A BIOGRAPHICAL HISTORY OF PHILOSOPHY. PART I. ANCIENT PHILOSOPHY. THE BIOGRA PHICAL HISTORY OF PHILOSOPHY, FROM ITS ORIGIN IN GREECE DOWN TO THE PRESENT DAY. BY GEORGE HENRY LEWES.' Man is not born to solve the mystery of Existence; but he must nevertheless attempt it, in order that he may learn how to keep within the limits of the Knowable."-GoETHE. "For I doubt not through the ages one increasing purpose runs, And the thoughts of men are widened by the process of the suns." TENNYSON. LIBRARY EDITION, MITCH ENLARGED AND TOROUJGIILY REVISED. NEW YORK: D. APPLETON AND COMPANY, 346 & 348 BROADWAY. I DCCC LyII. PREFACE. THIS new edition may almost be considered as a new work, so many are the additions and so extensive the alterations. Seven new names have been added to the list of philosophers,-ABELARD, ALGAZZALI, GIORDANO BRUNO, HARTLEY, DARWIN, CABANIS, and GALL. An Introduction, setting forth the distinguishing characteristics of Philosophy and Science, replaces the original Introduction. Under the heads of SOCRATES, the SOPIISTS, ARISTOTLE, BACON, SPINOZA, HUMEE, CONDILLAC, KANT, and ECLECTICISM, considerable additions and alterations will be found; and, throughout, the revision has been such that scarcely a paragraph remains unaltered. The work was written ten years ago, and was addressed to a popular audience. Ten years have not been without their influence on. the historian; and moreover, the success of the work has so greatly exceeded any thing that could reasonably have been anticipated-not only in respect to sale, but in the directions of its influence-that on undertaking this Library Edition I felt the necessity of modifying both the aim and scope of the work. A graver audience was to be addressed, a graver tone adopted. Without forgetting the general public, I had now to think also of what students would require. Many polemical passages, many ex iv PREFACE. tracts, and some digressions, have been removed; and the space thus gained has prevented the new matter from swelling the work to an inconvenient size. Many references and other bibliographical details have been added, although the principle of abstinence from unnecessary citation has still been preserved. The labor bestowed on this Edition will, I hope, render it more worthy of public acceptance. To my friend, the Rev. W. G. Clark, of Trinity College, Cambridge, an acknowledgment is due for the kindness with which he permitted me to profit by his accomplished scholarship and taste, in the revision of the proofs; but while thanking him publicly for his many suggestions and corrections, I must exonerate him from every iota of responsibility either as to the opinions or the statements in this volume. The Introduction explains the purpose of this History and the principles of its composition; let me therefore only add here that, although availing myself of the labors of other historians and critics, I have not restricted myself to them. The works of the vie ions plb;osophers, with rare exceptions, have been studied at first hand, and have furnished the extracts and abstracts; that is to say, I have either collected the passages mysel?, or have verified them by reference to the originals, in almost all cases. While, therefore, this History makes no pretension to a place beside the many erudite and comprehensive Histories previously published, it claims to be regarded as something very different from a mere compilation. The novelty of its conception made direct acquaintance with the originals indispensable. Having to exhibit the Biography of Philosophy in its rise, growth, and development, I could not always have PREFACE. V drawn my material from writers who had no such aim; many of the passages most significant for my purpose being totally disregarded by my predecessors. In another respect also I have innovated, namely, in the constant interweaving of criticism with exposition. This was necessary to my purpose of proving that no metaphysical system has had in it a principle of vitality; none has succeeded in establishing itself, because none deserved to succeed. In this way I have been led to express every conclusion to which the study of metaphysical problems has led me; in some places-especially in the refutation of Sensationalism, and in the physiological discussion of psychological questionsI have been forced to content myself with a brief and imperfect exposition of my own views; and the reader is requested to regard them rather in their bearing as criticisms, than as expressing what I have to say on such difficult topics. The following list comprises some of the many general Histories which the student will find useful, should he desire anipler detail than was consistent with the size and plan of this volume: In English.-Ritter, History of Philosophy, 3 vols.; Tennemann, Manual of the History of Philosophy, 1 vol.; Victor Cousin, Introduction to the I~istory of Philosophy, 1 vol.; IMorell, History of Speculative Philosophy in the Nineteenth Century, 2 vols. (2d edition, much improved). In French.-Degerando, Histoire Comparee des Systemes de Philosophie, 4 vols. (2d edition); Renouvier, J3anuel de la Philosophic Ancienne, 2 vols., and Manuel de la Philosophie Ioderne, 1 vol.; Damiron, Histoire de la Philosophie en France au Vi PREFACE. XIX Siecle, 1 vol.; Galuppi, Lettres Philosophiques, 1 vol. In German.-Ritter, Geschichte der Philosophie, 9 vols.; Tennemann, Geschichte der Philosophie, 11 vols.; Hegel, Geschichte der Philosophie, 3 vols.; Zeller, Die Philosophie der Griechen, 2 vols.; Brandis, Geschichte der Griechisch-R5mischen Philosophie, 2 vols. CONTENTS. PART I.-ANCIENT PHILOSOPHY. PAGE INTRODUCTION...................................................... Xi FIRST EPOCH. Speculations on the Nature of the Universe. CHAPTER I. THE PHYSICISTS.-Thales.-Anaximenes.-Diogenes of A pollonia....................................................... 1 CHAPTER II. THE MATHEMATICIANS.-Anaximander of Miletus.-Pythagoras.-Philosophy of Pythagoras.-Translations from Aristotle's M etaphysics..................................................... 10 CHAPTER III. THE ELEATICS. —Xenophanes.-The Philosophy of Xenophanes.-Parmenides.-Zeno of Elea........................ 37 SECOND EPOCH. Speculations on the Creation of the Universe, and on the Origin of Knowledge. Heraclitus.-Anaxagoras.-Empedocles.-Democritus................ 63 THIRD EPOCH. Intellectual Crisis.-The Insufficiency of all Attempts towards a Solution of the Problem of Existence, as well as that of Knowledge, produces the Sophists. THE SOPHISTS.-What were they?-Protagoras....................... 102 FOURTH EPOCH. A New Era opened by the Invention of a NVew Method. SocRATES.-The Life of Socrates.-Philosophy of Socrates............. 122. FIFTH EPOCH. Partial Adoption of the Socratic Method. The Megaric School.-Euclid.-The Cyrenaic School.-Aristippus.-The Cynics.-Antisthenes and Diogenes............................. 169 viii CONTENTS. SIXTH EPOCH. Complete Adoption and Application of the Socratic Method. PLATO.-Life of Plato.-Plato's Writings: their Character, Object, and Authenticity.-Plato's Method.-Plato's Ideal Theory.-Plato's Psychology.-Summary of Plato's Dialectics.-Plato's Theology and Cosmology.-Plato's View of the Beautiful and the Good.-Plato's Ethics.......................................................... 186 SEVENTH EPOCH. Philosophy again reduced to a System: Close of the Socratic Movement.Aristotle. CHAPTER I. ARISTOTLE.-Life of Aristotle.-Aristotle's Method.Aristotle's Logic. —Aristotle's Metaphysics....................... 241 CHAPTER II. SUMMARY OF THE SOCRATIC MOVEMENT............... 266 EIGHTH EPOCH. Second Crisis of Greek Philosophy: the Skeptics, Epicureans, Stoics, and the 2ew Academy. CHAPTER I. THE SKEPTICS.-Pyrrho............................ 268 CHAPTER II. THE EPICUREANS.-Epicurus....................... 274 CHAPTER III. THE STOICS.-Zeno................................. 281 CHAPTER IV. THE NEW ACADEMY.-Arcesilaus and Carneades..... 293 CHAPTER V. SUMMARY OF THE EIGHTH EPOCH.................... 305 NINTH EPOCH. Philosophy allies itself with Faith: the Alexandrian Schools. CHAPTER I. RISE OF NEO-PLATONISM.-Alexandria.-Philo......... 307 CHAPTER II. ANTAGONISM OF CHRISTIANITY AND NEO-PLATONISM.-Plotinus.-The Alexandrian Dialectics.-The Alexandrian Trinity.The Doctrine of Emanation...................................... 314 CHAPTER III. PROCLUS........................................... 332 CONCLUSION OF ANCIENT PHILOSOPHY................................ 336 PART II.-MODERN PHILOSOPHY. TRANSITION PERIOD. FROM PROCLUS TO BACON.-Scholasticism.-Life of Abelard.-Philosophy of Abelard.-Algazzali.-Revival of Learning.-Giordano Bruno.... 343 CONTENTS. ix FIRST EPOCH. Foundation of the Inductive Method. The Life of Bacon.-Bacon's Method.-The Spirit of Bacon's Method.Was the Method New and Useful............................... 898 SECOND EPOCH. Foundation of the Deductive Method. CHAPTER I. DESCARTES.-Life of Descartes.-The Method of Descartes.-Application of tie Method.-Is the Method True......... 435 CHAPTER II. SPINOZA.-Spinoza's Life.-Spinoza's Doctrine........ 456 CHAPTER III. FIRST CRISIS IN MODERN PHILOSOPHY................. 493 THIRD EPOCH. Philosophy reduced to a Question of Psychology. CHAPTER I. HOBBES.......................................... 495 CHAPTER II. LocKE.-Life of Locke.-On the Spirit of Locke's Writings.-Locke's Method.-The Origin of our Ideas —Elements of Idealism and Skepticism in Locke.-Locke's Critics............... 506 CIAPTER III. LEIBNITZ.......................................... 541 CHAPTER IV. SUMMARY OF THE THIRD EPOCH..................... 546 FOURTH EPOCH. The Subjective Nature of Knowledge leads to Idealism. BERKELEY.-The Life of Berkeley.-Berkeley and Common Sense.Idealism........................................................ 548 FIFTH EPOCH. The Arguments of Idealism carried out into Skepticism. HUME.-Life of Hume.-Hume's Skepticism.-Hume's Theory of Causation............................................................ 570 SIXTH EPOCH. The Origin of RKowledge reduced to Sensation by the confusion of Thought with Feeling: the Sensational School. CHAPTER I. CONDILLAC.-Life of Condillac.-Condillac's System... 589 CHAPTER II. HARTLEY.-Life of Hartley.-Hartley's System........ 603 CHAPTER III. DARWIN............................................. 609 SEVENTH EPOCH. Second Crisis: Idealism, Skepticism, and Sensationalism producing the Reaction of Common Sense. REID.............................................................. 618 1* X CONTENTS. EIGHTH EPOCH. Recurrence to the Fandamental Question respecting the Origin of Knowledge. KANT.-Life of Kant.-Kant's Historical Position.-Kant's Psychology.Consequences of Kant's Psychology.-Examination of Kant's Fundamental Principles.......................................... 630 NINTH EPOCH. Ontology reasserts its Claim.-The Demonstration of the Subjectivity of Knowledge once more leads to Idealism. CHAPTER I. FICHTE.-Life of Fichte.-Fichte's Historical Position.Basis of Fichte's System.