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 GERMAN PSYCHOLOGY OF TODAY. 
 
GERMAN PSYCHOLOGY 
 
 OF 
 
 ■ TO-DAY 
 
 THE em;pirioal school 
 
 BY 
 
 TH. RIBOT 
 
 DIRECTOR OF THE REVUE PHILOSOPHIQUE 
 
 TRANSLATED FliO.V THE SECOND FRENCH EDITION 
 BY 
 
 JAMES MARK BALDWIN, B. A. 
 
 LATE FELI/)W PRINCETON COLLEGE 
 
 WITH A PREFACE 
 By JAMES McCOSH, D.D., LL.D., Lir.D. 
 
 ^v or CO" 
 „ AP.T13 886^ V 
 
 NEW YORK 
 
 CHARLES SCRIBNERS SONS 
 
 1886 
 
.o^^^ 
 ^ 
 
 ^ ;^' :/^ 
 
 COPYEIGHT, 1886, BY 
 CHAKLES SCBIBNEB'S SONS 
 
 GRANT & PAIRES 
 PHILADELPHIA 
 
•s 
 
 TRANSLATOR'S NOTE. 
 
 The translation of M. Ribot's Psychologie allemande 
 contemporaine was nndertaken with the feeling that no 
 greater service of the kind could lie renderal to the " new 
 psychology." The second edition has been scrupulously 
 reproduced, since, as the author writes in a note sanctioning 
 the translation, " it alone is abreast of contemporar}' work." 
 There are no additions except some English bibliographical 
 notes. 
 
 The translator wishes to express his thanks to Prof. 
 Alexander T. Ormond and Prof. H. C. O. Huss for help- 
 ful suggestions, and to his friend Mr. W. R. Huston for 
 assistance with the proof-sheets. 
 
 J. M. B. 
 
 Princeton, April, 1886. 
 
PREFACE TO THE AMERICAN EDITION. 
 
 American and English students will be grateful to have 
 M. Ribot's valuable work in their own tongue by a com- 
 petent translator. It contains the combined result of care- 
 ful observations, experiments, and calculations which can 
 not be obtained otherwise, except by reading innumerable 
 books and monograplis most difîicult to collect. His inter- 
 pretations and criticisms also are original and profound. 
 
 If we would properly estimate the exact nature and 
 functions of what is called Physiological Psychology, we 
 must adhere resolutely to two positions, which to some may 
 seem opposed, but are really confirmatory of each other. 
 
 It is bv self-consciousness that in the first instance, and 
 in the last instance, and throughout, we know the actings 
 of the mind. We assume, what every one admits, that 
 there are a spc<'ial set of phenomena, that is, observed facts, 
 which we denominate mental or psychical : such are sensa- 
 tions, perceptions, judgments, ho\^si and fears. These are 
 not perceived by the senses. No man ever saw a recollec- 
 tion or touched an emotion. We have an inward as well 
 as an outward sense, and we are conscious of them. We 
 are more, we are conscious of them as acts of self. They 
 are not memories or feelings indefinite, or of our neighbors, 
 but of ourselves. We thus know self always in particular 
 modes and activities. More specifically we know sol f(l), 
 
Vlll PREFACE TO THE AMERICAN EDITION. 
 
 as existing, or what is the same thing, as having being. 
 We know it (2), as having being independent of our obser- 
 vation of it. It does not exist because we notice it, but we 
 notice it because it exists. It is (3), known as having 
 power, as acting and being acted on. 
 
 Whatever possesses these attributes may be regarded as 
 a substance (from subsista) ; not meaning thereby that it has 
 any occult substratum, which is the creation of metaphy- 
 sicians. Matter is a substance because it has existence, 
 existence independent of the observing mind, and is known 
 as exercising resisting power. Mind is also a substance, 
 because it possesses these three properties, all of which are 
 known to us. While mind and matter may both be called 
 substances, they are different kinds of existences. We 
 know them by different organs ; the one by self-conscious- 
 ness, the other by the senses. Again we know them as 
 possessing altogether different properties ; the one as per- 
 ceiving, reasoning, feeling, willing ; the other as extended 
 and exercising energy. The properties of the one can not 
 be predicated of the other. Thinking and feeling have no 
 place in that stone ; nor have softness, hardness or gravity 
 in our souls. 
 
