdom, enthusi- asm signifies that there is a divinity in us. Est Deus in nobis} Socrates maintained that a god or dsemon ' gave him internal warnings, so that enthusiasm would be a divine instinct. But men having consecrated their passions, fancies, dreams, and even their anger as something divine, enthusiasm began to sig- nify a mental disturbance attributed to the influence of some divinity, which is siipposed to be in those who are smitten there- with ; for the soothsayers, male and female, showed a mental derangement, when their god seized them, as the Cunntan Sibyl in Vergil.^ Since then we attribute it to those who be- lieve Avithout foundation that their movements come from God. Nisus in the same poet thinking himself pressed by I know not what impulse to a dangerous enterprise, in which he per- ished with his friend, proposed it to him in these terms full of a reasonable doubt : — Di ne hunc ardorem mentibus addunt, Euryale, an sua cuique Deus fit dha cupido ? * 1 Ovid, Fasti, 6, 5: " Est Deus in nobis, agitante calescimus illo." — Tr. 2 On the daemon of Socrates, cf. Zeller, Philos. d. Griech., II., 1 [Vol. 3], 7.3-91, 4th ed., Leipzig, 1889; J. S. Blackie, Four Phas?s of Morals, pp. 12.5- 127, New York, 1872; H. .Jackson, "On the Saifioviov of Socrates" in tlie "Journal of Philology," V., and article " Socrates," Encyclop. Brit., 9th ed.. Vol. 22, p. 240 (Amer. reprint). — Tr. 3 Cf. Vergil, JEneid, 6, 49: " Et rabie fera corda tninent." The view liere mentioned by Leibnitz, that persons gifted with inspiration or enthusiasm were also affected with some derangement or disturbance of the ordinary men- tal processes, was current in one form or another throughout all antiquity, and had its influence, through the contact of Greek thought with Chris- tianity, in shaping the Christian doctrine of inspiration. Cf. Plato, Phsedrv.f, 244, Jowett's trans., 2d ed., 187.^. 2, 121, .3d ed., 1892. 1, 449-450; Ion, .533-534, Jowett, 2d ed., 1, 247-248, 3d ed., 1, 501-503; Tlmmus, 71-72, Jowett, 2d ed., 3, 654-656, .3d ed., 3, 492-494; the Stoic view, Zeller, Philos. d. Griech., III., 1 [Vol. 5], .3.30 sq., Plutarch, iUd., III., 2 [Vol. 0], 193 sq., Philo, 414 sq., Plo- tinus. Oil sq. ; Pfleiderer, RHigionsphilosophie, 2d ed., 1884, 2, 339 sq., Eng. trans., 4, 40 .sg. — Tr. * Verg. Aen. 9, 184-185. — Tr. 1 CH. XIX] ON HUMAN UNDERSTANDING 599 He ceased not to follow this instinct althoiigk he knew not Avhether it came from God or from an unfortunate desire to disting'uish himself. But if he had been successful, he would not have failed to acquire authority in another case and to think himself impelled by some divine power. The enthusi- asts of the present think that they receive also from God the dogmas which they observe. The Quakers belong to this per- suasion, and Barclay, their first systematic author, maintains that they find in themselves a certain light which is made known by itself.^ But why call that light which reveals noth- ing ? I know that there are some persons of this disposition of mind who see sparks and even something more luminous, but this image of material light excited when their minds are aroused gives no light to the mind. Some idiots with a restless imagination form conceptions which they had not before ;' they are in a condition to say fine or at least very animated things in their opinion ; they admire themselves and make others admire this fertility which passes for inspiration. This ad- vantage comes to them largely from a vivid imagination which passion rouses and from an excellent memory which has well retained the methods of speech of the prophetic books which the reading or discourse of others has rendered familiar to them. Antoinette de Bourignon made use of the facility she had in speaking and writing as a proof of her divine mission.^ I know a visionary who based his divine mission upon the tal- 1 Cf. Leibnitz's letter to Thos. Burnett, July 17-27, 1696; Gerhardt, Leibniz, philos. Schrift., 3, 184. On the doctrine of the " inner light," the immediate revelation of the Spirit of God in each individual soul, " the light that lighten- eth every man," — the most characteristic doctrine of the Quakers, — cf. Robert Barclay, 1648-1690, An Apology for the True Christian Divinity, Prop. II., Of Immediate Revelation ; and the excellent account of Bancroft, Hist, of the U. S., chap. 23, Vol. 2, pp. 78 57., Centenary ed., Boston, 1876. — Tr. 2 Antoinette Bourignon, 1616-1680, an enthusiast whose religious doctrines made considerable stir in her lifetime and for a short time after in Holland and Scotland, but have long ceased to have any influence and are now almost wholly forgotten. Her complete works in French appeared at Amsterdam, 1686, 19 vols., 8vo ; 1717, 21 vols., 8vo, with a life of the author by Pierre Poiret, 1646-1719, a Calvinistic minister and famous mystic, who became her disciple, edited her works, and attempted to reduce to system her vague reveries in his CEconomie de la nature, Amsterdam, 1686, 21 vols., 8vo. Her prophetic views were expounded in her Traite de raveuc/lenient des homnies ((Eiivres, ed. 1686, Vol. 15), her La lumiere du monde {ibid.. Vol. 7), and her De la hnniere nee en tenebres (ibid.. Vol. 4), the last work being "a collection of letters, with a large explanation of Matt. 24 and 25 " ; Eng. trans. The Light of the 600 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv ents he had in speaking and praying aloud almost an entire day without ceasing and without becoming exhausted. There are some persons who, after having practised austerities or after a state of sadness, taste a peace and consolation in the soul which enraptures them, and they find therein so much de- light that they believe it to be an effect of the Holy Spirit. It is true that the contentment they find in considering the great- ness and goodness of God, in the accomplishment of his will, in the practice of the virtues, is a grace of God and one of the greatest ; but it is not always a grace which needs a new super- natural aid, as many of these good people maintain. Not long since there was a young lady very wise in everything else, who believed from her youth that she spoke with Jesus Christ and was his wife in a wholly peculiar manner. Her mother, to whom this was related, Avas a little given to enthusiasm, but the daughter having commenced early had gone very much farther. Her satisfaction and joy was unspeakable, her wis- dom appeared in her conduct, and her intelligence in her discourse. The thing went, however, so far that she received letters addressed to our Lord and she sent them back sealed as she received them with a reply which sometimes appeared appropriate and always reasonable. But finally she ceased to receive them from fear of making too much disturbance. In Spain she would have been another St. Theresa. But all per- sons who have similar visions do not conduct themselves in the same way. There are some who seek to form a sect, and even to make trouble : and England furnishes a strange proof of this.- When these persons act in good faith it is difficult to World, London, 1H96; The Light risen in Dcwkness, London, 1703. Leibnitz refers to her in a fragment, Sur Vesprit Sectaire, 1697, cf. Dutens, 1, 740. For further account, cf. J. C. Adehing, Gesch. d. mensch. Narrheit, Leipzig, 1785- 1789, 7 vols., 16mo, Vol. 5, pp. 245-391 : Gottfried Arnold, Kirchen u. Ketzerhis- tori-', Frankfort-on-the-Main, 1729, Theil. III., Cap. XVI., Vol. 2, pp. 153-176, Th. IV., Sect. III., Num. XVII.. Vol. 2, pp. 1065-1089; Wetzer u. Welte, Kir chenlex icon, Vol. 2, pp. 1167-1170, ed. 1883. — Tr. 1 Leibnitz here refers to the Independents, who, arising in obscurity in Eng- land in the reign of Elizabeth and gradually gaining in numbers and influence as a result of the persecution to which they were subject at the hands of thQ established Church and the State, and of their success in founding the New England States, came to the front in the time of the Revolution and changed at length the political as well as the religious life of England, and became a powerful and controlling foi'ce in the life and institutions of the American people. In their fundamental principle that religion is a matter of the indi- I CH. XIX] ON HUMAN UNDERSTANDING 601 reform them : sometimes the overthrow of all their plans cor- rects them, but often it is too late. There was a visionary who lately died who believed himself immortal because he was very old and very well, and without having read the book of an Englishman lately published (who wished to make us believe that Jesus Christ came to exempt true believers from bodily death) was almost of the same opinion- for some years past ; but when he perceived that he was dying he went so far as to doubt all religion because it did not correspond to his chimera. Quirin Kulman [s/c],^ a Silesian, a man of knowledge and judg- ment, but who had since indulged in two kinds of visions, equally dangerous, the one of the enthusiasts, the other of the alchemists, and who made some stir in England, Holland, and even in Constantinople, being at last advised to go into Russia and there to mix himself up in certain intrigues against the minister, at the time when the Princess Sophia governed it, was condemned to be burned, and did not die like a man per- vidual reason and conscience, wholly free from State or other control, they bore in a general way a somewhat close resemblance to the Quakers and other enthusiasts of their time. In this connection Schaarschmidt ventures the coniecture that Leibnitz may have had his attention called to the persons and circumstances men- tioned in this chapter by a large work, appearinn; not long before, entitled, Anabipt'ffticum et enthusiasticum Pantheon, und Geistliches Riisthauss wider die Alten Qiiiicker' und Neuen Frey-Geister. u. s. w., Cothen, W. A. Meyer, 1702, since his allegations strikingly call to mind this work. But may not Bayle's Dlctionnalrs as well have been the source of his information, inas- much as it contains considerably extended articles on the persons mentioned, and was a work witli which Leibnitz was thoroughly familiar? — Tr. 1 Quirin Kahlmann, Kiol-IGSO, in consequence of a disordered brain result- ing from a severe illness at the age of 18, became subject to hallucinations, lost his previous taste for study, claimed to possess a method by wliich he might know everything independent of the usual processes of acquisition, and that the Holy Ghost was his only teacher, and on these grounds considered himself a saint. At Leyden, falling in witii the works of Boehme, he imme- diately became an enthusiastic dis-iole. It is said that he wished to marry Antoinette Bourignon, but that her " inviolable chastity " caused her to refuse him. I^eaving Holland in 1(175 he travelled, it is believed, in England, France, and Turkey. At Constantinople he addressed a letter, Aug. 1, lfi78. to the Sultan Maliomet IV., in which he predicted the conversion of the Turks, and sought to win the Sultan to his views. Failing to attain his desired end, he went to Russia to set up the true kingdom of God, was opposed by Peter the Great, and after a brief trial condemned by the Greek Patriarch — it is said at tlie suggestion of a Lutheran clergyman — to be burned alive as a heretic in 1()89. For further account, cf. Adelung, Gfisch. ch men.- zig, 1665, 4to, ed. by Ch. Thomasius, Halle, 1699, 8vo, was for a long time the most accurate history of ancient philosophy. Brucker was greatly indebted toit. — Tr. 1 Cf. ante, pp. 553^ note 1, 582. Leibnitz, while admitting the possibility and on sufficient and proper evidence the actuality of miracles, nevertheless regards them from the philosophic point of view as exceptional and relatively CH. XX] ON HUMAN UNDERSTANDING 607 CHAPTER XX OF ERKOK § 1. Ph. After having spoken of all the means which make us know or divine the truth, let us also say something about our errors and bad judgments. Men must often be mistaken since there are so many dissensions among them. The reasons of this may be reduced to these four : (1) the lack of proofs ; (2) little skill in using them ; (3) lack of will to make use of them ; (4) false rules of probability. § 2. When I speak of the lack of proofs, I understand also those which we might find if we had the means and the opportunity, but this it is which we most frequently lack. Such is the condition of men whose life is passed in seeking their subsistence : they are as little informed of what goes on in the world, as a draught horse who always goes by the same road may become skilled in the map of the country. They would require languages, reading, con- versation, observations of nature and the experiments of art. § 3. Now, all this not agreeing with their condition, shall we say then that the bulk of men are led to happiness or misery only by blind chance ? Must they abandon themselves to the current opinions and authorized guides in the country, even as regards eternal happiness or misery ? Or will they be eternally unhappy to have been born rather in one country than in another ? We must admit, however, that no one is so com- pletely occupied with the care of providing for his subsistence as to have no time left to think of his soul and to be instructed in that which concerns religion, if he were to apply himself thereto as he does to less important things. Til. Suppose that men are not always in a condition to instruct themselves, and that not being able to give up with unimportant, and emphasizes, as here, the view that the essence of Christianity consists in its ethical content, a content intrinsically rational and accordant with nature. In addition to the authors referred to, ante, p. 55:5, note 1, rf- Piinjer, Gesch. d. christ. Religionsphilos., 1, :!59-3()0, 372-.S75, Eng;. trans., 480-51.O, espec. 485-486, 501-504; and for an acute and able discussion of Miracles, their idea, ofltice, etc., vf. E. G. Robinson, Christian Theolor/y, § 20, pp. 103-109, Rochester, N. Y., Press of E. R. Andrews, 1894. — Tr. (608 LEIBNITZ'S CUITIQUE OF LOCKE . [bk. iv prudence the care of the subsistence of their family in order to investigate difficult truths, they are obliged to follow the opinions authorized among them, it will always be necessary to judge that in the case of those who have the true religion without having its proofs, internal grace will supply the lack of the motives of credibility, and charity makes us also judge, as I have already indicated to you, that God does for persons of good will, brought up among the thick darkness of the most dangerous errors, all that his goodness and justice demand, although perhaps in a way which is unknown to us. We have histories commended in the Roman church of persons who have been expressly raised up in order that salutary aid be not want- ing. But God can assist souls by the internal operation of the Holy Spirit, without the need of so great a miracle ; and because it is good and consoling for the human race to put itself in the condition of the grace of God, only the good but sincere and serious will is needed. I admit that we have not indeed this good will without the grace of God, forasmuch as all natural or supernatural good comes from him ; but it is always enough that we must only have the will, and that it is impos- sible that God can demand a condition easier and more reason- able. § 4. Ph. There are those who are sufficiently at their ease to have all the opportunities suited to illumine their doubts ; but they are deterred from this by obstacles full of craftiness, which it is easy enough to see, while it is not necessary to display them in this place. § 5. I prefer to speak of those who lack the skill to avail themselves of the proofs which they have, so to speak, under their hand, and who cannot retain a long course of argu- ment nor weigh all the circumstances. There are some people of a single syllogism, and there are some of two only. This is not the place to determine whether this imperfection arises from a natural difference of the souls themselves or of the organs, or whether it depends upon the lack of exercise which polishes the natural faculties. It is sufficient for us here that it is visible, and that we have only to go from the palace or from the exchange to the hospitals and small houses to perceive it. Th. It is not the poor alone who are needy ; certain rich people lack more than they, because these rich people demand too much and put themselves voluntarily in a kind of poverty CH. XX] : ON HL'MAN UNDERSTANDING 609 whicli liinders thena from applying themselves to important con- siderations. Example does much here. One tries to conform to that of his equals, so that he is compelled to practise without showing a spirit of perverseness, and that makes it easy for him to become like them. It is very difficult to satisfy at the same time reason and custom. As for those who lack capacity, they are fewer perhaps in number than you think ; I think that good sense with application can suffice for everything which does not demand promptness. I presuppose good sense, be- cause I do not think, y ou , would demand the search for truth from the dwellers in small houses. It is true that there are not many who could not learn something of it, if we knew the means of so doing and what original difference exists between our souls (as I believe does in reality exist) ; it is always cer- tain that one soul might go as far as another (but not perhaps so rapidly) if it were led as it should be. § 6. Ph. There is another sort of people who lack only will. A strong attachment to pleasure, a constant application to what concerns their fortune, a general idleness or negligence, a par- ticular aversion to study and meditation, prevents them from thinking seriously of the truth. There are even some who fear that a research free from all partiality would not be fa- vorable to the opinions which most suit their prejudices and plans. We know persons who will not read a letter which they suppose brings bad news, and many people avoid agreeing upon their accounts or informing themselves of the state of their property, for fear of learning what they would desire always to be ignorant of. There are some who have large rev- enues and employ them all in provisions for the body without dreaming of the means of perfecting the understanding. They take great care always to appear in a suitable and brilliant equipage, and they suffer without difficulty their soul to be covered with the wretched rags of prejudice and error, and its nakedness, i.e. its ignorance to appear as an eccentricity. Not to speak of the interest they ought to take in a future state, they do not in the least neglect what they are interested to know in the life they lead in this world. And it is strange that very often those who regard power and authority as an appanage of their birth or their fortune, carelessly abandon it to ]jeople of a condition inferior to theirs, but who surpass them 2r 610 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv in knowledge. For it is very necessary that the blind be led by those who see, lest they fall into the ditch, and there is no worse slavery than that of the understanding. Th. There is no more evident proof of the negligence of men as regards their true interests, than the little care they take to know and practise what agrees with their health, which is one of our greatest blessings ; and although the great feel as much and more than others the bad effects of this negligence, they do not alter their course. As far as faith is concerned, many regard the thought which would lead to its discussion as a temptation of the devil, which they think they can the better surmount only by turning their minds to an entirely different thing. Men who only love pleasure, or who are attached to some occupation, are wont to neglect other matters. A player, a hunter, a drinker, a debauchee, and even a man curious about trifles, will lose his fortune and his property for lack of giving himself the trouble to institute a process or to speak to the men in a guard-house. There are some like the Emperor Honorius, who, when the news of the destruction of Kome was brought to him, thought it was his hen who bore this name, and this offended him more than the truth. ^ It is desirable that men who have power have knowledge in pro- portion ; but if the details of the sciences, of the arts, of history and languages, should not be theirs, a solid and prac- tised judgment and a knowledge of things equally great and general, in a word, summa rerum, might suffice. And as the Emperor Augustus had an abstract of the forces and needs of the State which he called Breviarium Imperii, he might have an abstract of human interests which would deserve to be called Enchiridion Sapientim, if men would care for that which is of most importance to them. § 7. Ph. Finally, the majority of our errors arise from the false measures of probability which we take, whether by sus- 1 The anecdote here mentioned by Leibnitz is thus given by Giovanni Bat- tista Egnazio, 1473-1553, in his Be Romanls prlnclpibus, Lib. III., Venice, 1516, near the end of Book I. {cf. Haurisius, Scriptores historlse. Romanx Latini veteres, qusR extant omiies, Heidelberg, 1743-1745, 3 vols., fol., Vol. 3, p. 625) : " Quum nuntiatum Honorio esset Ravennae Romam perditam, cre- didit ille de pugnaci Gallo, cui nomen erat Romae, significatum esse: adinira- tumque vehenienter tarn subito periisse eum quo cum paullo ante festivissime luserat." — Tr. CH. XX] ON HUMAN UNDERSTANDING 611 pending our judgment in spite of manifest reasons, or in giving it notwithstanding contrary probabilities. These false measures consist (1) in doubtful propositions taken as principles, (2) in the accepted hypotheses, (3) in the dominant passions or incli- nations, (4) in authority. § 8. We ordinarily judge of truth by its conformity with what we regard as indisputable principles, and this makes us despise the testimony of others and indeed of our own senses when they appear contrary thereto : but before relying upon these with so much assurance, we should examine them with the utmost exactness. § 9. Children receive the propositions taught them by their father and mother, nurses, teachers and others who are about them, and these propositions having taken root, are regarded as sacred as a Urim and Thum- mim which God might himself have put in the soul. § 10. We have some difficulty in admitting that which clashes with these internal oracles, while we believe the greatest absurdities which agree with them. This appears in the extreme obstinacy which we notice in different men who believe strongly opinions as directly opposed as the articles of faith, although they are very often equally absurd. Take a man of good sense, but per- suaded of this maxim that he must believe ivhat they of his communion believe, as they teach at Wittenberg or in Sweden, what disposition has he not to receive without difficulty the doctrine of consxibstantiation, and to believe that one and the same thing is flesh and bread at the same time. Th. It is very apparent, sir, that you have not been suffi- ciently instructed in the views of the Evangelicals,^ who admit the real presence of the body of our Lord in the Eucharist. They have explained a thousand times that they do not mean the consubstantiation of bread and wine with the flesh and blood of Jesus Christ, and still less that one and the same thing is flesh and bread at the same time. They teach only that, in receiving the visible symbols, we receive in an invisible and supernatural manner the body of our Saviour, without its being enclosed in the bread ; and the presence which they mean is not local or spatial, so to speak, i.e. determined by the dimen- sions of the present body, so that all that the senses can oppose ■ I.e. Lutherans. For the views and controversies regarding the Eucharist, and the Confessions alluded to in the remainder of this section, cf. the various Church Histories and Histories of Doctrine. — Tr. 612 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv to it does not concern them. And in order to show that the inconveniences which may be derived from reason no longer affect them, they declare that what they mean by the substance of the body does not consist in extension or dimension; and they make no difficulty in admitting that the glorious body of Jesus Christ preserves a certain ordinary and local presence, but congruous with his position in the exalted place where he is found, altogether different from this sacramental presence herein questioned, or from his miraculous presence by which he governs the church, which causes him to be not everywhere like God, but there where he prefers to be. This is the view of the more moderate, so that, in order to show the absurdity of their doctrine, it would be necessary to show that the entire essence of the body consists only in extension, and in that which is solely measured thereby, which no one, so far as I know, has yet done. This whole difficulty also concerns not less the Reformers who follow the Gallican and Belgian confes- sions, the declaration of the Council of Sendomir, composed of people of the two confessions, Augustan and Swiss, conformed to the Saxon confession, destined for the Council of Trent ; the profession of faith of the Reformers who came to the Conference of Thorn, convoked under the authority of Vladislas, King of Poland, and the constant doctrine of Calvin and of Beza, who have declared the most distinctly and the most strongly of everybody that the symbols really furnish what they represent, and that we become participants in the body and blood of Jesus Christ. Calvin, after having refuted those who content themselves with a metaphorical participation of thought or of seal and with a union of faith, adds that we can say nothing sufficiently strong to establish its reality, that he is not ready to subscribe to, pro- vided we avoid everything which looks to the circumscription of place or the diffusion of dimension ; so that it appears that at bottom his doctrine was that of Melanchthon and even of Luther (as Calvin himself conjectured in one of his letters), except that in addition to the condition of the perception of the symbols with which Luther contents himself, he demands also the condition of faith, in order to exclude the participation of the unworthy. I have found Calvin so positive upon this real communion in a hundred places in his works, and even in his familiar letters, where there was no need of being so, that I do not see any reason to suspect artifice. CH. ^x] ON HUMAN UNDERSTANDING 613 §11. Ph. [I ask your pardon if Ihave spoken of these gentle- men according to the common opinion. I remember now hav- ing remarked that some very clever theologians of the Anglican church have been for this real participation. But from estab- lished priiiciples let us pass to the accepted liyj)otlieses. Those who admit that they are only hypotheses often cease not to maintain them with warmth, almost as if assured principles, and to despise contrary probabilities. It would be unendurable to a learned professor to see his authority overturned in an instant by a new comer who should reject his hypotheses ; his authority, I say, which has been in vogue for thirty or forty years, acquired by much labor at night, sustained by much Greek and Latin, confirmed by a general tradition and by a venerable beard. All the arguments which we can employ to convince him of the falsity of his hypothesis will be as little capable of prevailing upon his mind as the efforts Boreas made to compel the traveller to leave his cloak, which he held so much the more firmly as the wind blew with more violence. Th. In reality the Copernicans have experienced in the case of their adversaries that hypotheses recognized as such ceased not to be maintained with an ardent zeal; and the Cartesians are not less positive regarding their grooved particles and little balls of the second element ^ than if they were the theorems of Euclid ; and it seems that zeal for our hypotheses is merely a result of the passion we have of making ourselves respected. It is true that those who condemned Galileo believed that the rest of the earth was more than an hypothesis, for they judged it in conformity with Scripture and reason. But since then it has been perceived that reason at least sustained it no longer ; and as for Scripture, Father Fabry, Penitentiary of St. Peter, an excellent theologian and philosopher, publishing in Rome itself an Apology for the Observations of Eustachio Divini,- 1 Cf. New Essays, Preface, cmte, y>- o\, line 11 ; Descartes, Princip. Philos., Pt. III., §§ 52, 90. The "grooved particles" and "little balls of ihe second element " are a part of the vortices-theory {cf. ante, p. 552, note 1). For the "matter of the first and second element" and the genesis of the "perfect globes " or " balls of the second element," cf. Princlp. Pliilos., Pt. III., § 48 sq. The notes of J. H. von Kirchmann in his German trans, of this work of Des- cartes (Philos. Bibliothek., Vol. 26, 2d ed., Heidelberg, 1887) are a valuable aid in the study of the theory. — Tr. ■^ Eustachio Divini, c. 1620 — c. 1()66, an Italian mechanicia'n, optician, and astronomer, noted for his skill in making optical instruments, especially tel- GU LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv a famous optician, hesitated not to declare that it was only pro- visionally that they understood in the sacred text a true move- ment of the sun, and that if the view of Copernicus were found true, there would be no difficulty in explaining it in like man- ner as this passage of Vergil : terrseque urbesque recedunt.^ However, they did not cease to continue in Italy and in Spain and even in the hereditary states of the emperor to suppress the doctrine of Copernicus, to the great detriment of these na- tions whose scholars might have raised themselves to more beautiful discoveries had they enjoyed a reasonable and philo- sophic liberty. § 12. Ph. The dominant passions appear to be in reality, as you say, the source of the love we have for hypotheses : but they also extend very much farther. The greatest probability in the world will avail nothing in showing his injustice to an avaricious and ambitious man; and a lover will have every facility in the world for allowing himself to be duped by his mistress, so long as it is true that we easily believe whatever we wish, and according to the remark of Vergil, qui ainant ipsi sibi somnia fingunt.^ This is what makes them make use of two means of escaping the most apparent prohahilities when they attack our passions and our prejudices. § 13. The first is to think that there may be some sophistry concealed in the argument which they oppose to us. § 14. The second in supposing that we might put before- hand wholly as good or even better arguments in order to beat the adversary, if we had the opportunity, or skill, or aid, which escopes, was the reputed author of a little work entitled Brevis annotatio in Sijsteina Saturnuini Christiani Hagenii [Hag. Com., 1(;59, 4to], Rome, KitiO, 8vo, in whicli an attempt was made to refute Huygens' theory of the planet Saturn. Divini, however, was no Latinist, and probably had little share in the book, contributing merely "his pretended observation of the three sepa- rate bodies"; the real author was most likely the Jesuit, Honore Fabri (';/'. ante, p. .586, note 2). Huygens reprinted the work together with his reply, Brevis assertio systematis Saturnii sni, Hag. Com., 1660; and Divini pub- lished his rejoinder, Septempedinius pro sua annotatione in syst. Saturn. Ch. Hagenii, adversum ejus assertlonem, Rome, 1661. On the whole subject, cf. Huygens, (Etivres completes, La Haye, 1888-1893, 5 vols., passim. — Tr, i^?i. 3, 72. — Tk. ^Eclog. 8, 108. — Tr. CH. XX] ON HUMAN UNDERSTANDING 615 we must have to discover them. § 15. These means of shield- ing themselves from conviction are sometimes good, but they are also sophisms when the matter is sufficiently explained and everything has been taken into account; for after that there are means of knowing with regard to all upon what side the probability is found. Thus there is no room for doubting that the animals have been formed by the movements of an intelli- gent agent, rather than by a fortuitous concourse of atoms ; as there is no one who doubts in the least whether the characters of printing which form an intelligent discourse have been brought together by an attentive man, or by a confused medley. I should think then that it does not depend upon us to suspend our assent in 'these instances ; but we can give it when the probability is less evident, and we can even content ourselves with more feeble proofs which better agree with our inclina- tion. § 16. It appears to me impracticable for the truth for a man to lean to the side upon which he sees the less probability ; perception, knowledge and assent are not arbitrary, as it does not depend upon me to see or not to see the agreement of two ideas, when my spirit is turned toward them. We can how- ever voluntarily arrest the progress of our researches ; without this ignorance or error could not in any case be a sin. It is in this that we exercise our liberty. It is true that in the in- stances where we have no interests, we embrace the common opinion, or the view of the first comer ; but in the points where our happiness or misery is concerned, the mind applies itself more seriously to weighing the probabilities, and I think that in this case, that is, when we are attentive, we have no choice in determining ourselves for the side we prefer, if between the two sides there are differences at once visible, and that it will be the greatest probability that will determine our assent. Th. I am of your opinion at bottom, and we have given sufficient explanation upon this matter in our preceding con- ferences when we spoke of liberty. I showed then that Ave never believe what we wish, but rather what we see is the most apparent ; and that nevertheless we can make ourselves believe indirectly what we wish by turning away the attention from a disagreeable object in order to apply ourselves to another which pleases us. This makes us in regarding more the reasons of a favorite side believe at last the more probable. As for the 616 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv opinions in which we take little interest and which we receive upon slight reasons, we do this because, noticing scarcely any- thing which opposes them, we find that the opinion which makes us regard them favorably surpasses as much or more the opposite opinion, which has nothing in its behalf in our perception, as if it had had many reasons on both sides, for the difference between and 1, or between 2 and 3, is as great as betvv^een 9 and 10, and we perceive this advantage, without thinking of the examination which would still be necessary in order to judge, but to which nothing impels us. § 17. Ph. The last false ineasure of probability that I in- tended to notice is improperly understood authority, which keeps more people in ignorance and error than all the others together. How many people we see who have no other basis for their views than the opinions received among our friends or among the members of our profession or of our party, or of our coun- try ! Such a doctrine has been approved by venerable antiq- uity ; it comes to me under the passport of preceding centuries ; other men yield to it ; this is Avhy I am shielded from error in receiving it. We have as much authority for tossing up in order to take these opinions, as to take them upon the basis of such rules. And besides the fact that all men are liable to error, I believe that if we could see the secret motives which actuate the scholars and chief men of a sect, we should find often something wholly different from the pure love of the truth. It is certain at least that there is no opinion so ab- surd that it cannot be embraced upon this basis, since there is scarcely an error which has not had its partisans. Til. It must, however, be admitted that in many instances we cannot avoid yielding to authority. St. Augustine has pro- duced quite a remarkable book "De utilitate credendi,"^ which deserves to be read on this subject, and as for the received opinions, they have for themselves something approaching to that which gives what is called presumption with the juriscon- sults : and although we are not obliged to follow them always without proofs, we are no more authorized to destroy them in the mind of another without having contrary proofs. This it is which does not allow us to change anything without reason. 1 Cf. Opera, Benedictine ed., Vol. 8, pp. 45-70, Paris, 1688; Migne, Patrol, s. Lat., Vol. 42 [Vol. 8 of Augustine], pp. 65-92. — Tr. CH. XX] ON HUMAN UNDERSTANDING 617 Tlie argument drawn from the great mimber of the approvers of an opinion has been much disputed since the late M. iSTicole published his book on the church ; ^ but all that may be drawn from this argument, when the question is of approving a reason and not of attesting a fact, may be reduced merely to what I have just said. And as one hundred horses do not run faster than one horse, though they can draw more, so it is with one hundi'ed men as compared with one single man ; they cannot go more justly, but they will work more effectively; they can- not judge better, but they will be capable of furnishing more matter upon which the judgment may be exercised. This is the meaning of the proverb : plus vident oculi qtiam octdtis. We notice it in the councils, where really a multitude of considera- tions are put upon the carpet which would perhaps escape one or two, but they run a risk often of not taking the better side in concluding upon all these considerations, when there are no skilful persons charged with directing and weighing them. Hence some judicious theologians of the Roman party, seeing that the authority of the church, i.e. that of the most exalted in dignity and the most supported by the multitude, could not be certain in a matter of reasoning, have reduced it to the mere attestation of the facts under the name of tradition. This was the opinion of Henry Holden,- an Englishman, doctor of the Sorbonne, author of a book entitled '' Analysis of the Faith," in which, following the principles of the " Commonitorium " of Vincent de Lerins,'^ he maintained that we cannot make new 1 Of. ante, p. 530, note 1. — Tr. 2 Henry Holden, 159f)-16(i2, was an English Roman Catholic divine, who graduated at the Sorbonne, and was appointed Professor of Theology there. In 1647 he petitioned the House of Commons for toleration of the Catholics, provided they would take the oath of allegiance. His Divinse Fidel Analysis, a concise exposition of the Catholic articles of faith as distinguished from matters of opinion, appeared at Paris, lti52, with an appendix consisting of a short treatise on Schism. It was reprinted at Paris, 1685, 1767, at Cologne, 16.55, 1782, Eng. trans., by " W. G.," 1658. Dupin, who gives a full abstract of the book in his Bibl. des Ant. ecdes., 1711, torn. 17, pp. 194-203, considers him one of the ablest controversialists of his time. In 1656 he was engaged in a controversy with Antoine Arnauld, the Jansenist {cf. ante, p. 4(>3, note 4), and his letters to Arnauld were printed in later editions of the Analysis. — Tr. 3 St. Vincent of Lerins, of Gallic origin, wlio died about 450. His Adversus profarias omnium novitates Hiereticoruni Cuninionitoriitni, written in 434, three years after the Council of Ephesus, energetically attirnis the authority of tradition against all religious and doctrinal innovations. In chap. 2 of this short treatise occurs the famous threefold test of orthodoxy : " Quod semper, 618 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv decisions in the church, and that all the bishops assembled in council can do is to attest the fact of the doctrine received in their dioceses. The principle is specious so long as we continue in generalities ; but when we come to the fact, it is found that in different countries different opinions have been received for a long time ; and in the same countries also they have gone from one extreme to another, notwithstanding the arguments of Arnauld against insensible changes ; besides often without confining themselves to attest them, they have taken it upon themselves to judge. It is also at bottom the opinion of Gret- ser,^ a learned Jesuit of Bavaria, author of another Analysis of Faith, approved by the theologians of his order, that the church may judge controversies by making new articles of faith, since the assistance of the Holy Spirit is promised it, although most frequently they try to disguise this view, especially in France, as if the church were only to explain doctrines already estab- lished. But the explanation is a statement already received, or a new one which they believe may be drawn from the re- ceived doctrine. Practice is most frequently opposed to the first sense, and in the second, what can the new statement which is established be but a new article ? I am not, however, of the opinion that we despise antiquity in the matter of relig- ion ; and I also believe that we may say that God has pre- served the truly ecumenical councils hitherto from all error contrary to wholesome doctrine. For the rest, sectarian prej- udice is a strange thing. I have seen people embrace with ardor an opinion for the sole reason that it is received in their order, or even solely because it is contrary to that of a man of a religion or of a nation which they do not like, although the quod ubique, quod ab omnibus creditum est." The work has been edited by Baluze, Paris, 1663, 1669, 1()84, Klupfel, Vienna, 1809, Pusey, Oxford, 1838, Herzog, Breslau, 1839, and others; Eng. trans, by Flower, London, 1866. See also Migne, Patrol. Theol. cur. compL, Vol. 1, p. 911, Paris, 1846. A full account of it is given in Smith-Wace, Diet, of Christ. Biog., 4, 1154- 1158.