-Fichte's Idealism.-Application of Fichte's Idealism....................................................... 675 CHAPTER II. SCHELLING.-Life of Schelling.-Schelling's Doctrines.. 705 CHAPTER III. HEGEL.-Life of Hegel.-Hegel's Method.-Absolute Idealism.-Hegel's Logic.-Application of the Method to Nature and History, Religion and Philosophy.............................. 715 TENTH EPOCH. Psychology seeking its Basis in Physiology. CHAPTER I. CABANIS............................................ 740 CHAPTER II. PHRENOLOGY.-Life of Gall.-Gall's Historical Position. -Cranioscopy.-Phrenology as a Science.......................... 749 ELEVENTH EPOCH. Philosophyfinally relinquishing its Place in favor of Positive Science. CHAPTER I. ECLECTICIS M......................................... 769 CHAPTER II. AUGUSTE COMTE..................................... 776 CONCLUSION..................................................... 788 IND EX........................................................... 791 INTRODUCTION. ~ I. ON THE DISTINCTION BETWEEN PHILOSOPHY AND SCIENCE. PHILOSOPHY is everywhere in Europe fallen into discredit. Once the pride and glory of the greatest intellects, and still forming an important element of liberal culture, its present decadence is attested no less by the complaints of its few followers than by the thronging ranks of its opponents. Few now believe in its large promises; still fewer devote to it that passionate patience which is devoted by thousands to Science. Every day the conviction gains strength that Philosophy is condemned, by the very nature of its impulses, to wander forever in one tortuous labyrinth within whose circumscribed and winding spaces weary seekers are continually finding themselves in the trodden tracks of predecessors, who, they know, could find no exit. Philosophy has been ever in movement, but the movement has been circular; and this fact is thrown into stronger relief by contrast with the linear progress of Science. Instead of perpetually finding itself, after years of gigantic endeavor, returned to the precise point from which it started, Science finds itself year by year, and almost day by day, advancing step by step, each accumulation of power adding to the momentum of its progress; each evolution, like the evolutions of organic development, bringing with it a new functional superiority, which in its turn becomes the agent of higher developments. Not a fact is discovered but has its bearing on the whole body of doctrine; not a mechanical improvement in the construction of instruments but opens fresh sources of discovery. Onward, and forever onward, mightier and forever mightier, rolls this wondrous tide of discovery, and the "thoughts of men are widened by the process of the suns." While the first principles of Philosophy are to this day as much a matter of dispute as they were two thousand years ago, the first principles of Science are securely established, Xii INTRODUCTION. and form the guiding lights of European progress. Precisely the same questions are agitated in Germany at the present moment that were agitated in ancient Greece; and with no more certain Methods of solving them, with no nearer hopes of ultimate success. The History of Philosophy presents the spectacle of thousands of intellects-some the greatest that have made our race illustrious-steadily concentrated on problems believed to be of vital importance, yet producing no other result than a conviction of the extreme facility of error, and the remoteness of any probability that Truth can be reached.* The only conquest has been critical, that is to say, psychological. Vainly do some argue that Philosophy has made no progress hitherto, because its problems are so complex, and require more effort than the simpler problems of Science; vainly are we warned not to conclude from the past to the future, averring that no progress will be made because no progress has been made. Perilous as it must ever be to set absolute limits to the future of human capacity, there can be no peril in averring that Philosophy never will achieve its aims, because those aims lie beyond all human scope. The difficulty is impossibility. No progress can be made because no certainty is possible. To aspire to the knowledge of more than phenomena,-their resemblances, co-existences, and successions,-is to aspire to transcend the inexorable limits of human faculty. To know more, we must be more. The reader will have perceived that I use the word Philosophy in some restricted sense; and as this is the sense which will be attached to it throughout the present History, an explanation becomes requisite. In all countries the word Philosophy has come to be used with large latitude, designating indeed any and every kind of speculative inquiry; nay, in England, as Hegel notices with scorn,t microscopes, telescopes, barometers, and balances, are freely baptized " philosophical instruments;"-New* Compare Kant in the Preface to the 2d ed. of the Kritik der reinen Vernunft: "Der Metaphysik... ist das Schicksal bisher noch so giinstig nicht gewesen dass sie den sichern Gang einer Wissenschaft einzuschlagen vermogt hatte; ob sie gleich lter ist als alle iibrige... Es ist also kein Zweifel dass ihr Verfahren bisher ein blosses Herumtappen, und, was das Schlimmste ist, unter hlossen Begriffen gewesen soy." t Geschichte der Philosophie, i. 72. INTRODUCTION. xiii ton is called a philosopher; and even Parliamentary proceedings get named philosophical;-so wide a range is given to this word. Such expressions may be criticised, but no criticism 6will root them out of our language; and it is futile to argue against whatever has become thus familiar and extensive. Nevertheless, when any one undertakes to write a History of Philosophy, he must define the limits of his undertaking; and as I have not the slightest intention of including either microscopic inquiries, or Parliamentary debates, within my narrative, but of rigorously limiting it to such topics as are comprised in other Histories of Philosophy, it is indispensable to define the word " Philosophy," by limiting it exclusively to Metaphysics, in direct antithesis to Science. This is the sense it bears in all other Histories; except that the demarcation from Science is not always rigorously made. In the early days of speculation all Philosophy was essentially metaphysical, because Science had not distinctly emerged. The particular sciences then cultivated, no less than the higher generalities on Life, Destiny, and the Universe, were studied on one and the same Method; but in the course of human evolution a second Method grew up, at first timidly and unconsciously, gradually enlarging its bounds as it enlarged its powers, and at last separating itself into open antagonism with its parent and rival. The child then destroyed its parent; as the mythic Zeus, calling the Titans to his aid, destroyed Saturn and usurped his throne. Observation and Experiment were the Titans of the new Method. There are many who deplore the encroachment of Science, fondly imagining that Philosophy would respond better to the wants of man. This regret is partly unreasoning sentiment, partly ignorance of the limitations of human faculty. Even among those who admit that Philosophy is an impossible attempt, there are many who think it should be persevered in, because of the lofty views it is supposed to open to us. This is as if a man desirous of going to America should insist on walking there, because journeys on foot are more poetical than journeys by rail and steam; in vain is he shown the impossibility of crossing the Atlantic on foot; he admits that grovelling fact, but his lofty soul has visions of some mysterious overland route by which he will pass. He dies without reaching America, but XiV INTRODUCTION. to the last gasp he maintains that he has discovered the route on which others may reach it. 0 Reader! let us hear no more of the lofty views claimed as the exclusive privilege of Philosophy. Ignorant indeed must the man be who nowadays is unacquainted with the grandeur and sweep of scientific speculation in Astronomy and Geology, or who has never been thrilled by the revelations of the Telescope and Microscope. The heights and depths of man's nature, the heights to which he aspires, the depths into which he searches, and the grander generalities on Life, Destiny, and the Universe, find as eminent a place in Science as in Philosophy, with the simple difference that they are less vague and are better founded. And even were we compelled to acknowledge that the lofty views of Philosophy were excluded from Science, the earnest mind would surely barter such loftiness for Truth. Our struggle, our passion, our hope, is for Truth, not for loftiness; for sincerity, not for pretence. If we cannot reach certain heights, let us acknowledge them to be inaccessible, and not deceive ourselves and others by phrases which pretend that these heights are accessible. Bentham warns us against "question-begging epithets;" and one of these is the epithet "lofty," with which Philosophy allures the unwary student. As a specimen of the sentiment so inappropriately dragged in to decide questions not of sentiment but of truth, consider the following passage delivered from the professorial chair to students whose opinions were to be formed: "A spirit of most misjudging contempt has for many years become fashionable towards the metaphysical contemplations of the elder sages. Alas! I cannot understand on what principles. Is it, then, a matter to be exulted in that we have at length discovered that our faculties are only formed for earth and earthly phenomenal Are we to rejoice at our own limitations, and delight that we can be cogently demonstrated to be prisoners of sense and the facts of sense? In those early struggles after a higher and more perfect knowledge, and in the forgetfulness of every inferior science through the very ardor of the pursuit, there is at least a glorious, an irresistible testimony to the loftier destinies of man; and it might almost be pronounced that in INTRODUCTION. XV such a view, their very errors evidence a truth higher than all our discoveries can disclose! When Lord Bacon, with his clear and powerful reasonings, led our thinkers from these ancient regions of thought (then newly opened to the modern world) to the humbler but more varied and extensive department of inductive inquiry, I represent to myself that angel-guide, all light and grace, who is pictured by our great poet as slowly conducting the first of our race from Paradise, to leave him in a world, vast, indeed, and varied, but where thorns and thistles abounded, and food-often uncertain and often perilous-was to be gained only by the sweat of the brow and in the downcast attitude of servile toil."