 We can observe the actings of the known self and get 
 individual facts. We can systematically observe them and 
 expose them to a process of abstraction and generalization, 
 or what is called induction, and thus construct a science 
 which is called Psychology. Aristotle is the founder of this ' 
 science, and brought out and exposed to view such qualities 
 as sensation, association, phantasy, memory, reminiscence, 
 and reason active and passive, besides orective or motive 
 powers. Since the days of the Stagyrite, the inductive psy- 
 chologies constructed mainly on the evidence supplied by 
 consciousness have been innumerable, and have all con- 
 tained more or less truth, which has landed us, as all truths 
 do, in mysteries. 
 
PREFACE TO THE AMERICAN EDITION. iX 
 
 Besides the knowledge which consciousoess gives us 
 directly it enables us indirectly to know what passes in the 
 minds of others by means of their deeds, speeches and 
 writings, which we cau*understand, because we are conscious 
 of like states in ourselves. We can understand the deeds 
 of Achilles, or the devils of Milton, because we have the 
 same elements within ourselves. A skillful analyst could 
 construct a psychology out of Shakespeare, or out of the 
 Hebrew and Greek Scriptures. 
 
 In Psychology as the science of the soul, and not of the 
 mere brain and nerves (which belong to physiology), we 
 start with conscious acts, we observe them as we proceed, 
 and our final appeal is to them. The universally recog- 
 nized distinctions between sensation and perception, between 
 the memory and the imagination, between simple appre- 
 hension and judgment, between the understanding and the 
 reason, between the judgment and the feelings, between the 
 reason and the will, between desire and volition (more im- 
 portant than any discovery yet made by the observation of 
 the brain) were all perceived and defined by inward in- 
 spection. 
 
 There can therefore be a psychology constructed out of 
 the data supplied by self-consciousness. There can not be 
 a science of the mind without such data. Any professed 
 psychical science which does not include the actings of tlie 
 conscious self, its perceptions, its memories, its reasonings, 
 its determinations is a physiology and not a psychology ; it 
 may exhibit the laws of the brain and nerves, but not of 
 the judging and feeling soul. A science of the mind can 
 no more be constructed by the senses than a science of mat- 
 ter by the inner consciousness. Dr. Tyndall says, "Let 
 the consciousness of love be associated with a right-angled 
 spiral motion of the molecules of the brain, and the con- 
 sciousness of hate with a left-handed spiral motion, we 
 should then know when we love that the motion is in one 
 
X PBEFACE TO THE AMERICAN EDITION. 
 
 direction, and when we hate that the motion is in the other, 
 but the why would still remain unanswered ;" not only so, 
 but without self-consciousness we could never know that 
 there was love, or that there was hate, or that they had any 
 connection with the motions of the brain. 
 
 II. 
 
 But while all this is true, on the one hand, and as 
 important as it is true, it is not to be forgotten on the other, 
 that mind and body, as the most determined spiritualists 
 admit, are closely connected, are, in fact, mutually depend- 
 ent. Many of our psychical states, particularly our sensa- 
 tions and sense perceptions, are produced by bodily action, 
 cerebral and nervous. Without the bodily senses we could 
 have no knowledge of anything external to the mind, and 
 so far as M^e can see even our mental experiences would be 
 very limited. Again, our intellectual and emotional states 
 have all an effect less or more marked on the body through 
 the brain and nerves. Every thought and every emotion 
 has an influence on the cells of the gray matter at the pe- 
 riphery of the brain, and this may be diffused through the 
 whole frame to j)romote or injure the health. Not only so, 
 but as substances are known by their acts, we may know 
 more of mind than we can do by mere self-inspection, by 
 its action on the cerebro-spinal mass. 
 
 The peculiar excellence of this new branch of inquiry is 
 that it uses the same means as those by which physical 
 science has reached such certainty, particularly experiments 
 conducted by instruments devised for the purpose, and can 
 test the results reached by measurements capable of being 
 expressed numerically. Tliese have therefore a definiteness 
 which can not be secured by the more immediate but looser 
 observations of consciousness. I claim, indeed, that we 
 have so far a compensation for this, in that we have a more 
 
PREFACE TO THE AMERICAN EDITIOJST. xi 
 
 direct and a much fuller knowledge of mind by the inner 
 sense ; but this can not be put in so scientific a form. The 
 result we reach is that we are to attain a knowledge of mind 
 by the judicious combination of the two processes, the one 
 aiding the other. But the impression should not be left 
 that W8 can gain a true knowledge of mind, of its lofty 
 ideas, say of order and design, of perfection and infinity, or 
 of its sentiments of reverence, benevolence, hope and love 
 by mere experimenting on its material adjuncts which act 
 and are acted upon by it. 
 