— Tr. 1 Jac. Gretser, 1561-1625, a learned Jesuit, was Professor of Philosophy and various parts of Theology at Ingolstadt for twenty-four years. A man of immense erudition, and a voluminous author, he was lacking in taste and critical power, and was very harsh and bitter in discussion. It is said of him that, when asked by the magistrates of Marckdorf in Swabia, his birthplace, for his portrait to be placed in the town hall, he refused it, saying they had no place therein for the head of an ass. His complete works appeared at Ratisbonne, 1739 sq., 17 vols., fol. — Tr. i CH. XX] ON HUMAN UNDERSTANDING 619 question had. almost no connection with the religion or the interests of the people. They did not know perhaps what was in reality the source of their zeal ; but I knew that, upon the first news that such an one had written this or that thing, they would ransack the libraries and puzzle their brains to find something to refute it. This it is which is practised so often by those who maintain theses in the universities and who seek to distinguish themselves against their adversaries. But what shall we say of the doctrines prescribed in the Symbolic books of the sect, even among ^ the Protestants, which we are often obliged to embrace with an oath ? which some think signi- fies with us only the obligation to profess what these books or formularies contain of Holy Scripture; in which they are contradicted by others. And in the religious orders of the Roman party, without contenting themselves with the doctrines established in their church, they prescribe narrower limits to those who teach them ; witness the propositions the teaching of which in their schools the General of the Jesuits, Claudio Acquaviva^ (if I am not mistaken), defends. It would be well (to mention it in passing) to make a systematic collection of the propositions determined and censured by councils, popes, bishops, superiors, faculties, which would be of use in ecclesi- astical history. We may distinguish between teaching and embracing an opinion. There is no oath in the world nor pro- hibition which can force a man to abide in the same opinion, for opinions are involuntary in themselves : but he may and should abstain from teaching a doctrine which is regarded as dangerous, unless he finds himself compelled thereto by his conscience. In this case he must declare himself sincerely and leave his post when he has been charged with teaching ; sup- posing, however, that he can do so without exposing himself to an extreme danger which might force him to leave without 1 Gerhardt, Erdmann, and Jacques read: " parmi " ; Janet reads: "par," i.e. "by."— Tr. 2 Claudius Aquaviva, 1543-1615, General of the Jesuits, 1581-1()15. For a brief account of his Ratio Studiorum, 1599, cf. Hughes, Loyola and the Edu- cational Sy.'iteni of the Jesuits, pp. 141 sq. (in The Great Educators Series, ed. by Nicolas Murray Butler), New York: Chas. Scribner's Sons, 1892. For the text of the Ratio, and a full account of its growth from its preliminary to its final form, with the letters of Aquaviva and other documents, cf. Monumenta Geriiumise Psedagoc/ica, Berlin, A. Hofmann & Co., 188(5 sq., Bd. V., Tom. II. — Tr. 620 LEIBNITZ'S CRITIQUE OF LOCKE [bk. r^ fame. We see but little other means of reconciling the rights of the public and of the individual ; the one being under obli- gation to prevent what it judges bad, and the other not being able to dispense with the duties demanded by his conscience. § 18. Ph. This opposition between the public and the indi- vidual and even between the public opinions of different sects is an inevitable evil. But often these very oppositions are only apparent and consist only in the formulas. I am obliged also to say, in order to be just to the human race, that there are not so many people involved in error as is ordinarily supposed. Not that I think that they embrace the truth, but because in reality upon the doctrines upon which they make so much stir, they have absolutely no positive opinion, and because without having examined anything and without having in the mind the most superficial ideas upon the matter in question, they are i^esolved to hold themselves fast to their party, as soldiers who do not examine the cause they defend : and if the life of a man shows that he has no sincere regard for religion, it is sufficient for him to have the hand and tongue ready to maintain the common opinion, in order to commend himself to those who can procure him support. Th. This justice which you render to the human race does not redound to its praise ; and men would be more excusable in following their opinions than in disguising them for the sake of their interests. Perhaps, however, there is more sincerity in their deeds than you seem to give any one to understand. For without any knowledge of a reason, they can perhaps attain to an implicit faith by submitting themselves in general and some- times blindly, but often in good faith, to the judgment of others whose authority they have- once recognized. It is true that the interest they find therein contributes to this submission, but this does not prevent them at last from forming an opinion. They are contented in the Eoman church with this almost implicit faith, not perhaps having any article thereupon, due to the revelation which is judged absolutely /Mrir/ow(e»/a/ thereto and which is considered as necessary necessitate meclii, i.e. the belief of which is a condition absolutely necessary to salvation. And they are all necessitate prce.cepti, by the necessity therein taught of obeying the church, as they call it, and of giving all attention to that which is proposed therein, all under pain of CH. XXI] ON HUMAN UNDERSTANDING 621 mortal sin. But this necessity demands only a reasonable docil- ity and does not compel absolute assent, accoi-ding to the most learned doctors of this church. Cardinal Bellarmine himself believed, however, that nothing was better than this faith of a child who submits himself to an established authority, and he relates with ap}3roval the statement of a dying man, who escaped the devil by this circle, which they heard him often repeat : I believe all that the church believes, The church believes what I believe. CHAPTER XXI OF THE DIVISION OF THE SCIENCES § 1. Ph. Here we are at the end of our course, and all the operations of the understanding are explained. Our purpose is not to enter into the detail indeed of our knowledge, yet it will perhaps be proper here, before we conclude, to make a general review by considering the division of the sciences. All that can enter into the sphere of human understanding is either the nature of things in themselves, or in the second place, man in the character of an agent, tending towards his end and in particular towards his happiness, or in the third place the means of accpiir- ing and communicating knowledge. Science then is divided into three kinds. § 2. The first is Physics or Natural Philoso- phy, which comprises not only bodies and their properties, as number, figure, but also spirits, God himself aiid the angels. § 3. The second is Practical Philosophy or Ethics, which teaches the means of obtaining good and useful things, and proposes to itself not only the knowledge of the truth, but also the practice of that which is right. § 4. Finally, the third is Logic or the knowledge of signs, for Xoyos signifies word. We need signs of our ideas to enable us to communicate our thoughts to one another, as well as to register them for our oAvn use. Perhaps if we should consider distinctly and with all possible care that this last kind of science revolves about ideas and words, we should have a logic and criticism ' different from that which has 1 Locke has: "critic," Philos. Wks., Vol. 2, p. .338, Bohn's ed. ; Fraset Lorl-p.'s Esxaif ritiicpvmng Human Uixler^tmidiutf, Vol. 2, p. 462. - Tr. 622 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv hitherto been seen. And these three kinds, Physics, Ethics, and Logic, are like three great provinces in the intellectual world, entirely separate and distinct the one from the other. TJi. This division has already been a celebrated one among the ancients ; for under Logic they comprised, as you do, all that relates to words and to the explication of our thoughts : Artes cUcendi. Nevertheless, tliere is some difficulty therein; for the science of reasoning, of judgment, of invention appears very different from the knowledge of the etymologies of words and the use of languages, which is something indefinite and arbitrary. Farther, in explaining words, we are obliged to make an incursion into the sciences themselves, as appears by the dictionaries ; and on the other hand, we cannot treat of science without giving at the same time definitions of the terms. But the principal difficulty found in this division of the sciences is that each part appears to absorb the whole ; in the first place, Ethics and Logic will fall into Physics, taken as generally as you have just stated ; for in speaking of spirits, i.e. of sub- stances having understanding and will, and in explaining this understanding to the bottom, you will make it include all logic : and in explaining in the doctrine of spirits what belongs to the will, it would be necessary to speak of good and evil, of happi- ness and misery, and it will only depend upon you to push this doctrine far enough to make it include all practical philosophy. In return, all might be included in practical philosophy as serv- ing for our happiness. You know that Theology is rightly con- sidered as a practical science, and Jurisprudence as well as Medicine are not less so ; so that the doctrine of human happi- ness or of our good and ill will absorb all these branches of knowledge, should we desire to explain sufficiently all the means serving the end which reason proposes to itself. Thus it is that Zwinger has included all in his " Magnum theatrum vitse humani," which Beyerling has disturbed by arranging in alpha- betical order.^ And in treating all matters in dictionaries fol- 1 Laurent Beyerlinck, or Beierlynck, 1578-1627, a Flemish scliolar, Professor of Poetry and Rhetoric at Vaulx, and Canon of the Antwerp Cathedral, pub- lished, with additions and corrections, tlie Theatrum vitse Immanas of Zwinger {cf. ante, p. 548, note 1), with the title Magnum theatrum vitse humai/si', Cologne, 1()31, 8 vols., fol. Schaarschmidt states that this new edition in alphabetical order is, in fact, worth less than the old redaction of the book, which handled the materials systematically in their essential aspects. — Tr. 1 CH. XXI] ON HUMAN UNDERSTANDING 623 lowing the order of the alphabet, the doctrine of languages (which you with the ancients put in Logic), i.e. in discursive logic, takes possession in its turn of the territory of the two others. Here, then, your three great provinces of encyclopedia are in continual war, since one is always encroaching upon the rights of the others. The ISTominalists believed that there were as many particular sciences as truths,^ which they composed after the wholes according as they arranged them ; and others compare the entire body of our knowledge to an ocean, which is all of a piece and which is divided into Caledonian, Atlantic, Ethiopic, Indian only by arbitrary lines. It is usually found that one and the same truth may be put in different places, according to the terms it contains, and also according to the mediate terms or causes upon which it depends, and according to the inferences and results it may have. A simple categoric proposition has only two terms ; but a hypothetic proposition may have four, not to speak of complex statements. A remark- able history may perhaps be placed in the annals of universal history and in the history of the country where it happened, and in the history of the life of a man who was interested therein. And suppose the question therein concerns some fine precept of morals, some stratagem of war, some invention use- ful in the arts which serve the conveniences of life or the health of men, this same history will be related to some purpose in the science or art it concerns, and indeed it can be mentioned in two parts of this science, viz., — in the history of the discipline in order to recount its efficient growth, and also in the precepts to conlirm them or illuminate them by examples. For example, what is very properly told in the life of Cardinal Ximenes, that a Moorish woman cured him by rubbings only of a hectic almost desperate, deserves also place in a system of medicine, as well in the chapter on hectic fever, as when the question concerns a 1 The phrase " as many sciences as truths " — "tot esse scientias qnot Veri- tates " — is, as Schaarschmidt says, "the sharpest expression of iioniinalistic individualism." " According to Nominalism, we have a knowledge of partic- ulars only, all universals being mevely figmenfa mentis, products of abstrac- tion. Hence true and genuine science always relates to particulars only, and thus there are as many sciences as (particular) truths." On Leibnitz's studies of Nominalism, cf. Guhrauer, Leibnit. Dissertatio de princ. Individ., pp. 39 sq., Leibnitz, I)e stilo philo.s. Nizolii, § 28, Gerliardt, 4, l.=)7-l.-)8, Erdmann, 68-G9. - Tr. 624 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv medicinal diet comprising these exercises ; and this observation will serve also the better to discover the causes of this disease. But we might further speak of this in medicinal logic, where the question is about the art of discovering remedies, and in the history of medicine, in order to show how remedies have come to the knowledge of men, and that it is often by the aid of sim- ple empirics and even charlatans. Beverovicius,^ in a remark- able book on ancient medicine, drawn wholly from authors not physicians, Avould have rendered his work still more useful, if he had passed down to modern authors. We see by this that one and the same truth may have many places according to the different relations it can have. Those who arrange a library very often do not know where to place certain books, being in suspense between two or three places equally suitable. But let us now speak only of general doctrines and put aside partic- ular facts, history and languages. I find two principal dispo- sitions of all doctrinal truths, each of which should have its deserts and' Avhich it would be well to unite. The one would be synthetic and theoretic, ranking truths according to the order of proofs, as the mathematicians do, so that each proposition would come after those on which it depends. The other dispo- sition would be analytic and practical, commencing with the end of men, i.e. \\\t\\ the goods whose consummation is happiness, and seeking in order the means available for acquiring these goods or avoiding the contrary evils. These two methods have place in general encyclopedia, while some have practised them in particular sciences ; for geometry itself, treated synthetically by Euclid as a science, has been treated by some others as an art, and might nevertheless be treated demonstratively under this form, which would show indeed some invention ; as if some 1 Jan van Beverwyck, — Latin Beverovicius, — 1594-1047, a noted Dutrh physician, who studied at Leyden, Caen, Pai'is, Montpelier and Padua, where he received his M.D., and on his return became Professor of Medicine at Dor- drecht and physician to the city, in which also he held several civil offices, among them that of burgomaster. He labored to simplify the methods of pre- scribing for disease. He published a number of books distinguished for purity of style and relation of facts, and which, adorned with copper-plates and with the verses of Jakob Cats, 1577-1660, one of the oldest and most popular Dutch poets, " made in his time much sensation and met with much approbation."' Among them was the Idea inedlcliise vetenim, Lugd. Bat., 1637, 12mo, here mentioned by Leibnitz. His entire works were j)ublished at Amsterdam, 1651, etc. — Tr. XXI] ON HUMAN UNDERSTANDING Oio one proposed to measure all kinds of plane figures, and begin ning with rectilinears, reflected that they may be divided int(' triangles and that each triangle is half of a parallelogram, and that parallelograms can be reduced to rectangles whose measure is easy. But in writing the encyclopedia, following both these two dispositions together, we might take measures iov references in order to avoid repetitions. To these two dispositions the third according to the terms should be joined, which in reality Avould be only a kind of index, either systematic, arranging the terms according to certain predicaments which >vould be common to all the notions, or alphabetical according to the languages received among scholars. Now this index woiild be necessary in order to find together all the propositions into which the term enters in a sufficiently remarkable manner ; for according to the two preceding ways, where the truths are arranged accord ing to their origin or use, truths concerning one and the sam& term cannot be found together. For example, it was not per- mitted Euclid, whe-n he Avas teaching how to find the half of an angle, to add the means of finding its third, because he would have been obliged to speak of the conic sections, knowledge of which he could not yet assume in this place. But tiie index mav and should indicate the places where are found the impor- tant propositions which concern one and the same subject. And we still lack such an index in geometry, which would be of great use in facilitating indeed invention and in pushing the science, for it would relieve the memory and often spare us the trouble of seeking again that which has already been found. And these indices would further be of use for a much stronger reason in the other sciences, where the art of reasoning has less power, and would be above all extremely necessary in Medicine. But the art of making such indices would be no slight one. Kow (■(Misidering these three dispositions, I find it remarkable that they correspond to the ancient division, which you have renewed, which divides science or philosophy into theoretic, practical and discursive, or rather into Physics, Ethics, and Logic. For the synthetic disposition corresponds to the theoretic, the analj'tical to the practical, and that of the index according to the terms to logic : so that this ancient division does very well, provided we understand these dispositions as I have just explained, i.e. not as distinct sciences, but as different arrangements of the same 2 s 626 LEIBNITZ'S CRITIQUE OE LOCKE [bk. iv truths as far as we judge it advisable to repeat them. There is also a civil division of the sciences according to the faculties and professions. We make use of it in the universities, and in the arrangements of libraries ;^ and Draudius/ with his continuer Lipenius,^ who have left us the amplest, but not the best cata- logue of books, instead of following the method of the Pandects of Gesner,* which is wholly systematic, have contented them- selves with the use of the great division of the materials (much 1 For Leibnitz's sketch of a library classification and catalogue, cf. his Idea Leibnitiana Bihliothecse Publivse secundum classes scientiarum ordinandas, Duteus, 5, 209-214. Cf. also his Representation a S, A. S. le Due de Wolfen- buttel,pourl'encouraqer a Ventretien de sa Bibliotheque, ibid., 5, 207-208; the same, in German, Guhrauer, Leibnitz's Deutsche Schrift., 2, 470-472. — Te. 2 Georg Draud, 1573-1630 or 1635, a student at Marburg University and afterwards a proof-reader at Frankfort, Basle, and at the famous typography at Feyerabend, and minister of the gospel at Gros-Carbeu, Ortenberg and Dauernheim, was the first to attempt an extended systematic bibliography. His Bibli&theca classica sive catalogus officinalis, in quo singuli singulani in facultatum ac professionum libri — secundum artes et ordine alphabetim recensentur, Frankfort, 1611, was the most complete bibliography of printed books that had then appeared. A 2d ed., increased by all the books printed from 1611-1625 of which the editor had knowledge, appeared in 1625. — Tr. 3 Martin Lipenius, 1630-1692, a learned German bibliographer, who studied at Wittemberg, and was co-rector of the gymnasium at Halle, and of the acad- emy at Lubeck, and rector and professor in the gymnasium at Stettin. He published Bibliotheca realis juridlca, 1679, the most valuable of his series, edited with additions by F. W. Struve, in 1720, by G. A. Jenichen, 1709-1759, a jurist, philologian and historian, with corrections in 1736, and a supplement in two parts, 1742 ; also several subsequent editions with corrections and addi- tions; Bibliotheca realis medica, 167'.), philosophica, 1682, theologica, 1685. They were called realis because the books were listed in the alphabetical order of subjects and not under the names of their authors. — Tr. 4 Conrad Gesner, 1516-1565, called the " German Pliny," because of his vast erudition, was Professor of Greek, 1537, at Lausanne, and of Physics and Natural History, 1541, at Ziirich. He made " the first comprehensive attempt at a general encyclopedia of literature, constructed in the form of a catalogue " in his Bibliotheca universalis. The work contained the titles of all then kno^Mi books, existent or lost, published or announced, in Hebrew, Greek and Latin. giving under each important name a vast amount of bibliographical informa- tion and criticism, original and selected, and often some specimens of their style. The first vol., Ziirich, 1545, is arranged alphabetically according to the authors' names; the second, entitled Pandectas sive pai-titionum univev- salium, lib. XXI., — totius philosophise et onuiium bonarum artium atque stu- diorum locos communes et ordines universales sim.ul et particulares, — Ziirich, 1548, is arranged according to subjects and divided into 19 books, book 21, a theological encyclopedia, not being published till 1549, and book 20, the medical writings, never appearing because in the author's view too imperfect for publication. It was reprinted and greatly enlarged by Simler in 1574, and by J. J. Fries, Zurich, 1583. — Tr. CH. XXI] ON HUMAN UNDERSTANDING 627 the same as the libraries) following the four faculties (as they are called) of theology, jurisprudence, medicine and philosophy, and have afterwards arranged the titles of each faculty accord- ing to the alphabetical order of the principal terms entering into the inscription of the books : this lightened the task of these authors, because they had no need to see the book or to understand the matter which the book treats, but it does not sufficiently serve others, at least it does not make references in the titles to others of parallel signification ; for not to speak of a number of mistakes they have made, we see that often one and the same thing is called by different names, as, for example, ohserodtiones juris, miscellanea, conjectanea, electa, semestria, prohahilia, benedicta, and a multitude of similar inscriptions ; such books of the jurisconsults signify only the miscellanies of the Roman Law. This is why the systematic disposition of the materials is without doubt the best, and we may join with it alphabetical indices very full according to the terms and the authors. The civil and received division, according to the four faculties, is not to be despised. Theology treats of eternal felicity and all that relates thereto, so far as it depends on the soul and the conscience ; it is like a jurisprudence which regards what is said to exist de foro interna and employs invisible sub- stances and intelligences : Jurisprudence has for its object gov- enunent and the laws, whose end is the happiness of men so far as the external and sensible can contribute thereto ; but it regards principally only that which depends upon the nature of the spirit, and does not enter much farther into the detail of material things whose nature it assumes in order to employ them as means. Thus is it relieved at once of an important point which concerns the health, strength and perfection of the human body, the care of which is given to the faculty of Medi- cine. Some have believed with some reason that we might add to the others the Economic Facidty, which would contain the Mathematical and Mechanical Arts, and all that concerns the detail of the subsistence of men and of the conveniences of life, in Avhich Agriculture and Architecture would be included. But we abandon to the faculty of Philosophy all which is not included in the three faculties which we call superior. AVe do this quite badly, for we do it without giving means to those who are of this fourth faculty for perfecting themselves by 628 LEIBNITZ'S CRITIQUE OF LOCKE [bk. iv practice as those can do who teach the other faculties. Thus the mathematics perhaps excepted, we consider the faculty of philosophy only as an introduction to the others.^ This is why we wish the youth to learn history, and the arts of speaking and some rudiments of theology and natural jurisprudence, independent of divine and human laws, under the title of meta- physics or psychology, ethics and politics with a little of physics also, in order to serve as young physicians. This, then, is the civil division of the sciences following the bodies and profes- sions of the scholars who teach them, without speaking of the profession of those who work for the public otherwise than by their discourses and who ought to be directed by true scholars, if the limits of knowledge were well understood. And even in the more noble manual arts, knowledge has been very much bound up with performance, and might be more so. As in fact they are joined together in medicine, not only formerly among the ancients (where physicians were also surgeons and apothe- caries), but also to-day especially among the chemists. This alliance also of practice and theory finds itself at variance both among those who teach what are called exercises, as also among the painters, or sculptors and musicians, and among some other kinds of virtuosi. And if the principles of all these professions and arts, and even of the trades, were taught practically among the philosophers, or in some other faculty of scholars as they might be, these scholars Avould be truly the teachers of the human race." But it would be necessary to change much of 1 I.e. in the broader sense of the term in which it is equivalent to the Humanities, — ai'tes liherales, — the liberal education, disciplinary, stimulative and cultural of the student's entire powers, which was considered until very recently, and is regarded even now by many of the deepest and farthest-sighted thinkers on education, as an essential precedent and preparation for all later special professional study. The custom of regarding the Faculty of Arts or Philosophy as introductory to that of Theology, Medicine and Jurispru- dence, goes back to the university curricula of the Middle Age, the Trivium and the Quadrivium, with their respective degrees of A.B. and A.M.. which in their essential character and principles, with the necessary changes incident to an advancing civilization, have been, till within a short time at least, the controlling influence in shaping the curricula and methods of all modern col- legiate and university education. — Tr. '^ On this, as on eveiy subject he touched, Leibnitz utters a suggestive and stimulating thought, which has in recent times brought forth much fruit in the establishment and maintenance of technical and art schools of every kind. -Tr. I] ON HUMAN UNDERSTANDING 629 the present state of things in literature and the education of the youtli, and consequently of the government. And when I con- sider how much men have advanced in knowledge in the last century or two, and how easy it would be for them to go incom- parably farther in order to render themselves happier, I do not despair that a considerable improvement will come in a more tranquil period under some great prince whom God will be able to raise up for the good of the human race.' 1 Leibnitz constantly labored to secure the sympathy and active co-opera- tion of the " great princes " in the initiation and furtherance of learning, sci- ence, and the higher ideal interests of mankind in general, a conspicuous exani2)le of his success being that of the great reformatory genius of his time, Peter the Great of Russia. Their correspondence is found in Foucher de Careil, QSavres de Leibniz, 7, 395-598. Cf. also W. Guerrier, Leibniz in seine)i Beziehungen zu Bussland unci Peter dem Gros&en, St. Petersburg and Leip- zig, 1873; Foucher de Careil, Leibniz et Pierre le Grand, Paris, 1873. For a general account of his various efforts in this direction, cf. Fischer, Ge.seh. d. it. Phiios., Vol. 2, Leibniz, 3d ed., 1889, pp. 211-249: and for a brief account, Merz, Leibniz (Blackwood's Phiios. Class.), pp. 74-83. — Tr. APPENDIX LEIBNITZ TO JACOB THOMASIUS' April 20-30, 1669 [From the Latin] How much that yevfm of philosophical history of yours has made the mouths of all water cannot be told ; for it is apparent how much difference there is between mere enumerations of names and those profound views concerning the connections of opinions. And cer- tainly all acquainted with the subject that I hear speak of your essay (you know that I never flatter), unanimously affirm that from no one man can a complete body of philosophical history preferably be expected. Very many skilled in antiquity rather than in art have given us lives rather than opinions. You will give the history not of philosophers but of philosophy. They say in England that Joseph Glanvill's History of the growth of the sciences since Aristotle is in press.2 But I think he will pursue for the most part the mathemati- cal, mechanical, and physical periods of this inquiry only, so I think 1 Gerhardt, Leibniz, philos. Schrift.l, 15-27; Erdmann, 48-54; Dutens, 4, Pt. 1.7-19; Kortholt, Leibnit. epist. ad diversos, Lipsise, 1734^2,2, 121-142. Kortholt's text gives the piece as printed by Leibnitz in his edition of Nizo- lius, and differs considerably from that given by Gerhardt, which is the text followed in this translation. Cf. also, Gerhardt, Leibniz, philos. Schrift., 4, 162-174. In this " impression," says Gerhardt, Einleitung, ibid., p. 9, note **, " the copy of the Royal Library at Hanover has been used, in which are found MS. notes of Leibnitz." — Tr. 2 Joseph Glanvill, 1636-1680, Court Chaplain to Charles II., published his defence of the Royal Society of London, entitled Plus Ultra, or the Progress and Advancement of Knowledge since the days of Aristotle, in 1668. In his idea of causation Glanvill was a predecessor of Hume. His Scepsis scientifica, or Vanity of Dogmatising, London, 1665, edited by John Owen, 1885, and his De incrementis scientiarum, London, 1670, attacked the Aristotelian and Car- tesian dogmatism. Though a thorough-going sceptic in the direction of the scholastic philosophy, he was opposed to the materialism of Hobbes. Some account of Glanvill's views will be found in Lecky, Rationalism in Europe, 1, 129 sq. D. Appletou &. Co., New York, 1876. —Tr. 631 632 LEIBNITZ'S CRITIQUE OF LOCKE he has forestalled you in nothing. But I wish that you would pro- duce a style and form for this more modern age and admonish our inconsiderate youth that neither everything nor nothing is to be attrib- uted to the restorers. Bagheminus^ is not the only critic to whom you are indebted ; there are the Patricii, Telesii, Campanellse, Bodini, Nizolii, Fracastorii, Cardanii, Galilaei, Verulamii, Gassendi, Hobbii, Cartesii, Bassones, Digbsei, Sennerti, Sperlingii, Derodones, Deusingii, and many other names among whom the cloak of philosophy is divided. 2 To remind the world of these will be a diversion for you, a profit to the pu^blic. Who does not assent to your estimate of Bagheminus ? There is no skilful adjustment in hypotheses,'^ no logical sequence of reasons, but in a word strange notions ; certainly unless he has something to observe useful in special physics, he will better be silent. But Scaliger, Sennert, and Sperling, — for he acknowledged himself a pupil of this one also, — seem to me to be the parents of the opinion of that one concerning God, the primary matter of things, who think that forms are produced not from the passive power of matter, but from the active power of the efficient one. AVherefore the conclu- sion is that they believe that God produces creatures rather from his own active power, than from nothing by objective and as it were passive power. God therefore in their opinion produces things out of himself, and so will be the primary matter of things. But as to this you will more properly judge. As to Descartes and Clauberg, I think in brief with you that the disciple is clearer than the master. Nevertheless, I should venture again to affirm that hardly any one of the Cartesians have added any- thing to the discoveries of the master. Certainly Clauberg, Rseus,* 1 Cf. the letter of Jacob Thomasius to Leibnitz, October 2, 1668, Gerhardt, Leibniz, philos. Schrift.,1, 14; Kortholt, Leibnit. Epistolse ad cUversos, 3, 35: " Bagheminus ille, cujus negotium geritur, Scabinus est Stetinensis, et a nostra turn theologica, turn philosophica facultate petiit philosophiae suse novte ceusuram. Theologi responderunt. A nobis nihil aliud repositum illi est, quam disputatio mea, quae si in manus hominis pervenit, facile judicabit, qno in banc novitatem animo simus." — Tr. ~ For some account of the lives and philosophy of the persons whose names are here mentioned, cf. Lasswitz, Gesch. d. Atornistik ; Stockl, Gesch. d. Philos. d. Mittelalters, III. [Vol. 4]. — Anton Deusing, 1612-16G6 (not referred to in the works cited), was a German physician and Professor of Medicine at Groningen. He had an extended knowledge of philosophy, mathematics, and oriental languages, and published many works, among them, De vero syste- mate mundi, dissertatio mathematica, qua Copernici systema ■numdireforma- tur, etc., Amsterdam, Elzevir, 1643, 4to. — Tr. 3 Erdmann reads : " hypothesibus ejus," i.e. his hypotheses. — Tr. * Jean de Raey, date of birth unknown, died 1702, was Professor of Philoso- phy in the University of Leyden 1652-1668, and entered upon his Professorship at Amsterdam in January, 1669, with an Oratio de sapientia veterum. In his I APPENDIX 633 Spinoza,! Clerselier,^ Heerbord,^ Tobias Andrese,* Henry Regius,^ have published nothing but paraphrases of their master. But I call those Cartesians only who follow the principles of Descartes, from which number those great men Bacon, Gassendi, Hobbes, Digby, Cornelius of Hogheland,® etc., whom the common people confound with the Clavis philosophise naturalis seu introductio ad naturx contemplationem Anstotelico-Cartesianam, 1654, 2d ed., 1677, he sought to improve and com- plete the doctrine of Aristotle through that of Descartes. He explained Erkenntnlsslehre wholly after the manner of Aristotle; but contested his assumption of the eternity of the world or the divine nature of the stars. He discussed mainly the nature of matter and the origin of motion, wholly on a Cartesian basis. — Tr. 1 In the impression of this letter given by Gerhardt, Leibniz, philos. Schrift., 4, 162 sq., Leibnitz has erased the names of Spinoza and Cornelius van Hooghelande, and added after Bacon that of Galileo. This impression omits also .the names of Rseus and Clerselier. For the other textual changes, cf. the impression itself. — Tr. 2 Claude Clerselier, 1614-1684, the father-in-law of Rohault (cf. ante, p. 23o. n. 2), was a zealous disciple of Descartes and edited some of his works: Le nionde, ou traite de la lumiere, Paris, 1677 ; Traite de Vhomme, Paris, 1664; Les lettres de Rene Descartes, 3 vols., Paris, 1657-1667. — Tr. 3 Adrian Heereboord, 1614-1659, Professor of Philosophy in the University of Leyden, was one of the first and most zealous advocates of the new ten- dency of thought introduced by the philosophy of Descartes. He united to a certain extent Cartesianism with the traditional authority of Aristotle, evi- dence of which appears in his Parallelismus Ari,itotelicse et Cartesianse phi- losophise naturalis, 1643. Other writings of Heereboord are: Meletemata philosophica, 1654; Philosophia rationalis, moralis, et naturalis, 1654, 2d ed., 1660 ; Philosophia pneumatica, 1659. — Tr. * Tobias Andreae, 1604-1674, Professor of History and Greek Language at Groningen, .successfully cultivated philosojihy and became known as a zealous partisan of the philosophy of Descartes. He wrote, in 1653, against Jacob Revius, Asser'tio methodi Cartesianse, and was also author of Brevis expli- cntio, brevi ezplicatione mentis humanse Henr. Regli reposita. — Tr. 5 Hendrik van Roy, 1598-1679, usually called Regins, was a Dutch physician, who in 1638 became Professor of Botany and Theoretical Medicine at Utrecht. He was a zealous disciple and advocate of the ideas of Descartes, until the Voet-Schoock-Descartes controversy and Descartes' rejection of him as a true representative of his views resulted in their falling out. Regius regarded the soul as a mode of the bodily substance, and in physics, while resting through- out on Cartesian principles, differed from Descartes in his conception of motion and rest. On this doctrine of Regius, significant lor the problem of body, cf. Lasswitz, Gesch. d. Atomistik, 2, 405-408. Regius published, among other works, Fundamenta physicse, Leyden, 1646; Philosophia naturaHi<, Amsterdam, 1661. Dr. James Martineau, A Study of Spinoza, London, Macmillan & Co., 1882, page 75, line 7, and foot-note 1, in ti'anslating " Regis " instead of "Regius" has misunderstood Leibnitz's reference and wrongly attributed to him a " lapsus memorise." — Tr. ^ Cornelius Van Hooghelande, a Catholic nobleman who lived at Leyden, was a friend and disciple of Descartes. In his Cogitationes, 164dvTaafia. But whatever they not only see but also touch, that is, in which they find dvTiTVTria, that they call body ; but whatever lacks dvTLTVTTta, that they deny to be body. In the two, therefore, men both educated and uneducated place the nature of body, in extension and dvTiTVTTta taken together ; they take that from sight, this from touch ; whence also from the union of both senses we ai-e wont to be certified concerning things that they are not phantasmata. But extension is nothing else than existence in space; avTirvTruL is the inability to exist with another in the same space, but the one or the other (alterutrum) must be moved or keep quiet. From these con- siderations it is evident that the nature of body is constituted by extension and antitypy, and since there is nothing in things without cause, nothing even must be assumed in bodies, the cause of which cannot be made to appear from their primary constitutive principles. Now the cause cannot be made to appear from these except through 648 LEIBNITZ'S CRITIQUE OF LOCKE their definitions. Nothing, therefore, is to be assumed in bodies which does not flow from the definition of extension and antitypy. But there flow from this definition only magnitude, figure, position, number, mobility, etc. Motion itself does not flow from these. Whence, properly speaking, motion is not given in bodies as a real entity in them, but I have demonstrated that whatever moves is continually created, that bodies at any instant in assignable motion are some- thing, at any intervening time between the instants in assignable motion are nothing, a thing which was unheard of till now, but which is plainly necessary and will shut the mouth of the atheists. From these considerations it is evident that the explanation of all qualities and changes must be taken from magnitude, figui'e, motion, etc., and that heat, color, etc., are nothing but subtile motions and figures. As to what remains, I dare aflirm that atheists, socinians, naturalists, sceptics, would never have been truly met unless by this established philosophy ; which I indeed believe a gift of God given to the old age of the world as an unique plank by which pious and prudent men are about to save themselves in the shipwreck of the now overhanging atheism. However small my knowledge of learned men after a little time, I nevertheless tremble as often as I think how many men at the same time intellectual and absolutely atheistic I have met. And there is flying through the hands of men an xmknown book of Bodin ^ (and would, as I wish in the case of Naudpeus, it was never to be published), powerful certainly, which he calls, " Arcana sublimium," in which he is the professed enemy of the Christian religion. The dialogues of Vaninus - are child's play when compared with it. I have read it carefully, and I thank God from my heart, because he furnished me with those defences of 1 Jeau Bodin, 1530-1596 or 1597, the eminent writer on Political Science, and advocate of tolerance in religion, published his greatest work, — "the first elaborate attempt in modern times to construct a system of political science," — Les six Livres de la Bepublique, at Paris, 1576. His Universas naturie theatrum appeared at Hanover, 1605, the Preface dated February 25, 1596. For some account of its doctrine, cf. Lasswitz, Gesch. d. Atomistik, 1, 326- .327, 411-413. G. E. Guhrauer published an Abstract, in German, with a partial translation of the Latin text, of his very famous MS., here referred to by Leibnitz, the Colloquium heptaplomeres de abditis rerum sublimium arca- nis, Berlin, 1841, and the complete original text, from a MS. in the Giessen Library, was edited and published by L. Noack, Schwerin, 1857. The work is "a conversation between seven learned men, — a Jew, a Mahometan, a Lutheran, a Zwinglian, a Roman Catholic, an Ej^icurean, and a Theist " ; and "the conclusion to which they are represented as coming is, that they will live together in charity and toleration and cease from further disi)uta- tions as to religion." — Te. ■- Lucilio Vauini, 1585-1619, who called himself by the name, among others, of Julius Csesar, was a disciple of Pomponatius {cf. ante, p. 581, n. 1). He denied the immortality of the soul, and advocated a doctrine of pantheistic APPENDIX 649 philosophy (in which I should be ungrateful, if I should deny that I owed much to you), by which I repelled his weapons with no difficulty. The labor of the distinguished Spizel is to be praised, which he now again expends in eradicating atheism. His letter on this subject, recently published (in these nine days), I think you have seen. Hear what happened to me in connection with him. I had written some time when at leisure, a leisure nevertheless disturbed in the inn, about two sheets, in which I was discussing the demonstration more accurately than usual of the immortality of the soul and the existence of God. These I had sent to my friend. Through him they came into the hands of the Most Rev- erend Spener,^ pastor at Frankfort, a neglected yet deserving author. Spener sent them to Spizel ; - Spizel placed them at the end of that recent letter of his to Ant. Reiser ^ on the eradication of atheism, under the title " Confessio naturae contra atheistas." I do not blame him, but I am grieved, because that tr^^eStov was so very incorrectly printed ; that sorites, especially, by which T tried to demonstrate the immortality of the soul, was thrown into strange confusion by the misplacing of its opening lines. Spizel acknowl- edged that he was ignorant of the author. I desire a judgment naturalism. He published Be admirandis natursereginse deseque mortaUum arcanis, lib. quat., Paris, 1616. His philosophical works, translated into French by Rousselot, appeared at Paris, 1841. Leibnitz, in a letter to Sebas- tian Kortholt, March 15, 1713, says: " Apologiam Vannini nondum vidi, nee luagnopere dignam legi puto. Scripta ejus parvi momenti sunt, sed homo ineptus, imo stultus comburi non merebatur, claudi jure poterat, ne alios inficeret " (Dutens, 5, 321). — Tr. 1 Philip Jacob Spener, 1635-1705, was chief pastor of the Lutheran church at Frankfort-on-the-Main, from 1666-1686, first Court-chaplain at Dresden, 1686-1691, and rector of St. Nicolas, in Berlin, with the title of " Consistorial- rath," from 1691. He directed the foundation of the University of Halle in 1691. Though, according to Ritschl, Gesch. d. Pietismus, 2, 163, Bonn, 1884, " himself not a Pietist," Spener has justly been called " the father of Pietism." He was a voluminous author. Two letters of Leibnitz to Spener are given by Dutens, 5, 467^68. — Tr. 2 Theophil Gottlieb Spitzel, or Spizel, 1639-1691, a German pastor and poly- historian, was deacon of St. James's church, Augsburg, in 1662 and pastor from 1682 to 1690. " As a theologian, in spite of his many-sided and universal sci- entific interests, he remained well-nigh unfruitful." Leibnitz refers to the matter here alluded to again in his letter to Spizel, December 12-22, 16()9 ; cf. Dutens, 5, 343. The Confessio Naturse contra Atheistas first appeared as a Postscriptum in Theo. Spizelii de Atheismo eradicando ad Viriim prxstantis- simum Dr. Antonium Reiserum Auf/ustanum, etc., Epistola. . . . August. Vindel. 