* It would be an insult to the reader's understanding to answer the several absurdities and" question-begging" positions of this passage, which however is a typical specimen of much that may be met in modern writers; all that I feel called upon to notice is the opening sentence. Contempt for the metaphysical speculations of the elder sages is the last feeling I should acknowledge, however erroneous I may believe them to be. They were the precursors of modern Science. Without them we should have been in darkness. The forlorn hope of Humanity can never be an object of contempt. We follow the struggles of the early thinkers with intense interest, because we trace in their defeats the causes of future victory. The historical connection of Science with Philosophy, and the essential differences between them, which led to their separation and the final neglect of Philosophy, will be understood better when the characteristics of the two are clearly set forth. The object of both is the same, namely, Explanation of all phenomena. Their characteristic differences, therefore, do not lie in the thing sought, so much as in the Method of search. I have met with no satisfactory statement of these characteristic differences; and the readiest way I can think of to make them intelligible, will be to exhibit the Metaphysical and Scientific Methods in * Archer Butler, Lectures on the Hist. of Ancient Philosophy, ii. 109. The varied and accurate erudition of Mr. W. H. Thompson's notes to these lectures gives these volumes their chief value. Xvi INTRODUCTION. operation on the search after the causes of the same phenomenon; for instance, that of " Table-turning."* A few persons stand round a table, gently resting their hands on it, but sedulously careful not to push in any direction. In a little while the table moves, at first slowly, afterwards with growing velocity. The persons are all of the highest respectability, above suspicion of wilful deceit. The phenomenon is so unexpected, so unprecedented, that an explanation is imperiously demanded. We have here an illustration of the origin of Philosophy. In presence of unusual phenomena, men are unable to remain without some explanation which shall render intelligible to them how the unusual event is produced. They are spectators merely; condemned to witness the event, unable to penetrate directly into its causes, unable to get behind the scenes and see the strings which move the puppets, they guess at what they cannot see. In this way Man is interpres Naturce. Whether he be metaphysician or man of science, his starting-point is the same; and they are in error who say that the metaphysician differs from the man of science in drawing his explanation from the recesses of his own mind in lieu of drawing it from the observation of facts. Both observe facts, and both draw their interpretations from their own minds. Nay, strictly considered, there is necessarily, even in the most familiar fact, the annexation of mental inference-something added by the mind, suggested by, but not given in, the immediate observation. Facts are the registration of direct observation and indirect inference, congeries of particulars partly sensational, partly ideal. The scientific value of facts depends on the validity of the inferences bound up with them; and hence the profound truth of Cullen's paradox, that there are more false facts than false theories current. The facts comprised in the phenomenon of " Table-turning" * There is difficulty in selecting a suitable illustration, because if an undisputed scientific truth be chosen, the reader may not be able to place himself at the metaphysical point of view: whereas if a disputed point be chosen he may perhaps himself adopt the metaphysical explanation, and refuse to acknowledge the scientific explanation. "Table-turning" escapes both objections. The mania is sufficiently recent to permit our vividly realizing the mental condition of the theorists; and the error is sufficiently exploded to admit of being treated as an error. INTRODUCTION. Xvii are by no means so simple as they have been represented. Let us however reserve all criticism, and fix our attention solely on the phenomenon, which, expressed in rigorous terms, amounts to this:-the table turns; the cause of its turning unknown. To explain this, one class of metaphysical minds refers it to the agency of an unseen spirit: connecting this spiritual manifestation with others which have been familiar to him, the interpreter finds no difficulty in believing that a spirit moved the table; for the movement assuredly issued fiom no human agency; the respectable witnesses declare they did not push. Unless the table moved itself, therefore, the conclusion must be that it was moved by a spirit. Minds of another class gave another explanation, one equally metaphysical, although its advocates scornfully rejected the spiritual hypothesis. These minds were indisposed to admit the existence of Spirits as agents in natural phenomena; but their interpretation, in spite of its employing the language of science, was as utterly removed from scientific induction as the spiritual interpretation they despised. They attributed the phenomenon to Electricity. Connecting this supposed electrical manifestation with some other facts which seemed to warrant the belief of nervous action being identical with electricity, they had no hesitation in affirming that electricity streamed from the tips of the fingers; and it was even suggested by one gentleman that " the nervous fluid had probably a rotatory action, and a power of throwing off some of its surplus force." Each of these explanations was very widely accepted by the general public, although few persons of any reasoning power now accept them. The obvious defect in both lies in the utter absence of any guarantee. We ought to be satisfied with no explanation which is without its valid guarantee. Before we purchase silver spoons we demand to see the mark of Silversmiths' Hall, to be assured that the spoons are silver, and not plated only. The test of the assayer dispels our misgivings. In like manner when the motion of a table is explained by spiritual agency, instead of debating whether the spirit bring airs from heaven or blasts from hell, we suffer our skepticism to fall on the preliminary assumption of the spirit's presence. Prove the pres Xviii INTRODUCTION. ence of the spirit, before you ask us to go further. We may admit that, ifpresent, the spirit is capable of producing this motion of the table; but we cannot permit you to assume such a presence merely to explain such a movement; for if the fact to be explained is sufficient proof of the explanation, we might with equal justice assume that the movement was caused by an invisible dragon who turned the table by the fanning of his awful wings. A similar initial error is observable in the electrical hypothesis. Electricity may be a less intrinsically improbable assumption, but its presence requires proof. After that step had been taken, we should require proof that electricity could comport itself with reference to tables and similar bodies in this particular manner. We have various tests for the presence of electricity; various means of ascertaining how it would act upon a table. But seeing that the gentleman who spoke so confidently of " currents issuing from the tips of the fingers" never once attempted to prove that there were currents; and knowing moreover that these currents, if present, would not make a table turn, all men of true scientific culture dismissed the explanation with contempt. Such were the metaphysical Methods of explaining the phenomenon. Let us now watch the scientific Method. The point sought is the unknown cause of the table's movement. To reach the unknown we must pass through the avenues of the known; we must not attempt to reach it through the unknown. Is there any known fact with which this movement can be allied? The first and most obvious suggestion is, that the table was pushed by the hands which rested on it. There is a difficulty in the way of this explanation, namely, that the persons declare solemnly they did not push; and, as persons of the highest respectability, we are bound to believe them. Is this statement of any value? The whole question is involved in it. But the philosophical mind is very little affected by guarantees of respectability in matters implicating sagacity rather than integrity. The Frenchman assured his friend that the earth did turn round the sun, and offered his parole d'honneur as a guarantee; but in the delicate and difficult questions of science paroles d'honneur have a quite inappreciable weight. We may therefore set aside INTRODUCTION. xix the respectability of the witnesses, and, with full confidence in their integrity, estimate the real value of their assertion, which amounts to this: they were not conscious of pushing. We now see that the fact, which was imagined to be simple, namely, that " the persons did not push," turns out to be excessively dubious, namely, " they were not conscious of pushing." If we come to examine such a case, we find Physiology in possession of abundant examples of muscular action accompanied by no distinct consciousness, and some of these examples are very similar to those of the unconscious pushing, which may have turned the table; and we are thus satisfied of three important points:1. Pushing is an adequate cause, and will serve to explain the movement of the table, as well as either the supposed spirit or electricity. 2. Pushing may take place without any distinct consciousness on the pait of those who push. 3. Expectant attention is known to produce such a state of the muscles as would occasion this unconscious pushing. Considered therefore as a mere hypothesis, this of unconscious pushing is strictly scientific; it may not be true, but it has fulfilled the preliminary conditions. Unlike the two hypotheses it opposes, it assumes nothing previously unknown, or not easily demonstrable; every position has been verified; whereas the metaphysicians have not verified one of their positions: they have not proved the presence of their agents, nor have they proved that these agents, if present, would act in the required manner. Of spirit we know nothing, consequently can predicate nothing. Of electricity we know something, but what is known is not in accordance with the table-turning hypothesis. Of pushing we know that it can and does turn tables. All then that is required to convert this latter hypothesis into scientific certainty, is to prove the presence of the pushing in this particular case. And it is proved in many ways, positive and negative, as I showed when the phenomenon first became the subject of public investigation. Positive, because if the hands rest on a loose tablecloth, or on substances with perfectly smooth surfaces which will glide easily over the table, the cloth or the substances will move, and not the table. Negative, because if the persons are duly warned of their liability to unconscious pushing, and are XX INTRODUCTION. told to keep vigilant guard over their sensations, they do not move the table, although previously they have moved it frequently. When we have thus verified the presence of unconscious pushing, all the links in the