 I do not regard this physiological psychology as consti- 
 tuting a new psychology, as is claimed by M. Ribot. It is 
 a new and promising branch of the old science. It has not 
 altogether been overlooked in ages past. The founder of 
 Psychology, Aristotle, treated of the senses, and sought to 
 determine the functions of each. Descartes made observa- 
 tions on the brain, and Berkeley showed that we can not 
 discern distance directly by the eye. The Scottish school 
 has given attention to the same inlets ; and its principal 
 masters, Eeid, Brown, and Hamilton were acquainted with 
 the most advanced physiology of their day. But it is 
 admitted on all hands that science now requires and has 
 vigorously commenced a more searching examination than 
 our older inquirers could institute as to the mutual relations 
 of mind and brain. Young inquirers are rushing into the 
 field as adventurers do to a newly discovered mine. 
 
 There are certain departments in which physiological 
 psychology has made valuable discoveries and will make 
 more, and these of increasing value. In particular : 
 
 1. By it and by it alone we can investigate the bodily 
 senses, including the sense of temperature, in all of which 
 there are still mysteries whose solution will throw light on 
 the mode of the mind's action. It will, I believe, at no 
 distant date be settled whether each of the senses, as is 
 probable, has a special seat in the brain. 
 
Xll PREFACE TO THE AMERICAN EDITION. 
 
 2. The relation of language, as a mental exercise and 
 as articulation, to the brain, specially to the third convolu- 
 tion of the left side of the brain as discovered by M. Broca, 
 will be accurately determined. ^ 
 
 3. There are laws of the association of ideas which are 
 purely mental, and these have been approximately ascer- 
 tained. Aristotle made them Contiguity, Resemblance, and 
 Contrast; perhaps they may be more fully classified as 
 Contiguity and Correlation, including Resemblance, Con- 
 trast and others. But in explaining our experience we meet 
 with difficulties : for example, we find that the flow of 
 thought is stayed at one time, as when we are wearied at 
 night, but is resumed at another time, as when we are fresh 
 in the morning, and this no doubt is to be explained by 
 cerebral laws not yet discovered. 
 
 4. It is of importance for many scientific purposes to 
 determine the rapidity of thought and feeling in ordinary 
 and extraordinary circumstances, and also to find out how 
 this rapidity may be hastened or slackened. We already 
 know approximately what time is occupied by a sensor 
 nerve in the transmission of an excitation to the brain, and 
 the time occupied by the motor nerve in the voluntary 
 reaction ; and there have been attempts at the measurement 
 of pure thought and feeling, of choice and discernment 
 (Wundt), and of memory (Ebbinghaus). 
 
 5. An interesting field is opened in discovering at what 
 age certain acts begin to be performed and certain ideas 
 begin to rise, as, for instance, at what age infants fix their 
 eyes on objects or think of space and time, right and wrong. 
 A beginning has been made in these investigations by 
 Darwin, Spencer, Stanley Hall, and they will be followed 
 by others. 
 
 The most systematic and valuable researches on the gen- 
 eral subject have been made by German investigators. Much 
 knowledge was imparted and much impetus to inquiry by 
 
PEEFACE TO THE AMERICAN EDITION. XIU 
 
 the great work of John Miiller on Physiology. Special 
 works began with Herbart of Leipsic, who sought to apply 
 mathematics to psychical phenomena. Little positive truth 
 was thereby discbvered, as mathematics, which deals only 
 with quantity and position, can throw little light on the 
 operations of the mind ; but inquirers were taught to seek 
 scientific definiteness of results. Weber made curious 
 discoveries as to the sensitiveness of different parts of 
 the body such as the tongue and back. Fechner, in his 
 Psychophysik, has made some important observations as to 
 the relation between the external excitation and the psychical 
 perceptions, and these have been tabulated. It has been 
 difficult to reach a law applicable to all the senses. It may 
 be remarked that this subject will not be cleared up thor- 
 oughly till the inquirers take the view of causation given 
 by John S. Mill, that a cause always consists of two or 
 more agents. The external excitant does not constitute the 
 entire cause of the perception, but the two acting and re- 
 acting constitute the cause of the effect that follows. 
 