1669.— Tr. 3 Anton Reiser, 1628-1686, a learned and distinguished Lutheran theologian, was an earnest defender of evangelical truth. He published De, orifjine, pro- fjressn et incremento antitheismi seu Atheismi, .\ugsburg, 1669, 8vo; Inde.c MSS. bibliothecas AugustaiiSR, Augsburg, 1675, 4to. — Tr. 650 LEIBNITZ'S CRITIQUE OF LOCKE concerning the reasoning itself of the demonstration. Nor do I seek praise, but criticism, since it is important to religion that it be not perfunctorily defended. Although meanwhile I seem to myself to have penetrated far more deeply into both. For neither the thoughts which I have thrown out since that time concerning perpetual creation in motion, nor the inmost nature of thinking being or mind, are brought together therein. I wi'ote you at one time about the society which certain Germans are starting. It will show its existence by a German paper published by the book- seller Goezius with the title " Collegium Philadelphicum." But to me it seems a pleasant dream, like the society of the Red Cross. It is wonderful how great a dissension in Parnassus that Schui'z- fleisch 1 who is with you excited. I very much wish to know what the great men with you by whom he hopes he will be advanced, think of this specimen. Boeder ^ threatens that one from the court. The author of the " Itinerarium politicum " which is now appearing is without doubt Burgoldensis,^ that commentator on the " Instru- mentum pacis." I am astounded at the audacity of the man. As for the rest, most illustrious sir, I have discoursed the more 1 Konrad Samuel Schurtzfleiscli, 1641-1708, was Professor of History at Wittenberg, and because of his great learning was given the nickname of a living library and a walking museum. While at Wittenberg he published, under the name of Eubulus Theosdatus Sarckmasius, a pamphlet, Jvdicia de novissimis prudentise civilis Scriptoribus, Leipzig, 1669, in which he freely ex- pressed his opinion of the most celebrated German jurisconsults, and which aroused against him many adversaries. He continued the history of Sleidan {cf. ante, p. 114, n. 1). — Tr. 2 Johann Heinrich Boeder, 1611-1692, Professor of Eloquence at Strassburg and Upsala, and afterwards of History at Strassburg, was author of many commentaries on classical authors and of works of history, politics, criticism, morals, etc. Among them were: De jure Gcdlise in Lotharingiam, Sti-ass- burg, 1663; Ad Grotiitrri de jure belli et pacis dissert., V., 1665. The Elector of Mayence appointed him "conseiller " in 1662, and the next year the Em- peror Ferdinand III. bestowed on him the same title and made him Count Palatine. — Tr. 3 Philippus Andrea Oldenburgerus, the anagram of which is Burgoldensis, a pupil of H. Conring, was Professor of Law and History at Geneva, where he died in 1678. He publislied a large number of valuable works, some of them under assumed uames, among which are : Itinerarium Germanise Politicum, modernam prsecipuarum Aularum Imperii faciem reprsesentans, Cosmopoli (Geneva) , 1668, 12mo ; Limnseus enucleatus, an abstract of Limne, De jure imperii Roma7io-germanici, Geneva., 1670, fol. ; Notitia Imperii, sive Discur- sns in Instrumentum Pacis Osnabrugo-Moriasteriensis (tliis work under the name of Burgoldensis), Freistadt, 1669, 4to. Of the Itinerarium Germaniie Politicum, Morhof, Polyhistona, 2, 497, says: " in quo multa est rerum iuep- tissimarum farrago, quibus nonnunquam immiscentur aliqua notatu non iu- digna, sed lectore prudente opus est, qui cum judicio ilia legere posit." The freedom with which the author spoke of the political interests and vices of the German courts led to the interdiction of his book. It was, nevertheless, APPENDIX 651 at length of this whole matter to you for this reason, because I had no more learned and equitable judge of these things. Since you have examined all the recesses of the ancients and do not despise the discoveries of the moderns when deserving, you alone of all can best examine this and also illustrate them. For you rightly judge, that although new opinions are brought forth and their truth most evidently shown, yet from the views publicly received we must scarcely ever depart, a thing which we shoidd not strive for if the Scholastics had done it. Farewell, ornament of our country, and do not bring to an end (absolve) your noble thoughts (for many are both begun and at the same time perfected with rare felicity of mind), but produce them. II FRAGMENT^ [F7'om the Latin] The primary matter ^ of Aristotle is identical with the subtile matter of Descartes. Each is divisible to infinity. Each is per se lacking in form and motion, and each receives forms through motion. Each receives motion from mind. Each is formed into certain rings {g//ros), and there is no more solidity in the vortices of Aristotle than of Descartes. Each has solidity from motion, because nothing drives it asunder, although Descartes himself has not assigned this cause of solidity. Each ring (gyrus) extends (propagat) the action im- pressed through motion on account of the continuity of matter into another ring. For Aristotle also, no less than Descartes or Hobbes, derives all particulars from the motion alone of universal rings. Whence Aristotle adds intelligences only to the principal rings, because from the impacts of these rings the actions of the others follow. In this Aristotle erred, because he made the earth the centre of the iiniverse and of all gyrations. But he should be par- several times reprinted. In Ft. IV. of his Thesaurus rerum puhUcarum totius orbis, Geneva, 1675, 4 vols., 8vo, he repudiated the errors and condemned the reprehensible expressions which he had employed in the earlier work. Of the Discursus in Instrumentum Pads, Lenglet du Fresnoy remarks : " a bold and learned piece." — Tr. 1 Gerhardt, Leibniz. philos. Schrift., 7, 259-60. In his Elnleitung, ibid., 251, G. says: " The fragment, n. I., which was written, perhaps, at the time of the composition of the Hi/pothesis physica (1671), contains a comparison of the metaphysics of Aristotle and Descartes, what Leibnitz borrowed from both, and what he has added of his own." — Tr. 2 Upon a bit of paper without date and superscription, proceeding according to the handwriting from the earliest period. — Gerhardt's Xote. — Tr. 652 LEIBNITZ'S CRITIQUE OF LOCKE doned for this, because philosophy was not yet sufficiently instructed by observations. To these I now add, that primary matter if at rest is nothing. This also is a statement which certain Scholastics have obscurely made, that primary matter also has existence from form. Of this fact there is demonstration. Because whatever does not think, is nothing. But that in which there is no variety also does not think. In like manner : If primary matter moves in one direction, that is, in parallel lines, it is at rest, and consequently is nothing. All things are full, because primary matter and space is the same thing. Therefore every motion is circular, either composed of circulars or at least returning into itself. Many circulations mutually hinder each other, or mutually lead into each other. Many circulations try to unite in one or all bodies tend to rest, that is, annihilation. If bodies are without mind, it is impossible for motion to have been eternal. ^ From universal conflicting circulations are produced particular bodies. Matter is actually divided into infinite parts. There are infinite creatures in any given body whatever. All bodies cohere amoiig themselves. All are indeed forcibly separated (distrahuntur) from all, but not without resist- ance. There are no atoms, or bodies whose parts are never forcibly separated. There are two principles by which motion is changed : compositions of efforts (conatuum), and compositions ... [a woi'd and two lines are in consequence of the destruction of the paper illegible. — Gerhardt]. Ill DEMONSTRATION AGAINST ATOMS TAKEN FROM THE CONTACT OF ATOMS ^ October 23, 1690 [From the Latin] Definition I. A thing is distinguished from other things in two Avays, either through itself, or extrinsically. Through itself a thing is distinguished from another, when a method of distinguishing through the consideration alone of the thing is used, no operation or change being made in the thing. Extrinsically, when by external application something new is produced in the thing, which does not appeal' in 1 Over the words, " motum fuisse aeternum," Leibnitz has written, " potest diminui sine tine," i.e. can be diminished without end. — Gerhardt's Note. — Tr. 2 Gerhardt, Leibniz, philos. Schrift., 7, 284-288; Stein, Leibniz, u. Spinoza, Beilage XIV., pp. 325-328. — Tr. APPENDIX 65-] another. Thus the sphere and the cube can be distinguished both by consideration and also by operation ; by consideration, because in the sphere no angles are found, of which there are eight in the cube ; by operation, as, if both are placed upon an inclined plane, the sphere will descend the plane by rolling, the cube by sliding. Axiom. Whatever is distinguishable extrinsically from another, is also distinguishable through itself.^ For example, let there be two coins from the same stamp Qypu), one of true gold, the other of false, which may be easily distinguished extrinsically by the blow of the hammer. I say even before the blow, by an attentive consideration, differences in the composition itself of each would be detected by the naked or equipped eye, and although the keenness of vision could not reach thither, yet differ- ences exist within and can be detected by some more acute creature (for example, by an angel). ^ Observation. Certain bodies are mutually separated violently from each other. Conceded Hypothesis. Matter is uniform, or, motion and figure excepted, everywhere like itself. Definition II. An Atom is a body which cannot be broken. Postulate. If there ai-e atoms, we may assume them of any figure and size whatever and in any position whatever. theorem. It is impossible for all bodies to consist of atoms. Let us assume (by the postul.) three atoms, A, B, C, of which A is cubical, but B and C are triangular prisms, composing the cube D, similar and equal to the former A. The cube D cannot (by the conceded hypothesis) be distinguished from the cube A. Therefore they cannot be distinguished extrinsically (by Axiom I.). If there- fore other bodies strike against the cube D, they will be able either to separate the atoms B and C, or they will not be able. If able to' sepai-ate them, then the same bodies striking in the same way against 1 On the margin of the Ms., Leibnitz has remarked: "Whatever is dis- tinguishable in itself, is also distinguishable extrinsically. If two bodies are similar through a third similar body, they cannot be distinguished. If two bodies are similar, but mutually unequal per se, they can be distinguished, no third body even being assumed. Similar and equal bodies cannot be dis- tinguished extrinsically, nay, rather, in any way, and so are one and the same." — Gerhardt's Note. — Tr. 2 Stein here inserts in his text the following marginal gloss, wanting in Gerhardt's text : " Hie ostenditur ex hypothesi Atomistica sequi, quod novae Atomi nasci possint, nee taraen iterum dissolvi contra naturae morem," I.e. Here it is shown to follow from the Atomistic hypothesis, that new atoms can be produced, but nevertheless cannot again be dissolved contrary to the law of nature. — Tr. 654 LEIBNITZ'S CRITIQUE OF LOCKE the cube A will be able violently to separate the same into parts, for otherwise A and B might be distinguished extrinsically (by Defin. I.), the contrary of which has been shown. But if the cube A is vio- lently separated into parts, it certainly (by Defin. II.) will not be an atom, as was supposed. But if other bodies cannot again separate the cube D into component parts, it follows that the atom was not R c / / \/ \ \ / A / / D Fig. 1. produced from non-atoms through contact. And the same principle will hold, whatever figure the atoms be assigned. Whence it follows that atoms which have once touched each other cannot again be violently separated. Now if all bodies are composed of atoms, bodies do not touch each other except through the atoms. Therefore they cannot be violently separated after contact, unless the atom of the one is violently separated from the atom of the other, which we have shown cannot be done. But bodies not be violently sepa- rated. . . . ^ And so it is not true that all bodies are composed of atoms. Q. E. D. Scholium to the Demonstration against Atoms taken FROM THE Contact of Atoms. October 24, 1690. I do not see what reply can be made to this demonstration unless by a denial of the postulate. For we postulated that it be conceded us : If there are atoms, they can be assumed of any figure and size and in any position whatever. This alone seems possible to be said with any reason, atoms cannot be granted, the parts of which are connected only by a point or line. And so there cannot (for example) be an 1 More words illegible. - sentence. — Tr. Gerhardt's Note. Stein omits this incomplete APPENDIX 655 atom similar to one composed from two spheres touching each other. But if then atoms spherical or terminated by any other curved sur- faces whatever are granted, they never touch each other save in a point, and so never compose a body similar to an atom. Here in some way I think a reply can be made, in the first place if the contact in the surface is the cause of stability, it follows that stability is gTeater when the surface is greater. Whence the atoms would not be equally stable. And so there would be a certain determinate force of violent separation by which stabilities could be measured. I do not see where we can find this force, if it is not in the motion of bodies, unless we advocate certain spiritual powers whose method of acting in bodies nevertheless cannot be known. But if the stability of all atoms is equal, it does not matter how great the contact is ; even contact in a line, nay in a point, would suffice. A second reply which can be made is this : it has at least been demonstrated by us that bodies cannot be composed of atoms ter- minated by plane sides. But besides the fact which can be doubted, whether indeed curvilinears properly called are granted, this excep- tion does not seem in agreement with the reasons of things, that if composition from atoms is possible it miist necessarily take place through bodies destitute of a plane surface. The third reply is this : not only the atoms of plane surfaces but also of concave must be assumed (Jollendas') from nature. Otherwise we shall be permitted to make atoms from the non-atom, as often as the concave surface of one atom happens to be applied to the convex surface of another, and that will happen until all the atoms of the concave surfaces shall be filled as far as can be done by the convex existing in nature. But this restriction also does not seem in har- mony with the reasons of things. And in general, if any one denies that there are other atoms than the perfectly spherical, in order to escape the force of the demonstration, these things are devised which indeed are accommodated to the latter, but do not accord with the primal reasons and amplitude of nature. In brief : from the hypo- thesis of atoms I can deduce absurdity, provided I am allowed to assign to the atoms size, figure, and motion as 1 will.^ 1 On the margin of the Ms., Leibnitz has remarked: "Another argument could be set up, namely: If atoms could be granted, bodies similar and equal, and nevertheless different from each other, as would be tvro equal spheres, could be granted. If atoms were granted, no cause of reflection, which in fact must be taken from an elastic body (Elaterio), could be perceived, nor would the atoms striking each other leap apart, in turn, from each other. Further superficial contact is the cause of cohesion, two atoms coming together in sides or surfaces would not leap apart ; thus, if the velocity of each approach is equal, the whole force would perish." — Gerha7-dt's Note. Stein has put this marginal gloss into the text, with a note stating that it is a marginal gloss. — Tk. 656 LEIBNITZ'S CRITIQUE OF LOCKE Appendix to the Demonstration against Atoms taken FROM the Contact of Atoms. If any one denies that there can be atomSj the parts of which touch each other in a point only or line, and so requires contact in the sur- face for cohesion, that he may avoid the force of our demonstration, that one will entangle himself in other new difficulties. For if cohesion arises from superficial contact, a case can be seen in which an atonr is unable to graze (j-adere) an atom ; for where a part of the side of the atom B coincides with a »A lA part of the side of the atom 3^!, they are not ; 1 I only unable to leap apart and also to separate — J L 1 violently, but even the one will not be able to slide upon the other, for they touch each other in the surface. N^ay, rather, what is more Fig. 2. wonderful, the atom A coming by its own mo- tion from the place ^A into the place 2^1 so situated, that it is unable to proceed farther, because it grazes the atom jB, is there arrested without any obstacle as if it were an en- chanted object. Nor does it suffice to say that no such atoms are given, and that no others exist unless spherical or at least bounded by convex surfaces. For it suffices that atoms bounded by plain or concave sides are possible, if those bounded by convex sides are possible; and from the supposed possibility of these that which is absurd follows, whence it follows that convex atoms are not to be admitted. But if any oTie because of these considerations now requires no longer superficial contact only, but also the rest of bodies tangent to each other for cohesion, lest forsooth one atom be kept from sliding upon another, that one is unable to bring forth proof of his opinion, nor does it appear why the nature and the force of the present state which is contact must depend upon a past state, so that forsooth the present contact causes cohesion, if it has remained for some consider- able time in the same place, as if there were need of a certain habi- tude, whence indeed it would follow that stability is increased by duration and that atoms newly produced are the more stable the longer they cohere, a fact which no one will surely easily affirm. But neither can the moment be assigned in which the cohesion of two atoms begins, because it is entirely perfect at once. And if it does not begin unless it has continued for some time, it will never begin, for it would itself be prior to itself. Moreover, all rest can be under- stood as composed of two motions, so that if a body is moved at the same time by two moving bodies and so remains quiet accidentally, shall it then be understood also to adhere to the sides of another body APPENDIX 657 which it grazes ? And so whithersoever we are turned, we fall into anopa, which is not strange, because we assumed an hypothesis lack- ing in reason, namely, that the highest stability is without an intelli- gible cause. But if any one thinks that atoms can be produced at least by the decree of God, we confess to him that God can make atoms, but a perpetual miracle would be needed to resist a forcible separation, since in a body itself a principle of perfect stability cannot be per- ceived. God can perform whatever is possible, but it is not always possible to transfer his power to creatures, and to bring it to pass that they themselves can do per se what they accomplish through his own power alone. IV ESSAY ON DYNAMICS ON THE LAWS OF MOTION, IN AVHICH IT IS SHOWN THAT NOT THE SAME QUAN- TITY OF MOTION IS PRESERVED, BUT THE SAME ABSOLUTE FORCE, OR RATHER THE SAME QUANTITY OF MOVING ACTION {V ACTION MOTRICE)^ [From the French] The opinion that the same quantity of motion is preserved and abides in the concourse of bodies has reigned a long time, and passed as an incontestable axiom among modern philosophers. We under- stand by the quantity/ of motion the product of the mass by the velocity, so that the mass of the body being as 2 and the velocity as 3, the quantity of motion of the body will be as 6. Thus if there were two concurrent bodies, multiplying the mass of each by its velocity and taking the sum of the products, it is maintained that this sum must be the same before and after the concourse. We begin now to be disabused of this opinion, especially since it has been abandoned by some of its most ancient, most skilful, and most eminent defenders, and above all by the author himself of the " Search after Truth." - But in this case an inconvenience has arisen, namely, that we have been thrown too far into the other extreme, and do not recognize the conservation of anything absolute which might liold the place of the quantity of motion. But our mind looks for this, and it is for this reason that I remark that philosophers who do 1 (ierhardt, Leibniz, math. Schrift., II. 2 [Vol. 6], pp. 215-231. Published I'riiin the Ms. in the Royal Library at Hanover. Written, according to Ger- haidt, probably about 1691, c/. op. cit., Einleitung, p. 14. — Tr. .. 2 Cf. ante, p. 176, note 1. — Tr. 2 c 658 LEIBNITZ'S CRITIQUE OF LOCKE not enter into the profound discussions of mathematicians have diffi- culty in abandoning an axiom such as this of the quantity of con- served motion without giving themselves another to which they may hold. It is true that the mathematicians who a long time since established the rules of motion based on experiments have remarked that the same relative velocity is preserved between the concurrent bodies. For example, if one of the two is at rest, or if both are in motion, and proceed the one against the other, or in the same direction, there is a relative velocity, with which they approach or depart the one from the other ; and we find that this relative velocity remains the same, so that the bodies depart after the impact with the velocity with which they were approaching before the impact. But this relative velocity can remain the same although the true velocities and absolute forces of the bodies change in an infinite number of ways, so that this conser- vation does not concern that which is absolute in bodies. I remark also another conservation, namely, that of the quantity of progress, but neither is this the conservation of that which is abso- lute. I call progress the quantity of motion with which a body pro- ceeds in a certain direction, so that if the body went in a contrary direction, this progress would be a negative quantity. Now if two or more bodies are concui'rent, we take the progress from the direction whence proceeds their common centre of gravity, and if all these bodies proceed from the same direction, then w^e must take the sum of the progress of each for the total progress; and it is plain that in this case the total progress and the total quantity of motion of the bodies are the same thing. But if one of the bodies proceeded from a contrary direction, its progress in the direction in question would be negative and consequently must be subtracted from the others in order to have the total progress. Thus if there are only tw^o bodies, one of which proceeds in the direction of the common centre, and the other in a contrary direction, from the quantity of motion of the first must be subtracted that of the second, and the remainder w^ill be the total progress. Now it will be found that the total progress is con- served, or that there is as much progress in the same direction before or after the impact. But it is also plain that this conservation does not correspond to that which is demanded of something absolute. For it may happen that the velocity, quantity of motion, and force of bodies being very considerable, their progress is null. This occurs when the two opposed bodies have their quantities of motion equal. In such case, according to the sense we have just given, there is no total progress at all. Long since I corrected and rectified this doctrine of the conser- vation of the Quantity of Motion, and put in its place the con- servation of some other absolute thing; but as regards the precise APPENDIX 669 form in which this doctrine should be conceived,^ that is to say, the conservation of absolute force, it is true that commonly they do not appear to have entered sufficiently into my reasons nor to have appre- hended the beauty of that which I have observed, as I remark in all that has been published in France or elsewhere on the laws of motion and mechanics, even after what I have written on Dynamics. But as some of the most profound mathematicians, after many discussions have yielded to my opinion, I promise myself with time general ap- proval. To return then to what I said of the conservation of absolute force, we must know that the origin of the error concerning the quan- tity of motion arises from that which has taken it as force. We have been led, I think, naturally to believe that the same quantity of the total force abides before or after the impact of the bodies, and I have found this very true. Now the quantity of motion and force being taken as one and the same thing, we have concluded that the quan- tity of motion is conserved. What has contributed the most to con- found force with quantity of motion is the abuse of the static doc- trine. For we find in statics that two bodies are in equilibrium when in virtue of their position their velocities are reciprocal to their masses or weights, or when they have the same quantity of motion. But we must know that this equality of force in this case arises from another principle, for generally absolute force must be estimated by the violent effect which it can produce. I call the effect violent which consumes the foi'ce of the agent, as, for example, to give such a velocity to a given body, to raise a given body to such a height, etc. And we can conveniently estimate the force of a heavy body by the product of the mass or of the weight multiplied by the height to which the body might rise by virtue of its motion. Now two bodies being in equilibrium, their heights to which they might rise or from which they might descend are reciprocal to their weights, or rather the products of the heights by the weights are equal. And it happens only in the case of equilibrium or of dead force, that the heights are as the velocities, and that thus the products of the weights by the velocities are as the products of the weights by the heights. ^ This, I say, happens only in the case of dead force, or of the infinitely small motion which I am accustomed to call solicitation, which takes place 1 The French is : " Mais justement de cette chose qu'il fallait." — Tr. 2 On the margin of the manuscript Leibnitz has remarked: "Thus it is astonishing that Descartes has avoided so well the rock of velocity taken for force, in his little treatise on Statics or dead force, where there was some danger, having reduced all to weights and heights, when it was indifferent, and that he has abandoned the heights for the velocities in the case where he should have done wholly the contrary ; that is to say, when he discusses percussions or living forces which must be measured by weights and heights." — Gerhardt's Note. — Tr. 660 LEIBNITZ'S CRITIQUE OF LOCKE when a heavy body tries to commence movement, and has not yet conceived any impetuosity ; and this happens pi'ecisely when bodies are in equilibrium, and, trying to descend, are mutually hindered. But when a heavy body has made some progress in descending freely, and has conceived some impetuosity or living force, then the heights to which this body might attain- are not proportional to the veloci- ties, but to the squares of the velocities. And it is for this reason that in case of living force the forces are not as the quantities of motion or as the products of the masses by the velocities. Nevertheless it is noticeable, and has contributed to the error ,i that two bodies unequal in absolute living force, — for it is of this I speak, — but whose quantity of motion is equal, can stop each other, which fact has made men believe them absolutely equal in force ; as, for example two bodies A of mass 3 velocity 2, and B of mass 2 velocity 3. For although A is absolutely weaker than B, A being able to raise a pound only 12 feet, if B can raise a pound 18 feet ; nevertheless in the concourse they can stop each other, the reason of which is that bodies are hindered only according to the laws of dead or static force. For being elastic as we suppose, they act between themselves only by dead forces or according to the equilibrium in the concourse, that is to say, by inassignable changes, because in pressing, resisting, and continually weakening each other more and more until they come to rest, they destroy one another at each moment only by the infinitely small motion, or dead force, equal on both sides ; now the quantity of dead force is estimated according to the laws of equilibrium by the quantity of motion, infinitely small in truth, but whose continual repetition exhausts at last the whole quantity of motion of the two bodies, which being supposed equal in both bodies, each quantity of motion is exhausted in the same time, and consequently the two bodies are reduced to rest in the same time by the pressures of their elasticities, which, restoring themselves afterwards, reproduce the motion. It is (in) this continual diminution of the quantity of motion according to the equilibrium in the concourse of the two elasticities that the cause of this paradox consists, that two absolute unequal forces, but which have the quantities of motion equal, must stop each other because this happens in a relative action where the contest takes place only according to the quantities of motion infinitely small continually repeated. Xow it is found by reason and by experiment, that it is living abso- lute force, or that which is estimated by the violent effect it can pi'o- duce, which is preserved, and nowise the quantity of motion. For if this living force could ever be augmented, the effect would be more 1 Tlie French text reads : " Cependant il est remarquable et a contribuer k I'erreur," etc. The reading should be : " et a contribue'," etc. — Tr. APPENDIX 661 powerful than the cause, or rather the perpetual mechanical motion, that is to say, which could reproduce its cause and something more, which is absurd. But if the force could be diminished, it would perish at last entirely; for never being able to increase, and being able never- theless to diminish, it would always go more and more into decay, which is without doubt contrary to the order of things. Experiment con- firms it also, and we shall find always tliat if bodies should convert their horizontal into ascending motions, they could always raise on the whole the same weight to the same height before or after the impact, supposing that no force has been absorbed in the impact by the parts of the bodies, when these bodies are not perfectly elastic, wnthout speaking of that which the medium, the base, and other cir- cumstances absorb. But as this is a thing which I have sufficiently explained before, I will not repeat it here. Now I am very happy to give still another turn to the matter and to show further the conservation of something approaching more the quantity of motion, namely, the conservation of moving action fraction motrice). Here then is the general rule that I establish. Whatever changes may take place between concurrent bodies, of whatever num- ber, tTiere must always be in the concurring bodies bettveen themselves alone the same quantity of moving action in one and the same interval of time. For example, there must be during this hour as much moving action in the universe or in the given bodies, acting between themselves alone, as there will be during any other hour whatever. To understand this rule, it is necessary to explain the estimate of moving action (faction motrice), wholly different from the quantity of motion, in the manner that the quantity of motion has been wont to be understood as has been explained above. Now in order that the moving action may be estimated, we must first esti- mate the formal effect of motion. This formal or essential effect of motion consists in that which is changed by the motion, namely, in the quantity of the mass which is transferred, and in the space or in the length through which this mass is transferred. There is the essential effect of motion, or that which finds itself changed : for this body was there, now it is here : the body is so much and the distance is so much. 1 conceive in order to greater facility that the body is moved so that each point describes a straight line equal and parallel to that of every other point of the same body. I mean also a motion uniform and continuous. This assumed, the formal effect of motion is the product of the mass which is transferred multiplied by the length of the removal, or rather the formal effects are in reason com- posed of the masses and the lengths of the removal, so that a body, as 2, being transported the length of 3 feet, and another body, as o, being transported the length of 2 feet, the formal effects are equal. It is necessary carefully to distinguish what T here call ih^ formal effect, or 662 LEIBNITZ'S CRITIQUE OF LOCKE that essential to motion, from that which I called above the violent effect. For the violent effect consumes the force and is exercised upon something without; but the formal effect consists in the body in motion, taken in itself, and does not consume the force, and even conserves it rather, since the same translation of the same mass must always be continued, if nothing from without prevents ; it is for this reason that the absolute forces are as the violent effects which con- sume them, but nowise as the formal effects. Now it will be easier to understand what moving action {V action motrice) is : it must then be estimated not only by the formal effect which it produces, but also by the vigor or velocity with which it pro- diices it. We wish to transport 100 pounds to a distant place ; that is the formal effect which is demanded. One desires to do it in one hour, another in two hoiirs ; I say that the action of the first is double that of the second, being doubly quick with reference to an equal effect. I suppose always continual and uniform motion. We may say also that a body, as 3, being transported the length of 5 feet, in 15 minutes, is the same action as if a body, as 1, were transported the length of one foot in one minute. This definition of moving action {Taction motrice') is justified suffi- ciently a priori because it is manifest that in a purely formal action taken by itself, as is here that of a moving body considered by itself, there are two points to examine, — the formal effect or that which is changed, and the promptness of the change ; for it is very manifest that that which produces the same formal effect in less time is the more active. But if any one is obstinately bent upon disputing with me this definition of moving action, it would suffice me to say that I am free to call moving action what I just explained, provided that nature justifies afterwards the reality of this nominal definition, which will be when I shall show that it is precisely this whose quantity nature conserves. Now since moving action is that which comes by multiplying the formal effect by the velocity, I wish to give more distinctly the esti- mate of velocity. We know that when two movable bodies run over uniformly the same space in unequal times, the velocity of that one which runs over it in less time will be the greater, in proportion as the time is shorter. Thus the spaces gone over being equal, the velocities are reciprocally proportional to the times. But if the times were equal, the velocities would be as the spaces gone over. For one body in motion having gone over a foot in one minute, and the other two feet, it is manifest that the velocity of the second is double. Thus the velocities are in reason composed of the direct of the spaces gone over and of the reciprocal of the times employed. Or what is the same thing, to estimate the velocity, we must take the space and divide it by the time. For example, A accomplishes 4 feet in 3 APPENDIX 663 seconds and B 2 feet in 1 second; the velocity of A will be as 4 divided by 3, namely as |, and the velocity of B will be as 2 divided by 1, namely as 2, so that the velocity of A will be to that of B as | to 2, that is to say, as 2 to 3. Now the question is to verify the conservation of the moving action {V action motrice). I can give its general demonstration in a few words, because I have already proved elsewhere that the same force is conserved, and because at bottom the exercise of force or the force taken at the time is action, the abstract nature of force consisting only in that. Thus since the same force is conserved, and since action is the product of the force by the time, the same action will be con- served in equal times. But I wish to verify it by the detail of the laws of motion established by experiment and commonly received. I shall content mjj^self with one example ; but we shall find it the same in every other example we might choose. And indeed we could see at once the general reason of it, by making the calculation in abstracto, or in general and by letters, without employing any particular numbers. But to suit the intelligence of everybody I prefer to give an example in numbers. Let there be a right angle LMN (Fig. 3), whose sides LM,MN ma,y i^S^S^ Fig. 3. .E ,E be prolonged at discretion. Let a straight line AM be taken, so that prolonged beyond the point M it would cut the angle LMN into two equal parts. We might consider ^^AM as the hypotenuse of a square whose side may be called 1.