chain have been verified, and certainty is complete. Reviewing the three explanations which the phenomenon of table-turning called forth, we elicit one characteristic as distinguishing the scientific Method, namely, the verification of each stage in the process, the guaranteeing of each separate point, the cultivated caution of proceeding to the unknown solely through the avenues of the known. The germinal difference, then, between the metaphysical and scientific Methods, is not that they draw their explanations from a different source, the one employing Reasoning where the other employs Observation, but that the one is content with an explanation which has no further guarantee than is given in the logical explanation of the difficulty; whereas the other imperatively demands that every assumption should be treated as provisional, hypothetical, until it has been confronted with fact, tested by acknowledged tests, in a word, verified. The guarantee of the metaphysician is purely logical, subjective: it is the intellectus sibi permissus; the guarantee of the other is derived from a correspondence of the idea with experience. As Bacon says, all merely logical explanations are valueless, the subtlety of nature greatly surpassing that of argument: "Subtilitas naturae subtilitatem argumentandi multis partibus superat;" and he further says, with his usual felicity, " Sed axiomata a particularibus rite et ordine abstracta nova particularia rursus facile indicant et designant." It is these "new particulars" which are reached through those already known, and complete the links of the causal chain. Open the history of Science at any chapter you will, and its pages will show how all the errors which have gained acceptance gained it because this important principle of verification of particulars was neglected. Incessantly the mind of man leaps forward to " anticipate" Nature, and is satisfied with such anticipations if they have a logical consistence. When Galen and Aristotle thought that the air circulated in the arteries, causing the pulse to beat, and cooling the temperature of the blood, they INTRODUCTION. Xxi were content with this plausible anticipation; they did not verify the facts of the air's presence, and its cooling effect; when they said that the "spirituous blood" nourished the delicate organs, such as the lungs, and the " venous blood" nourished the coarser organs, such as the liver; when they said that the "spirit," which was the purer element of the blood, was formed in the left ventricle, and the venous blood in the right ventricle, they contented themselves with unverified assumptions. In like manner, when in our own day physiologists of eminence maintain that in the organism there is a Vital Force which suspends chemical actions, they content themselves with a metaphysical unverified interpretation of phenomena. If they came to rigorous confrontation with fact, they would see that so far from chemical action being "suspended" it is incessantly at work in the organism; the varieties observable being either due to a difference of conditions (which will produce varieties out of the organism), or to the fact that the action is masked by other actions. If the foregoing discussion has carried with it the reader's assent, he will perceive that the distinguishing characteristic of Science is its Method of graduated Verification, and not, as some think, the employment of Induction in lieu of Deduction. All Science is deductive, and deductive in proportion to its separation from ordinary knowledge, and its co-ordination into systematic Science. " Although all sciences tend to become more and more deductive," says a great authority, "they are not therefore the less inductive; every step in the deduction is still an induction. The opposition is not between the terms Inductive and Deductive, but between Deductive and Experimental."* Experiment is the great instrument of Verification. The difference between the ancient and modern philosophies lies in the facility with which the one accepted axioms and hypotheses as the basis for its deductions, and the cultivated caution with which the other insists on verifying its axioms and hypotheses before * Mill's System of Logic: perhaps the greatest contribution to English speculation since Locke's Essay. Had Mr. Mill invented a new terminology and expressed himself with less clearness, he would assuredly have gained that reputation for profundity which, by a thorough misconception of the nature of thought, is so often awarded to obscurity. Xxii INTRODUCTION. deducing conclusions from them. We guess as freely as the ancients; but we know that we are guessing; and if we chance to forget it, our rivals quickly remind us that our guess is not evidence. Without guessing, Science would be impossible. We should never discover new islands, did we not often venture seawards with intent to sail beyond the sunset. To find new land, we must often quit sight of land. As Mr. Thompson admirably expresses it: —"Philosophy proceeds upon a system of credit, and if she never advanced beyond her tangible capital, our wealth would not be so enormous as it is."* While both metaphysician and man of science trade on a system of credit, they do so with profoundly different views of its aid. The metaphysician is a merchant who speculates boldly, but without that convertible capital which can enable him to meet his engagements. Ile gives bills, yet has no gold, no goods to answer for them; these bills are not representative of wealth which exists in any warehouse. Magnificent as his speculations seem, the first obstinate creditor who insists on payment makes him bankrupt. The man of science is also a venturesome merchant, but one fully alive to the necessity of solid capital which can on emergency be produced to meet his bills; he knows the risks he runs whenever that amount of capital is exceeded; he knows that bankruptcy awaits him if capital be not forthcoming. The contrast therefore between Philosophy and Science, or Metaphysics and Positive Philosophy, is a contrast of Method; but we must not suppose that the Method of the one is Deduction, while that of the other is Observation. Nothing cal be more erroneous than the vulgar notion of the " Inductive Method," as one limited to the observation of facts. Every instructed thinker knows that facts of observation are particular theories; that is to say, every fact which is registered as an observation is constituted by a synthesis of sensation and inference. We shall see this illustrated presently. To it must be added the truth that Science is constantly making discoveries by Reasoning alone, aloof from any immediate exercise of Observation, aloof indeed from the very phenomena it classifies; for when facts are regis* Outlines of the Laws of Thought, p. 312. INTRODUCTION. XXiii tered in formulas, we resign ourselves to the manipulation of these formulas as symbols or equations, assured that the result will accord with Nature. Fresnel predicted the change in polarization from no observation of facts immediately lying before him, but from a happy elucidation of algebraic symbols. Astronomy is more studied on paper than through the telescope, which however is called upon to verify the results figured on paper. So that if we compare our astronomical and geological theories with the cosmical speculations of a Plato or a Hegel, we shall not find them deficient in the speculative daring which outruns the slow process of observation, but we shall find the difference to lie initially in the rigor with which our deductive formulas are established, and in the different estimates we form of what is valid evidence. Galileo made Astronomy a science when he began to seek the unknown through the known, and to interpret celestial phenomena by those laws of motion which were recognized on the surface of the earth. Geology became possible as a science when its principal phenomena were explained by those laws of the action of water, visibly operating in every river, estuary, and bay. Except in the grandeur of its sweep, the mind pursues the same course in the interpretation of geological facts which record. the annals of the universe, as in the interpretation of the ordinary incidents of daily life. To read the pages of the great Stonebook, and to perceive from the wet streets that rain has recently fallen, are the same intellectual processes. In the one case the mind traverses immeasurable spaces of time, and infers that the phenomena were produced by causes similar to those which have produced similar phenomena within recent experience; in the other case, the mind similarly infers that the wet streets and swollen gutters have been produced by the same cause we have frequently observed to produce them. Let the inference span with its mighty arch a myriad of years, or span but a few minutes, in each case it rises from the ground of certain familiar indications, and reaches an antecedent known to be capable of producing these indications. Both inferences nay be wrong: the wet streets may have been wetted by a water-cart, or by the bursting of a pipe. We cast about for some other indication of Xxiv INTRODUCTION. rain besides the wetness of the streets and the turbid rush of gutters, which might equally have been produced by the bursting of a water-pipe. If we see passers-by carrying wet umbrellas, some still held above the head, our inference is strengthened by this indication, that rain, and no other cause, produced the phenomena. In like manner, the geologist casts about for other indications besides those of the subsidence of water, and as they accumulate, his conviction strengthens. While this is the course of Science, the course of Philosophy is very different. Its inferences start from no well-grounded basis; the arches they throw are not from known fact to unknown fact, but from some unknown to some other unknown. Deductions are drawn from the nature of God, the nature of Spirit, the essences of Things, and fiom what Reason can postulate. ~ Rising from such mists, the arch so brilliant to look upon is after all a rainbow, not a bridge. To make his method legitimate, the Philosopher must first prove that a co-ordinate correspondence exists between Nature and his Intuitional Reason,* so that whatever is true of the one must be true of the other. The geologist, for example, proceeds on the assumption that the action of waters was essentially the same millions of years ago as it is in the present day; so that whatever can be positively proved of it now, may be confidently asserted of it then. He subsequently brings evidence to corroborate his assumption by showing that the assumption is necessary and competent to explain facts not otherwise to be consistently explained. But does the Philosopher stand in a similar position? Does he show any validity in his preliminary assumption? Does he produce any evidence for the existence of a nexus between his Intuitional Reason and those noumena or essences, about which he reasons; does he show the