 Lotze was a man of genius, and has had great influence 
 both in Germany and in this country. He has called in 
 Local Signs to account for sense perceptions in space. I 
 believe that there is truth in his theory, although he has 
 mixed it up with metaphysics ; but the precise nature of 
 these Local Signs, which appear to me to be physiological 
 and not psychical, will require to be definitely determined. 
 
 The observations and speculations of Fechner and Lotze 
 have raised a great many discussions, and earnest inquirers 
 have reached different results. Hering of Prague has 
 attacked the psychophysics of Fechner at nearly every point, 
 denying that he has been able to establish any of his laws. 
 On the other hand the latter has been defended in some of 
 his positions by Delbœuf, who seeks, by experiment, to 
 establish certain laws of his own discovery. 
 
 Helmholtz, the great physicist, has thrown himself into 
 
Xiv PEEFACE TO THE AMERICAN EDITION. 
 
 this discussion and has inquired particularly into the origin 
 of our idea of space. He divides the theories into those of 
 the nativist and empiricist, he himself holding the latter. 
 Under the former he includes the a 'priori theory of Kant, 
 which supposes that the mind adds to the knowledge 
 acquired through the senses ; a view which can not be enter- 
 tained by those of us who oppose the doctrine that the 
 mind imposes forms on things. On the other hand I can 
 not see that the idea of space can be obtained from a 
 gathered induction or from a series of experiences no one 
 of which contains the idea. We may maintain that the 
 mind by its native power discovers at once objects in space 
 and occupying space ; and by an easy process of abstrac- 
 tion we separate the space from the objects it contains. 
 
 Wundt is the most eminent living representative of the 
 school of physiological psychology. When he brings in 
 metaphysics, however, exception may be taken to some of 
 his conclusions. Thus he will find few to follow him when 
 he says that our sense perceptions are the conclusions of a 
 process of reasoning instead of being immediate, as if we 
 could by any legitimate process of reasoning get the percep- 
 tion of an extended thing from that which has no extension. 
 I am pleased to find that he is abandoning this theory (see 
 p. 220 of this treatise) in favor of a theory of apperception, 
 a word used by Leibnitz, and pointing to a truth. But in 
 treating of his own subject, the relation of the cerebro-spinal 
 mass to mind, he has shown much ability, discrimination, 
 and wisdom ; as he has also done in measuring the time occu- 
 pied by nervous action and reaction. 
 
 We have now a clear and comprehensive account of the 
 German observations, experiments, and discussions in this 
 work of M. Eibot, with which every student of psychology 
 should be acquainted. I am not sure that he has set a 
 sufficiently high value on the observations of consciousness ; 
 but just here another of his excellencies is seen : he has 
 
PEEFACE TO THE AMEEICAN EDITION. XV 
 
 carefully separated psychology, which is a science of obser- 
 vation, external and internal, throughout from all meta- 
 physical speculation. 
 
 The work has» been well translated by one who was a 
 distinguished student and Fellow in Mental Science of 
 Princeton College, and who has since studied under the 
 great masters in Germany. 
 
 James McCosh. 
 
PREFACE 
 
 TO THE SECOND EDITION. 
 
 WoEKS published in Germany during tlie last six 
 years have made it necessary to revise this volume. 
 To simplify it, quite a little has been suppressed. 
 The principal additions have reference to recent 
 monographs on psychology, new discussions of the 
 law of Weber, and work done in the psycho-physical 
 laboratory of Wundt. The chapter devoted to 
 Wundt has also been worked over in view of the 
 second edition of his Physiological Psychology^ of 
 which a French translation is being prepared. It 
 has seemed better, therefore, not to give a detailed 
 analysis of the book, but to devote more space to 
 works which have not been translated, and probably 
 will not be. 
 
 February y 1885. 
 
CONTENTS. 
 
 Translator's Note, v 
 
 Preface hj James McCosh, D. D. LL. D , vii 
 
 Preface to the Second Edition, xvii 
 
 Introduction, 1 
 
 The old psychology — The new psychology — Its principle — Its 
 method — Physiological psychology — Comparison of English 
 and German psychology ; general characteristics of the latter 
 — Object of the book. 
 
 Beginnings: Herbart, 24 
 
 I. Principles of the psychology of Herbart — 11. Mathemetical 
 method : static and mechanic of mind — III. Feeling — IV. 
 Critique of the psychology of Herbart. 
 