^ This being so, I suppose that the body, A,^ J We take no account here of the thickness of the bodies, which we suppose inconsiderable. — Leibnitz's Note. 6G4 LEIBNITZ'S CRITIQUE OF LOCKE being in the place ^A afc the moment 1, A goes from the point ^A to the point M, during the time 1, 2, and there meets at the moment 2 the two bodies B and C, which had been in repose during the 1, 2, which is known in the figure in that their place is designated by j6 and by .^B, as also by ^C and by .^C. Now the body A meeting the two bodies in M at the moment 2, being in Mor 2^, will drive them forward and come to rest in M, a point which will also be o.4 and ^A, because ^1 will remain there during the times 2, 3 and 3, 4, as I suppose the two mutually equal, and to the times 1, 2. But B will go towards L from the moment 2 during the time 2, 3 with a velocity as 1, and will meet at the moment 3 the body D, which had before gone in front of it during the times 1, 2, from the place ^Z) to the place jA and during the times 2, 3, from the place ^D to the place gZ), with a velocity as ^. Now B, meeting D at the moment 3, will give it the velocity ^^D^D ; that is to say, in the times 3, 4, ^D will reach ^D, and durmg that time, B will go fronr ^B to ^B with the velocity 3-64^. It will be the same on the other side, where C, pushed by A in the moment 2, will go towards N with the velocity 1, and will meet, at the moment 3, the body E, which goes against it, having gone before, during the times 1, 2,.. from the place yE to the place ^E, and during the times 2, 3 from the place 2^^ to the place oE, with a velocity as |. Now C, meeting E at the moment 3, will give it the velocity ^E^E; that is to say, that in the times 3, 4, it comes from ^E to ^E. And during this time, C will go from gC to ^C with the velocity ^C^C. The register of the masses and velocities follows. The masses of the bodies A, B, C, D, E are 1, 1, 1, 2, ^. During the times 1, 2 the velocities of the bodies A, B, C, D, E are V2, 0, 0, J, f . During the times 2, 3 the velocities of the bodies ^4, B, C, D, E are 0, 1, 1, \, f. During the times 3, 4 the velocities of the bodies A, B, C, D, E are 0, |, |^, |, ^, whei-e it is to be remarked that the body C, instead of advancing, reflects backward with the velocity i. The justification of these nurabers will be found in the rules or equations which we shall assign farther on. Let us now make the calculation of the moving actions (actions motrices) during the times equal between them — 1, 2 : 2, 3 ; 3, 4. During the times 1, 2. ^4 is in mass 1, the length of the transfer ^A.^A is ^2. Then multiplying one by the other, the formal effect is ^2. The velocity comes from dividing the length ^2 by the time 1, which makes y/2. And multiplying the effect by the velocity, the moving action is 2. • B and C are at rest during this time in ^B, .,B, or jC, oC. conse- quently their moving action is 0. APPENDIX 665 D is in mass 2, the length of the transfer ^, the formal effect 2 by J or 1. The length \ being divided by the time 1, the velocity J arises, and the effect multiplied by the velocity is 1 by \, or ^, which is the action of Z). E is in mass J, the length of the transfer |, consequently the effect ^. Now the length | divided by 1 gives the velocity |-, which, nniltiplied by the effect, furnishes f the action of E. And the sum of all the moving actions of the bodies A, B, C, D, E, during the times 1, 2, is 2 + + 0+^+ | = ff. During the times 2, 3. A is at rest, and its action is 0. B is in mass 1, the length of the transfer 1 (namely, .yB^B), the formal effect 1 ; the length 1 divided by the time 1 gives the velocity 1, which, being multiplied by the effect 1, 1 arises, which is the action oiB. C; the calculation is the same in regard to C and there arises the same action 1. D has the same action as in the preceding time ; namely, ^. E likewise has the same action as in the preceding time ; namely, |. And the sum of all the moving actions of the bodies A, B, C, D, E, during the times 2, 3, is + 1 4- 1 + 1 + | = jf , as before. Finally, during the time 3, 4. A is at rest, and its action is 0. B is in mass 1, the length of the transfer, namely, ^B^B, is I, conse- quently the effect is i. The same length, I, divided by the time 1, §ives ] for the velocity, which multiplied by the effect, ^ arises, the action of B. C is in mass 1, the length of the transfer :,C^C is |, consequently the formal effect is ^. For it matters not here when we seek absolute things, whether C advances by oC^C, or reflects backward, as it does in fact. The same length, i, divided by the time 1 gives the velocity |, which, multiplied by the effect, there arises Jj as the action of C. D is in mass 2, the length of the transfer .,D^D is f , consequently the effect is f . The same length divided by the time 1 is f, or the velocity, which multiplied by the effect, there arises j-f, which is the action of D. E is in mass \, the length of the transfer is y, the effect |. The same length divided by the time 1 is if, that is to say, the velocity, which, multiplied by the effect, produces |f for the action of E. And the sum of all the moving actions of the bodies A, B, C, D, E, during the time 3, 4, is ^1 1 25 98 _^ 18 + 2 + 225 + 196 _ 441 _ 49 9 81 18 81 162 162 18' as in each one of the preceding times. LEIBNITZ'S CRITIQUE OF LOCKE I have followed in this calculation the general method, for as the moving actions are not only equal in equal times, but proportional to the times in unequal times, I have divided the space by the time, in order to have the velocity ; but when the time is always the same, as here, and thus we can take it as unity, the division by the time changes nothing, and consequently for the velocity we can take the number of the length of the transfer, the velocities being as the spaces : whence it is manifest that the eifect being the product of the mass and the space, and the velocity being as the Space, the action is as the product of the mass by the square of the space of the transfer (we mean a horizontal transfer in falling bodies), or as the product of the mass by the square of the velocity. Now, I shall prove, further on, in the 8d equation, that the sum of these products of the masses by the squares of the velocities is conserved in the concourse of the bodies. Con- sequently, it is proved that the moving action is conserved, without speaking of other proofs by which I have shown elsewhere that the forces are conserved, and that the forces are as the products of the masses by the squares of the velocities, while the actions are as the products of the forces by the times, so that if we did not know elsewhere this estimate and conservation of force, we might learn it here, in finding by the calculation in detail, or even in general, by the 3d equation, further on, that the moving action is conserved ; now it is clear that the moving actions are in reason composed of the forces and the times, and the times being the same, the moving actions are as the powers or forces. But shall we be astonished whence comes this success, which will never fail, however intricate may be the example which we may choose? It may be proved a priori, independently of the rules of motion received ; and this is what I have shown many times in dif- ferent ways. But here I shall show that it is proved by these very rules of percussion which experience has justified, and whose rationale we may give by the method of a boat, as Huygens has done, and in many other ways, although we are always obliged to assume something non-mathematical, which has its source higher. But I shall reduce the whole to three equations very simple and beautiful, and which contain all which concerns the central concourse of two bodies in one and the same straight line. Conspiring velocities of the body a before the impact v after x. b y z. I call these conspiring velocities, because I suppose they all tend from the side whence proceeds the centre of gravity common to the two bodies. But if perchance any velocity proceeds really in the contrary direction, then the letter which expresses the conspiring velocity sig- nifies a negative quantity. But we shall always take the body a as a APPENDIX 667 body whose velocity is really conspiring, or proceeds from the side of the centre of gravity before the impact, and also in such a manner that the body a follows and does not precede the common centre of gravity. Thus the signs do not vary in v, but they may vary in y, z, x. Here, now, are our three equations : — I. Lineal equation, which expresses the conservation of the cause of the impact, or of the relative velocity v~y = z-x, and V — y signifies the relative velocity between the bodies before the impact with which they approach, and z — x signifies the relative velocity with which they depart after the impact. And this relative velocity is always the same in quantity before or after the impact, supposing that the bodies are very elastic, which this equation states. It is necessary only to remark that while the signs vary in the explica- tion of the detail, this general rule will embrace all the particular cases. This also occurs in the following equation : — II. Plane equation, which expresses the conservation of the common or total progress of the two bodies av + by = ax -f bz. I call progress here the quantity of motion which proceeds from the side of the centre of gravity, so that if the body b, for example, should proceed in the contrary direction before the impact, and thus its con- spiring velocity ?/ be negative or be expressed by —(y), understand- ing by {y) mass (molem), or that which is positive in y, then the progress of a will be av, the progress of b will be —b(y). And the total progress will be av — b(y), which is the difference of the quanti- ties of motion of the two bodies. If the bodies a and b proceed from one and the same side before and after the impact, these letters, v, y, X, z, signify only conspiring velocities real or affirmative, and conse- quently in this case it appears by this equation that the same quantity of motion will be conserved after and before the impact. But if the bodies a and b should proceed in a contrary direction before the impact and in the same direction after the impact, the difference of the quantity of motion before the impact would be equal to the sum of the quantity of motion after the impact. And there will be other similar variations according to the variation of the signs of the lettei-s y, X, z. III. Solid equation, which expresses the conservation of the total absolute force or of the moving action aw + byy = axx + bzz. This equation has this excellence, that all the variations of the signs which can arise only from the diverse direction of the velocities y, x, z, y cease, by the fact that all the letters which express these veloci- LEIBNITZ'S CRITIQUE OF LOCKE ties mourit here to the square. Now — y and + y have the same square + yy, so that all these different directions of y produce noth- ing more. And it is also for that reason that this equation gives something absolute, independent of the relative velocities, or of the progressions from a certain side. The question here concerns only the estimating of masses and velocities, without troubling ourselves from what side these velocities arise. And this it is which satisfies at the same time the rigor of the mathematicians and the wish of the philoso- phers, — the experiments and reasons drawn from different principles. Although I put together these three equations for the sake of beauty and harmony, nevertheless two of them might suffice for our needs. For, taking any two of these equations, we can infer from them the remaining one. Thus, the first and the second give the third in the following manner. By the first, we shall have v + x= y + z-^ by the second, we shall have a, v — x = b, z — y ; and, multiplying one equation by the other, according to the coi'responding sides, we shall have a, v — x, v + x = b, z — y, z + y, which makes aw — axx = bzz — byy, or the third equation. In the same way, the first and the third give the second ; for a, vv — xx — b,zz — yy, which is the third, divided by the first V + X = z + y, side by side, we shall have a, vv — xx, :,v + x — b, zz — yy, :, z + y, which makes a, v — x — h, z — y, that is, the second equation. Finally, the second and the third equation give the first. For the third a, vv — xx = b, zz — yy divided by the second, namely, by a, V — X = b, z — y, gives a, vv — XX _ b, zz — yy a, V — X b, z — y which makes v + x :^ z + y, according to the first equation. I would add only one remark, which is that many distingixish between hard and soft bodies, and the hard themselves as elastic or not, and build thereupon different rules. But we may take bodies naturally as hard-elastic, without however denying that the elas- ticity must always come from a fluid more subtile and penetrating, whose motion is disturbed by the tension or by the change of the elasticity. And as this fluid must be composed itself in its tuni of little solid bodies, elastic between themselves, we see well that this replication of solids and of fluids continues to infinity. Now this elasticity of bodies is necessary to nature, in order to obtain the execution of the grand and beautiful laws which its infinitely wise author has proposed, among which not the least are these two laws of nature which I first made known, the first of which is the law of the conservation of absolute force or of moving action in the uni- verse, with some other absolutely new conservations which depend upon it and which I will explain some day, and the second is the law of continuity, in virtue of which, among other effects, every change APPENDIX 669 must take place through inassignable passages and never by a leap. This also is the reason why nature suffers no hard non-elastic bodies. In order to show this, let us pretend that a hard non-elastic globe proceeds to strike against a similar globe at rest : after the impact it is necessary that the two globes rest, in which case the law of the conservation of force is violated, or that there be some motion and that the globe which was at rest receive it, being unable to be taken as immovable, although' even if it should feign to be such, the striking body (in order to preserve the force) would nec- essarily be reflected suddenly backward. This is a forbidden {defend u) change, since it would be by a leap, a body which proceeds from a certain side being obliged to abate its motion, even to rest, before beginning to proceed gradually further and further backward. But the globe which is struck being obliged to receive motion, there will also be a change by a leap, the struck globe which was at rest being obliged to receive a certain degree of velocity suddenly, not being pliable so as to receive it gradually and by degrees. It being also manifest, as is necessary, either that the globe striking passes suddenly to rest, which would be already a change by a leap, or that if this striking globe retains a certain velocity, the struck globe which was at rest receives suddenly an amount which is not less than that of the striking globe, since the globe struck must either stop the striking globe, or go befoi'e it. Thus the striking globe passes suddenly from velocity to rest, or at least the struck globe passes suddenly from rest to a certain degree of velocity, without passing- through the intermediate degrees, which is contrary to the law of continuity, which admits no change by a leap in nature. I have also many other reasons all of which concur in banishing hard non-elastic bodies, but this is not the place to enlarge upon them. But it is necessary to admit, that although bodies must be thus naturally elastic in the sense which I have just explained, nevertheless the elasticity often appears insufficient in the masses or bodies which we employ, even if these masses should be composed of elastic parts and should resemble a sack full of hard balls which would yield to a moderate impact, without leaving the sack, as we see in the case of soft bodies or those which yield without recovering themselves sufficiently. The reason is that the parts are not sufficiently united therein to ti-ans- fer their change to the whole. Whence it comes that in the impact of such bodies a part of the force is absorbed by the small parts which compose the mass, without this force being given to the whole ; and this must always happen when the pressed mass does not recover per- fectly ; although it also happens that a mass shows itself more or less elastic according to the different manner of the impact, witness the water itself which yields to a moderate impression, and makes a can- non-ball rebound. 670 LEIBNITZ'S CRITIQUE OF LOCKE Now when the parts of the bodies absorb the force of the impact, as a whole, as when two pieces of rich earth or of clay come into collision, or in part, as when two wooden balls meet, which are much less elastic than two globes of jasper or tempered steel ; when, I say, some force is absorbed by the parts, it is as good as lost for the absolute force, and for the respective velocity, that is to say, for the third and the first equation, which do not succeed, since that whicTi remains after the impact has become less than what it was before the impact, by reason of a part of the force being turned elsewhere. But the quantity of prog- ress, or rather the second equation, is not concerned therein. And even the motion of this total progress remains alone, when the two bodies proceed together after the impact with the velocity of their com- mon centre, as do two balls of rich earth or clay. But in the semi- elastics, as two wooden balls, it happens still further that the bodies mutually depart after the impact, although with a weakening of the first equation, following this force of the impact which has not been absorbed. And in consequence of certain experiments touching the degree of the elasticity of this wood, we might predict what should happen to the balls which should be made of it in every kind of col- lision or impact. But this loss of the total force, or this failure of the third equation, does not detract from the inviolable truth of the law of the conservation of the same force in the world. For that which is absorbed by the minute parts is not absolutely lost for the universe, although it is lost for the total force of the concurrent bodies. V ESSAY ON DYNAMICS IN DEFENCE OF THE WONDER- FUL LAWS OF NATURE IN RESPECT TO THE FORCES OF BODIES, DISCLOSING THEIR MUTUAL ACTIONS AND REFERRING THEM TO THEIR CAUSES i [From the Latin] Part I From the time we made mention of the founding of a New Science of Dynamics, many distinguished men in various places have asked for a fuller explication of this doctrine. Since, therefore, we have not 1 Gerhardt, Leibniz, math. Sehrift., II., 2 [Vol. 6], pp. 234r-246. Dutens, Leibnit. op. om., 3, 315-324. First published in the " Acta Eruditor. Lips.," in April, 1695. — Tr. APPENDIX 671 yet leisure to compose the book,^ we will give in this place those things which may kindle some light, which perhaps will return to us with interest, if, indeed, we shall elicit the opinions of those who unite energy of thought with elegance of speech, whose judgments also we openly confess will be acceptable to us, and we hope useful in the set- ting forward of the work. We have elsewhere suggested that there is in corporeal things something besides extension, nay, prior to ex- tension, namely, the force itself of nature everywhere implanted by its Author, which consists, not in the simple faculty with which the schools seem to have been content, but, besides, is provided with a tendency (conatu) or effort (nisu) which will have its full effect unless impeded by a contrai'y tendency (conatu). This effort often appears to the senses, and in my judgment is known everywhere in matter by the reason, even when it does not appear to the sense. But if ilow this force must not be assigned to God through a miracle, it is certainly necessary that this force in bodies themselves be produced from the body itself, nay, that it constitute the inmost nature of bodies, since to act is a mark of substances, and extension means nothing else than the continuation or diffusion of the already presupposed struggling and withstanding, that is, resisting substance, so far is it from being itself able to produce substance. Nor is it necessary, because every corporeal action arises {est) from motion, and motion itself does not exist unless from motion, either in the body already before exist- ing or impressed from something external to it {aliunde). For motion (just as time) never exists, if you reduce the thing to d/cpt- ySetav, because a whole never exists, when it has not coexisting parts. And nothing is so real in itself, as that momentary increment {momen- taneum) which must be constituted in a force striving for change. To this, therefore, returns whatever there is in corporeal nature besides the object of geometry or extension. And by this method, in fact, regard is had at the same time for both the truth and the doctrine of the ancients. And as our age has freed from contempt the atoms of Democritus, the ideas of Plato, and the tranquillity of the Stoics in the best nexus of things, so now the traditions of the Peripatetics concern- ing forms or entelechies (which deservedly seemed enigmatical and scarcely rightly perceived by the authors themselves) will be referred to intelligible notions, so that we think it necessary rather to explain the philosophy thus received by so many ages, so that it may be con- sistent (where this is permitted) and to illustrate and then increa,?.^ it with new truths, than to destroy it. And this kind of studies seems to me especially suited both to the intelligence {prudentice) of the teacher and to the profit of the learners, 1 For the work referred to, cf. Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], pp. 281s(/.— Tr. 672 LEIBNITZ'S CRITIQUE OF LOCKE so' that we may not seem more desirous of destroying than of building, nSt be tossed between perpetual changes of doctrine, daily uncertain because of the pride of audacious geniuses, but at length the human race, the lust of sects being curbed (which the inane glory of change [noi)andi'] stimulates), the certain dogmas established, without stum- bling, not less in philosophy than in mathematics, will make further advance, since in the writings of distinguished men, ancient and mod- ern (if you take away entirely those things in which they speak too severely against others), there is wont to be very much that is true and good, which deserves to be rescued and to be distributed into the pub- lic treasury. And would that men preferred to do this rather than spend their time in censures by which they only appease their own vanity. But somehow very many even hostile views do not displease us certainly, whom fortune has so favored in certain new views of ours, that friends often bade us think of these only, and each view is considered according to its own value, although diverse ; the reason of which perhaps is that in discussing many things we have learned to despise nothing. But now let us return to our subject. Active force (which with some you call not ill potver — virtus) is two- fold, namelj primitive, which exists in every corporeal substance per se (since I think a wholly quiescent body abhorrent to the nature of things), or derivative, which by a limitation as it were of the primi- tive, resulting through the conflicts of bodies with each other, is vari- ously exercised. And the primitive force indeed (which is nothing- else than ivreXex^M 17 irpiaTrj) corresponds to the substantial soul or form, but indeed for this reason pertains only to general causes, which cannot suffice for the explanation of phenomeua. And so we agxee with those who deny that forms must be employed in handing down the particular and special causes of sensible things : to point out which is worth while, lest, while we lead them as it were back again to the open fountains of things, at the same time we seem to desire to return to the ' vain repetitions ' (battologias) of the vulgar school. Meanwhile a knowledge of them is necessary to correct philosophiz- ing, nor may any one think he is master of the nature of body, imless he has turned his mind to such things and understood that that crass notion of corporeal substance is imperfect, not to say false, and depends upon the imagination alone and was introduced inconsider- ately some years since by an abuse of the corpuscular philosophy (in itself excellent and most true), as indeed is evident by this argument which does not entirely exclude cessation and rest from matter, and cannot bring forward reasons for the laws controlling the derivative force of nature. In like manner passive force also is twofold, either primitive or derivative. And indeed the primitive force of enduring or resisting constitutes that very thing which is called primary matter, if you rightly interpret it, in the schools, by which it happens that body APPENDIX 67i is not penetrated by body, but forms an obstacle to it, and it is en- dowed at the same time with a certain laziness, so to speak, that is, repugnance to motion, and does not indeed suffer itself to be set in motion unless by the somewhat broken force of the active body. Whence afterwards the derivative force of enduring variously exhibits itself in secondary matter. But it is our part now to proceed farther, having removed those general and primitive forces and substituted those by which we are taught that because of form every body always acts and because of matter every body always endures and resists, and in this doctrine of derivative forces and resistances to investigate how far bodies prevail by various efforts or again variously resist ; for the laws of actions, which are known not only by reason, but are confirmed also by sense itself through phenomena, are adapted to these. Derivative force therefore, by which bodies in action act mutu- ally on each other or mutually suffer from each other, we under- stand in this place as no other than that which is connected with motion {i.e. local), and in turn tends to produce further local motion. For we admit that through local motion other material phenomena can be explained. Motion is a continual change of place, and thus requires time. Yet the movable element {mobile) existing in motion, as it has motion in time, so in any moment whatever has velocity, which is so much the greater as more space is run over and less time is expended. Velocity taken in connection with direction is called conatus ; but impetus is the product of the mas? of the body into the velocity, and its quantity is so much that the Cartesians are wont to call it the quantity of motion, namely, the mo- mentary increment (mo)?ie»itoneam), although, speaking more accuratelj-, the quantity of motion itself, existing forsooth in time, arises from the aggregate of the impetuses (equal or unequal) existing in the mov- able element in the given time multiplied in order into the time. We, nevertheless, in discussing with these have followed their fashion of speaking. Nay even as (not inconvsnientl}^ for the doctrinal use of speaking) we can distinguish the accession which now is made from the accession already made or to be made, as an increment of accession or element ; or as we may distinguish the present descent from the descent already made, which it increases ; so we can discern and call Motion the momentary or instantaneous element of motion diffused by the motion itself through a period of time; and so that which is com- monly ascribed to motion is called the quantity of motion. And although in the use of terms we are conqjliant {faciles) in accord with an ac- cepted interpretation, nevertheless it especially behooves us to be care- ful in their use lest we be caught by their ambiguity. Moreover, as the estimate of motion through a period of time is made from infinite impulses, so in turn the impulse itself (although 2 X ' 674 LEIBNITZ'S CRITIQUE OF LOCKE a momentary thing) is made from infinite degrees successively im- pressed iipon that same movable body (^mobile), and has a certain ele- ment from which, unfolded, nothing but infinity can arise. Conceive a tube AC (Fig. 4) to revolve with a certain fixed uniform velocity in the horizontal plane of this page about an immovable centre C, and a ball B, existing in the cavity of the tube, to be freed from its chain or impediment, and to begin to be moved by the centrifugal force ; it is manifest that the attempt in the beginning to depart from the centre by which, namely, the ball in the tube tends towards its extremity A, is infinitely small in respect to the impulse which it already has from the rotation, or by which with the tube itself, the ball B tends from the place D towards (Z>), its distance from the centre being- retained. But with the continuance for some time Fig. 4. of the centrifugal impression proceeding fi'om the rotation, from its own progress there must arise in the ball a certain complete centrifugal impulse (D)(B), comparable with the impulse of rotation D(^D). Hence it is evident that the effort is twofold, elementary to be sure, or infinitely small, which I call, also, solicitation, and formed by the continuation or repetitiom of elementary efforts ; that is, the impulse (impetum) itself, although I do not, for that reason, mean that these mathematical entities are really so found in nature, but only that they are useful in making accurate estimates by mental abstraction. Hence force also is twofold : the one elementary, which I call also dead, because motion (motus) does not yet exist in it, but only a solicitation to motion (solicitatio ad motum), such as that of the ball in the tube, or of the stone in the sling, even while it is held still by the chain ; the other, however, is ordinary f oi'ce, united with actual motion, which I call living. And an example of dead force indeed is the centrifugal foi'ce itself, and likewise the force of gravity or centripetal force, the force also by which the tense elastic body (elastrurn) begins to restoi'e itself. But iii percussion, which arises from a heavy body falling already for some time, or fi'om a bow restoring itself for some time, or from a similar cause, the force is living force, which has arisen from an infinite number of con- tinued impressions of dead force. And this is what Galileo meant, when in his enigmatical manner of speaking he spoke of the infinite force of percussion, namely if compared with the simple eifort of gravity. But although the impulse (impetus) is always united with living force, yet we shall show below that these two are different. Living force in any aggregate of bodies again can be known as APPENDIX 675 twofold, namely total, or partial ; and partial again is either re- spective or directive, that is, either proper or common to the parts. Respective (respectiva) or proper (propria) force is that by which the bodies comprised in the aggregate can act among themselves mutually; directive or common force is that by which, besides, this aggregate can act outside itself. But I call it direct, because the total force of direction is preserved intact in this partial force. But this alone would remain, if suddenly the aggi'egate were imagined to congeal by the intercepted motion of its parts among themselves. Whence from respective and directive taken together total absolute force is composed. But these things will be better understood from the rules to be propounded below. The ancients, as far as known, had a science of dead force alone, and this it is which is commonly called Mechanics, treating of the lever, block, inclined plane (where belongs the wedge and the spiral), the equilibrium of liquids, and similar things, in which they treat in turn only of the first tendency (conatu) of the bodies among themselves, before they received an impulse by acting. And although the laws of dead force can in some fashion be transferred to living force, yet there is need of great caution, as even they may have been deceived, for this reason, who confounded force in general with the quantity produced by the multiplication of the mass into the velocity, because they understood that force is dead in the regular theory of these. For this thing happens there for a special reason, as we already long ago suggested, since (for example), in dif- ferent descending weights, in the very beginning of motion at least the descents themselves or the quantities of the spaces gone through in the descent, certainly infinitely small or elementary hitherto, are proportional to the velocities or to the efforts to descend. But the progress being made and living force having arisen, the acquired velocities are no longer proportional to the spaces already run over in the descent, by which, nevertheless, we have shown formerly and shall further show, that the force must be estimated, but only to the elements of these velocities. Galileo began to discuss concerning living force (although under another name, nay, I should rather say, concept) and was the first to explain how by the acceleration of descending weights motion arises. Descartes rightly distinguished velocity from direction, and saw even in the conflict of bodies that follow by which the former conditions are least changed. But he did not rightly estimate the least change, while he changes the direction alone or the velocity alone, since the change moderated by mixing would be obtained from both : but how this must come about escaped him, because to him, intent at that time upon modal manifestations rather than upon realities, phenomena so heterogeneous did not seem capable of being compared 676 LEIBNITZ'S CRITIQUE OF LOCKE and modified by vinion, so that we shall say no more of his other errors in this doctrine. Honoratus Fabri,i Marcus Marci,'^ Joh. Alph. Borellus,^ Ignatius Baptista Pardies,* and Claudius de Chales,^ and other men very acute in leai'ning have published things not to be despised on motion, but nevertheless have not shunned these capital errors. Huygens,^ the first that I know who has adorned our age with splendid discoveries, seems to me in this argument also to have reached the pure and un- adulterated truth and to have freed this doctrine from paralogisms, 1 Of. ante, p. 586, note 2. — Tr. 2 Johannes Marcus Marci von Kronland, 1595-1667, a German physician, mathematician, and physicist, published his De proportione niotus, seu regula sphygmica ad celentatem et tarditatem pidsuum, ex illius motu pondei-ibus geometricis librato, absque errore metiendam, Pragte, 1639, a remarkable work on the theory of impact, preceding by thirty years the researclies of Wallis, Wren, and Huygens. This is probably the work to which Leibnitz here refers. — Tr. 3 Giovanni Alfonso Borelli, 1608-1679, a distinguished Italian physician and mathematician, the founder of the iatromathematieal theory of medicine, was Professor of Mathematics at Pisa and Naples. He was the author of several medical and mathematical works, among which were Theorica mediceorum planetai'um ex causis physicis deducta, Florent., 1666; De motu animalium, Rome, 1680-1681; De vi percussionis, Lugd. Bat., 1686; and De Motionibus naturalibus, a g?xivitate pendentibus, Lugd. Bat., 1686. The two latter works are probably the ones referred to by Leibnitz. For an account of his views, cf. Lasswitz, Gesch. d. Atomistik, Hamburg u. Leipzig, 1890, Vol. 2, pp. 300-328. — Tr. 4 Ignace Gaston Bardies, 1636-1673, a French Jesuit and geometer, was Professor of Philosophy, and afterwards of Mathematics, at Paris. In his correspondence with Newton, he sought to explain the dispersion of light as a diffraction by aid of the assumption that the transmission of light depends upon a wave-movement. He intended to write a great work on Mechanics, of which only Pts. 1 and 2, Discoiirs du rnouvement local, Paris, 1670, and La statique ou la science des forces mouvantes, Paris, 1673, appeared. His GEuvres de mathematiques, etc., 4th ed., appeared a La Haye, 1710. Cf. Lasswitz, Gesch. d. Atomistik, 2, 340. Leibnitz refers to Pardies in a communication to H. Fabri, cf. Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], 81, 84 ; Gerhardt, Leibniz, philos. Schrift., 4, 244, 247. —Tr. s Claude Francois Milliet Deschales, 1621-1678, a French Jesuit and dis- tinguished mathematician and physicist", published his Cursus seu mimdvji inathematicus, 3 tomi, 1st ed., Lugduni, 1674, 2d ed., 1690. Leibnitz refers to him briefly in a communication to H. Fabri, Gerhardt, Leibniz. philos. Schrift., 4, 245; Leibniz, math. Schrift., II., 2 [Vol. 6], 81. Brief account of his views is given in Lasswitz, Gesch. d. Atomistik, 2,487-490. — Tr. fi Cf. ante, p. 150, note 3. The doctrine of Huygens, here referred to, is found in his De motu corporum ex percussione (1669) , which was first published in 1703 ; Opera reliqua, Amstel., 1728, Vol. 2 ; CEuvres comjjletes, La Haye, 1888 sq. His correspondence with Leibnitz is found in Gerhardt, Leibniz. m.ath. Schrift., I., 2 [Vol. 2], 1-208. References to the doctrine of motion occur on pp. 140, 184. An account of Huygens' physical and mechanical views is given in Lass- witz, Gesch. d. Atomistik, 2, 341-397. — Tr. APPENDIX 677 by certain rules formerly published. Wren ^ also, Wallis ^ and Mariotte,^ men excellent in these studies though diverse in method, demonstrated nearly these same rules. But concerning the causes, nevertheless, opinion is not the same ; whence men distinguished in these studies do not always admit the same conclusions. And indeed the true sources ot- this science have not yet, as is evident, been dis- closed. Nor indeed is what seems certain to me admitted by all : that rebounding or reflection springs only from elastic force, that is, from internal resistance to motion. Nor has any one before us ex- plained the notion itself of forces, which thing hitherto has disturbed the Cartesians and others, who, even for this reason, could not com- prehend that the sum of the motion or impulse (which they regard as the quantity of the forces) can appear different after the encounter from before, because for this very reason they believed the quantity of the forces to be changed. From me, still a youth, and at that time constituting the nature of body, with Democritus and his adherents in this matter, Gassendi and Descartes, in inert mass alone, there escaped a little book " Hypothesis Physica " * by title, in which I set forth a theory of motion, at the same time abstract (cibstractam) from the system and concrete {concretam) for the system,^ which beyond the merit of its 1 Sir Christopher Wren, 1631-1723, best known as the architect of St. Paul's, London, was distinguished at Oxford for his knowledge of geometry and applied matliematics. In 1660 he was elected Savilian Professor of Astronomy at Oxford. Newton, in his Prineipia, ed. 1713, p. 19, sijeaks higlily of his work as a geometrician. Leibnitz refers to him in the Hypoth. phys., cf. Gerhardt, Leibniz, math. Schrift., IL, 2 [Vol. 6], 26, 29, 30, 75 ; Philos. Schrift., 4, 187, 190, 191, 236. — Tr. 2 John Wallis, 1616-1703, an eminent English mathematician, appointed Savilian Professor of Geometry, at Oxford, 1649, published his Mechanica, sive cle Motu Tractatiis Geometricus, 3 parts, 1669-1671. His complete works were published, Oxford, 1695-1699, 3 vols., fol. The correspondence between Leibnitz and Wallis is found in Vol. 3 of this ed., and also in Gerhardt, Leibniz, math. Schrift., I., 4 [Vol. 4], 1-82.