probability of there being such a correspondence between the two, that what * By Intuitional Reason I here wish to express what the Germans call Vernunft, which they distinguish from Verstand, as Coleridge tried to make Englishmen distinguish between Reason and Understanding. The term Reason is too deeply rooted in our language to be twisted into any new direction; and I hope by the unusual' Intuitional Reason" to keep the reader's attention alive to the fact that by it is designated the process of the mind engaged in transcendental inquiry. INTRODUCTION. XXV is true of the one may be accepted as probable of the other Nothing of the kind. He assumes that it is so. He assumes, as a preliminary to all Philosophy, that Intuitional Reason is competent to deliver verdicts, even when the evidence is entirely furnished by itself. He assumes that Intuitions are face to face with Existences, and have consequently immediate knowledge of them. But this immense assumption, this gratuitous begging of the whole question, can only be permitted after a demonstration that the contrary assumption must be false. Now it is certain that we can assume the contrary, and assume it on evidence as cogent as that which furnishes his assumption. I can assume that Intuitions are not face to face with Existences; indeed this assumption seems to me by far the most probable; and it is surely as valid as the one it opposes? I call upon the metaphysician to prove the validity of his assumption, or the invalidity of mine. I call upon him for some principle of verification. He may tell me (as in past years the Hegelians used to tell me, not without impatience) that " Reason must verify itself;" but unhappily Reason has no such power; for if it had, Philosophy would not be disputing about first principles; and when it claims the power, who is to answer for its accuracy, quis custodiet ipsos custodes? If Philosophy is possible, its only basis rests on the correspondence between Nature and Intuitional Reason. But a correct analysis of our intellectual processes will furnish a solvent which will utterly destroy the last shred of organic basis out of which Philosophy grows. Reasoning, if I rightly apprehend it, is the same intellectual process as Perception, with this difference, that Perception is inferential respecting objects present, and Reasoning is inferential respecting objects absent. In the laxity of current language, sensations and perceptions are almost convertible terms; but if we rigorously separate from our perceptions all those elements not actually given in the momentary sensations, it will be evident that Perception is distinguished from Sensation by the addition of certain inferences: as when we perceive a substance to be hard, square, odorous, sweet, etc., from certain inferences rising out of its form, color, etc., although we do not actually touch, smell, or taste the object. What is this process of inference? It 2 XXvi INTRODUCTION. is a presentation before the consciousness of something which has been formerly observed in conjunction with the object, and is therefore supposed to be now actually present in fact, although not present in sensation. I have no sensation of sweetness when I see the lumnp of sugar; but the sight of the sugar brings before my consciousness the sweetness, which the sugar will bring to my sensibility when in contact with my tongue. I perceive the sweetness; and I do this by making present to my mind what is absent from sense. I infer that the lump of white substance before me is sugar, as I infer that it rains when I see, fron my window, water falling on the streets. In both cases the inference may be wrong. The white substance may be salt; the falling water may be the spray of the garden-hose. But in each and every case of Perception, a something is added to the Sensation, and that something is inferential, or the assumption of some quality present in fact which is not present in sense. Reasoning is likewise inferential, but about objects which, although they were formerly given in sense, are now absent altogether. Reasoning is the presentation before the consciousness, of objects which, if actually present, would affect the consciousness in a similar way. It mentally supplies their existence. Thus, when from the wet streets and turbulent gutters I conclude, or infer, that it has rained, I make present to myself the phenomena of falling water in somewhat the same order as the falling water would follow if present. On closely attending to any chain of Reasoning we shall find that if it were possible to realize all the links in the chain, i. e. so to place the actual objects in their connected series that we could see them, this mental series would become a visible series, and, in lieu of reasonings, would afford direct perceptions. Good reasoning is the ideal assemblage of facts, and their re-presentation to the mind in the order of their actual series. It is seeing with the mind's eye. Bad reasoning will always be found to depend on some of the objects not being mentally present; some links in the chain are dropped or overlooked; some objects instead of being re-presented are left absent, or are presented so imperfectly that the inferences from them are as erroneous as the inferences from imperfect vision are erroneous. Bad reasoning is imperfect re-presentation. INTRODUCTION. XXVii This explanation of the intellectual operations is, I believe, novel; should it be accepted, it will light up many obscure questions. But for the present we must only notice its bearing on Philosophy. When the table-turners concluded that electricity was the cause of the table's movement, they did not make present to their minds the real facts of electricity and its modes of operations; otherwise they would have seen that electricity would not turn the table round, and they would have seen this almost as vividly as if a battery had been then and there applied to the table. Faraday, on the contrary, did make these facts mentally present, so as not to need the actual presence of a battery; and his correct reasoning might not be owing to any greater general vigor of ratiocination, but to his greater power of making these particular facts mentally present. Describe an invention to Dr. Neil Arnott, and he will be able to reason on its practicability almost as well as if he saw the machine in operation: because he can mentally make present to himself all the details of structure, and from these infer all the details of action, just as his direct inferences would follow the actual presentation of the objects. There are two modes of detecting false logic, and there are but two: either we must reduce the argument to a series of sensations-make the facts in question visible to sense, and show that the sequences and co-existences of these facts are not what the reasoner asserted them to be; or we must mentally supply the place of this visible demonstration, and by re-presenting the objects before the mind, see where their sequences and co-existences differ from what the reasoner asserted them to be. If all Reasoning be the re-presentation of what is now absent but formerly was present, and can again be made present,-in other words, if the test of accurate reasoning is its reduction to fact,-then is it evident that Philosophy, dealing with transcendental objects which cannot be present, and employing a Method which admits of no. verification (or reduction to the test of fact) must be an impossible attempt. And if I am asked how it is that philosophers have reasoned at all on transcendental subjects, since according to my statement they could only reason by making such subjects present to their minds, the reply is that they could not, and did not, make present to their minds any XXViii INTRODUCTION. such subjects at all; the Infinite was really conceived by them as Finite, the Unconditioned as Conditioned, Spirit as Body, Noumenon as Phenomenon; for only thus were these things conceivable at all. Thus it is only possible to take the first step in Philosophy by bringing transcendental subjects within the sphere of experience, i. e. making them no longer transcendental. Thus, and thus only, is it possible for us to reason on such topics. All this will doubtless be utterly denied by metaphysicians. They proceed on the assumption that Intuitional Reason, which is independent of experience, is absolute and final in its guarantee. The validity of its conclusions is self-justified. Hegel boldly says, " Whatever is rational is real, and whatever is real is rational,-das Vernuinftige ist wirklich und das Wirkliche verniunftig." And writers of less metaphysical rigor frequently avow the axiom, and always imply it. Thus in a remarkable article on Sir W. Hamilton, which appeared in the Prospective Review (understood to be by Mr. James Martineau), we read that Philosophy in England has dwindled down to mere Psychology and Logic, whereas its proper business is with the notions of Time, Space, Substance, Soul, God; "to pronounce upon the validity of these notions as revelations of real Existence, and, if they be reliable, use them as a bridge to cross the chasm from relative Thought to absolute Being. Once safe across, and gazing about it in that realm, the mind stands in presence of the objects of Ontology." "; Once safe across;" this is indeed the step which constitutes the whole journey; unhappily we have no means of getting safe across; and in this'helplessness we had better hold ourselves aloof from the attempt. If a man were to discourse with amplitude of detail and eloquence of conviction respecting the inhabitants of Sirius, setting forth in explicit terms what they were like, what embryonic forms they passed through, what had been the course of their social evolution and what would be its ultimate stage, we should first ask, And pray, Sir, what evidence have you for these particulars? what guarantee do you offer for the validity of these conclusions? If he replied that Intuitional Reason assured him these things must be so from the inherent necessities of the case, he having logically evolved these conclu INTRODUCTION. XXiX sions from the data of Reason; we should suppose him to be either attempting to mystify us, or to be hopelessly insane. Nor would this painful impression be removed by his proceeding to affirm that he never thought of trusting to such fallacious arguments as could be furnished by observation and experimenttests wholly inapplicable to objects so remote from all experience, objects accessible only by Reason. In the present day, speculations on Metaphysics are not, intrinsically, more rational than speculations on the development of animated beings peopling Sirius; nay, however masked by the ambiguities of language and old familiarities of speculation, which seem to justify Metaphysics, the attempt of the Philosopher is really less rational, the objects being even less accessible. Psychology has taught us one lesson at least, namely, that we cannot know causes and essences, because our experience