 School of Herbart and the Ethnographic Psychology, 49 
 
 I. Influence of Herbart: His principal disciples — II. Ethno- 
 graphic psychology : Th. Waitz — III. Lazarus, Steinthal, and 
 their views. 
 
 li-i 
 
 otze: Theory of Local Signs, 
 
 I. In what sense Lotze is an empirical psychologist — Meta- 
 physical tendencies of his spirit and method — Unfortunate 
 consequences — II. Object of the theory of local signs : general 
 sketch of the theory — Extension referred to intensity — III. 
 Special study of visual and tactile local signs — Importance of 
 Lotze's theory : its critics. 
 
XX CONTENTS. 
 
 Nativists and Empiricists : Oeigin or the Notion of Space, 96 
 
 Status of the problem — I. Tactile space — Nativist theories: 
 Millier, Weber, Stumpf — Empirical theories — IÎ. Critical 
 study of the question — III. Visual space — Nativist theory: 
 Hypothesis of identity (Millier) ; of projection (Volkmann, 
 Bonders, Nagel, &c.) — Theory of Panum ; theory of Hering, 
 of Stumpf — The empiricists — Theory of Helmholtz, of Wundt, 
 &c. — Logical and association theories — Critical study of the 
 question : advantages and defects of the empirical position. 
 
 Fechneb anb Psychophysics, 134 
 
 General aspects of psychophysics before Fechner — II. Psycho- 
 physical researches : observations of Weber — Three methods 
 employed — III. Experimental determination of the smallest per- 
 ceptible difference, for sensations of touch, muscular effort, temp- 
 erature, sound, light — IV. Experimental determination of the 
 smallest perceptible sensation in the same cases — V. The logarith- 
 mic law — VI. The critics of Fechner, Bernstein, Brentano, 
 Hering — Researches of Delbœuf — Objections to the mathema- 
 tical expression of the law, to its experimental basis — Differ- 
 ence between Weber's and Fechner's laws — Résumé of the ques- 
 tion — Discussion of Wundt and Zeller as to the possibility of 
 measuring psychic facts. 
 
 WtTNBT AND PHYSIOLOGICAL PSYCHOLOGY, 188 
 
 Wundt's general conception of psychology and his method — 
 II. Nerve physiology : specific energy of the nerves ; criticism 
 of this theory — III. Perception — Extension referred to a psy- 
 chological synthesis — Function of local signs and movement — 
 IV. Abstract notions — V. Apperception — VI. Feeling in gen- 
 eral — ^VII. The aesthetic feelings — VIII. Moral feelings — IX. 
 Eeligious feelings — X. Will and apperception: liberty and 
 character — XI. Consciousness. 
 
 The Duration op Psychic Acts' 250 
 
 I. Eesearclies on this subject to the present — II. Determina- 
 tion of the physiological time in different conditions. Mean 
 figures of experiment. Probable duration of the simplest in- 
 tellectual act — III. Second period of psychometric research — 
 Extent of consciousness — Duration of different kinds of associa- 
 tion — Judgment — ^Pathological variations — Epitome of results. 
 
CONTENTS. 
 
 Conclusion, 
 
 XXI 
 
 287 
 
 I. Condition of psychology in Germany: Study of additional 
 questions in natural psychology — Horwicz, feeling prominent 
 — Bretauo: relation to Stuart Mill — Kussmaul — Strieker — 
 Schneider : psychology of evolution, &c., &c. — II. Analysis of 
 elements of sensation (Helmholtz) — General results and resume 
 of the work. 
 
GERMAN PSYCHOLOGY OF TO-DAY. 
 
 INTEODUCTION. 
 
 Thirty years ago, at most, if any one had dared main- 
 tain, in this country, that psychology was still in a state of 
 childhood, and had little prospect of growth, he would 
 have been accused of paradox. One would have advised 
 the critic to read again the works that have been devoted, 
 since Locke, to the different manifestations of the human 
 spirit, and the reply v>^ould have been judged sufficient. 
 
 To-day it would be no longer sufficient for any one. The 
 point of view has changed, and many are disposed to think 
 differently. In recognizing — as is just — that the old psy- 
 cliology has rendered service, has established some points 
 definitely, shown in analysis a penetration and delicacy 
 difficult to surpass, one refuses to see in all this more that 
 attempts. The spirit of the natural sciences has invaded 
 psychology and made it more difficult. One asks whether 
 a collection of ingenious remarks, of fine analyses, of 
 observations clothed in terms of elegant exposition, of 
 metaphysical hypotheses set with precious truths, that must, 
 by right, be forcible, constitute a body of doctrine, a true 
 science ; — whether it is not time to resort to a method more 
 rigorous. Thus has arisen the separation, every day more 
 apparent, between the old and the new psychology. 
 