— Tr. 3 Cf. ante, p. 121, note 4. An elaborate treatise on the percussion of bodies, De la percussio7i ou choc des corps, probably the one to which Leibnitz here refers, is found in first volume of his fEuvres, Leyden, 1717. — Tr. * Cf. Gerhardt, Leibniz, math. Schrift., IL, 2 [Vol. 6], 17-80 ; Gerhardt, Leib- niz.philos. Schrift., 4, 177-240; Dutens, Leibnit. op. om., 2, Pt. II., 1-48. — Tr. 5 The compressed and somewhat obscure text is explained by the titles of two essays forming the Hypothesis Physica nova. The title of the first essay is: Theoriamotus concreti sezi Hypothesis de rationibus phsenomenorwn nostri Orbis ; that of the second is : Theoria motus abstracti sexi Rationes motuum universales a sensu et phsenomenis independentes. Cf. Gerhardt's Einleitnng, Leibniz, philos. Schrift., 4, 9-12, and especially the portion, there quoted, of a letter to Foucher, found also in ox>. cit., 1, 415 ; Erdmann, Leibnit. op. philof.. 117; F. de Careil, Lettres et Opuscules inedits de Leibniz, Faris, 1854, 119-120: Dutens, Leibnit. op. om.,2, Pt. I., 242 ; transl. Duncan, Philos. Wks. of Leibnitz, 64-65.— Tr. 678 LEIBNITZ'S CRITIQUE OF LOCKE mediocrity I see has pleased many distinguished men. I there estab- lished, having assumed such a conception of body, the fact that every striking body gives its impiilse (conaturn) to the receiving or directly opposing body as such. For since, in the moment of attack, the receiving body undertakes to go forward and thus run away with itself, and that impulse (on account of the indifference then believed by me of the body to motion or rest) must have its effect wholly in the receiving body, unless hindered by a contrary impulse, nay, even if hindered by it, since it is so necessary that these different impulses should be adjusted among themselves ; it was manifest that no cause could be given why the striking body should not attain the effect towards which it tends, or why the receiving body should not receive the entire impulse of the striking body, and so the motion of the receiving body was composed of its own pristine impulse, and of the newly received or foreign impulse. From which then I was showing that if mathematical notions alone, — magnitude, figure, place, — and the change of these, or in the moment itself of impact (concursus) the impulses to change were perceived in the body, no theory of meta- physical notions being held, namely, of power active (actricis) in form and of inactivity (ignavke), or of resistance to motion in matter, and so if it were necessary for the concourse of events to be determined by the geometrical composition of impulses alone, as we have ex- plained : then it mvist follow that the impulse of the striking body, even the least, is impressed upon the entire receiving body, although the greatest, and so the gi'eatest body at rest is dragged away by the striking body, however small, without any retardation of this body, since indeed no repugnance, but rather indifference of it to motion, is contained in such a notion of matter. Whence it would not be any more difficult to impel a large quiescent body than a small one, and thus there would be action without reaction, and there could be no estimate of power, since anything whatever could be proved by any- thing whatever. And since these things, and many others of the same kind, are opposed to the order of things and conflict with the principles of a true metaphysic, I thought at that time therefore (and indeed truly) that the most wise Author of things in the construction of the system shunned those things which would follow of themselves from the mere laws of motion derived from pui"e geometry. But afterwards, having examined things more deeply, I saw in what the systematic explanation of things consisted, and regarded that former hypothesis of the notion of the body as incomplete, and both by other arguments and also by this itself it was proved that in body there must be placed something besides magnitude and impene- trability, whence the consideration of forces arises, by adding the met- aphysical laws of which to the laws of extension those very rules of motion are produced which T called systematic ; namely, that every APPENDIX 679 change takes place gradually, and every action is accompanied with reaction, and new force is not produced without loss of the former, and so the one dragging always is retarded by the one dragged, and neither more nor less power is contained in the effect than in the cause. And since this law is not derived from the notion of mass, it must necessarily follow from another thing, which is in bodies, namely, from the force itself, which certainly always preserves its own quan- tity the same, although it is employed by different bodies. Hence therefore, besides considerations purely mathematical, and subject to the imagination, I have concluded that certain considerations meta- physical, and perceptible by the mind alone, must be admitted, and a certain principle superior to the material mass, and, so to speak, a formal addition, since indeed all the truths of corporeal things can- not be concluded from logical and geometrical axioms alone, namely, from great and small, whole and part, figure and position, but some others must be added from cause and effect, and action and passion, by which the reasons of the order of things are saved. Whether we call that principle form, or evreXe'xeta, or foi'ce, does not matter, pro- vided we remember that it is intelligibly exhibited through the notion of forces alone. But although to-day certain distinguished men, seeing this very thing, that the common notion indeed of matter is not sufficient, fetch in God d7ro /x?;x"i^?) ^^d take away all force of acting from things, a kind of Mosaic philosophy as it were (as Fludd once called it), I cannot assent. For although I admit that it has been very clearly perceived by them that there is no proper influx of one cre- ated substance into another, if the thing is driven to metaphysical strictness, and I confess even freely that all things always proceed from a continuous creation by God ; yet I think there is no natural truth in things, the reason of which is to be sought immediately in the divine action or will, but that always in the things themselves something has been placed by God, whence all their predicates are explained. It is certainly evident that God has created not only bodies, but also souls, to which correspond the primitive entelechies. But these things will be demonstrated elsewhere by their own proper reasons more profoundly drawn out. Meanwhile, although I admit an active principle superior to mate- rial notions and, so to speak, vital everywhere in bodies, yet T do not therefore here agree with Henry More and other men, distinguished for piety and genius, who so make use of a certain Archseus ^ or hylar- chic principle even for the management of phenomena {ad phcenomena procuranda), as if forsooth all things cannot be explained mechani- cally in nature, and as if those who undertake this seem to make way 1 Cf. New Essays, ante, p. 67, note 3. — Tr. 680 LEIBNITZ'S CRITIQUE OF LOCKE with incorporeal things, not without suspicion of impiety ; or as if with Aristotle it is necessary to imagine intelligences in the revolving orbs, or the elements must be said to be driven up or down by their own form, by a short (compendiosa) but useless method of teaching : with these, I say, I do not agree, nor has that philosophy pleased me any more than that theology of certain ones, who so believed that Jupiter thundered or snowed that they even branded the searchers after proper causes with the crime of atheism. In my opinion the temperament is the best which satisfies both piety and science, so that we admit that all corporeal phenomena indeed can be sought from efficient mechanical causes, but we know that the mechanical laws in the universe are derived fron) higher reasons, and so we make use of a higher efficient cause only in establishing general and remote things. But these once established, as often as afterwards we treat of the near and special efficient causes of natural things, we give no place to souls or entelechies, no more than to the idle faculties or inexplicable sympathies, since the primal and most iiniversal efficient cause itself, must not intervene unless as far as the ends are regarded, which the divine wisdom had in so ordering things, that we neglect no occasion of singing his praise and the most beau- tiful hymns. And in truth final causes (as I have shown by a wholly remarkable example of an optical principle, with the strong approval of the very celebrated Molyneux in his " Dioptrics ") are repeatedly employed with large result even in special physics, not only that we may admire the more the most beautiful works of the supreme Author, but also that we may sometimes in this way divine what through the way of efficient causes not equally or only hypothetically are manifest. Thus far perhaps philosophers have not yet sufficiently observed this use. And it must be maintained in general, that everything in things can be explained in two ways: through the kingdom of poiver or efficient causes, and through the kingdom of loisdom or through final causes : God regulating bodies as machines after the manner of an architect according to the laws of magnitude or mathematical laivs, and indeed for the use of souls ; but soiils, capable of wisdom, as his own fellow- citizens and sharers of a certain society with himself, after the manner of a leader, nay of a father rather according to the laws of goodness or moral laivs for his own glory, both kingdoms everywhere inter- penetrating, yet unconfused and undisturbed the laws of each, so that at the same time both in the kingdom of power the great- est and in the kingdom of wisdom the best is obtained. But we propose in this place to establish the general rules of productive forces, which we can then use in the explanation of special efficient causes. Next I came to the true, and indeed precisely the same, estimate APPENDIX 681 of forces, by the most different ways : one indeed a priori, from the simplest consideration of space, time, and action (which I elsewhere will explain), the other a posteriori, namely, by estimating the force by the effect which it produces in consuming itself. For I under- stand here not any effect, but that for which force must be expended or in which it must be consumed, which you can call, for that reason, violent, such as that effect is not, which a heavy body employs in run- ning through a perfectly horizontal plane, because in such an effect however produced it always retains the same force, although, also in this very effect rightly treated, so to speak, as harmless, we have followed this our method of estimating, but now it is laid aside by us. Further I chose that effect of the violent effects which is especially capable of homogeneity or division into similar and equal parts, such as exists in the ascent of a body possessed of weight : for the elevation of a heavy body two or three feet is precisely double or triple the eleva- tion of the same heavy body oiie foot ; and the elevation of a doublj' heavy body one foot is precisely double the elevation of a single heavy body to the height of one foot; whence the elevation of a doubly heavy body three feet is precisely six times the elevation of a simple heavy body one foot, supposing namely (at least for the sake of teaching, although perhaps in truth the matter is otherwise constituted, but the error here nevertheless is imperceptible), that the heavy bodies gravitate equally in the greater or less distance from the horizon. For in an elastic body homogeneity has not with equal ease a place. When therefore I wdshed to compare bodies different or endowed with different velocities, I easily saw that, if the body A is single and the body B is double, but the velocity of each equal, the force of that one is simple, of this double, since, in short, whatever is placed in that once is placed in this twice. For in B there is a body twice the equal and equivalent of A itself, and nothing besides. But if the bodies ^4 and C are equal, but the velocity in A is simple and in C double, I saw that, not in short what is in A, is doubled in C, since the velocity indeed is doubled, yet not also the body. And I saw that here an error has been made by those who believed that the force itself is doubled by that reduplication of modality (modalitatis) alone ; as already I once observed and sug- gested, and that the true and not hitherto (although after so many Elements of universal Mathematics have been written) handed-down art of estimating consists in this, that finally it attains to something homogeneous; that is, a reduplication accurate and of all kinds, not only of modes, but also of things. Of which method no other better or more remarkable specimen could be given than that which is exhibited in this argument itself. In order, therefore, to obtain these results, T considered whether these very two bodies A and (^, equal in magnitude but different in 682 LEIBNITZ'S CKITIQUE OF LOCKE velocity, could produce some effects equal to their causes and homo- geneous among themselves. For thus those things which by them- selves could not easily be compared, by their effects at least might be compared accurately. I assumed, Jf E_ moreover, that the effect must be j ^^v equal to its cause if it is produced \ j "'->, by the expenditure or consumption \ i ^v 2C of the entire force: in which case \ • ^V it matters not in how much time it WA [ y' I is produced. Let us suppose, there- ^ [^_-rrfll_-(i~-_-----''-l -I fore, the bodies A and C (Fig. 5) ^ '^ iC R to be heavy, and to convert their •p g force into an ascent, which will hap- pen, if at the moment in which they have their said velocities, A simple, B double, are known to exist at the extremities of the vertical pendulums PA, EC. But it is evident from the demonstrations of Galileo and others that, the body A with a velocity as 1 at the highest ascending above the horizon HR to the height of one foot ^A H, the body C with a velocity as 2 can surely ascend (at the highest) to the height ^CR of four feet. Whence it already follows that a heavy body having a velocity as 2 is in power four times as much as the one having a degree of velocity as 1, since by the expenditure of all its'force it can accomplish, in short, four times as much. For raising a pound (that is, itself — id est se ipsum) four feet, in short raises four times one pound one foot. And in the same manner it is inferred generally that the forces of equal bodies are as the squares of the velocities, and thence the forces of bodies in general are in reason composed of the simple of the bodies and the doubles of the velocities. I have confirmed the same things to absurdity (namely, to per- petual motion) by bringing back the contrary opinion, generally received, especially among the Cartesians, according to which forces are believed to be in reason composed of bodies and velocities : which method, indeed, I used repeatedly to define a posteriori two states unequal in force, and to distinguish the greater at the same time from the less by a certain mark. And since in substituting the one for the other, perpetual mechanical motion or an effect more powerful than the cause does not arise, those states are not in the least equivalent to themselves, but that which was substituted for the other was more powerful because it has caused something greater to be performed. But I assume as certain that nature never substitutes things unequal to the forces themselves, but the complete effect is always equal to the full cause ; and, in turn, those things which are equal to the forces, with safe reckoning can be substituted by us for them with the freest supposition, as if we made that substitution in act, and thus APPENDIX 683 with no fear ^ of perpetual mechanical motion. But if, therefore, it were true, as men generally persuade themselves, that a heavy body ^ as 2 (for so now we assume it) endowed with a velocity as 1, and a heavy body C as 1 endowed with a velocity as 2, are equivalent to each other, we ought to be able to substitute with impunity the one for the other. But this is not true. For let us assume that A as 2 has acquired a velocity as 1 in the descent 2^4 j4 from the height oAJI less than a foot; and now in ^A itself or in the existing horizon, let us substitute instead of it the equivalent (as they wish) weight (pondus) C as 1 with a velocity as 2, which ascends as far as to C, or to the height of four feet. And so by the descent alone of the weight A of two pounds from the height of one foot ^AH, and having sub- stituted its equivalent, we have accomplished the ascent of one pound four feet, which is double the former. Therefore we have gained just as much force, or we have produced perpetual mechanical mo- tion, which is certainly absurd. And it does not matter whether by the laws of motions we can actually accomplish this substitution; for between equivalents indeed substitution can safely be made. Although, indeed, we have thought out various plans by which it will be accomplished actually so nearly as we wish, that the entire force of the body A will be transferred to the body C, before at rest, but which now (A itself being brought to I'est) is alone put in motion. Whence it will happen, that, instead of a weight of two pounds of a velocity as 1, would succeed one pound of a velocity as 2, if these were equivalent ; whence we have shown that an absurdity arises. For these things are not indeed worthless, nor do they consist in logomachies, but are of the greatest use in comparing machines and motions. For if any one has force from water or animals or from other cause, by which a heavy body of a hundred pounds is kept in constant motion, so that within a fourth part of a minute of time it can complete a horizontal circle of a diameter of thirty feet ; but another maintains that a double weight in its place, in the same time, uniformly accomplishes only half the circle with less expendi- ture, and reckons that to you as if it were a gain ; be it known that you are deceived and caught by half of the forces. But now having put to flight errors, let us set forth a little more distinctly in the second part of this hastily thrown-off production (Schediasmatis) the true and truly to be admired laws of nature."^ 1 Gerhardt reads, " motu,' ' evidently a typographical error. Dutens, Leibnit. op. om., 3, 324, reads, " metu," wliicli the translation follows. — 'I'r. 2 Dutens (Leibnit. op. om., 3, 324) adds: "proponemus, mense Maio exhi- benda," i.e. to be presented in the montli of May. The article, however, never appeared in print, but remained in Ms. among Leibnitz's papers, and was first printed by Gerhardt, in his edition of Leibnitz's mathematical writings. A translation of the article is herewith given. — Tk. 684 LEIBNITZ'S CRITIQUE OF LOCKE ESSAY ON l^YXAMICS IX DEFENCE OF THE AVONDER- FUL LAWS OF NATURE IN RESPECT TO THE FORCES OF BODIES, DISCLOSING THEIR MUTUAL ACTIONS AND REFERRING THEM TO THEIR CAUSES ^ [From the Latin] Part II The nature of body, nay, of substance in general, not being suffi- ciently known, had brou.ght it about (a fact we have already touched upon) that certain distinguished philosophers of our time, since they placed the notion of body in extension alone, were compelled to have recourse to God in order to explain the union between the soul and the body, nay, also, the communication of bodies with each other. For it must be confessed that it is impossible for a mere extension, involving only geometrical notions, to be capable of action and passion: and so this alone seemed to be left to them, that, when man thinks and undertakes to move his arm, God, as it were, by a primeval compact, moves his arm instead of he himself ; and on the other hand, when the motion exists in the blood and spirits,^ God excites percep- tion in the mind. But these vei'y things, since they are foreign to a correct method of philosophizing, ought to admonish the authors that they are resting upon a false principle, and that they have not assigned ]-ightly the notion of body, from which such things followed. We have shown, therefore, that there is in every substance a force of action and, if it is created, of passion also, that the notion of extension is in itself not complete, but that a relation to something which is extended, whose diffusion or continued replication it makes known, and so the substance of a body is presupposed, which involves a power of acting and resisting, and everywhere exists as a corporeal mass, and the diffusion of this is involved in extension. Whence one day we shall kindle a new light, also, for the explanation of the union of the soixl and the body. But now we must show how from thence follow wonderful and extremely useful practical theorems, pertaining to Dynamics, that is, the science which teaches the rules especially of corporeal forces. It must be known before all things that force, indeed, is some- thing truly real, even in created substances; but space, time, and motion have something of a rational entity, and are true and real, iGerhardt, Leibniz, math. Schrift., 11., 2 [Vol. 0], pp. 246-254; aus d. Manuscript, der Konigl. Biblioth. zu Hannover. ^ Cf. Bacon's theory of the Spiritus, a brief account of which is given by Lasswitz, Gesch. d. Atomistic, 1, 431-432. — Tr. APPENDIX 685 not of tliemselv'es, bat since they involve divine attributes, — im- mensity, eternity, operation, or the force of created substances. Hence it already follows that there is no vacuum in space or time; that motion, moreoA'er, separated from force, or where in it only the geo- metrical notions, — magnitude, figure, — and the variation of these are considered, is in truth nothing else than a change of position, and so motion, as far as (quoad) phenomena are concerned, consists in a mere relation, which also Descartes acknowledged, when he defined transla- tion from the neighborhood of one body into the neighborhood of another. But in deducing his consequences he forgot his definition, and determined the rules of motions as if motion was something real and absolute. So, therefore, we must consider, if an indefinite num- ber of bodies are in motion, that from the phenomena it caimot be deduced in which of them absolute determinate motion or rest exists, but to any one you please taken from these can be attributed rest, provided that the same phenomena come forth. Hence it follows (a result which Descartes did not notice) that the uniformity of the hypotheses is changed neither by the encounters (concursus) of bodies ivitk each other; and besides, that such rules of motions must be assigned that the respective nature of motion may remain intact, nor from the event after the encounter can it be divined through the phenomena where before the encounter there had been rest or determinate abso- lute motion. Whence the rule of Descartes does not at all accord with the facts, by which he asserts that a body at rest can in no way be driven from its place by another smaller body, and other things of this sort. Than which nothing is more remote from the truth. It follows, also, from the relative nature of motion, that the action of bodies against each other by turns or percussion is the same, provided they approach each other loith the same velocity ; that is, the same appearance remaining in the given phenomena, whatever at length be the true hypothesis, or to whichever at length we rightly ascribe motion or rest, the same event appears in the phenomena sought or resulting, even in respect to the action of bodies among themselves. And this also is what we find by experience (experimur), that we shall feel the same pain, whether our hand runs against a stone at rest, suspended, if you please, from a thread, or the stone with the same velocity runs against our hand at rest. Meanwhile, we speak thus, according as the thing demands, for a more suitable and simpler explanation of the phenomena, precisely as in spherics we employ the motion of the primum mobile, and in the theory of the planets we must use the Copernican hypothesis, so that already these disputes, urged on with so much effort (in which even theologians were implicated), straight- way disappear. For although force is something real and absolute, nevertheless motion pertains to the class of relative phenomena, and tnitli is looked for not so much in phenomena as in causes. 686 LEIBNITZ'S CRITIQUE OF LOCKE From our notions also of body and forces this principle arises, that what happens in substance can be known to happen spontaneously and in an orderly manner. With this is connected the principle that no change takes place by a leap. This posited, it follows also that atoms cannot be allowed. That we may seize the jA oA „B iB force of this conclusion, let us assume I I I r^ r\ that the bodies A and B (Fig. 6) meet A y B together and that ■^A comes to g^^j and ' '"■^^ ^'^^ — "^ again ^B to ^B, and thus meeting in oAc,B Fig. (i. are reflected from ^A to ^A and from ^B to nij. But supposing that atoms exist, that is, bodies extremely hard and thus inflexible, it is evi- dent that the change takes place by a leap or momentary incre- ment (jiiomentaneam) , for direct motion in the moment (jnomento) itself of the encounter becomes retrograde unless we can assume that immediately after the encounter the bodies rest, that is, lose their foi'ce, which thing, besides the fact that it would otherwise be absurd, would continue again the change by a leap, a momentary increment {momentaneam'), namely, from motion to lA n ..Ax j.,B iB rest, and not however a transition by r^ intermediate stef)s. And so we must know, if the bodies A and B (Fig. 7) meet and come from ^A^B into the place -piG, 7. of concourse o^^aS, that there they are gradually compressed like two inflated balls, and more and more approach each other in turn by the con- tinually increased pressure ; that, moreover, by this thing the motion itself is weakened, the foi'ce itself of the effort being carried over into the elasticities (elastra) of the bodies, until at length they are reduced to rest ; but then at length the elasticity of the bodies restoring them, they themselves rebound from each other in turn with a retrograde motion begun again from rest and continually increasing ; at length with the same velocity wdth which they ap- proached each other, i-egained but turned in the opposite direction, they recede in turn from each other and return into the positions 3^4 gjB which coincide with the positions ^A^B, if the bodies are supposed equal and of equal velocity. Thence it is already evident how no change takes place by a leap, but the progress being gradually dimin- ished and at length reduced to rest, then at length a regress arises. So that as from one figure another is not made (as from a circle an oval) unless through innumerable intermediate figures, nor is there any passing over from a place to a place or from a time to a time unless through all intermediate places and times, so not from motion is rest produced, and much less an opposite motion, unless through all the intermediate degrees of motions. And since this principle APPENDIX 687 is of so great consequence in nature, I wonder it is so little thought of. From these considerations follows what Descartes had attacked in his letters, and now also certain great men are unwilling to admit, that all reflection arises from elasticity, and a reason is given of many remarkable experiments which indicate that a body bends before it is propelled, as Mariotte has very beautifully illustrated. Finally, that especially wonderful principle follows from these considerations, that no body is so poor but that it has elasticity, and so is pervaded by a fluid still more subtile ; and then that //tere a?-e no elements of bodies, and that neither the most fluid matter nor certain solid globules of the second element, exact and durable, are to be granted, but that analysis proceeds to infinity. It is consistent with this law of continuity, excluding leap from change, that a case of rest can be considered as a special case of motion, namely, as an evanescent or very small motion, and a case of equality can be considered as a case of evanescent inequality. Whence the consequence is, that such laws of motions must be assigned that there be no need for peculiar rules for bodies equal and at rest, but these rules spring from the rules of bodies Unequal and moving of themselves, or, if we wish to enounce peculiar rules for rest and equality, we must be careful lest we assign such as do not agree with the hypothesis which considers rest as the last m^otion or equality as the last inequality, otherwise we shall violate the harmony of things and our rules will not agree among themselves. This new system of testing our own or others' rules, I published first in the "Xouvelles de la Republique des Lettres," July, 1(387, article 8,^ and called it a general principle of order (principiwn ordinis gen- erale), springing from the notion of the infinite and the continuum, adding to it the axiom, that from orderly data the results also are orderly (datis ordinatis etiam qucesita sunt ordinata). I expressed the principle universally thus : If a case approaches a case continually in the data and at length disappears in itself, the results of the cases must also approach each other continually in the things sought for, and at length cease in turn in themselves. (Si casus ad casiim continue accedat in dati& tandemque in ipsum evanescat, necesse est ut etiam eventus casuitm sibi con- tinue accedant in qucesitis tandemque in se invicem desinant.) Precisely as in geometry the case of the ellipse approaches continually the case of the parabola, in proportion as one focus remaining another more and more remote is regarded as assumed, until in the case of another focus infinitely removed the ellipse passes into the parabola. Whence all the rules of the ellipse must be verified in the pai'abola (taken as an ellipse whose other focus is infinitely distant). Whence the radii falling parallel into a parabola can be conceived as coming from 1 Vf. Gerhardt, Leibniz. philos. Schrift., 3, .51-55; Erdmann, 104-lOG. — Tr. LEIBNITZ'S CRITIQUE OF LOCKE another focus or tending towards it. Since, therefore, in the same way a case in which the body A runs against B in motion can be varied continually, so that the motion of A itself remaining, the motion of B itself is regarded as less and less, until at length it is regarded as disappearing in rest and thence again grows in the con- traiy direction ; I say the result of the attack, but rebounding into what whether in A itself or in B itself, continually approaches by both motions the result of the attack which exists in the case of B at rest, and in it finally ceases ; and thus the case of rest both in the data (in datis) and in the result or that which is sought (qucesitis) is the limit of the cases of motion in a straight line, or the common limit of direct and continuous motion, and thus as it were a special example of either. With regard to this touchstone (h/dium lapideni), brought over by me from geometry to physics, when I examined the Cartesian rules of motions, it happened, wonderful to say, that a cer- tain hiatus or leap showed itself utterly abhori-ent to the nature of things, for in expressing quantities by lines, and taking for abscissas {})ro ahscissis) the motions of B itself before the encounter, the data, and for ordinates (j)ro ordinatim appUcatts) the motion of the same after the encounter, the results sought for, and by drawing the line through the extremities of the ordinates (ordinatarum), according to the precept of the rules of Descartes, this line was not a continuum, but something wonderfully gaping and leaping in a certain absurd and unthinkable manner. And when on that occasion I observed also that the rules of Rev. Father Malebranche did not bear this examina- tion in all things, the distinguished man having considered the matter again according to his candor, declared publicly that from this an occasion had arisen for him to change his rules, for which reason, also, he published a brief pamphlet. Although it must be confessed, that because he had not yet directed his attention sufficiently to the use of this new system, he has left something now also not yet suffi- ciently in all things complete {quadrant). From what has been said, this wonderful principle also follows, that the passion of every body is spontaneous, or arises from internal force, although upon external occasion. I understand here, however, passion proper, which arises from percussion, or which remains the same, whatever hypothesis at length is assigned, or to whatever at length we ascribe absolute rest or motion. For since the percussion is the same, to whatever at length true motion corresponds, it follows that the result of the percussion is distributed equally between both, and thus both act equally in the encounter, and thus half the result arises from the action of the one, the other half from the action of the other ; and since half, also, of the result or passion is in one, half in the other, it is sufficient that we derive the passion which is in one from the action also which is in itself, and we need no influence of the one upon APPENDIX 689 the other, although by the action of one an occasion is furnished the other for producing a cliange in itself. Certainly, while A and B meet, the resistance of the bodies, united with their elasticity, causes them to be compressed because of the percussion, and the compression is equal in each and according to whatever hypothesis, as the experi- ments show also, if any one conceives two inflated balls to meet, whether botli are in motion, or each is at rest, even if the one at rest be sus- pended from some thread, in order that it may most easily recede ; for, always provided the velocity of approach or the respective velocity be the same, the compression, or the intensity of the elasticity, will be the same and equal in both. Then the balls A and B, restoring them- selves by the force of their own violent, namely, compressed and con- fined, elasticity, mutually repel each other by tui'ns, and spread out,- as it were, in an arc, and, with a force equal on both sides, each is driven back by the other, and so, not by the force of the other, but by its own force, it recedes from that one. But what is to be understood in the case of inflated balls is to be understood in the case of every body so far as it is passive in percussion, namely, that the rebounding and leaping apart arises from the elasticity in itself, that is, from the motion of the permeating etherial fluid matter, and thus from force internal, or proceeding from within. I understand, however, as I have said, that the proper motion of bodies is separated from the common, which can be ascribed to the centre of gravity ; whence their proper motion is so to be conceived (to be conceived, I say, by the way of hypothesis) as if they were produced on board a ship, which would have the motion of their common centre of gravity, but they them- selves on board ship were so moved that from the composite common motion of the ship or centre, and their own proper motion, the phenomena are preserved. From what has been said, also, it is under- stood that the action of bodies is never loithout reaction, and both are equal to each other, and directly contrary. Since, then, only force, and thence nascent effort exists in any mo- ment (for motion never truly exists, as we have explained above), and every effort tends in a straight line, it follows that all motion is rectilinear, or composed of rectilinears. Hence, already it not only fol- lows that those bodies ivhich move in a curved line, try always to proceed in the straight line tanyent to it, but also, what any one least expects, hence arises the true notion of stability (frmitatis). For, if we suppose that some one of those bodies which we call stable (although in truth nothing is absolutely stable or fluid, but everything has a certain degree of stability or fluiditj', by us, however, it is named from a predominant regard for our senses) circulates about its own centre, the parts will attempt to fly away by the tangent, nay, they will really begin to fly away ; but since this separation of themselves from each other in turn disturbs the motion of the encircling bodv, hence they are repelled, or 2t 590 LEIBNITZ'S CRITIQUE OF LOCKE again crowded together towards themselves in turn, as if there were in the centre, a magnetic force of attraction, or as if there were in the parts themselves a centripetal force, and therefore the revolution will arise from the composition of the effort (?»'