is limited to sequences and phenomena. Nothing is gained by despising Experience, and seeking refuge in Intuition. The senses may be imperfect channels, but at any rate they are in direct communication with their objects, and are true up to a certain point. The error arising from one sense may be corrected by another; what to the eye appears round, the hand feels to be square. But Intuition has no such safeguard. It has only itself to correct its own errors. Holding itself aloof from the corroborations of Sense, it is aloof from all possible verification, because it cannot employ the test of confrontation with fact. This conviction has been growing slowly. It could never have obtained general acceptance until Philosophy had proved its incapacity by centuries of failure. In the course of our History we shall see the question of Certitude continually forced upon philosophers, always producing a crisis in speculation, although always again eluded by the more eager and impatient intellects. Finally, these repeated crises disengage the majority of minds from so hopeless a pursuit, and set them free to follow Science which has Certitude. If our History has any value, it is in the emphatic sanction it thus gives to the growing neglect of Philosophy, the growing preference for Science. In the former edition I adopted the common view which regards the distinction between Philosophy and Science as lying in the pursuit of XXX INTRODUCTION. different objects. "Philosophy aspires to the knowledge of essences and causes. Positive Science aspires only to the knowledge of Laws. The one pretends to discover what things are, in themselves, apart from their appearances to sense; and whence they came. The other only wishes to discover their modus operandi, observing the constant co-existences and successions of phenomena among themselves, and generalizing them into some one Law." But this I no longer regard as the whole truth. It does not discriminate between scientific and metaphysical speculation on subjects within the scope of Science; such for instance as the phenomena of life, or such as table-turning. The vital and fundamental difference between the two orders of speculation does not lie in their objects, but in their methods. A priori, indeed, we might conclude that such a circumscription of the aims of speculation as is implied in Science would necessarily bring about a corresponding change in Method; in other words, that men having once relinquished the pursuit of essences and causes would have been forced to adopt the Method of Verification, because that alone was competent to lead to certitude. But History tells a different tale. Men did not adopt the Method of Verification because they had previously relinquished all attempts to penetrate into causes; but they relinquished all attempts to penetrate into causes because they found that the only Method which could lead to certainty was the Method of Verification, which was not applicable to causes. Hence a gradual elimination followed the gradual rise of each particular science; till at last, in the doctrine of Auguste Comte, all inquiry is limited to such objects as admit of verification, in one way or another. The Method of Verification, let us never forget, is the one grand characteristic distinguishing Science from Philosophy, modern inquiry from ancient inquiry. Of the ancients, Fontenelle felicitously says: " Souvent de faibles convenances, de petites similitudes, des discours vagues et confus, passent chez eux pour des preuves: aussi rien ne leur coute a prouver." The proof is, with us, the great object of solicitude. We demand certainty; and as the course of human evolution shows certainty to be attainable on no other Method than the one followed by Science, the condemnation of Metaphysics is inevitable. INTRODUCTION. XXxi Grand, indeed, has been the effort of Philosophy; great the part it has played in the drama of civilization; but the part is played out. It has left the legacy bequeathed by every great effort. It has enriched all succeeding ages, but its work is accomplished. Men have grown less presumptuous in speculation, and inconceivably more daring in practice. They no longer attempt to penetrate the mystery of the universe, but they explore the universe, and yoke all natural forces to their splendid chariot of Progress. The marvels of our age would have seemed more incredible to Plato, than were the Arabian Nights to Bentham; but while Science thus enables us to realize a wonderland of fact, it teaches us to regard the unhesitating temerities of Plato and Plotinus as we regard the efforts of a child to grasp the moon. Philosophy was the great initiator of Science. It rescued the nobler part of man from the dominion of brutish apathy and helpless ignorance, nourished his mind with mighty impulses, exercised it in magnificent efforts, gave him the unslaked, unslakable thirst for knowledge which has dignified his life, and enabled him to multiply tenfold his existence and his happiness. Having done this, its part is played. Our interest in it now is purely historical. The purport of' this history is to show how and why the interest in Philosophy has become purely historical.- In this purport lies the principal novelty of the work. There is no other History of Philosophy written by one disbelieving in the possibility of metaphysical certitude. ~ II. LIMITS OF THE WORK. Having explained what is the final purpose of this History, and makes it subservient to the general History of Humanity rather than to any philosophical system, I will now briefly indicate the reasons which, apart from the limitations of my own knowledge, have determined the selection of the illustrative types. Brucker, having no purpose beyond that of accumulating materials, includes in his History the speculations of Antediluvian, Scythian, Persian, and Egyptian thinkers. Mr. Maurice, who has a purpose, also includes Hebrew, Egyptian, Hindoo, XXxii INTRODUCTION. Chinese, and Persian philosophies.* Other historians vary in their limits, upon not very intelligible grounds. I begin with Greece, because in the history of Grecian thought all the epochs of speculative development are distinctly traceable; and as I write the Biography of Philosophy, it is enough for my purpose if anywhere I can find a distinct filiation of ideas. Rome never had a philosophy of its own; it added no new idea to the ideas borrowed from Greece. It occupies no place therefore in the development of Philosophy, and is omitted from this Biography. The omission of the East, so commonly believed to have exercised extensive and profound influence on Greece, will to many readers seem less excusable. But to unfold the arguments which justify the omission here, would require more space than can be spared in this Introduction. It is questionable whether the East had any Philosophy distinct from its Religion; and still more questionable whether Greece borrowed its philosophical ideas.t True it is that the Greeks themselves supposed their early teachers to have drunk at the Eastern fount. True it is that modern orientalists, on first becoming acquainted with the doctrines of the Eastern sages, recognized strong resemblances to the doctrines of the Greeks; and a Rotht finds Aristotle to be the first independent thinker, all his predecessors having drawn their speculations fiom the Egyptian; while a Gladiscl~ makes it quite obvious (to himself) that the Pythagorean system is nothing but an adoption of the Chinese, the Heraclitic system an adoption of the Persian, the Eleatic of the Indian, the Empedoclean of the Egyptian, the Anaxagorean of the Jewish. But neither the vague tradition of the Greeks, nor the fallacious ingenuity of moderns, weigh heavy in the scale of historical criticism. It is true that coincidences of thought are to be found between Grecian and many other systems; but coincidences are no evi* Moral and Metaphysical Philosophy, part i., second edition, 1850: a work of singular fascination and great ingenuity. t I have elsewhere stated reasons for this belief.-Edinburgh Review, April, 1847, p. 852 sq. 4 Geschichte unserer abendliindischen Philosophie, i. p. 228 sq. ~ Die Religion und die Philosophie in ihrer weltgesch. Entwickelung. INTRODUCTION. XXxiii dence of direct filiation; and he has studied the history of speculation to little purpose who is not thoroughly familiar with the natural tendency of the mind to sweep into the same tracks, where others have been before, where others will find themselves afterwards. Moreover, many of these coincidences, upon which historical theories are based, turn out, on close inspection, to be merely verbal, or at the best, approximative. Thus the physical speculations of the Greeks often coincide in expression with those of modern science. Does this prove that the moderns borrowed their science fiom the ancients? M. Dutens thought so, and has written an erudite but singularly erroneous book to prove it. Democritus asserted the Milky Way to be only a cluster of stars; but the assertion was a mere guess, wholly without proof, and gained no acceptance. It was Galileo who discovered what Democritus guessed. Thus also Empedocles, Pythagoras, and Plato, are said to have been perfectly acquainted with the doctrine of gravitation; and this absurdity is made delusive by dint of forced translations, which elicit something like coincidence of expression, although every competent person detects the want of coincidence in the ideas.* Waiving all discussion of disputable and disputed points, it is enough that in Greece fiom the time of Thales, and in Europe fromn the time of Descartes, a regular development of Philosophy is traceable, quite sufficient for our purpose, which is less that of narrating the lives and expounding the opinions of various thinkers, than of showing how the course of speculation necessarily brought about that radical change in Method which distinguishes Philosophy from Science. In pursuance of such an aim it was perfectly needless to include any detailed narrative of the speculations which, under the name of Scholasticism, occupied the philosophical activity of the Middle Ages. Those speculations were either subordinate to Theology, or were only instrumental in perfecting philosophical language; and in this latter respect the historian of Philosophy is no more called upon to notice them, than a writer on the art of War would be called upon to * Karsten expresses the distinction well: " Empedocles poetice adumbravit idem quod tot seculis postea mathematicis rationibus demonstratum est a Newtono."