 Although it has cut a good figure enough, the old psychol- 
 ogy is doomed. In the new surroundings that have recently 
 
 1 
 
2 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 grown np the conditions of its existence have disappeared. 
 Its methods do not suffice for the increasing difficulties of 
 the task, for the growing exigencies of the scientific spirit. 
 It is compelled to live upon its past. In vain its wisest 
 representatives attempt a compromise, and repeat in a loud 
 voice that it is necessary to study facts, to accord a large 
 share to experience.^ Their concessions amount to nothing. 
 However sincere their intentions; in fact, they do not 
 execute them. As soon as they put hand to the work the 
 taste for pure speculation seizes upon them. Besides, no 
 reform is possible of that which is radically false, and the 
 old psychology rests upon an illegitimate conception, and 
 should perish with the contradictions that are in it. The 
 effi^rts that are made to accommodate it to the exigencies of 
 the modern spirit, to work a change in its real nature, 
 bring only delusion. Its essential characteristics remain 
 always the same ; one can show it in few words. In the 
 first place, it is possessed of the metaphysical spirit ; it is 
 the " science of the soul ; " internal observation, analysis, 
 and reasoning are its favorite processes of investigation : it 
 distrusts biological science, associates with it only in reluct- 
 ance and by necessity, and is ashamed to acknowledge its 
 debt. Feeble and old, it makes no progress, and asks only 
 to be let alone, that it may spend its age in peace. 
 
 Such a conception is no longer vital. Its metaphysical 
 tendencies exclude the positive spirit, forbid the employ of 
 a scientific method, deprive psychology of the fruits of free 
 research. It does not dare to assert itself as a study of 
 psychic phenomena alone, distinct and independent. Yet 
 
 ^ Others more determined in Germany, some few Hegelians, and with 
 us the disciples of the school that takes the name " spiritual realism," 
 make psychology a branch of metaphysics and despise natural psychoid 
 ogists. We have no intention of combating these mystics ; no discus- 
 sion is possible with them, because there is nothing common ; neither 
 principles, methods, language, nor end. 
 
INTRODUCTION. 3 
 
 this is a real necessity. In proportion as the old habits of 
 mind are effaced, will we see, more and more clearly, that 
 psychology and metaphysics, formerly confounded under 
 the same title, presuppose intellectual aptitudes that are 
 opposite and exclusive. We will perceive that talent in 
 metaphysics bears an inverse ratio to talent in psychology ; 
 that henceforth, apart from some rare geniuses who com- 
 bine the two perhaps, the psychologist should renounce 
 metaphysics and the metaphysician psychology. 
 
 For the old school, since taste for internal observation 
 and subtilty of spirit were exclusive signs of a call to psy- 
 chology, the programme summed itself up in two words — 
 observation and reasoniiig. Internal observation is, with- 
 out doubt, the first step ; there is always a necessary pro- 
 cess of verification and interpretation ; but it can not be a 
 method. To maintain this is to forget or to disown entirely 
 the conditions of a scientific method. If psychology cau 
 be constructed in this way, good eyes and fixed attention 
 will suffice for the construction of physiology. 
 
 Subtilty of spirit is also too fragile an instrument to pene- 
 trate the compact and serrated line of the facts of conscious- 
 ness. For the last two hundred years it has been testing. 
 We owe to it good descriptions, excellent analyses ; but its 
 work is done. Its province now is simply details, shades 
 of meaning, refinements, subtilties. And as far as it dare 
 touch upon the profound, it will be only to heaj) up more 
 delicate and hidden distinctions. It does not reach the 
 general — can never explain it. Under these conditions the 
 psychologist becomes a romancer, a poet of an especial kind ; 
 he seeks the abstract rather than the concrete ; he dissects 
 instead of producing, and psychology becomes a kind of 
 literary criticism, very penetrating and acute, but nothing 
 more. The study of psychic phenomena in their totality 
 from the lowest form in animals to the highest in man is 
 forbidden him. Such a psychology is incapable of referring 
 
4 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 these manifestations to the laws of life ; it has neither full- 
 ness nor strength. 
 