*■«) to recede from the rectilinear by the tangent and the centripetal effort {conatu). And thus it remains that all curvilinear motion arises from the composition among themselves of rectilinear efforts, and at the same time it is understood that this crowding together by the encircling body is the cause of all stability. Otherwise it could not be that all curvilinear motion was composed of nothing but rectilinear motions. Whence, also, again, we have a new and not less than before unexpected argu- ment against atoms. Moreover, nothing could be devised more incon- .sistent with things than that stability be sought from rest, for trtie rest never exists in bodies, nor from rest can anything arise but rest ; but although A and B are mutually at rest with themselves, if not in fact, at least relatively (although this never occurs exactly, for no body preserves exactly the same distance from another, however small the time), and although whatever is once at rest will always be at rest unless a new cause is added, nevertheless it does not follow, for this reason, that because B resists the impelling body, it resists, also, the one separating it from another, so that certainly, as the resistance of B itself is overcome, or B itself driven forward, at the same time xL follows. But were the attraction, which is not given in nature, but from the primitive stability (Jirmitate), explained through rest or something similar, it would assuredly follow. And so stability, also, should not be explained unless by the crowding together produced by the encircling body. For pressure alone does not sufficiently explain the matter, as if the separation of B itself from A itself only is im- peded, but it is to be understood that in fact they separate from each other in turn, that moreover one is again impelled to the other by the encircling body, and thus, from the composition of the two motions, this conservation of the conjunction is produced. And so those who conceive in bodies certain tablets or insensible layers (for example, of two polished marbles, which are exactly applied to each other), whose separation is made difficult on account of the resistance of the ambient body, and hence explain the stability of two sensible bodies, although very often they speak truly, yet when they suppose some stability in the layers again, they do not give the last reason foi" stability. From these considerations, also, it can be understood why I cannot in this thing continue (stare) in certain philosophic opinions of certain great mathematicians, who, besides the fact that they admit vacant space, and seem not to shrink back from attraction, consider motion, also, as an absolute thing, and hasten to prove it from the revolution and the centrifugal force which has thence arisen. But since the revolu- tion also arises only from the composition of rectilinear motions, it APPENDIX 691 follows, if the equivalent of the hypotheses is sound in rectilinear motions, however assumed, that it will be sound in the curvilinears. From what has been said it can also be understood that the common motion in 7nany bodies does not change their actions among themselves, since the velocity with which they approach each other in turn, and thus the force of the encounter by which they act on each other in turn, is not changed. Whence the remarkable experiments follow which Gassendi mentions in his letters on motion impressed by a trans- ferred motor, that he might satisfy those Avho seemed to themselves to be able to infer the rest of the earth's sphere from the motion of projectiles. Nevertheless, it is certain that, if any [persons] are borne in a large ship (closed, if agreeable, or certainly so constituted that the external phenomena cannot be observed by the travellers), and if the ship is moved, although with great velocity, yet quietly or uniformly, they themselves will have no principle by which to dis- tinguish (from those things, namely, which take place on shipboard) whether the ship is at rest or moves, even if by chance they play ball on the ship, or practice other movements. And this fact must be noted in favor of those whose belief accords with the not rightl}'^ understood notion of the Copernicans, that according to these, things projected from the earth into the air are carried off (abripi) by the air with the gyrating earth, and thus the motion of the bottom fol- lows, and fall back upon the earth just as if this were at i"est ; a view which is properly judged insufficient, since the very learned men who make use of the Copernican hypothesis conceive, rather, that some- thing on the surface of the earth is moved with the earth, and, just as if discharged from a bow or hurling machine (tormento), carries with itself the impetus made by the gyration of the earth, together with the impetus made by the projection. Thence, when their double motion is the one common with the earth, the other peculiar to the projection, it is no wonder that the common motion changes nothing. Meanwhile, it is not to be disguised that, if the projectiles could be driven so far, or if the ship were conceived so large, and borne with such velocity, that before the descent the heavy earth or ship described an arc perceptibly different fi'om a straight line ; a distinction would be discovered, because then, indeed, the motion of the earth or ship (because circular) does not remain common to the motion which was impressed upon the missile by the gyration of the ship or earth (because rectilinear). And in the effort of heavy bodies towards the •centre, external action is added, which can no less produce a diversity of phenomena, than if the compass were kept closed on the ship, which would certainly indicate a variation of the ship. As often, however, as the question concerns the equivalence of hypotheses, all things must be united which concur in the phenomena. From these considera- tions, also, it is understood that any composition of motions or reso- 692 LEIBNITZ'S CRITIQUE OF LOCKE lutioii, whatever, of one motion into two or more can safely be employed, concerning which, nevertheless, a certain very clever man in the works of Wallis had hesitated, not without reason. For the matter certainly deserves proof, and cannot (as is done by many) be assumed as in itself known. VI ON THE EADICAL ORIGIN OF THINGS^ November 23, 1697 [From the Latin] Besides the world or the aggregate of finite things, there is a Unique Being who rules, not only as the mind in me, or rather as I in my body rule mj^self, but also in a much higher manner. For this unique sovereign of the universe not only rules the world, but also frames or fashions it, and is superior to the woi'ld and, so to speak, outside the world {extramundanuni) , and thus is the ultimate reason of things. For the sufBcient reason of existence can be found neither in any single thing, nor in the entire aggregate and series of things. Let us suppose that there was an eternal book of the Elements of Geometry, one copy always made from another, it is evident that, although we can account for the present book by the past, whence it has been copied, nevertheless we never, by assuming in the past as many books as we jDlease, come to the complete reason, for we may always wonder why, from all time, such books have existed ; that is to say, why these books were written, and why so written. What is true of books is likewise true of the different states of the world, for the following state has in a measure been copied from the preceding (although according to certain laws of change), and so to whatever extent you go back into anterior states, you will never find in these states the full reason; that is to say, why any world exists rather than none, and why such an one. Therefore, although you imagine the world to be eternal, since, nevertheless, you assume only a succession of states, and do not find in any one of these whatever the sufficient reason, nay more, since by assuming any number you please you do not advance even the least towards accounting for them, it is evident that the reason must be sought elsewhere. For in eternal things we must understand that, 1 Gerhardt, Leibniz. pJdlos. Schrift., 7, 302-308; Erdmann, 147-150; Janet, 2, 546-553 (in French) . — Tk. APPENDIX 695 even if there were no cause, yet there is a reason, which in persisting things is the necessity itself or the essence ; but in a series of chang- ing things, if we suppose that this series proceeds from a prior series eternally, the reasou would be the prevalence of inclinations, as we shall soon see, in which, that is to say, the reasons do not necessitate (with an absolute or metaphysical necessity so as to imply the con- trary), but incline. From these considerations it is evident that we cannot escape the ultimate extramundane reason of things or God by assuming the eternity of the world. • The reasons therefore of the world lie concealed in something outside the world, different from the chain of circumstances or series of things, M'hose aggregate constitutes the world. We must then come from physical or hypothetical necessity, which determines tlie posterior states of the world fi'om the prior states, to something whicli is of absolute or metaphysical necessity, the reason for which cannot be given. For the present world is physically or hypothetically but not absolutely or metaphysically necessary. In fact, having assumed that it is what it is, it follows that henceforth things must be what they are. Since, therefore, the ultimate root must be in something which is metaphysically necessary, and since there is no reason of the existing unless from the existing, it is therefore necessary that a unique being exist of metaphysical necessity, or whose essence is existence, and that thus something exists different from the plurality of beings or the world, which we have admitted and shown not to be of metaphysical necessity. But that we may explain a little more distinctly how temporal, contingent or physical truths originate in eternal, or essential or metaphysical truths, we must first know, that, by the very fact itself that something rather than nothing exists, there is some demand for existence in possible things or in possibility itself or essence, or (so to speak) a stretching forth to existence, and, to sum it up in a word, that essence per se tends to existence. Whence it hereafter follows, that all possible things, or those expressing essence or pos- sible reality, with equal right tend to essence (essentiam ^) in pro- portion to the quantity of essence or reality, or in jH'oportion to the degree of perfection which they involve ; for perfection is nothing- else than quantity of essence. But from this we see most clearly that from the infinite conibina- tions of possible things and possible series there stands forth one through which the greatest quantity of essence or possibility is brought through to existence. There is always, in fact, in things a 1 The reading according to both Gerhardt and Erdmann. Janet's French version reads: " I'existence." The argument would seem to require the read- ing " existentiam." — Tr. LEIBNITZ'S CRITIQUE OF LOCKE principle of determination which is to be sought from the maximum or minimum, so that beyond question the greatest effect is manifested with, so to speak, the least expense. And here time, place, or, in a word, the receptivity or capacity of the world can be considered as the expense or ground upon which, as conveniently as possible, it must be built, while the varieties of the forms correspond to the proportion of the building and the number and elegance of the rooms. And it is as in certain games when all the places at a table must be filled according to certain laws, where, unless you employ a certain skill, hindered finally by the unfavorable places, you will be compelled to leave vacant more places than you were able or desired to do. There is, however, a certain method by which the greatest possible space is most easily filled. If therefore, for instance, we assume that it has been decreed that there be a triangle, though with no other accidentally determining condition, the result is an equilateral triangle ; and if it is assumed that we must proceed from point to point, though nothing determines the road beyond, the easiest and the shortest way will be chosen; thus having once assumed that being prevails over non-being, or that there is a reason why something rather than nothing existed, or that from possibility a transition must be made to act, it follows hence, in the absence of any further determination, that the quantity of existence is as great as possible in proportion to the capacity of the time and place (or the order of possible existence), just as tiles are so laid that in the proposed area as many as possible may be contained. From these considerations we understand already in a wonderful way how, in the vei-y original formation of things, a certain Divine Mathematics or Metaphysical Mechanics is employed, and the deter- mination of the greatest amount of existence has place. Thus the right angle is the determinate of all the angles in Geometry, and liquids placed in different media arrange themselves in the most capacious form, namely, the spherical; but especially in general Mechanics itself, when many heavy bodies struggle with each other, such a motion at length arises, through which the greatest descent on the whole is accomplished. For if all possibilities with equal right tend to existence according to the measure of reality, so all weights by equal right tend to descend in proportion to the measure of gravity, and as here the motion appears, in which is contained the greatest possible descent of the heavy bodies, so there the world appears, through which is realized the greatest possible production of possibilities. And so also we already have physical necessity from metaphysical : for although the world is not metaphysically necessary, so that the contrary implies contradiction or logical absurdity, it is nevertheless physically necessary or determined so that the contrary implies APPENDIX 695 imperfection or moral absurdity. And as possibility is the source of essence, so perfection or the degree of essence (through which the greatest number of things are conipossible) is the source of exist- ence. Whence it is at the same time evident how freedom exists in the Author of the world, although he does all things determinately because he acts from the principle of wisdom or perfection. Indif- ference certainly arises from ignorance, and the greater one's wisdom the more he is determined to the most perfect. But (you will say) this comparison of a certain determining meta- physical mechanism with the physical one of heavy bodies, although it seems elegant, nevertheless is wanting in this because the struggling heavy bodies truly exist, but the possibilities or essences before or besides existence are imaginai-y or fictitious, therefore no reason of existence can be sought in them. I reply that neither these essences nor the eternal truths which they call from them are fictitious, but exist in a certain so to speak region of ideas, namely in God himself, the source of every essence and of the existence of the rest. That we do not seem to have spoken gratuitously, the existence itself of an actual series of things indicates. For since reason is not found . in this series, as we showed above, but must be sought in meta- physical necessities or eternal truths ; moreover, since existences cannot exist unless from existences, as already we maintained above, eternal truths must have existence in a certain absoliite or meta- physically necessary subject, that is in God, through whom these things, which otherwise would be imaginary, are (to speak barbar- ously but significantly) realized. And in truth actually in the world we observe that all things take place according to the laws of the eternal verities not only geomet- rical but also metaphysical, that is, not only according to material necessities, but also according to formal reasons; and that is true not only generally in that reason of the existing rather than non- existing, and the so rather than otherwise existing world which we have now explained (which certainly is to be sought from the tend- ency of possibilities to existence), but also by descending to specials Ave see, by a wonderful plan in all nature, the metaphysical laws of cause, power, action, have place, and these prevail over the purely geometrical laws themselves of matter, as in giving the reasons of the laws of motion I have observed to such an extent that I was finally compelled to abandon, as elsewhere I have more at length ex- plained, the law of the geometrical composition of impulses (conotuum), defended formerly by me, a youth, when I was more materialistic. Thus, therefore, we have the ultimate reason of ideality both of essences and of existences in one, which assuredly greater, above and before the world itself is necessarily existent, since through itself not only existences, which the world embraces, but also possibilities, 696 LEIBNITZ'S CRITIQUE OF LOCKE have reality. But this can be sought only in one source on account of the connection of all things with each other. It is evident, more- over, that from this source existing things continually spring forth (promanare) and are produced and the products exist, since it is not apparent why one state of the world rather than another, yesterday rather than to-day, flows from itself. It is also evident how God acts not only physically but also freely, and is in himself not only the efficient but also the final cause of things, and how an account is taken by him, not only of grandeur and power in the mechanism of the universe already constituted, but also of goodness and wisdom in that to be constituted. And lest any one may think that moral perfection or goodness is here confounded with metaphysical perfection or magnitude, and the latter being granted may deny the former, it is to be understood that it follows from what has been said, not only that the world is the most perfect physically, or, if you prefer, metaphysically, or that that series of things has been produced in which the greatest pos- sible reality is actually manifest, but also that it is the most perfect .morally, because in reality moral perfection in souls themselves is physical. Whence the world is not only an especially admirable mechanism, but also, as far as it is composed of souls, is the best Republic, tlu-ough which there is brought to souls the greatest pos- sible felicity or joy in which their physical perfection consists. But, you will say, we experience the contrary in the world, for the best verj' often fare the worst, the innocent, not only beasts, but also men, are struck down, and even killed with torture ; finally, the world, especially if the government of the human race be regarded, seems rather a certain confused chaos than a thing arranged by a certain supreme wisdom. So at first view I confess it seems, but the contrary must be established by a more thorough inspection ; a priori, it is evident from these very considerations which have been brought for- ward, that the highest possible perfection, namely, of all things, and so also of mind, is obtained. And in truth it is unjust to judge, unless after an investigation of the whole law, as the jurisconsults say. We know a small part of the eternity extending into immensity ; for how little is the memory of a few thousands of yeai-s which history recounts for us. And yet, from so small experience we judge rashly concerning the immense and the eternal, as men in a prison, or, if you prefer, born and educated in the subterranean salt-pits of the Sarmatians, thought that there is no other light in the world but that dim lamp light scarcely sufficient to direct their steps. We look at. a very beautiful picture, we cover this entirely, reserving a small portion ; what else in this will appear, even if you look very attentively, nay, how much more will you observe- from near by than a certain confused congeries of colors without APPENDIX 697 choice, without art; and nevertheless, when the whole covering is removed, and you shall see the whole picture in the pi'oper position, you will know that that which seemed thoughtlessly spread upon the canvas has been done with the highest art by the author of the work. What the eyes observe in pictures, the ears perceive in music. Eminent composers very often mix discords with concords in order to arouse, and, as it were, sting the hearer, and as more solicitous concerning the outcome, all having soon been restored to order, that he may rejoice so much the more, in short, that we may take pleasure in petty dangers or experiences of evils by the sense itself, or by the display of either our power or happiness ; or, as we delight in the spectacle of the rope-dancers, or in the sword-dance (saliatione inter gladios- — sauts perilleux, Leibnitz), things that themselves excite terror, and we, our veiy selves, half let down the children in sport, as it were, now almost about to throw them before us, just as the ape bore Christian, king of Denmark, when an infant, and wrapped in swaddling clothes, to the roof of the house, and while all were anxious, like one in sport bore him safe back again into his cradle. In accord with the same principle, it is insipid always to eat sweet things ; sharp, sour, nay more, bitter things which excite the taste, are to be mixed with them. He who has not tasted the bitter, has not deserved, nay more, will not appreciate the sweet. This itself is the law of joy, that pleasure does not proceed uninterruptedly ; for this produces disgust, and makes us inert, not joyful. But what we have said of this part which can be disturbed while the harmony on the whole is preserved is not so to be interpreted as if no account is taken of the parts, or as if it would suffice that the whole world be complete in its own parts, although it can happen tliat the human race is wretched, and that there is no care for justice in the universe, or account taken of us, as some think, who judge not . rightly enough concerning the totality of things. For we must know that, as in the best constituted republic, care is taken that it be as well as possible with individuals, so the universe would not be suffi- ciently perfect unless, while the harmony of the universe is preserved, as much regard is had for particular interests. Of which thing no better measure could be constituted than the law itself of justice, saying tliat each should take part in the perfection of the universe, and in happiness proper in proportion to the measure of his own virtue and of that will which is a disposition of mind (affectus) toward ^ the common good, by which that itself is completed which we call the affection and love of God, in which alone the foi'ce and also the power of the Christian religion consists, in the judgment even of the wise theologians. Xor should it seem wonderful that so much is conferred ^ Gerhardt reads, incorrectly," ersro '' : Enlmann. pnrreotly. ■' erga'" -Tr. 698 LEIBNITZ'S CRITIQUE OF LOCKE upon souls in the universe, since they very closely reproduce the image ^ of the supreme author, and are related to him not only as machines to the maker (like the rest), but also as citizens to the prince, and will continue in existence equally with the universe itself, and express and concentrate in a measure the whole in themselves, so that it can be said that souls are the entire parts. But as regards the sufferings especially of good men, it must cer- tainly be maintained that they result in their greater good, and that is true not only theologically, but also physically, as the grain cast into the earth suffers before it bears fruit. And on the whole, it can be said that sufferings, temporarily evil, are in effect good, since they are the short roads to greater perfection. So, in physics, those liquors which ferment slowly are improved more slowly, but those in which the fermentation is stronger are improved more readily, the parts being thrown off with greater force. And this is, as you would say, to go back, in order, by a greater effort, to leap forwards (qu'on recule pour mieux saiiter, — you go back to take a better leap) . These views, therefore, must be maintained to be not only pleasing and comforting, but also most true. And iii general, I think there is nothing, both truer than happiness, and more j)ropitious and more delightful than truth. Respecting the increase also of the beauty and general perfection of the divine works, a certain perpetual and very fi-ee progress of the whole universe is to be recognized, so that it proceeds to ever greater culture. As for instance, a great part of our earth receives culture and will receive more and more. And although it is true that some- times some parts grow wild again or are destroyed and depreciated, yet this must so be understood, as a little before we interpreted suf- fering, namely, that this destruction and depreciation itself is useful in the attainment of something greater, so that in some measure we gain by the very loss. And as to the objection which might be made that thus the world should long ago have been made a paradise, the reply is at hand : although already many substances have attained great perfection, nevertheless, on account of the divisibility of the continuum to infinity, there always remain in the abyss of things parts hitherto asleep, to be aroused and carried forwards to something greater and better, and, in a word, to a better culture. And accordingly, progress never comes to an end. 1 Both Gerhardt and Erdmann read, " imagine " ; manifestly a typographi- cal error for " imaginem." — Tr. APPENDIX 699 VII APPENDIX! May, 1702 [From the Latin] Up to the present time, I have published no book, indeed, against the Cartesian philosophy, but often in the " Acta Eruditorum Lipsien- sium " and the " Journaux " of France and Holland hastily-thrown-off productions {Schediasmata) will be found inserted by me, in which 1 have borne witness to my dissent from it. But first (not to speak now of the others), about the nature of the body and what motive forces are in the body ; in all others my opinion was the same. The Cartesians, it is true, place the essence of body in extension alone, but I, although with Aristotle and Descartes against Democritus and Gas- sendi I admit no vacuum, and against Aristotle with Democritus and Descartes think there is nothing but an apparent rarefaction and con- densation, yet I think with Democritus and Aristotle against Des- cartes, that there is something passive in body besides extension, that, namely, by which body resists penetration ; but besides this, I also recognize with Plato and Ai-istotle against Democritus and Descartes an active force or evreXe'xeia, so that I think Aristotle so far rightly defined nature as the source ( principium) of motion and rest, not because I think any body, unless already in motion, can be moved by itself or be put in motion by any qiiality such as gravity, but because I think every body always has implanted in it motive force (motricevi), nay, rather motion actually intrinsic (motimi Intrinscum actualem), from the very beginning of things. Moreover, I agree with Democritus and Descartes against the multitude of the Scholastics, that the exercise of the motive (mot)-icis) power and the phenomena of bodies can always be explained mechanically, the causes themselves of the laws of motion being withdrawn which spring from a higher source, namely, from the entelechy, which cannot be derived from the passive mass alone and its modifications. But in order that my opinion may be better understood and its reasons also may be somewhat apparent, I think, in the first place, that the nature of body does not consist in extensibn alone, because in evolving the notion of extension we must notice that it is relative to something that is extended and signifies a diffusion or repetition 1 Gerhardt, Leibniz, math. Schrift., II, 2 [Vol. G], 98-106 ; Gerhardt, Leibniz, philos. Schrift., 4,090-400; cf. G.'s Einleitung, ibid., 271-272. The letter to Honoratus Fabri, and this Appendix, were printed by Gerhardt from tlie Ms. iu the Royal Library at Hanover. 700 LEIBNITZ'S CRITIQUE OF LOCKE of a certain nature. For every repetition (or multitude of the same things) is either discrete, as in numbers where aggregate parts are discerned; or is continuous, where the parts are indeterminate and can be assumed in infinite ways. Continua, liowever, are of two kinds ; the one successive, as time and motion, the otlier simultaneous or consisting of coexisting parts, as space and body. And as in time we conceive nothing else than the disposition or series itself of varia- tions, which can occur in itself, so in space we perceive nothing- else than the possible disposition of bodies. And so when space is said to be extended, we accept the statement in the same sense as when time is said to endure or number to be numbered ; for, in truth, time adds nothing to duration nor space to extension, but as successive variations are in time, in body those things are diverse which can be diffused. For, because extension is a simultaneous continuous repetition as duration is a successive one, as often as the same nature is diffused at the same time through many things, as ductility or specific gravity or the yellow-color in gold or the white- color in milk, extension is said to have place generally in body as resistance or impenetrability, although it must be confessed that that diffusion continuous in color, weight, ductility, and things similar in kind but homogeneous, is only apparent and has no place in parts however small, and so the extension of resistance alone which is diffused through matter preserves this name with the strict investi- gator. But it is evident from these considerations, that extension is not an absolute predicate, but relative to that which is extended or diffused, and from the nature of which, diffusion can just as little be separated as number from the thing numbered. And hence those who assumed extension as an absolute primitive attribute, indefinable and apprjTov, erred by defect of analysis and took refuge in the occult qualities which for the rest they so despised, as if extension were something that cannot be explained. The question now is asked. What is tliat natui-e whose diffusion constitutes body? We have already said that matter is constituted by the diffusion of resistance; but since in our opinion there is some- thing else in body besides matter, the question is asked in what its nature consists. We say, therefore, it can consist in nothing else than iv rw SwafxiKtS or the indwelling principle of change and per- sistence. Whence also it uses the physical doctrine of the two mathe- matical sciences to whose principles it was subordinated, geometry and dynamics, the elements of which latter science not yet sufficiently propounded, I have elsewhere promised. Moreover, geometry itself, or the science of extension, again is subordinated to arithmetic, be- cause in extension, as I said above, there is repetition or multitude, and dynamics is subordinated to metaphysic which treats of cause and effect. APPENDIX 701 Again, to SvvafiiKov or power in body is twofold, — passive and active. Passive power properly constitutes matter or mass, active cvT€\6;)(£ia or form. Passive power is the resistance itself by which body resists not only penetration but also motion, and by which it happens that another body cannot enter into its place unless itself yields, but itself does not yield unless by retarding somewhat the motion of the impelling body, and so it attempts to continue steadfastly in its former state, not merely that it may not depart thence voluntarily, but also that it may resist change. And so there are therein two resistances or masses : the iirst antitypy, as they call it, or impenetra- bility ; the second resistance, or what Kepler calls the natural inertia of bodies, which Descartes also somewhere in his letters acknowledged, from the fact that bodies certainly receive no new motion unless by force, and so resist the impression and break its force. This would not happen if there were not in the body, besides extension, to Swa- fiLKov or the principle of the laws of motion, by which it happens that the quantity of forces cannot be increased, nor can a body even be impelled by another unless its own force is broken. This passive force in the body, moreover, is everywhere the same and proportional to its magnitude. For although some bodies appear more dense than others, this nevertheless happens because their pores are more filled with matter pertaining to the body, while, on the contrary, the rarer bodies have the nature of a sponge, so that another more subtile matter glides through their pores which is not reckoned with the body nor its motion follow^ed or looked for. Active force, which also absolutely is customarily called force, is not to be conceived as a simple common power of the schools, or as a receptivity of action, but involves a conatus or tendency to action, so that, unless something else hinders, action follows. And in this properly consists ivTeXix^ia, too little understood by the schools ; for such a power involves act {actum), and does not persist in a naked faculty, although it does not always proceed wholly to the action (actionem) to which it tends, as often, namely, as an impediment is thrown in its way. Again active force is twofold, — primitive and deri- vative ; that is, either substantial or accidental. Primitive active force, which is called by Aristotle evTeXe;i^£ia 17 tt/jwtt;, generally the form of substance {forma suhstantice), is another natural principle which with material or passive power conjpletes the corporeal substance, which is, forsooth, a unum per se, not a mere aggregate of many substances; for there is much difference, for example, between an animal and a flock. And so this entelechy or soul, or something analogous to the soul, exists, and always naturally actuates some organic body, which itself separately assumed (quod ipsum separation sumttoyi), when the soul is separated forsooth or removed, is not one substance, but an aggregate of many ; in a word, a natural machine. 702 LEIBNITZ'S CRITIQUE OF LOCKE This natural machine, moreover, has tliis highest prerogative as compared with an artificial, that exhibiting a proof of a divine author, it consists of infinite organs wrapped up in itself, and so can never be utterly destroyed, just as it cannot be absolutely produced, but can be diminished only and increased, and be involved and evolved, this being to a certain extent itself a substance, and in it (however trans- formed) a certain etegree of vitality, or, if you prefer, of primitive activity being always preserved. For what is said of animate things must also be said proportionally of those which are iiot properly ani- mals. Meanwhile, it must be maintained that intelligences, or the more noble souls which are also called spirits, are ruled by God not only as machines, but also as subjects, and are not liable to those changes to which other living beings are exposed. Derivative force is that which some call impetus, a conatus evidently or tendency, so to speak, to a certain determinate motion, by which accordingly primitive force or the principle of action is modified. I have shown that this is not preserved the same in the same body, but yet, however distributed in many, it remains the same in the amount and differs from motion itself, whose quantity is not preserved. And this itself also is the impression which a body receives by impulse, by whose aid projectiles continue their motion and do not need any new impulse, which Gassendi also has illustrated by elegant experiments made on shipboard. Thus also some incorrectly think that projectiles have their motion continued bj' the air. Further, derivative force differs from action only as the instantaneous from the successive ; for there is already force in the first instant, but action requires a period of time, and so is brought to pass by the prolongation of forces in time, which is perceived in any part of the body whatever. And so action is in reason composed of body, time, and force (vis) or energy (virtutis), since by the Cartesians the quantity of motion is estimated by the calculation of velocity in the bodj^, and forces are considered far otherwise than as velocities, as will soon be stated. To place active force in bodies moreover, many things compel us, and especially the experience itself, which shows that motions are in matter, although these motions must be attributed originally to the general cause of things, — God; immediately, however, and specifically, they must be attributed to the force placedin things by God. For to say that God in creation has given to bodies a law of action, is nothing unless he has given at the same time something by which the law is observed ; otherwise he himself will be obliged always to procure in an extraordinaiy manner the observance of the law^ Yea, rather his law is efficacious, and makes bodies efficient ; i.e. he gave to them natural (insitam) force. Further, we must consider that derived force and action is a certain mode (modale), since it admits change. But every mode is constituted by some modification of something persist- APPENDIX 703 ing or more absolute. And just as figure is a certain limitation or modification of passive force or extended mass, so derivative force and moving action (actio matrix) is a certain modification not certainly of a thing merely passive (otherwise a modification or limit would involve more reality than the thing itself which is limited), but of something active, that is, of the primitive entelechy. Therefoi'e, derivative and accidental or changeable force will be a certain modification of the primitive energy (virtutis) essential to and abiding in every corporeal substance. Whence the Cartesians, since they acknowledge no active principle substantial and capable of modification in the body, are compelled themselves to reject (abjudicare) all action, and to trans- fer it to God alone, a far-fetched mechanical view (accersitum ex Machina), which is not philosophical. But primitive force is changed by derivative in the impacts of bodies, according as the exercise of primitive force is turned within or without. For in truth, every body has an internal motion, nor can it ever be brought to rest. This internal force, again, turns itself with- out, when it performs the duty of elastic force, when, namely, internal motion is impeded in its accustomed course, whence every body is essentially elastic, water not even excepted, and how violently this rebounds, even the cannon balls (pilce tormentarice) show. Arid unless every body were elastic, the laws of motions could not be proved true and binding. Meanwhile this force does not always render itself conspicuous in the sensible parts themselves of bodies, since these manifestly do not sufficiently cohere. Biit the harder a body is, the more elastic it is and the more strongly it rebounds. Indeed in impact, when bodies mutually rebound from each other, this occurs through elastic force, whence indeed bodies always have their own special motion from impact by their own special force, to which a foreign impulse furnishes only an occasion of acting, and, so to speak, a determination. Hence, moreover, we understand that, although that primitive force or form of substance (which, it is true, determines even the forms in matter, while it produces motion) is admitted, yet in ex- plaining elastic force and other phenomena we must always proceed mechanically, certainly by the forms which are modifications of matter and by impulses which are modifications of form. And it is useless, when distinct and specific reasons should be given, to have recourse immediately and in general ((/e?ie?-ice) to forui or primitive force in a thing, as it is useless in explaining the phenomena.of created things to recur to the first substance or God, unless his means or ends are at the same time specifically explained, and the proximate efficient or even the special final causes are rightly assigned, so that his power and wisdom appear. For in general (whatever Descartes may have said), not only efficient, but also final causes, belong to physical dis- 704 LEIBNITZ'S CRITIQUE OF LOCKE cussion (tractationis) ; precisely as a house is badly exhibited, if any of its parts betrays its structure only, not its use. I have further already pointed out above that, since we affirm that all things in nature are explained mechanically, the reasons themselves of the laws of motion or the principles of mechanics must be excepted, which should be deduced not from mathematics alone and the imagination of the sub- ject, but from a metaphysical source, namely, from the equality of cause and effect, and from other laws of this kind which are essential to entelechies. Certainly, as has already been said, physics is subor- dinate through geometry to arithmetic, through dynamics to meta- physics. But the Cartesians, not sufficiently understanding the nature of forces, confounding motive force with motion, have seriously erred in determining the laws of motions. For although Descartes knew^ that the same force must be preserved in nature, and that a body, although he attributed a part of its force (namely, the derivative) to another, so retains a part that the sum of the forces remains the same, (yet), deceived by the example of equilibrium or dead force as I call it (which here does not enter into the reckoning, and of living force or of that which is now in question, it is only an infini- tesimal part), (he) believed that force exists in a composite system {ratione composita) of masses and velocities, or that it is the same as that W'hich he calls quantity of motion, by which term he under- stands the product of the mass into the velocity (ex ductu massce in celeritatem), when, nevertheless, it has elsewhere been demonstrated by me a priori that forces exist in a composite system of simple masses and double velocities. I know that lately certain learned men, when at length they were compelled to admit against the Cartesians that the same quantity of motion is not preserved in nature, and considered this too alone as absolute force, concluded that this force also does not abide, and took refuge in the conserva- tion alone of relative (respectivce) force, but we have discovered that not in the conservation of absolute force even has nature been mindful of her ow-n constancy and perfection. And the opinion of the Cartesians indeed, in which the quantity of motion is pre- served, contradicts all the phenomena, (while) ours is wonderfully confirmed by experiments. The Cartesians err, also, in this, because they think that changes occur by a leap {per saltum) ; as if, for example, a body at rest can in a moment pass over into a state of determined motion, or as if a body placed in motion can suddenly be brought back to rest, not by passing through the intermediate grades of velocity, because they have plainly not understood the use of elastic force in the concourse of bodies. Which, if it were absent, 1 confess that neither the law which I call the law of continuity would be observed in things, through which APPENDIX 705 leaps are avoided, nor the law of equivalence by which absolute forces are conserved, nor other excellent inventions of nature's architect have place, by which the necessity of matter and the beauty of form are united. Moreover, the elastic force itself implanted in every body shows that there is in every body, also, internal Tnotion and infinite (so to speak) primitive force, although in the impact itself, when circumstances demand, it is determined by derivative force. [For, as in an arch, any part whatever sustains the entire weight, or in a tense cord the traction, and any portion whatever of compressed air, has as much force as the weight of the aii' pressing upon it, so any corpuscle whatever, of the entii-e ambient (rnnbientis) mass is solicited to action by the conspiring force, and awaits nothing but an occasion for exer- cising its power, as is shown by the example of gunpowder (puh-e7-is P!jru)-\. There are many other things in which I have been obliged to de- part from Descartes, but those which I have now brought forth relate chiefly to the principles themselves of corporeal substances, and, if you interpret them rightly, are capable of vindicating the ancient philos- ophy of a healthier school, which I see deserted by many of the more recent scholars, even those well disposed towards it, where there was no need. The philosophy of Rev. Father Ptolemgeus,i a man very versed in the principles of the ancients and the moderns, whose remarkable teaching I examined myself, at Rome (from which philos- ophy I promise myself very much), has not yet reached us. In a note, Leibnitz has added : In addition, I am pleased to state, that although very many Cartesians boldly reject forms and forces in bodies, Descartes nevertheless spoke more moderately, and professed this only, that he found no reason for using them. I indeed admit that they should be rejected if of no use ; but in this very thing I have shown that Descartes has erred. For not only in entelechies, or Tw Swa/xtKw, are placed the principles of mechanism, by which all things are regulated in bodies, but I have also shown in the " Acta Eruditorum," - when I was replying to the very celebrated man, John Christopher Sturm,^ who attacked, in his " Fhysica Eclectica," my in- 1 Giovanni Battista Tolomei, 1653-1726, was acquainted with all the Euro- pean languages and had a very extensive knowledge of all the sciences of his time, and was reputed a profound theologian and skilful critic. Among his works was Phihsophia mentis et sensuum, Roma?, 1696, fol., Augustfe Viu-' delicorum, 16!I8, fol. — Tr. - Sept. 16ii!S. The piece is the De ipsa natura, cf. Gerhardt, Leibniz, philoa. Sc/(/-i/'/., 4.. lOl-Sie; Erdmann, 154-160; Jacques (in French), 1,455-468; Janet (in Frencli), 2, 55?