-Philos. Graecor'um Operum Reliquice, p. xii. XXXiV INTRODUCTION. give a history of the armorers of Milan or the sword-manufacturers of Toledo. The same principle which determines the selection of Epochs also determines the selection of the points of doctrine to be expounded. It is obvious that in nothing like the space to which this work is limited could even the barest outline of all the opinions held by all the philosophers be crowded; nor would ten times the space suffice for an exposition of those opinions with any thing like requisite detail. Brucker's vast compilation, and Ritter's laborious volumes, are open for any student desirous of more detailed knowledge; but even they are imperfect. My purpose is different; I write, the Biography, not the Annals of Philosophy, and I am more concerned about the doctrines peculiar to each thinker than about those held by him in common with others. If I can ascertain and make intelligible the doctrines which formed the additions of each thinker to the previous stock, and which helped the evolution of certain germs of philosophy, collateral opinions will need only such mention as is necessary to make the whole course of speculation intelligible. Thus limited in scope, I may find myself more at ease in the discussion of those points on which attention should be fastened. More space can be given to fundamental topics. In restricting myself to Descartes, Spinoza, and Kant, without noticing Cartesians, Spinozists, and Kantians, I also on the same principle restrict myself to what is in each thinker peculiar to him, and directly allied to the course of philosophical development. The student who needs the Pandects of Philosophy will have to look elsewhere: this work only pretends to be a Summary. FIRST EPOCH. SPECULATIONS ON THE NATURE OF THE UNIVERSE. CHAPTER I. THE PHYSICISTS. ~ I. THALES. ALTHOUGH the events of his life, no less than the precise doctrines of his philosophy, are shrouded in mystery, and belong to the domain of fable, nevertheless Thales is very justly considered as the father of Greek Speculation. He made an epoch. He laid the foundation-stone of Greek philosophy. The step he took was small, but it was decisive. Accordingly, although nothing but a few of his tenets remain, and those tenets fragmentary and incoherent, we know enough of the general tendency of his doctrines to speak of him with some degree of certitude. Thales was born at Miletus, a Greek colony in Asia Minor. The date of his birth is extremely doubtful; but the first year of the 36th Olympiad (B. c. 636) is generally accepted as correct. He belonged to one of the most illustrious families of Phoenicia, and took a conspicuous part in all the political affairs of his country,-a part which earned for him the highest esteem of his fellow-citizens. His immense activity in politics has been denied by later writers, as inconsistent with the tradition, countenanced by Plato, of his having spent a life of solitude and meditation; while on the other hand his affection for solitude has been questioned on the ground of his political activity. It seems to us that the two things are perfectly compatible. Meditation does 1 2 THE PHYSICISTS. not necessarily unfit a man for action; nor does an active life absorb all his time, leaving him none for meditation. The wise man will strengthen himself by meditation before he acts; and he will act, to test the truth of his opinions. Miletus was one of the most flourishing Greek colonies; and at the period we are now speaking of, before either a Persian or a Lydian yoke had crushed the energies of its population, it was a fine scene for the development of mental energies. Its commerce both by sea and land was immense. Its political constitution afforded the finest opportunities for individual development. Thales both by birth and education would naturally be fixed there, and would not travel into Egypt and Crete for the prosecution of his studies, as some maintain, although upon no sufficient authority. The only ground for the conjecture is the fact of Thales being a proficient in mathematical knowledge; and from very early times, as we see in Herodotus, it was the fashion to derive the origin of almost every branch of knowledge from Egypt. So little consistency is there however in this narrative of his voyages, that he is said to have astonished the Egyptians by showing them how to measure the height of their pyramids by their shadows. A nation so easily astonished by one of the simplest of mathematical problems could have had little to teach. Perhaps the strongest proof that he never travelled into Egyptor that, if he travelled there, he never came into communication with the priests-is the absence of all trace, however slight, of any Egyptian doctrine in the philosophy of Thales which he might not have found equally well at home. The distinctive characteristic of the Ionian School, in its first period, was its inquiry into the constitution of the universe. Thales opened this inquiry. It is commonly said: "Thales taught that the principle of all things was water." On a first glance, this will perhaps appear a mere extravagance. A smile of pity may greet it, accompanied by a reflection on the smiler's part, of the unlikelihood of his ever believing such an absurdity. But the serious student will be slow to accuse his predecessors of THALES. 3 sheer and transparent absurdity. The history of Philosophy may be the history of errors; it is not a history of follies. All the systems which have gained acceptance have had a pregnant meaning, or they would not have been accepted. The meaning was proportionate to the opinions of the epoch, and as/ such is worth penetrating. Thales was one of the most extraordinary men that ever lived, and produced an extraordinary revolution. Such a man was not likely to have enunciated a philosophical thought which any child might have refuted. There was deep meaning in the thought, to him at least. Above all, there was deep meaning in the attempt to discover the origin of things. Let us endeavor to penetrate the meaning of his thought; let us see if we cannot in some shape trace its rise and growth in his mind. It is characteristic of philosophical minds to reduce all imaginable diversities to one principle. As it is the inevitable tendency of religious speculation to reduce polytheism to monotheism,-to generalize all the supernatural powers into one expression,-so also was it the tendency of early philosophical speculation to reduce all possible modes of existence into one generalization of Existence itself. Thales, speculating on the constitution of the universe, could not but strive to discover the one principle-the primary Factthe substance, of which all special existences were but the modeos Seeing around him constant transformations-birth and death, change of shape, of size, and of mode of existence-he could not regard any one of these variable states.of existence as Existence itself. He therefore asked himself, What is that invariable Existence of which these are the variable states? In a word, What is the beginning of things? To ask this question was to open the era of philosophical inquiry. Hitherto men had contented themselves with accepting the world as they found it; with believing what they saw; and with adoring what they could not see. Thales felt that there was a vital question to be answered relative to the beginning of things. He looked around him, and 4 THE PHYSICISTS. the result of his meditation was the conviction that Moisture was the Beginning. He was impressed with this idea by examining the constitution of the earth. There also he found moisture everywhere. All things he found nourished by moisture; warmth itself he declared to proceed from moisture; the seeds of all things are moist. Water when condensed becomes earth. Thus convinced of the universal presence of water, he declared it to be the beginning of things. Thales would all the more readily adopt this notion from its harmonizing with ancient opinions; such for instance as those expressed in Hesiod's Theogony, wherein Oceanus and Thetis are regarded as the parents of all such deities as had any relation to Nature. "He would thus have performed for the popular religion that which modern science has performed for the Book of Genesis: explaining what was before enigmatical."* It is this which gives Thales his position in Philosophy. Aristotle calls him o rr rosau'r, dpr.XYS qpiXooopiag, the man who made the first attempt to establisr a physical Beginning, without the assistance of myths. He has consequently been accused of Atheism by modern writers; but Atheism is the growth of a much later thought, and one under no pretence to be attributed to Thales, except on the negative evidence of Aristotle's silence, which we conceive to be directly counter to the supposition, since it is difficult to believe Aristotle would have been silent had he thought Thales believed or disbelieved in the existence of any thing deeper than Water, and prior to it. Water was the adp, the beginning of all. When Cicero, following and followed by writers far removed from the times of Thales, t says that he " held water to be the beginning of things, but that God was the mind which created things out of the water," he does violence to the chronology of speculation. We * Benj. Constant, Du Polytheisme Romain, i. 167. t And uncritically followed by many moderns who feel a difficulty in placing themselves at the point of view of ancient speculation. ANAXIMENES. 5 agree with Hegel that Thales could have had no conception of God as Intelligence, since that is the conception of a more advanced philosophy. We doubt whether we had any conception of a Formative Intelligence or of a Creative Power. Aristotle* very explicitly denies that the old Physicists made any distinction between Matter (a iv X xa; r vfoxsipsvov) and the Moving Principle or Efficient Cause (m dp pX rs xv'rsgS); and he further adds that Anaxagoras was the first who arrived at a conception of a Formative Intelligence.t Thales believed in the Gods and in the generation of the Gods: they, as all other things, had their origin in water. This is not Atheism, whatever else it may be. If it be true that he held all things to be living, and the world to be full of demons or Gods, there is nothing inconsistent in this with his views about Moisture as the origin, the starting-point, the primary existence. It is needless however to discuss what were the particular opinions of a thinker whose opinions have only reached us in fragments of uncritical tradition; all we certainly know is that the step taken by Thales was twofold in its influence:-first, to discover the Beginning, the prima materia of all things (' dp'i); secondly, to select from among the elements that element which was most potent and omnipresent. To those acquainted with the history of the human mind, both these notions will be significant of an entirely new era. ~ II. ANAXIMENES. Anaximander is by most historians placed after Thales. We agree with Ritter in giving that place to Anaximenes. The reasons on which we ground this arrangement are, first, that in so doing we follow our safest guide, Aristotle; secondly, that the doctrines of Anaximenes are the development of those of Thales; whereas Anaximander follows a totally different line of speculation. Indeed, the whole ordinary arrangement of the Ionian * Arist. Metaph. i. 8. t It will presently be seen that Diogenes was the