 What strikes one, in fact, in the old psychology, is its 
 extreme simplicity ; it is simple in its object, simple in its 
 means. It presents a character that is narrow, and, to 
 speak it in a word, childish. It lacks air and horizon. 
 Questions are proposed in a shallow and insufficient form, 
 treated by a verbal method which approaches the scholastic. 
 All resolves itself into deductions, arguments, objections 
 and replies. In this refinement of subtleties, always in- 
 creasing, we reach at last symbols only: all reality has 
 disappeared. In the solitary spirit that racks and torments 
 itself to draw everything from within, that meditates v/ith 
 closed eyes, taking from without only what is necessary to 
 save itself from death by inanition, a rarefied atmosphere 
 is produced, that nothing living can breathe. The soul is 
 haunted with wild visions. 
 
 To any one who takes up these questions in their suc- 
 cession, it ia easy to show that this metaphysical preoccu- 
 pation, this abuse of the subjective method and the reason- 
 ing powers, paralyze the best minds. The state of con- 
 sciousness isolated from that which precedes, accompanies 
 and follows it, i. e., its anatomical, physiological, and other 
 conditions, is nothing more than an abstraction ; and when 
 we have duly classified it, referred it to a hypothetical fac- 
 ulty which is itself attributed to a hypothetical substance, 
 what have we discovered, what have we learned ? If, on 
 the other hand, the state of consciousness be studied as part 
 of a natural group whose elements mutually suppose one 
 another, and are to be studied each apart and in its relation 
 to the others, we rest in reality. We are not satisfied with 
 the formula so dear to the old psychologists : " This is from 
 physiology." But we take our own wherever we find it ; 
 we receive instruction from all sides, and do not mistake for 
 a science the nomenclature of phantoms of our own making. 
 
INTRODUCTION. 5 
 
 Too much reasoning : this is the impression that the old 
 psychology makes upon the disciples of the new. Reason- 
 ing — that is confidence of the spirit in itself, and faith in 
 the simplicity of things. The new psychology submits 
 that the spirit ought to distrust itself, and believe in the 
 complexity of things. Even in the less complex order of 
 biological science, our inductions and deductions are baffled 
 at each step. What ougM to be, is not ; what is inferred is 
 not verified ; where logic says yes, experience says no. 
 
 Do the representatives of the old psychology — and they 
 are still many, though differing in shades of opinion — 
 understand the position they have taken with reference 
 to contemporary science? The physicist and the chem- 
 ist trust themselves only in their laboratories : the biolo- 
 gist daily adorns his workshop with new machines, arms 
 himself with all his weapons, raulti2)lie3 his instruments 
 and means of experiment, strives to substitute the passive 
 and mechanical registry of phenomena for their sub- 
 jective estimation, since the latter is always vacillating 
 and uncertain. The psychologist, on the contrary, dealing 
 with facts of the extremest complexity, is unable to begin 
 again the work of his predecessors, or reconsider what 
 is already well established, is compelled " to interrogate 
 himself," without information, experience, apparatus, or 
 means of procedure. If his work is a science, it must be 
 confessed that it resembles nothing else that bears that 
 name. 
 
 IL 
 
 The new psychology differs from the old in its spirit : it 
 is not metaphysical ; in its end : it studies only phenomena ; 
 in its procedure : it borrows as much as possible from the 
 biological sciences. 
 
 We have tried elsewhere to show the advantages of a 
 psychology without metaphysics, or, as has been said since, 
 
6 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 " a psychology without a soul." Let us set aside this neg- 
 ative aspect of our subject to consider it now under its 
 positive aspect. 
 
 One of the greatest obstacles to the progress of psychol- 
 ogy, now, for a long time, a signal obstacle, is the very 
 nature of the facts of consciousness, so vague, so fleeting, so 
 difficult to fix. While objective plienomena are distin- 
 guished from one another by their specific qualities, their 
 relations in time, and especially their form, figure, and all 
 their quantitative determinations in space ; psychical states, 
 taken in themselves, recognized in consciousness alone, have 
 differences only of quality and relation in time. Thus it 
 has been the task of the new psychology from the first to 
 attempt to increase their determinateness, or, what amounts 
 to the same thing, the sum of their relations. It is here 
 that the discoveries of physiology have been a great help. 
 It being established that psychical movements are connected, 
 in a general way, with the cerebro-spiual system, physiology 
 has shown more recently, that every psychical state is 
 invariably associated with a nervous state, of which reflex 
 action is the most simple type. This principle is uncon- 
 trovertible for the majority of cases, in the highest degree 
 probable for the remainder. 
 