>-567; transL, Duncan, 112-126. Cf. also Gerhardt's Einlei- tunr/, op. cit., 4, 417. — Tr. 3 .Johann Christoph Sturm, 1635-1703, was. from 1669, Professor of Mathe- matics and Physics at the University of Altdorf. His Plujsica Eclecticd appeared at Nuremburg, 1697, 4to. While not celebrated for physical dis-' 9 -/ Ibe LEIBNITZ'S CRITIQUE OF LOCKE sufficiently understood doctrine, with irrefragable demonstration that, completeness being assumed, if there were nothing in matter but mass itself and arrangement of its parts, it would be impossible for any perceptible variation whatever to occur, since equivalences are substi- tuted for limits, and by banishing conatus, or the force of tendency, to the future (the entelechies, that is, being removed), the state of things present at one moment cannot be distinguished from the state at any other moment. And I think Aristotle perceived this when he saw that, besides local motion, change is necessary in order to satisfy the phenomena. But changes, although in appearance manifold, just as qualities, are reduced in the last analysis to variation alone of forces. For all the qualities of bodies, that is, all their real stable accidents, except forms (that is, those which do not exist in transition, as motion, but are known as present, although referred to the future), are at length, when analysis is set up, reduced to forces. Further, when forces are removed, nothing real remains in motion itself, for from variation alone of arrangement it cannot be determined where the true motion or the cause of variation is. VIII LETTER OF LELBXITZ TO BASNAGE DE BEAUVAL, EDITOR OF THE '^ HISTOIRE DES OUVRAGES DES SAVANTS," PRINTED IN THAT JOURNAL, JULY, 1(398, pp. 329 sq.'>- Explanation of the difficulties which M. Bayle has found in the New System of the Union of the Soul and the Body [From the French'] I take the liberty, Sir, to send you this explanation of the diffi- culties which M. Bayle has found in the hypothesis which I have proposed in order to explain the union of the soul and the body. Toothing is kinder than the manner which he has used towards me, and I consider myself honored by the objections he has placed in his excellent Dictionary, in the article Rorarius. Moreover, a mind as great and as profound as his cannot make them without instruct- ing, and I shall try to profit by the light which he has shed upon coveries, he emphasized the method of experiment, and spread abroad a taste for experimenting. Germany is said to owe to him the introduction of the teaching of mathematics into the gymnasia and the common schools. — Tr. 1 Cf. Gerhardt, Leibniz, phllos. Schrift., 4, 517-524, cf. G .' & Einleitung , ibid., 419; Erdmann, Leib7iit. op. philos., 150-154; Jacques, (Eiivres de Leibniz, 1, 481-487; Dutens, Leibnit. op. om., 2, Pt. I., 74-79. APPENDIX 707 these matters in this part as well as in many other parts of his work. He does not reject what I had said of the conservation of the soul and also of the animal, but he does not yet appear tsatisfied with the maimer in which I have claimed to explain the nnion and the inter- course of the soul and the body in the " Journal des Savants " of June 27 and of July 4, 1695, and in the " Histoire des ouvrages des savants," February, 1696, pp. 274, 275. Here are his words, which seem to indicate wherein he has found difficulty : " I cannot understand," he says, " the series of actions, internal and spontaneous, which would cause the soul of a dog to feel pain immediately after having felt joy, although it were alone in the universe." I reply that when I said that the soul, although only God and it should exist in the world, would feel all that it now feels, 1 only employed a fiction in supposing that which cannot happen naturally, in order to show that the feelings of the soul are only a consequence of that Avhich is already in it. I know not whether the proof of incomprehensibility which M. Bayle finds in this series must be sought alone in that which he calls lower, or whether he wished to introduce it from this time by the example of the spontaneous pas- sage from joy to pain ; perhaps, by wishing to throw out a hint that this passage is contrary to the axiom which teaches us that a thing always continues in the state in which it is once if nothing occurs which obliges it to change, and that thus the animal having once joy will always have it if it is alone or if nothing external makes it pass to pain ; in every case I agree with the axiom, and, further, I main- tain that it is in my favor, as in fact it is one of my grounds. Is it not true that from this axiom we conclude, not only that a body at rest will always be at rest, but also that a body which is in motion will alw^ays preserve this motion or change, that is to say, the same volocity and the same direction, if nothing occurs to hinder it? Thus a thing does not remain only so long as it depends upon itself ((Felle) in the state in which it is ; but also when this is a state of change, it continues to change, following always one and the same law. Now it is, according to my view, the nature of created substance to change continually according to a certain order which conducts it spontane- oudy (if I may avail myself of this word) through all the states which will happen to it, so that he who sees all, sees in its present state all its past and future states. And this law of order, which con- stitutes the individuality of each particular substance, has an exact relation to that which happens in every substance and in the entire imiverse. Perhaps I do not make too bold a statement if I say that I can demonstrate all this, but at present the question is only of maintaining it as a possible hypothesis suitable for explaining the piienomena. Now in this way the law of the change of the substance of the animal bears it from joy to pain at the moment that a continti- 708 LEIBNITZ'S CRITIQUE OF LOCKE ous solution is made in its body, because the law of the indivisible substance of this animal is to represent what is done in its body in the way that we experience it, and also to represent in some fashion and in relation to this body all that is done in the world ; the unities of substance being nothing else than different concentrations of the universe represented according to the different points of view which distinguish them. M. Bayle continues : " I understand why a dog passes immediately from pleasure to pain when, being very hungry, and eating bread, we give him a blow with a stick." I do not know whether we understand it sufficiently. No one knows better than M. Bayle him- self, that it is in this that the great difficult}' consists of explaining why that which passes in the body produces a change in the soul, and that it is this which has forced the defenders of occasional causes to recur to the care which God must take to represent continually to the soul the changes which take place in the body ; whilst I believe that it is the nature itself which God has given it to represent in virtue of its own laws what passes in the organs. He continues : " But that his soul is constructed in such a way that at the moment he is struck he would feel the pain, although we should not strike him, although he should continue to eat the bread undisturbed and unhindered, this is what I cannot understand." I do not remember, also, to have said it, and we could say it only by a metaphysical fiction, as when we suppose that God annihilates a body in order to produce a vacuum, both being equally contrary to the order of things. For since the nature of the soul was made at first in a manner suited to represent successively the changes of matter, the case we suppose cannot happen in the natural order. God could give to each substance its phenomena independent of those of others ; but in this way he would have made, so to speak, as many worlds without connection as there are substances ; almost, as we say, that when we dream we are in a world apart, and that we enter into the common world when we awake. It is not that the dreams are unrelated to the organs and the fest of the body, but that they are related in a manner less distinct. Let us continue with M. Bayle : "I find, also," says he, "the spontaneity of this soul very incompati- ble with the feelings of pain, and, in general, with all the perceptions which are displeasing to it." This incomprehensibility would be cer- tain, if spontaneous and voluntary were the same thing. Everything voluntary is spontaneous ; but thei'e are spontaneous actions which are without choice, and consequently are not voluntaiy. It does not depend upon the soul, always, to procure feelings which please it, since the feelings it will have depend upon those which it has had. M. Bayle proceeds : " Moreover, the reason why this clever man does not approve the APPENDIX 709 Cartesian system appears to me to be a false supposition : for it cannot be said that tlie system of occasional causes makes the action of God intervene by a miracle {Deum ex machina) in the reciprocal dependence of the body and soul ; for, as God intervenes only according to general laws, he does not act there in an extraordinary way." It is not for this reason alone that I do not approve of the Cartesian system ; and if you consider mine a little, you see clearly that I find in itself that which leads me to embrace it. Moreover, if the hypothesis of occa- sional causes should not need miracle, it seems that mine would not cease to have other advantages. I have said that we may imagine three systems to explain the intercourse we find between the soul and the body ; namely, first, the systeui of the influence of the one upon the other, which is that of the schools taken iu the common sense, which I believe impossible, after the Cartesians; second, that of a perpetual overseer, who represents in the one that which takes place in the other, very much as if a man were charged with making two bad clocks always to agree, which of themselves would not be capable of agreeing, and this is the system of occasional causes; and third, that of the natural agreement of two substances such as would exist between two very accurate clocks : and I find this as possible as the system of the overseer, and more worthy of the author of these sub- stances, clocks or automata. But let us see whether the system of occasional causes does not in reality suppose a perpetual miracle. They say here, no, because God would act according to this system only through general laws. I agree, but, in my opinion, that is not sufficient in order to remove the miracles : if God did it continually, they would not cease to be miracles, taking this word not popularly, as a thing rare and wonderful, but philosophically, as that wliicli exceeds the forces of created beings. It is not sufficient to say that God has made a general law ; for, besides the decree, there miist also be a natural means of executing it ; that is to say, what takes place ijiust be capable of being explained by the nature which God gives to things. The laws of nature are not so arbitrary or so indiiferent as many think. If God decreed, for example, that all bodies should have a tendency toward a circular line, and that the radii of the circles should be proportional to the size of the bodies, it would be necessary to say that there is a means of executing this decree by more simple laws, or rather, it would be necessary to admit that God will execute it miraculously, or at least by angels expressly charged with this care, very nearly like those who were sometimes given to the celestial spheres. It would be the same if some one said that God has given to the bodies natural and primitive gravities by which each should tend to the centre of its globe, without being pushed by other bodies ; for iu my opinion this system would need a perpetual miracle, or at least the assistance of the angels. 710 LEIBNITZ'S CRITIQUE OF LOCKE " Does the internal and active property communicated to the forms of bodies know the series of actions it is to produce? Not at all; for we know by experience that we are ignorant that we have in an hour such or such perceptions." I reply that this property, or rather this soul or form, does not know them distinctly, but that it feels them confusedly. There is in each substance traces of all which has hap- pened to it and of all which will happen to it. But this infinite mul- titude of perceptions hinders us in distinguishing them ; as when I hear a great confused noise of a whole people, I do not distinguish one voice from another. "It would be necessary, then, that the forms be directed by some external principle in the production of their acts ; would not this be the Deus ex machina, just the same as in the system of occasional causes?" The preceding reply puts a stop to this inference. On the contrary, the present state of each substance is a natural result of its preceding state ; but there is only one infinite intelligence therein which can see this result, for it envelops the universe in souls as well as in each portion of matter. M. Bayle concludes with these words : " Finally, as he supposes with much reason that all souls are simple and indivisible, we cannot understand how they can be compared to a pendiilum, that is to say, that by their original constitution they can diversify their operations, by availing themselves of the spontaneous activity which they would receive from their Creator. We conceive clearly that a simple being will alw^ays act uniformly, if no foreign cause turns it aside. If it were composed of many pieces, as a machine, it would act diversely, because the particular activity of each piece might change at every moment the course of that of the others ; but in a single substance, where will you find the cause of the change of operation ? " I find that this objection is worthy of M. Bayle, and that it belongs to those which most deserve to be cleared up. But I also think that if I had not pi'ovided for it at first, my system would not deserve to be ex- amined. I have compared the soul to a pendulum only in regard to the regulated precision of its changes, which is indeed but imperfect in the best clocks, but which is perfect in the works of God ; and we may say that the soul is an immaterial automaton of the most accurate kind. When it is said that a simple being will always act uniformly, there is a distinction to be made, if to act uniformly is to follow- per- petually one and the same law of order or of continuity, as in a cer- tain rank or series of numbers, I admit that every simple being itself, and indeed every complex being acts uniformly ; bi;t if uniformly means likewise, I do not agree. To explain the difference of this sense by an example, a movement in a parabolic line is uniform in the first sense ; but it is not so in the second, the portions of the para- bolic line not being similar among themselves like those of the straight APPENDIX 711 lines. It is true, to mention it in passing, that a simple body left to itself describes only straight lines, if we speak only of the centre wliich represents the motion of this entire body ; but when a simple and rigid body, having once received a turbination or circulation around its centre, retains it in the same sense and with the same velo- city, it follows that a body left to itself may describe circular lines by its points distant from the centre, when the centre is at rest, and even certain quadratrice)^, wheir this centre is in motion, which have the ordinate composed of the straight line running through the centre, and of the right sine whose versed sine is the abscissa, the area being to the circumference as this straight line is to a given straight line. We must consider also that the soul, wholly simple as it is, has always a feeling composed of many perceptions at once, which fact effects as much for our purpose as if it were composed of pieces like a machine. For each preceding perception influences the following, conformably to a law of order which exists in perceptions as in move- ments. Thus the majority of philosophers, for many centuries, who allow thoughts to soids and to angels, which they believe destitute of all body, to say nothing of the intelligences of Aristotle, admit a spontaneous change in a simple being. I add that since the percep- tions which are found together in one and the same soul, at the same time, involve a multitude veritably infinite of minute indistinguishable feelings as the sequel must develop, we must not be astonished at the infinite variety of that which must result therefrom in time. All this is only a consequence of the representatiA^e nature of the soul, which must express what passes and indeed what will pass in its body, and in some fashion in all others, through the connection or correspon- dence of all parts of the world. It would perhaps suffice to say that God, having made atoms corporeal, might also well have made them immaterial to represent the first ; but we have thought it would be well to dwell upon it a little more. For the rest, I have read with pleasure what M. Bayle says in the article Zeno. It might, perhaps, be perceived that what can be drawn therefrom agrees better with my system than with every other, for what there is of reality in extension and motion consists only in the ground of the order and the regulated series of phenomena and per- ceptions. In like manner, as many academicians and sceptics as those who wish to reply to them, seem to be embarrassed principally only because they sought a greater reality in sensible things outside of us than that of the regulated phenomena; We conceive extension in conceiving an order in coexistences, but we must not conceive it any more than space, after the fashion of a substance. It is like time, which presents to the mind only an order in changes. And as for motion, what is real therein is the foi-ce or the power ; that is to say, what there is in the present state which carries with itself a 712 LEIBNITZ'S CRITIQUE OF LOCKE cliauge for the future. The rest is only phenomena and relations. The consideration of this system shows also that, when we enter into the heart of things, we find more reason than we thought in the majority of the philosophic sects. The little substantial reality of the sensible things of the Sceptics; the reduction of all to harmonies or numbers, ideas, and perceptions of the Pythagoreans and Platon- ists ; the one and also the all of Parmenides and of Plotinus without any Spinozism ; the Stoic connection, compatible with the spontaneity of the others; the vital philosophy of the Kabbalists and Hermetics who put feeling above everything; the forms and entelechies of Aristotle and the Scholastics, and even the mechanical explanation of all particular phenomena, according to Democritus and the moderns, and so forth, find themselves reunited as in a centre of perspective, whence the object, obscured in regarding it from an entirely different point, shows its regularity and the agreement of its parts ; we have failed through a sectarian spirit in limiting ourselves by the rejection of others. The formalist philosophers blame the material or cor- pusculary ones, and vice versa. We wrongly give limits to the division and subtilty as well as to the richness and beauty of nature when we posit atoms and the vacuum, when we imagine certain primary ele- ments, such as the Cartesians, instead of veritable unities, and when we do not recognize the infinite in everything, and the exact expres- sion of the greatest in the smallest, united to the tendency of each to develop itself in a perfect order, which is the most admirable and the most beautiful result of the sovei'eign principle, whose wisdom would leave nothing better to be desired by those who could under- stand its economy. IX FRAGMENT OF A LETTER TO AK UNKNOWN PERSON October 16, 17071 {From the French] I think, then, I have good reasons for believing that all the differ- ent classes of beings whose union forms the universe, exist in the ideas of God only as so many ordinates of the same curve, the union of which does not allow the placing of others between them, because that would indicate disorder and imperfection. Men are connected 1 Guhrauer, Leibnitz, Fine Biographie, Anmerkungen z. zw. Buche, pp. 31-33. Guhrauer says in the note which contains the Fragment here translated : "^The Principle of Continuity, with whicli Leibnitz accomplislies so much in APPENDIX 713 with the animals, these with the plants, and these again with the fossils, which will be vmited in their turn with bodies which the senses and the imagination represent to us as perfectly dead and shapeless. Now since the law of continuity demands that token the essetitial determinations of a being approach those of another so that like- wise accordingly all the properties of the first must gradually approach those of the last, it is necessary that all the orders of natural beings form only one chain, in which the different classes, like so many links, connect so closely the one to the other, that it is impossible for the senses and the imagination to fix the precise point where any one begins or ends : all the species which border on or which occupy, so to speak, the regions of inflection and retrogression being obliged to be equivocal and endowed with characters which can refer to tlie neighboring species equally. Thus the existence of Zoophytes for example, or, as Buddeus^ calls them. Plant- Animals, is nowise mon- strous, but it is indeed agreeable to the order of Nature that thei'e are some. And such is the force of the principle of continuity with me that, not only should I not be astonished to learn that beings had been found which as regards many properties, for example, those of maintaining and multiplying themselves, might pass for vegetables with as good right as for animals, and which would reverse the oi'di- nary rules, based upon the supposition of a perfect and absolute sepa- I'ation of the different orders of simultaneous beings which fill the universe ; I should be so little astonished, I say, that I am indeed convinced that there must be such, that Natural History will perhaps some day succeed in knowing them, when it shall have studied more this infinite number of living beings, whose minuteness hides them from ordinary observation and which are found concealed in the Psychology, led him to surprising glimpses in his views of animate nature. Nowhere has Leibnitz expressed himself so clearly upon this subject, as in the letter to an unknown person, of Oct. 16, 1707, of which a fragment occasioned the notorious controversy between Maupertuis and Konig, 1752. It stands with many others in Konig's Appel an Public du Jugement de Vacademie royale de Berlin, etc. See p. 45. [Then follows the letter]. . . . This is the same letter which the Berlin Academy, under the inspiration of Maupertuis, declared a forgery, and struck off the list of the Academicians Professor Konig as an impostor. — There are perhaps few pieces of Leibnitz, whose genuineness are so certified to the connoisseur, as this letter (which Dutens and Erdmann have overlooked). Voltaire also (in his letter to Konig) recog- jiized its genuineness at once, although only from motives which he drew from the style. The Academy was right only in the fact that the letter could not have been addressed to Hermann. Cf. Leibn. opp. [ed. Dutens], 3, 531." — Tr. 1 Leibnitz probably refers to Johann Franz Buddeus, 16H7-1729, assistant in the philosophical faculty at Wittenberg, Professor of Greek and Latin at Coburg Gymnasium, of Philosophy at Halle, and of Theology at Jena. He published Ele/nenta philosophise practice instrumentalis et theoreticx, HaliP, 1703.— Tr. 714 LEIBNITZ'S CRITIQUE OF LOCKE bowels of the earth and the depths of the waters. We remarked only since yesterday what grounds have we for denying to reason what we have not yet had occasion to see? The principle of con- tinuity is then beyond doubt with me, and might aid in establishing many important truths in the true philosophy, which, raising itself above the senses and the imagination, seeks the origin of phenomena in the regions of the intellect. I flatter myself that I have some ideas concerning them, but this age is not qualified to receive them. X THAT THE MOST PERFECT BEING EXISTS ^^ [Fro7n the Latin] I call every simple quality which is positive and absolute, or expresses whatever it expresses without any limits, a perfection. But a quality of this sort, because it is simple, is therefore irresolv- able or indefinable, for otherwise, either it will not be a simple quality but an aggregate of many, or, if it is one, it will be circum- scribed by limits and so be known through negations of further progi-ess - contrary to the hypothesis, for a purely positive quality was assumed. From these considerations it is not difficult to show that all perfec- tions are compatible with each other or can exist in the same subject. For let the proposition be of this kind : A and B are incompatible (for understanding by A and B two simple forms of this kind or perfections, and it is the same if more are assumed like them ^), it is evident that it cannot be demonstrated without the resolution of the terms A and B, of each or both ; for otherwise their nature would not enter into the ratiocination and the incompatibility could be demonstrated as well from any others as from themselves. But now (by hypothesis) they are irresolvable. Therefore this proposi- tion cannot be demonstrated from these forms. But it might certainly be demonstrated by these if it were true, because * it is not true per se, for all propositions necessarily true are 1 Gerhardt, Leibniz, philos. Schrift., 7, 261-2G2. Cf. Gerhardt's Einleitung, ibid., 25\. — Tn. 2 Leibnitz had first written : " atque ita ope negationum," i.e. and thus also by means of negations. — Gerhardt. — Tr. 3 The words, " idemque est . . .," were added later. — Gerhardt. — Tr. * For the following, up to the words: " aut per se notai," Leibnitz at first wrote: "(esset enim necessaria, neque tamen per se nota)" i.e. for it would be necessary, and yet not known per se. — Gerhai^dt. — Tr. APPENDIX 715 either demonstrable or known j)er se. Therefore, this proposition is not necessarily true. Or ^ if it is not necessary that A and B exist in the same subject, they cannot therefore exist in the same subject, and since the reasoning is the same as regards any other assumed qualities of this kind, therefore all perfections are compatible. It is granted, therefore, that either a subject of all perfections or the most perfect being can be known. Whence it is evident that it also exists, since existence Is contained in the number of the perfections.'^ Gerhardt says : " In the foregoing is found what Leibnitz brought before Spinoza. The following he appeal's later to have added : " [The same can be shown also as regards the forms composed from the absolute forms, provided they are granted.] I showed this reasoning to D. Spinoza when T was in The Hague,^ who thought it solid; for when at first he opposed it, I put it in writ- ing and read this paper before him. SCHOL. Tlie reasoning of Descartes concerning the existence of the most perfect being assumed that the most perfect being can be known, or is possible. For this being assumed because a notion of this kind is granted, it immediately follows that that being exists, since w^e framed the notion in such a way that it immediately contains existence. But the question is asked whether it is within our power to conceive such a being, or whether such a notion exists on the side of the thing, and can be clearly and distinctly known without contradiction. For the opponents will say that such a notion of the most perfect being or of a being existing through his essence is a chimera. Nor is it sufficient for Descartes to appeal to experience and to allege that he perceives the same in such a manner in himself clearly and distinctly, for this is to break oif, not to complete the demonstration, unless he shows the method through which others also can attain the same experience; for as often as we bring experiences into the midst of the demonstra- tion, we ought to show others also the method of producing the same experience, unless we wish to convince them by our authority alone. 1 This sentence up to "omnes perfectiones," was added VAtev.— Gerhardt. — Tr. - At first : " inter perfectiones." — Gerhardt. — Tr. 3 November, 1676 ; cf. Gahrauer, Leibnitz, Eine Blographie, Ft. I., 184. — Tr. 716 LEIBNITZ'S CRITIQUE OF LOCKE XI WHAT IS IDEA^ [Ft^oni the Latin] First of all (however), by the term Idea we mean something wJilch is In our mind ; marks (^vestigia) therefore impressed upon the brain are not ideas, for I assume as certain that the mind is something else than the brain, or a more subtile part of the brain substance. But there are many things in our mind — for example, thoughts, perceptions, affections — which we know well are not ideas, although without ideas they would not be produced. For idea for us consists not in a certain act of thought, but in a potcer (facultnte), and we say we have an idea of a thing, although we do not think of it, provided we can on a given occasion think of it. There is nevertheless also in this a certain difficult}', for we have a remote power of thinking about all things, even of those of which we have not perchance ideas, because we have the power of recoveriug them ; idea, therefore, demands a certain power near at hand of thinking about, a thing or facility. But not even this suffices, for he who has a method which if he follows he can attain the thing, does not, therefore, have ah idea of it. As, if I should enumerate in order the sections of a cone, it is certain that I would come into the knowledge of oj^posite hyperbolas, although T have not yet an idea of them. There must necessarily, therefore, be something in me, which not only leads to the thing, but also expresses it. That is said to express anything in which are contained conditions corresponding to the conditions of the thing to be expressed. But these expressions are varied ; for example, the model of the machine expresses the machine itself, a perspective drawing of a thing in a plane expresses a solid, an oration expresses thoughts and truths, letters express numbers, an algebraic equation expresses a circle or other figure; and because these expressions have something common,, from the contemplation of the conditions of the expressing thing, we can come into the knowledge of the corresponding properties of the thing to be expressed. Whence it is evident that it is not necessary that that which expresses be similar to the thing expressed, provided a certain analogy of conditions is preserved. It is also evident that some expressions have a basis in nature, but others at least are partly based in will (arbitrio), as are the expressions which are produced by sounds or characters. Those things which ^Gerhardt,- Leibniz, philos. Schri/t., 7, 263-264. C/. Gerhardt's Einleitung, ibid., 251-252. — Tr. f APPENDIX 717 are based upon nature demand either some similitude, such as exists between a great circle and a little one, or between a region and a map of the region ; or at least a connection such as exists between a circle and an ellipse which represents it in perspective (optice), for any point whatever of an ellipse corresponds, according to a certain fixed law, to some point of a circle. Nay, rather, the circle, by any other similar figure in such a case, would be badly represented. In like manner, every complete effect represents a complete cause ; for I can always from the knowledge of such eifect, come to the knowledge of its caus^ Thus the deeds of each one represent his mind, and the world itsell in a measure represents God. It can also happen that those things which arise from the same cause express themselves by turns; for example, gesture and discourse. So certain deaf persons understand those who speak, not by the sound, but by the motion of the mouth. And so the idea of things existing in us is nothing else than the fact that God, the author alike of things and the mind, has impressed this power of thought upon the mind, so that out of its own workings it can draw those things which perfectly correspond to those which follow from things. And so, although the idea of a circle is not like the circle, yet from it truths can be drawn which in the true circle experience would no doubt confirm. XII ON THE METHOD OF DISTINGUISHING REAL FROM IMAGINARY PHENOMENA ^ [Fi'om the Latin] Being is that the concept of which involves something positive, or that which can by us be conceived, provided that which we conceive is possible, and does not involve a contradiction, which we know, both if the concept is perfectly explained, and involves no confusion ; and briefly, if the thing actually exists, for that which exists is cei- tainly a being or a possible thing. But as far as Being is explained by a distinct concept, so is Existence by a distinct perception ; and that we may the better understand tliis. we must see in what ways existence is proved. And in the first place, without proof, I affirm existence, from the simple perception oi- ex- perience of which I am conscious within myself; that is, in the fiist place, myself, thinking the various things, then the various pheiiomciia 1 Gerhardt, Leibniz, philos. Schrift., 7, ol9-322: Enimanii, Lpibnit. opera pli ilos., 443-445. — Tr. 718 LEIBNITZ'S CRITIQUE OF LOCKE themselves, or the appearances which exist in my mind. For these two, since they are immediately perceived by the mind with the inter- vention of no other, can be wholly proved, and it is equally certain that there exists in my mind the species of a mountain of gold or of a centaur, when I dream of these, as it is certain that I exist who dream ; for each is contained in this one thing, that it is certain that the centaur appears to me. Let us now see by what signs we may know what phenomena are real. We determine this now, both from the phenomenon itself, and from the antecedent and consequent phenomena. From the phenomenon itself, whether it be vivid, multiplex, congruous. It will be vivid, if the qualities, as light, color, heat, appear sufficiently intense; it will be multiplex if they are varied, and adapted to many tests and to the institution of new observations ; for example, if we experience in the phenomenon not only colors but also sounds, odors, flavors, tactile qualities, and those things both in the whole and in its various parts, which again we can discuss in various relations {variis caiisis trac- tare). Which things, indeed, a long series of observations, instituted especially with design and with choice, is wont to meet neither in dreams nor in those images which the memory or the phantasy pre- sents, in which the image is very often weak and also disappears {(lisparei) in the course of the discussion. The phenomenon will be congruous when it consists of many phenomena, the reason of which can be given from themselves in turn, or from some common hypothesis sufficiently simple ; then it will be congruous if it preserves the usage of other phenomena which have frequently presented themselves to us so that the parts of the phenomenon have that position, oi'der, result, which similar phenomena have had. Otherwise, they will be suspected ; for if we should see men moved in the air, sitting upon the hippogryphs of Ariosto, we should doubt, I think, whether we were dreaming or awake. But this pi'oof can be referred to another head of con- siderations assumed from the preceding phenomena. With which phenomena the present phenomenon must be congruous, if, namely, they preserve the same usage, that is, if the reason of this can be given from the preceding, or all agree with the same hypothesis as a common reason. But, undoubtedly, the strongest proof is the agree- ment with the whole course of life, especially if very many others affirm that the same agrees with their own phenomena also ; for, that other substances similar to us exist, is not only probable, but indeed, certain, as I shall soon saJ^ But the most powerful proof of the reality of phenomena, which, indeed, alone suffices, is the success in predicting future phenomena from the past and present, whether that prediction is founded in reason, or in the hypothesis thus far succeeding, or in the usage thus far observed. Nay, although this entire life were said to be nothing but a dream, and the visible world nothing but a APPENDIX 719 phantasm, I should call this dream or phantasm real enough, if, using reason well, we were never deceived by it ; but just as we know from these what phenomena must be regarded as real, so, on the other hand, whatever phenomena conflict with these which we judge real, also those whose fallacy we can explain from their own causes, these only we think apparent. But it must be confessed that the proofs of real phenomena which thus far have been brought forward, howsoever united, are not demon- strative; for, although they have the greatest probability, or, as is commonly said, produce a moral certainty, they, nevertheless, do not create a metaphysical certainty, so that the assertion of the contrary implies a contradiction. And thus, by no argument can it be abso- lutely demonstrated that there are bodies, nor anything keep certain well-ordered dreams from being objects to our mind, which are considered by us as true, and on account of the agreement among themselves with respect to use are equivalent to truths. Nor is the argument of great weight, as they commonly allege, that thus God would be a deceiver ; certainly, every one sees how far this is from a demonstration of metaphysical certainty, for we are deceived by our own judgment, not by God, when we assert anything without accu- rate proof. And although there is present great probability, never- theless God is not therefore a deceiver who presents this to us. For what, if our nature were not perchance capable of real phenomena; surely God would be not so much to be blamed as to be thanked, for, by causing these phenomena, since they could not be real, to be at least accordant, he showed us that which in the entire usage of life would equal in worth real phenomena ; what, indeed, if this whole short life were