first to conceive this. 6 THE PHYSICISTS. School seems to have proceeded on the conviction that each disciple not only contradicted his master, but also returned to the doctrines of his master's teacher. Thus Anaximander is made to succeed Thales, though quite opposed to him; whereas Anaximenes, who only carries out the principles of Thales, is made the disciple of Anaximander. When we state that 212 years, i. e. six or seven generations, are taken up by the lives of the four individuals said to stand in the successive relations of teacher and pupil, Thales, Anaximander, Anaximenes, and Anaxagoras, the reader will be able to estimate the value of the traditional relationship. The truth is, only the names of the great leaders in philosophy were thought worth preserving; all those who merely applied or extended the doctrine were very properly consigned to oblivion. This is also the principle upon which the present history is composed. No one will therefore demur to our placing Anaximenes second to Thales: not as his disciple, but as his historical successor; as the man who, taking up the speculation where Thales and his disciples left it, transmitted it to his successors in a more developed form. Of the life of Anaximenes nothing further is known than that he was born at Miletus, probably in the 63d Olympiad (B. c. 529), others say in the 58th Olympiad (B. c. 548), but there is no possibility of accurately fixing the date. He is said to have discovered the obliquity of the Ecliptic by means of the gnomon. Pursuing the method of Thales, he could not satisfy himself of the truth of his doctrine. Water was not to him the most significant element. He felt within him a something which moved him he knew not how, he knew not why; something higher than himself; invisible, but ever-present: this he called his life. His life he believed to be air. Was there not also without him, no less than within him, an ever-moving, everpresent, invisible air? The air which was within him, and which he called Life, was it not a part of the air which was without him? and, if so, was not this air the Beginning of things? DIOGENES OF APOLLONIA. 7 He looked around him and thought his conjecture was confirmed; The air seemed universal.* The earth was as a broad leaf resting upon it. All things were produced from it; all things were resolved into it. When he breathed, he drew in a part of the universal life. All things were nourished by air, as he was nourished by it. To Anaximenes, as to most of the ancients, Air breathed and expired seemed the very stream of life, holding together all the heterogeneous substances of which the body was composed, giving them not only unity, but force, vitality. The belief in a living world-that is to say, of the universe as an organism-was very ancient, and Anaximenes, generalizing from the phenomena of individual life to universal life, made both dependent on Air. In many respects this was an advance on the doctrine of Thales, and the reader may amuse himself by finding its coincidence with some speculations of modern science. A grave chemist like Dumas can say, "Les Plantes et les Animaux derivent de l'air, ne sent que de l'air condens6, ils viennent de lair et y retournent;" and Liebig, in a well-known passage of the Chemical Letters, eloquently expresses the same idea. ~ III. DIOGENES OF APOLLONIA. Diogenes of Apollonia is the proper successor to Anaximenes, although, from the uncritical arrangement usually adopted, he is made to represent no epoch whatever. Thus, Tennemann places him after Pythagoras. Hegel, by a strange oversight, says that we know nothing of Diogenes but the name. Diogenes was born at Apollonia, in Crete. More than this we are unable to state with certainty; but as he is said to have been a contemporary of Anaxagoras, we may assume him to have flourished about the 80th Olympiad (B. c. 460). His work On * When Anaxirenes speaks of Air, as when Thales speaks of Water, we must not understand these elements as they appear in this or that determinate form on earth, but as Water and Air pregnant with vital energy and capable of infinite transmutations. 8 THE PHYSICISTS. Nature was extant in the time of Simplicius (the sixth century of our era), who extracted some passages from it. Diogenes adopted the tenet of Anaximenes respecting Air as the origin of things; but he gave a wider and deeper signification to the tenet by attaching himself more to its analogy with the Soul.* Struck with the force of this analogy, he was led to push the conclusion to its ultimate limits. What is it, he may have asked himself, which constitutes Air the origin of things? Clearly its vital force. The air is a Soul; therefore it is living and intelligent. But this Force or Intelligence is a higher thing than the Air, through which it manifests itself; it must consequently be prior in point of time; it must be the apXn philosophers have sought. The Universe is a living being, spontaneously evolving itself, deriving its transformation from its own vitality. There are two remarkable points in this conception, both indicative of very great progress in speculation. The first is the attribute of Intelligence, with which the dpX; is endowed. Anaximenes considered the primary substance to be an animated substance. Air was Life, in his system, but the Life did not necessarily imply Intelligence. Diogenes saw that Life was not only Force, but Intelligence; the air which stirred within him not only prompted, but instructed. The Air, as the origin of all things, is necessarily an eternal, imperishable substance; but as soul, it is also necessarily endowed with consciousness. " It knows much," and this knowledge is another proof of its being the primary substance; "for without Reason," he says, "it would be impossible for all to be arranged duly and proportionately; and whatever object we consider will be found to be arranged and ordered in the best and most beautiful manner." Order can result only from Intelligence; the Soul is therefore the first (apx ). This conception was undoubtedly a great one; but that the * By Soul (Auvx;) we must understand Life in its most general meaning, rather than Mind in the modern sense. Thus the treatise of Aristotle 7repi Auvxls is a treatise on the Vital Principle, including Mind, not a treatise on Psychology. DIOGENES OF APOLLONIA. 9 reader may not exaggerate its importance, nor suppose that the rest of Diogenes' doctrines were equally reasonable and profound, we must for the sake of preserving historical truth advert to one or two of his applications of the conception. Thus: The world, as a living unity, must like other individuals derive its vital force from the Whole: hence he attributed to the world a set of respiratory organs, which he fancied he discovered in the stars. All creation and all material action were but respiration and exhalation. In the attraction of moisture to the sun, in the attraction of iron to the magnet, he equally saw a process of respiration. Man is superior to brutes in intelligence because he inhales a purer air than brutes who bow their heads to the ground. These naive attempts at the explanation of phenomena will suffice to show that although Diogenes had made a large stride, he had accomplished very little of the journey. The second remarkable point indicated by his system is the manner in which it closes the inquiry opened by Thales. Thales, starting from the conviction that one of the four elements was the origin of the world, and Water that element, was followed by Anaximenes, who thought that not only was Air a more universal element than Water, but that, being life, it must be the universal Life. To him succeeded Diogenes, who saw that not only was Air Life, but Intelligence, and that Intelligence must have been the First of Things. We concur therefore with Ritter in regarding Diogenes as the last philosopher attached to the Physical method; and that in his system the method receives its consummation. Having thus traced one great line of speculation, we must now cast our eyes upon what was being contemporaneously evolved in another direction. 1l CHAPTER II. THE HEMEEMATICIANS. ~ I. ANAXIMANDER OF MILETUS.' As we now, for the first time in the history of Greek Philosophy, meet with contemporaneous developments, the observation will not perhaps be deemed superfluous that in the earliest times of philosophy, historical evidences of the reciprocal influence of the two lines either entirely fail or are very unworthy of credit; on the other hand, the internal evidence is of very limited value, because it is impossible to prove a complete ignorance in one, of the ideas evolved and carried out in the other; while any argument drawn from an apparent acquaintance therewith is far from being extensive or tenable, since all the olden philosophers drew from one common source-the national habit of thought. When indeed these two directions had been more largely pursued, we shall find in the controversial notices sufficient evidence of an active conflict between these very opposite views of nature and the universe. In truth, when we call to mind the inadequate means at the command of the earlier philos, ophers for the dissemination of their opinions, it appears extremely probable that their respective systems were for a long time known only within a very narrow circle. On the supposition, however, that the philosophical impulse of these times was the result of a real national want, it becomes at once probable that the various elements began to show themselves in Ionia nearly at the same time, independently and without any external connection."* * Ritter, i. 265. ANAXIMANDER OF MILETUS. 11 The chief of the school we are now about to consider was Anaximander' of Miletus, whose birth may be dated in the 42d Olympiad (B. c. 610). He is sometimes called the friend and sometimes the disciple of Thales. We prefer the former relation; the latter is at any rate not the one in which this history can regard him. His reputation, both for political and scientific knowledge, was very great; and many important inventions are ascribed to him, amongst others that of the sun-dial and the sketch of a geographical map. His calculations of the size and distance of the heavenly bodies were committed to writing in a small work, which is said to be the earliest of all philosophical writings. IIe was passionately addicted to mathematics, and fralned a series of geometrical problems. He was the leader of a colony to Apollonia; and he is also reported to have resided at the court of the tyrant Polycrates, in Samos, where also lived Pythagoras and Anacreon. No two historians are agreed in their interpretation of Anaximander's doctrines; few indeed are agreed as to the historical position he is to occupy. Anaximander is stated to have been the first to use the term dpXx for the Beginning of things. What he meant by this term principle is variously interpreted by the ancient writers; for, although they are unanimous in stating that he called it the infinite (ro a