nothing but a certain long dream, and we should awake only in death ? a conception such as the Platonists seemed to have ; for since we are destined for eternity, and this whole life, although it should continue many thousands of years, has in respect of eternity the value of a point, how small will be the interposition of such a little dream in the full truth, the ratio of which is much less than that of the dream to life ; and yet no sane person will say that God is a deceiver, if by chance he should happen to observe any short but distinct and congruous dream in his mind. Hitherto I have spoken of those things which appear; now we must see about those which do not appear, which, nevertheless, can be inferred from those which do appear. And indeed it is certain that every phenomenon has some cause. Now if any one says that the cause of the phenomena is in the nature of our mind, in which the phenomena are, he will affirm nothing indeed false, but nevertheless he will not express the whole truth. For, in the first place, there is necessarily a reason wliy we ourselves exist rather than not exist, and although we should assume that we existed from eternity, yet the 720 LEIBNITZ'S CRITIQUE OF LOCKE reason of the eternal existence must be sought, which reason must be found either in the essence of our mind or outside it. And, indeed, there is nothing to prevent the existence of innumerable other minds as well as ours ; but all possible minds do not exist, which I prove from this, because all existing things have intercourse with each other. Further, minds can be known of another natui'e than ours and having intercourse with this of ours. Moreover, that all existing things have intercourse with each other is demonstrated both from this, that otherwise we cannot say whether anything in respect to these things happens now or not, and so the truth or falsity of such a proposition is not given, which is absurd, and because many extrinsic denominations are given ; nor does any one become a widower in India by the death of his wife in Europe, without a real change happening in him. For every predicate is truly contained in the nature of the subject. If now some possible minds exist, we ask why not all ; then because it is necessary that all existing things have intercourse, it is necessary that there be a cause of this intercourse, nay, it is necessary that all express the same nature, but in a different way ; but the Cause through which it happens, that all minds have intercourse or express the same thing and so exist, is that which per- fectly expresses the universe, namely God. The same cause has no cause and is unique. Hence it is at once evident that many minds exist besides ours, and since it is easj'^ to think that men who are con- versant with us can haA'e just as much reason to doubt concerning us as we concerning them, and no greater reason wages war in our behalf, they also exist and will have minds. Hence already, sacred and profane history, and whatever things pertain to the state of minds or rational substances, are considered as confirmed. With respect to bodies, I can demonstrate that not only light, heat, color, and similar qualities are apparent, but also motion and figure and extension. And if anything is real, that alone is the jjower of acting and enduring, and so in this (as it were matter and form), consists the substance of the body ; but those bodies which have no substantial form, those only are phenomena, or at least aggregates of the true. Substances have metaphysical matter or passive power as far as they express anything confusedly, active, as far as they express it distinctly. ADDITIONS AND CORRECTIONS The following Additions and Corrections are made in the interest of the greater accuracy and completeness of the book. The material incorporated therein has been obtained cliiefly since the earlier portion of the book was in type. As it could not be introduceil in its proper place, it is deemed best to insert it here rather than to omit it altogether. It will be noticed that it per- tains chiefly to the earlier portion of the New Essays, the annotation of which, not a part of the Translator's plan at the outset, began with the print- ing and has grown with the progress of the work. — Tr. Page 3, note 2, add : Erdmann, 677-678. The letter, after speaking of the nature, processes, and extent of our knowledge of physics, proceeds thus : •' You enquire concerning the things of spirits or rather concern- ing incorporeal things ; and you say that we see the mechanical disposir tion of the parts, but that we do not see the principles of the mechanism, A^ery well, but when we see motion also, then we know the cause of the motion or force. The source of the mechanism is primitive force (vis primitiva) , but the laws of motion, according to which impulses {impetus) or derivative forces arise out of this primitive force, proceed from the perception of good and evil, or from that which is most fitting. Thus it happens that efficient causes depend upon final causes, and spiritual things are by nature prior to material things, as indeed to us they are prior in knowledge, because we perceive more immediately (inter iiis) the mind (nearest — intimam — to us) than the body, as indeed Plato and Descartes have observed. This force, you say, is known by its effects, not as it is in itself. I reply that so it would be if we had no mind, and did not know. The mind has in itself perceptions and appetites, and in these its nature consists. And as in the body we know avTLTviriav, and form in general, although we do not know what the forms of the insensible bodies are, so in the mind we know perception and appetite, although we do not know distinctly the insensible ingredients of the confused percep- tions, by which the insensible things of bodies are expressed. Spiritual things are perceived, you say, just as the air, the wind, the light, yet not on that accoiuit sufiBciently known ; but to me the air, the wind, the light seem to be no more spiritual than running water, nor do they differ from this save in subtility. Spirits, minds, and simple substances or monads in the universe cannot be comprehended by the senses and the imagination, because lacking in parts. Do you ask whether I believe that there are bodies which do not fall within the range of vision? Why may I not o A 721 722 LEIBNITZ'S CRITIQUE OF LOCKE believe ? nay, rather, concerning them I think I cannot doubt. In micro- scopes we see animalcula otherwise imperceptible, and the nerves of these animalcula and other animalcula by chance swimming in their own fluids cannot be seen. The subtility of nature proceeds into infinity. Finally you seek for definitions of matter, body, spirit. Matter is that which con- sists in antitypia, or that which resists penetration, and so naked matter is merely passive. Body, moreover, has besides matter also active force. Body, moreover, is either a corporeal substance or a mass collected from corporeal substances. Corporeal substance I call that which consists in a simple substance or monad (i.e. in the mind or somewhat analogous ito the mind) and in an organic body united to it. But mass is an aggregate of corporeal substances, as a cheese sometimes consists of a couflux of worms. Then a monad or a substance simple in kind contains perception and appetite, and is either primitive or God, in which is the ultimate reason of things, or derivative, that is a created monad, and this is either endowed with reason. Mind (mens), or endowed with sense, that is Soul (ahima), or endowed with a certain lower grade of perception and appetite, or analogous icith soul (^animce analoga) , which is content with the naked name of monad, since we do not know its various grades. Every monad, furthermore, is inextinguishable ; for simple substances can neither begin nor end, except by creation or annihilation, that is, miraculously. And, moreover, every created monad is endowed with a certain organic body, by means of which it perceives and appetizes, although it is variously (e)volved through births and deaths, involved, transformed, and exists in a perpetual flux. Monads, then, contain in themselves the Entelechy, or the primitive force (vis primitiva), and without them matter would be passive merely ; and any mass whatever contains innumerable monads, for although each organic body of nature has its own corresponding monads, yet it contains in the parts other monads endowed in like manner with their own organic bodies serving the primary body ; and all nature is nothing else, for all aggregates must necessarily result from simple substances, as it were from true elements. But atoms or extended bodies, and yet infrangible, are a fiction, which cannot be explained except by a miracle, and are without reason ; nor may we from them assign the causes of the forces and motions. And although they might be admitted, they would not be truly simple, for this very reason, because they are extended and endowed with parts. Thus I have replied to your questions, and set forth my views, as far as may be in a few words and by letter. " Page 9, line 15. For " 1709," read " 1704," and cf. infra, p. 101, note 1, line 3 from bottom, and infra, p. 531, note 2, 1[1[ 2, 3, where this por- tion of note 1, p. 101, is corrected. Page 13, note 1. Add: translation also in Duncan, Philos. Wks. of Leibnitz, 94-99 ; German translation in J. H. v. Kirchmann, Die klein. philos. loichtig. Schrift. v. Leibniz, 86-92 (Philos. Bibliothek, Bd. 81; Erlauterungen, Bd. 82), Leipzig, 1879. ADDITIONS AND CORRECTIONS. 723 Page 15, note 2. After "translation," instead of "Appendix," etc., read " Duncan, Philos. Wks. of Leibnitz, pp. 71-80 ; German translation in J. H. V. Kirchmann, Die klein. philos. icichtig. Schrift. v. Leibniz, Page 16, line 22, *' Huygens." Cf. infra, p. 150, note 3. On Huygens' physical views, cf. Lasswitz, Gesch. d. Atomistik, 2, 341-397. New ed. Huygens, (Euvres completes, La Haye, 1888-1893, 5 vols., still in prog- ress. These 5 volumes contain correspondence only. Page 16, line 30, "pliable." " Leibnitz means," says J. H. v. Kirch- mann, Erlduterungen zu Leibniz, d. klein. philos. wichtig. Schrift., Leipzig, 1879, p. 109, " that, although bodies contain no vacuum, yet from the fact that they can become greater or lesser in extent, the other substances which fill out the gaps of the body proper are by pressure removed from it, or conversely with the cessation of the pressure penetrate into its vacuum. An actual extension or cohesion of a definite homogeneous body, which contains no gaps, Leibnitz does not assume, although the Scholastics affirmed it for a long time." On the development of Leibnitz's views from the atomism to which he was at first inclined, but almost immedi- ately rejected, to the dynamic idealism of his monad doctrine, cf. D. Selver, Der Entwicklungsgang d. Leibniz. Monadenlehre bis 1695, Leip- zig, William Englemann, 1885 ; Lasswitz, Gesch. d. Atomistik, 2, 446 sq. Page 17, line 11, " De Seriebus infinitis." Cf. infra, p. 424, note 2. Page 21, line 12, "Fabritius." Cf. infra, p. 102, note 2. The letter of Fabritius to Spinoza here mentioned is found in Spinoza, Opera, ed. Van Vloten and Land, 2, 181-182 ; Philos. Wks. Elwes' translation, 2, 374. Page 26, line 4, " Clerc." Jean Le Clerc, 1657-1736, Professor of Philosophy, Belles-Lettres, and Hebrew in the Remonstrant Seminary at Amsterdam, 1684-1712, and thereafter of Church History, exercised con- siderable influence in the direction of scientific Biblical criticism, and wrote several philosophical works ; but his greatest literary influence was exercised through the serials or reviews of which he was the editor, among which were the " Bibliothfeque universelle et historique," here mentioned; the " Bibliotbfeque choisie," Amsterdam, 1703-1713; and the " Bibliothfeque ancienne et moderne," 1714-1726. Page 28, line 6, "Understanding." Cf, also, infra, p. 41. The term is used in the sense of the Greek voOs, Latin intellectus, to indicate the totality of the human intellectual powers, the Reason in the larger sense of that term, in the language of Kant and his school, Vermuift. Page 42, line 10, "Plato." Schaarschmidt says: "This comparison is to be considered as provisional only, in order to illustrate the opposition between the author's and Locke's point of view by a familiar example. Strictly taken the parallel does not hold good, as may be seen from the 724 LEIBNITZ'S CRITIQUE OF LOCRE addition Leibnitz makes. Aristotle, tliat is to say, — to call to mind only the chief antitheses of the respective theories of knowledge, — assumes before all things principles which are peculiar to the spirit as such, while Locke denies the same ; Plato, again , recognizes experience by means of sense-perception in a wholly different, more real, sense than Leibnitz and affirms in no wise, as Leibnitz, an absolute spontaneity of the presenta- tive power." Page 42, line 13, " Acroamatic." Gf. infra, p. 272, note 1. Page 42, line 5 from bottom, "Aristotle." Schaarschmidt says: "Aristotle has certainly compared the mind (or the Reason — in his language vov%), though not the soul in general, with an unwritten tablet." Cf. Ilepl ^vx^s, Bk. IIL, chap. 4, § 11, Berlin Academy ed., 439 b 31 ; ed. E. Wallace, Cambridge, 1882, p. 159 : Set 5' o'vtws uxnrep iv ypan/jiaTeitfi (^ nr)dkv virdpx^i- ePTeXexeiq, ye-ypaixp-ivov 6irep avp-^aivei. iirl tqv vov. " This meanwhile is by no means to be understood in the sense that thought is merely something taken up from without, the spirit a merely receptive faculty. According to Aristotle, the thinking spirit is rather partly re- ceptive or passive, partly productive or active, as is clear from this same Bk. IIL of the Hepi ^ux^s." C/"., also, Zeller, Philos. d. Griech., 3d ed., 11. , 2 [Vol. 4], 566 sq. Page 43, line 1, "Schoolmen." The Scholastic philosophy, to which Leibnitz frequently refers in this and other works, "assumed," says Schaarschmidt, " a three-fold source of knowledge: 1. Experientia, ex- perience through the senses ; 2. Ratio, the logical faculty of drawing conclusions ; 3. Intellectus, the faculty of ideas, which is precisely the understanding (or spirit) of Aristotle, active for itself from within, not creative out of sense-experience." Page 43, line 4, "Prolepses." The Stoics derived general ideas or conceptions, — Koival ewoiat or irpoKr)\peLs, communes notiones, — like all knowledge, from sensuous perception, explaining them by the persistence and combination of the sense-impressions. They are not to be under- stood, therefore, in the later sense as innate ideas, independent of ex- perience and peculiar to the spirit as such. The Stoic theory was more like Locke's than like Aristotle's ; and according to Plutarch, Placita philosophorum, IV., 11, considered the soul as originally a blank tablet (tabula rasa), upon which the outer world made its impressions. Through Boethius [470-524] the Stoic theory of knowledge became the source of mediaeval nominalism. On the Stoic doctrine of knowledge, cf. Zeller, Philos. d. Griech., 3d ed., Leipzig, 1880, IIL, 1 [Vol. 5], 70-86 ; Benn, Greek Philosophers, 2, 15 ; Windelband-'l\ifts, Hist, of Philos., 202 sq. Page 43, line 14, "Necessary truths." "Leibnitz," says Schaar- schmidt, ' ' here hints at his later more closely grounded division of truths into necessary and factual (contingent). The former are, according to ADDITIONS AND CORRECTIONS 725 Leibnitz, the 'eternal truths of reason,' partly logical laws, partly general notions which belong to the mind as such, and are developed out of itself in order to come into consciousness. The latter, the factual truths, are formed by us through abstraction from experience, and therefore real. To this antithesis, further developed in the second book, Kant joins on that of the so-called a priori and a posteriori thought, in that he assigned to the former the character of necessity and universality, to the latter that of contingency and actuality (particularity)." Page 44, line 13, "Innate." Leibnitz, in here maintaining that expe- rience can never furnish anything absolutely and universally valid, and is therefore incapable of serving as the foundation of the sciences dealing with and requiring absolutely universal fundamental truths, such as Logic, Metaphysics, and Ethics, indicates in the sharpest and clearest manner his opposition to Locke's theory of knowledge. As regards the nature of these pure truths of reason and the method by which they arise in consciousness, Leibnitz assumes and maintains that they are developed by the mind out of itself, and thus come into conscious- ness. Of this self-development, "this transition from potentiality to actuality (a potentia ad actum), ^'' sense-experience furnishes the occasion, but is not the sufficient reason. Leibnitz to this extent, thei'efore, main- tains against Locke the "Innateness of Ideas." But "he oversteps this idealistic principle in so far as he assumes an absolute spontaneity of the understanding, while at the same time that the understanding itself in its development is plainly shown in reciprocal action with experience, which forms the expression of real relation to other beings. In Leibnitz's theory the ' eternal ' and ' necessary ' truths of reason are in substance the principles of all knowledge, and furnish accordingly not only the ground-principles of the formal sciences, like Logic and Mathematics, but also of Metaphysics and Ethics " (Schaarschmidt). Page 44, line 9 from bottom, "The same reasons hold good." Cf. H. S. Reimarus, 1694-1768, AUgemeine Betrachtungen uber die Kunst- triehe der Tliiere, 1760, 4th ed. 1798, chap. 2, who, says Schaarschmidt, has treated the antithesis between the knowledge of man and brute, the investigation of which in our times has led to interesting contro, versies, better than most of the later writers. Leibnitz assumes a specific difference between the souls of brute and man, and does not at all agree with Descartes' view that animals are living but soulless automata. On animal intelligence, cf. Romanes, Animal Intelligence [International Sci- entific Series, Vol. 44, D. Appleton & Co., New York, 1st ed. 1883, 2d ed. 1886]; Mental Evolution in Animals, New York, 1884, D. Appleton & Co. ; Wm. Wundt, Lectures on Human and Animal Psychology, translated from the 2d German edition, by J. E. Creighton and E. B. Titchener, London and New York, 1894, Lectures 23, 24, pp. 340-366. Wundt's Lectures include some criticism of Romanes, as somewhat wanting in critical attitude and exhibiting too much sympathetic imagination. 726 LEIBNITZ'S CRITIQUE OF LOCKE Page 45, line 6 from bottom, " Intellectual ideas." Intellectual, i.e. as opposed to "sensuous" (i.e. belonging to, or arising fi-om, the senses). Leibnitz means to say, says Schaarschmidt, either we fasten our attention upon sense-pictures, whose source is sense-perception, or upon intellect- ual, verstandesmdssigen (formulated, sprachgeformten), ideas, thought- pictures, for whose rise those general ideas, which Kant called Kategories or original notions of the understanding, are requisite ; general ideas which do not arise from experience through the senses, but must belong to our understanding as such and therefore be considered as " innate" or "implanted." Page 46, line 18, " Virtual." I.e. Potential, or, as opposed to " actual," the real-possible. " It is here," says Schaarschmidt, "the faculty through which a substance (the soul) out of its own supreme power goes over into a new condition as for it a new realization. Our soul contains an unend- ing number of possible ideas, as capacities, seeds or traces left behind and remains of former activity, which upon definite occasion it realizes, i.e. calls into consciousness. This Leibnitzian application of the — originally wider — Aristotelian concept of power to the soul has become for modern philosophy in the highest degree weighty and fruitful." Page 46, line 7 from bottom, " Eeminiscence." On the Platonic doc- trine of " reminiscence " or " recollection" {avdixv-qms) ., an essential part of his doctrine of Ideas, cf. Windelband-Tufts, Hist, of Pliilos. pp. 118, 119; Zeller, PMlos. d. Griech., 4th ed. 1889, II., 1 [Vol. 3], 823, 824, 835, 836. In Plato's philosophy the ideas which are the objects of our rational thought were intuited by the soul in its pre-existent and exalted state when it dwelt in the presence of the archetypal forms (irapadelyfiaTa), which Plato called ideas (ei'Sr? or lS4ai). The soul in its earthly life is but dimly, if at all, conscious of these archetypal forms, till the percep- tion of their imperfect copies in corporeal things arouses the slumbering recollection and stimulates the soul to reproduce them in consciousness and with the aid of dialectic again to attain the knowledge of true and ideal reality. Cf, also, Neio Essays, Book I., chap. 1, § 5, Th. (3), infra, p. 79 Page 47, line 8, "Reflection." "Provided," as Schaar.schmidt says, ' ' that Reflection, which with Locke has to do only with the activities of the inner nature as such, receives that further content which embraces the ' eternal ' and ' necessary ' ground-truths, and to which we are in fact led if we keep in mind the presuppositions and modalities under which those activities proceed." Page 47, lines 18, 19, "The book of Boyle against absolute rest." Of infra, p. 324, note 2. The treatise is also found in Vol. 1 of the Latin version of his works. Opera varia, Geneva, 1680, and later, with the title Dissertatio de intestinis motihus particularum solidornm quiescentium, in qua absoluta corporiim quies in disqiiisitionem vacatur. On Boyle, cf. ADDITIONS AND CORRECTIONS 727 Lasswitz, Gesch. d. Atomistik, 2, 261-293 ; Lange, Gesch. d. Materialis- mus, 2d ed. Iserlohn, 1873. 1, 255; English translation, Boston, 2d ed. 1879, 1, 299-306. Page 47, line 21, "Doing away with atoms." Leibnitz rejects atoms in favor of his own monads, because the monads contain in themselves the principle of motion as active force, while the atoms are assumed in conse- quence of a force in movement foreign to them. On Leibnitz's view and its development, c/. Lasswitz, Gesch. d. Atomistik, 2, 470 sq. Page 48, line 7 from bottom, "Confused in the parts." Cf. infra, pp. 120, 317, note 2, 319, 320, 458, 459. Leibnitz's doctrine of " minute perceptions" or, in the philosophical language of to-day, "unconscious mental states," is of the greatest significance in psychology and episte- mology, and never more so than at the present time. For an excellent exposition of it, cf. Windelband-Tufts, Hist, of Philos., pp. 423 sq., 462 sq. Page 48, last line, "Hippocrates." Cf. infra, p. 476, note 2. Page 49, line 15, " SuflBciently distinguished." That is, to reach con- sciousness. The perceptions are not sufficiently strong to call forth a conscious activity of the soul. Page 49, line 12 from bottom, "Author of the most excellent of dic- tionaries." The reference is to Bayle. Gf. infra, p. 507, note 1. Page 49, note 1. The note should read: Cf. Vergil, Georg. IV., 393. Gerhardt's reading : "que" is evidently a typographical error. Erdmann and Janet read : '■'■ qum mox futura," etc.; Jacques, correctly: qiice mox Ventura trahantur." Page 50, line 15, " Pneumatology. " Cf. infra, p. 362, note 2. Page 50, line 20, ^^ Law of Continuity.'''' Cf. infra, p. 334, note 1; p. 552. Page 50, note 3. Add : The correspondence of Leibnitz and Basnage is found in Gerhardt, Leihniz. philos. Schrift., 3, 73 sq. Page 51, line 7, ^^ Numero.''^ Cf., also, infra, p. 332, note 1. Page 51, lines 11-13, "Perfect globes of the second element, born of cubes perfect and original." The reference is to Descartes, Principice Philosophice, Pt. III., §§ 48 sq. Cf, also, New Essays, infra, p. 552, note 1. Mahaffy, Descartes, Blackwood's Philosophical Classics, Edin- burgh, 1881, p. 159, says Descartes' theory of general physics was elabo- rated as regards minerals. This fact perhaps accounts for Schaarschmidt's translation : " des sichtbaren Metalls" and his reference to Prin. Philos., Pt. IV., §§ 70, 75, in his note, ErlHuterung , 400, p. 101, to the passage, New Essays, Bk. IV., chap. 16, § 12, Th., p. 532 of his German transla- tion. Descartes, says Mahaffy, ihid., p. 159, gave special explanation of the growth of the human body, but that of plants and the lower animals was wanting when he died. On Descartes' theory, cf. Lasswitz, Gesch. d. Atomistik, 2, 89. 728 LEIBNITZ'S CRITIQUE OF LOCKE Page 51, lines 19, 20, "Present considerations." While tlie process of abstraction allows us, in order to their better apprehension, to concen- trate our attention for the time on certain properties or attributes of a subject to the exclusion of others, yet we must remember that in so doing we are departing from reality and only partially representing it in con- sciousness. Page 51, line 20. Instead of the rendering: "If it were very well understood," read, after Schaarschmidt, "If we take it as pure and simple gospel," etc. Page 61, line 29, "Some exception." Nature gives us no perfect circles, perfect spheres, etc. Perfect mathematical regularity of form exists only in thought. Page 52, line 7 from bottom, "Strong-minded." That is, the "Free- thinkers," as Leibnitz at other times called them, who thought they might deny immortality itself after the pretended proofs for it given by Scholas- ticism had been disproved. Page 53, line 8 from bottom, " Averroists and some bad Quietists." Cf. infra, p. 581, note 1. The Mystics and Quietists approached very nearly this Averroistic doctrine of a denial of personal immortality. In Leibnitz's time the Mystics and Quietists were especially the followers of Madame Guy on, who was ready "to burst from an overplus of divine grace," and of Ant. Bourignon, on whom cf. infra, p. 599, note 2 ; also, according to Schaarschmidt, Leibnitz's letter CXLIV., Feder, Commercii epistolici Leibnitiani, Hanover, 1805, p. 459. Page 54, note 1. Add: Leibnitz was much interested in the Locke- Stillingfleet controversy, as his correspondence with Thomas Burnett shows. Cf. Gerhardt, Leibniz, philos. Schrift., 3, 149-329, passim, and especially pp. 205, 216, and the two essays, pp. 223-242 ; also Foucher de Careil, Lettres et opuscules inedits de Leibniz, Paris, 1854, Introduc- tion, pp. Ixii sq., and Leibnitz's Bemarques sur le Sentiment de 31. de Worcester et de 31. Locke, ibid., pp. 1-26. The latter piece is identical Avith that published — not therefore for the first time — by Gerhardt, op. cit., 3, 229-242. The controversy, like that of Leibnitz and Arnauld, served to bring Locke to the further explication and limitation of his views. Page 55, lines 16, 17, "French version." That is, by Pierre Coste, with the co-operation of Locke. It appeared in 1700, then in 1729, and again in 1742. Cf. ante, p. 4, note 1. For the correspondence of Leib- nitz and Coste, cf. Gerhardt, Leibniz, philos. Schrift., 3, 377-436. Before Locke published, in 1690, his Essay, he published an abstract, translated into French by Le Clerc in Le Clerc's " Bibliothfeque universelle," Janu- ary, 1688. Cf. ante, p. 4, note 1, and Eraser's Locke''s Essay, 1, 15, note 2. The abstract or " Epitome " is found in Lord King's Life and Correspondence of Locke, new ed., London, 1830, 2, 231-293 ; Bohn's ed., 1858, 1 vol., pp. 365-399. ADDITIONS AND CORRECTIONS 729 Page 55, last line, " Intentional species." Cf. infra, p. 381, note 1. Page 56, line 3. For the Latin verse, cf. Ovid, Tristia, I., 8, 7. Page 59, line 4 from bottom, "Inexplicable qualities." That is, the qualitates occultce of the mediaeval philosophers. Page 60, line 6 from bottom, "Instructive." Leibnitz, as Schaar- schmidt says, "avails himself of Stillingfieet's polemic against Locke, which is of particular interest because it shows Locke's uncertainty in regard to the weighty question of the substantiality of the soul, to add thereto the statement that the soul must be immaterial. Locke himself, so he argues, has admitted that thought is not conceivable as a modifica- tion of matter, or that, in other words, a thinking being cannot be a mere mechanism ; thus the soul is to be considered as something immaterial, since the thought, that God may through a miracle have bestowed, thought upon matter, is an unpermissible subterfuge." For further discussion of the point, cf. Neio Essays, Bk. IV. Page 62, line 10 from bottom, " Miracle pure and simple." Cf. infra, p. 428. The doctrine of a purifying fire through which souls have to pass after death goes back to the early period of the church, but became more prominent and was more generally adopted from the time of Gregory the Great (c. 540-604). Cf. Hagenbach, Hist, of Doctrines, ed. H. B. Smitli, § 141, Vol. 1, p. 373 ; § 206, Vol. 2, p. 126. Clement of Alexandria, Stro- mateis, vii. , 6, says: p6vifxov) , or as Bigg, llie Christian Platonists of Alexandria [Bampton Lectures for 1886], p. 113, tran.slates it, " wise fire," "comes," says Bigg, "from Heraclitus and the Stoics.") Cf. Bigg, op. cit., 295; Hagenbach, op. cit., § 77, 1, 222. And Augustine, De Civit. Dei, Bk. XXL, chap. 10, Benedictine ed., Paris, 1685, Vol. 7, p. 631, says: "Cur enim non dicamus, quamvis miris, tamen veris modis etiani spiritus incorporeos posse poena corporalis ignis affligi, si spiritus homi- num, etiam ipsi profecto incorporei, et nunc potuerunt includi corporali- bus membris, et tunc poterunt corporum suorum vinculis insolubilitei alligari ? " i.e. " For why may we not assert that even immaterial spirits may, in some extraordinary way, yet really be pained by the punishment of material fire, if the spirits of men, which also are certainly immaterial, are both now contained in material members of the body, and in the world to come shall be indissolubly united to their own bodies ? " ( The City of God, 2, 435, translated by Rev. Marcus Dods, M.A., T. & T. Clark, Edinburgh, 1871). In chapter 7, after having in previous chapters cited many real or supposed facts from the natural world in support of the pos- sibility at least of the view, he admits that it is miraculous and beyond our 730 LEIBNITZ'S CRITIQUE OF LOCKE knowledge, and maintains tlie omnipotence of God as the ultimate reason for belief in miracles. Thos. Aquinas, Summa Theol, Qusest. 70, Art. 3, Concl.,says: " Respondeo : Dicendum quod ignis inferni [i.e. purgato- rial fire, according to the context] non sit metaphorice dictus, nee ignis imaginarius, sed verus ignis corporeus," etc. Only those requiring purga- tory go there, according to St. Thomas, cf. Qusest. 69, Art, 2. Bellamin, 154-2-1621, in his De Purgatorio, chaps. 10-12, investigates the method of the purgatorial fire and follows Augustine in teaching that it is mate- rial and miraculous in its action upon the soul. Page 63, line 10 from bottom, "Demons or goblins." "Leibnitz is perhaps here thinking,' ' says Schaarschmidt, ' ' of the so-called Spirits of the Elements (Elementargeister'), of which the 'philosophers and physi- cians of the past,' especially Theoph. Paracelsus [cf. infra, p. 645, note 1], had treated, both in his Philosophia sagax, and in a special book, De nymphis, sylphis, pygmoeis et salamandris, or even of the ' spiritus famili- aris ' of others, as of the Italian philosopher and physician Hieronymus . Cardanus [cf. infra, p. 566, note 1], who in his interesting autobiography [De vita prop7'ia'], chap. 47, discusses the subject and at the same time narrates marvellous experiences of his own past life." Page 63, note 3.. Add : In the Philos. Mosaica, and also in his Utriusque Cosmi — Metaphysica, physica atque technica Historia, Oppen- heimii, 1617 fol., "God appears," says Schaarschmidt, "as the ani- mating and moving principle of things, in that all power streams forth in a miraculous way from him into matter, in order afterwards to turn back again from the thereby occurring differentiation to unity." On Pludd, cf. Lasswitz, Gesch. d. Atomistik, 1, 329 ; Stockl, Gesch. d. Philos. d. Mittelalters, III. [Vol. 4], 472-476. Page 64, note 1. Add : Prof. A. C. Fraser, in his edition of Locke's Essay concerning Human Understanding, Oxford, 1894, follows Coste's French version in separating the introductory chapter from the First Book, and making, with Leibnitz here, but three chapters in Bk. I. Page 64, note 2, line 2. After "1674," add: new ed. with notes by Bouillier, Paris, 1880, 2 vols. ; line 4, after " Bernier," add : On Gassendi, cf Stockl, Gesch. d. Philos. d. Mittelalters, III. [Vol. 4] 316-327 ; Lange, Gesch. d. 3Iaterialismus, 2d ed., Gerlohn, 1873, 1, 223-234, Eng. trans. 2d ed. 1, 253-269 ; Lasswitz, Gesch. d. Atomistik, 2, 126-188. On Bernier's later divergence from Gassendi, cf. ibid. 2, 504. Page 65, line 13. Instead of "Doctors," read: "scholars." Page 65, note 1. Add: Lady Masham, 1659-1708, was one of Locke's most intimate and truest friends, kept him by her at her country seat at Oates and nursed him in his last illness. Cf. Gerhardt, Leibniz, philos. Schrift. 3, 365. Lady Masham presented Leibnitz with a copy of her father's Intellectual System, as appears by his letter of March 29, 1704, cf. Gerhardt, 3, 338. ADDITIONS AND CORRECTIONS 731 Page 65, note 3. Add : The objections referred to in the text are the objectiones quintce against Descartes' Meditationes de prima philosophia, "which indeed," as Schaarschmidt says, "contain a series of very acute objections and gave Descartes much trouble." The Cinquiemes Objec- tions of "Gassendy," with the lieponses of Descartes thereto, are found in Cousin, (Etivres de Descartes, 2, 89 sq., 241 sq. Page 66, line 6, " Inclined towards ethics." Leibnitz, who to a certain extent may be considered as giving utterance to his own views in thfe person of Theophilus, here throws out a hint to be well taken to heart as regards his own course of development. As a natural consequence of his early studies in jurisprudence, Leibnitz was led to a deeper study of ethical conceptions, and in like manner his study of Descartes made him acquainted with the problems of mathematics and physics, which he thoroughly examined only later after his sojourn in Paris. Page 66, lines 13, 14, "No longer a Cartesian." Cf. the entire context, pp. 66-69, also Leibnitz's letter to Remond de Montmort, January 10, nU,GerhsiTdt, Leibniz, philos. Schrift. 3, 606-607, Erdmann, 701-702, in which Leibnitz gives a brief account of his own philosophical studies and development, including, Plato, Aristotle, and the Scholastics and thence passing to the moderns, rejecting the " substantial forms " for the mechan- ism of the Cartesian system, and then developing his own doctrine of Pre- established Harmony. The diificulties and controversies within the Cartesian School and against it led Leibnitz to his own doctrine, and he remarks in his Considerations sur le Principe de Vie, 1705, Gerhardt, 6, 540, Erdmann, 430, as also in the letter here cited, that if Descartes had known that Nature conserves not only the same force, but also the same total direction in the laws of motion, he would himself have come to the system of pre-established harmony. Cf. W. Sigwart, Die Leibniz'' sche Lehre v. d. prcistabilirten Harmonie. Tiibingen, 1822, pp. 110-112, 117, 118, 121, 132, etc. For Leibnitz against Descartes and Cartesianism, cf. Gerhardt, 4, 265-406 ; also. Stein, Leibniz u. Spinoza, 60 sq. Page 66, line 17, "New System." That is. The System of Pre- established Harmony, in explanation and defence of which Leibnitz published in the journals mentioned many essays, most, if not all, of which are mentioned later in either the text of the New Essays or notes thereto. "Leibnitz," as Schaarschmidt well says, "can truly boast that he has turned to account for his own system moments of all the doctrines named in the text," it being "a characteristic feature of Leibnitz's thought to ascribe a relative truth to each philosophic system and accordingly to wish to extract from it a good side in order, by harmonizing these different elements, to bring to pass the possibly best view of the world." Cf. Leibnitz's letter to Remond de Montmort, January 10, 1714, Gerhardt, Leibniz, philos. Schrift. 3, 606, Erdmann, 701 : " Outre que j'ay eu soin de tout diriger a I'edification, j'ay tache de d^terrer et de r6unir la v^rite ensevelie et dissip^e sous les opinions des differentes Sectes des Philosophes, 732 LEIBNITZ'S CRITIQUE OF LOCKE et je crois y avoir adjoute quelque chose du mien pour faire quelques pas en avaut." Page 66, note 1. Add: Geronimo Rorario, 1485-1566, an Italian litterateur, Nuncio of Clement VII. at the Court of Ferdinand, King of Hungary, maintained, against the Cartesians and the followers of Aristotle, that the beasts have reason and make better use of it than man. His book, Quod animalia bruta scepe ratione utantur melius homine, appeared first in 1648, then 1654 at Amsterdam. Page 67, lines 3, 4, " Life and perception in all things." The doctrine of the universal soulhood (Allbeseeltheit) goes back to the world-soul of Plato, as developed especially by Plotinus. (c/. Windelband-Tufts, Hist, of Fhilos., 245 sq.), and is connected in part therewith, and partly with the pantheistic tendencies represented, for example, by the Averroists (c/. New Essays, infra, p. 581, note 1). Leibnitz rejects both errors by his Monadology, which conceives the universal soulhood of substances in an individual and not in a pantheistic way. In modern times the doctrine appears in Giordano Bruno, 1548-1600 (c/. Bella Causa, Vol. II., pp. 239- 241, ed. A. Wagner, Leipzig, 1829, new ed. by P. de Lagarde, 2 vols., Gottingen, 1888, German trans, by Lasson, Berlin, 1872, in J. H. v. Kirch- mann's Philos. Bihliothek, Vol. 53), and in Jacob Boehme (cf. infra, p. 298, note 1). On the doctrine as found in Bruno and Boehme, cf. Windelband-Tufts, op. cit., 367 sq., 373 sq. Spinoza. Ethica, Pt. II., Prop. XIII., Scholium, ed. Van Vloten and Land, 1, 86-88 ; Elwes' trans., 2, 92, also gives expression to the same thought. Page 67, line 5, " Countess of Connaway." Anne — Viscountess Con- way — died Feb. 23, 1678-9, was a metaphysician and an earnest student of Plato, Plotinus, Philo Judseus and the " Kabbala Denudata." In spite of never-ceasing sufferings from a severe headache lasting till her death, she pursued her metaphysical studies with extraordinary devotion and assiduity. Her physician, Francis Mercury vau Helmont {cf. infra, 242, note 2), encouraged her in this course. She was very friendly with H. More and corresponded with him on philosophical and theological topics. She wrote many works of which only one has been printed : Opuscula philosophica quibus rontinentur principia philosophice antiquissimm et recentissimce, Amsterdam, 1690. It was the first in a collection of philo- sophical treatises appearing in Latin in that year at Amsterdam, translated as "a work by a certain English countess, 'learned beyond her sex,' " and ascribed by Leibnitz in a German literary journal, on the authority of Van Helmont, to the Countess of Conway. The treatise was re-trans- lated into English and published with the title The Principles of the Most Ancie7it and Modern Philosophy, etc., London, 1692, Bvo. Page 67, note 1. Add: On Campanella, cf. Stockl, Gesch. d. Philos. d. Mittelalters, III. [Vol.4.], 343-366 ; Lasswitz, Gesch. d. Atomistik, 1, 340- 342. Page 67, note 2. Add : On Van Helmont, cf. infra, p. 242, note 2 ; on H. More, cf. infra, pp. 380, note 1 ; 382, note 2, and addition thereto, infra p. 768. ADDITIONS AND CORRECTIONS 733 Page 67, note 3. Add: Further references to Archteus in Leibnitz's writings are : Specimen Dynamicum, Gerhardt, Leibniz, math. Schrift., II., 2 [Vol. 6], 242, also infra, Appendix, p. 679 ; Hypothesis phys. nova, Theoria motets concreti, § 60, Gerhardt, Leibniz, philos. Schrift. 4, 217; math. Schrift., IT., 2 [Vol. 6], 57; Dutens, Leibnit. op. om., 2, Pt. II., o3 ; Leibnit. Animadversiones circa Assertiones aliquas Theorice Medicce veroi Clar. Stahlii, Dutens, op. cit., 2, Pt. II., 136. Of, also, Windel- band-Tufts, Hist, of Philos. 371 sq. Page 68, line 10, "■ 3Iorte carent anivuK.'" Cf. Ovid, Metamorphoses, 15, 158. Page 68, line 20, "Spontaneity." Leibnitz ascribes absolute .spon- taneity to the soul, to which the activity of the body perfectly corresponds through the Pre-established Harmony, and therefore neither influences nor disturbs it. Page 68, line 7 from bottom, "Epitome." That is hi the Monad, each monad representing in itself and to itself the entire universe. Leibnitz constantly recurs to this thought, which is one of the chief points of his system. Cf. Systeme nouveau de la nature, § 16 ; Monadologie, § 65, etc. Page 69. note 1. Add: also G. Croom Robertson, Philos. Iiemain. 1 : toCto ydp iffTiv 6 xP^^'o^i d.pidp.o's Kivf](TediTov (^oi/dkv yap 6vofxa Koivbv e7r' dfxcpoiv) a'v^r](7is Kal cpOicns tov 5i yev-qrov Kal (p.dapTOV yevecns Kal (p6opd, tov 5k (popTjTov