 It is impossible for us to show here in detail that every 
 state of consciousness is accompanied by a correlative well- 
 determined physical state. Some general indications of it 
 will suffice. As far as tlie five senses and the visceral sense 
 are concerned there is no doubt. In regard to mental 
 images, it is not induction alone that supports the position 
 that ideal reproduction supposes physical conditions anal- 
 ogous to those of sensation ; but pathological facts, hallu- 
 cinations in particular, show that the idea-process (ideation) 
 is connected with definite states of the nerve centres. Fur- 
 ther, we find desire, feeling, volition, accompanied, each 
 after its kind, by a physical change ; changing states of the 
 
INTRODUCTION. 7 
 
 organism, movement, cries, gestures, secretions, vascular 
 modifications. Yet, in the totality of the psychic life, there 
 are certain states of consciousness of which this general 
 position may be 'doubted. Do not reflection, abstract 
 reasoning, exalted feeling, seem, as the old psychology 
 maintains, to be manifestations of pure mind ? This propo- 
 sition can not be maintained. The psychic life is a 
 continuity beginning with sensation and ending with 
 movement. At one extreme we find sensation and images 
 connected with physical states ; at the other extreme, desire, 
 feeling, and volition, also connected with physical states; 
 can we suppose in tlie centre the existence of a terra incog- 
 nita under other conditions and ruled by other laws ? " It 
 would contradict all we know of cerebral action to suppose 
 that the physical cliain leads abruptly to a physical chasm 
 occupied by an immaterial substance which communicates 
 the results of its work to the other end of the physical 
 chain. . . In fact, there is no interruption in nervous con- 
 tinuity" (Bain). But plausible as this conclusion seems, 
 psychology can do more than reason from an analogy 
 founded on the continuity of natural law. In the first 
 place, the most profound and abstract reflection is not pos- 
 sible without symbols that suppose a physical determina- 
 tion, feeble though it may be. Again, general physiology 
 informs us that if something is produced, something decays ; 
 that the period of functional discharge is a period of dis- 
 organization, and that this biological law is applicable to 
 the brain as to any other organ, to the work of the brain 
 as to any other function. Let us notice, also, the production 
 of heat which accompanies psychical activity (Schiff), modi- 
 fications in the excretions produced by intellectual work 
 (Byasson) ; and without accumulating details that would fill 
 a volume, we can conclude — that every definite psychical state 
 is connected with one or more definite physical events which 
 we recognize well in most cases, little, or not at all, in others. 
 
8 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 This principle admitted, — and it is the basis of physiolo- 
 gical psychology, — the inquiry presents itself under an 
 entirely new aspect, and justifies the employment of a new 
 method. For the vague and commonplace formula of the 
 " relations of soul and body," as the old school employs it, 
 for the arbitrary and barren hypothesis of two substances 
 acting upon each other, let us substitute the study of two 
 phenomena which have, for each particular case, so con- 
 stant a connection that they can be most exactly designated 
 as one phenomenon of a double face. 
 
 Accordingly, the domain of psychology is specific : it 
 has for its object nervous phenomena accompanied by 
 consciousness, finding in man the type most easy of recog- 
 nition, but bound to pursue the investigation through the 
 whole animal series, however difficult. At the same time, 
 the distinction between psychology and physiology is es- 
 tablished. Nervous process in its simple aspect belongs 
 to physiology; nervous process in its double aspect 
 belongs to psychology. There can be no hesitation in 
 cases where consciousness merges little by little into autom- 
 atism (habitude), and in cases where automatism merges 
 into consciousness. The soul and its faculties, the great 
 entity and the small entities, disappear, and we have to do 
 only with internal events, which as sensations and mental 
 images translate physical events, or which, as ideas, move- 
 ments, volition and desire, are translated into physical 
 events. A great result is thus obtained ; the state of con- 
 sciousness ceases to be an abstraction filling a vacuum. It 
 is fixed. By connection with its physical concomitant, it 
 enters with it and througli it into determined conditions 
 which make science possible. Psychology is connected 
 again with the laws of life and with its mechanism. 
 
 This does not, as is unreasonably said, give psychology 
 over to physiology. By a logical necessity the superior 
 science rests upon the inferior. Does not contemporary 
 
rNTEODucno]^. 9 
 
 physiology descend at each instant into chemistry and 
 physics to acknowledge its debt to them? Would any 
 one say on that account that it is thus absorbed to their 
 profit? Between the science of the phenomena of con- 
 sciousness and physiology there is the same relation as 
 between the latter and the physico-chemie^al sciences. If 
 one objects that the passage from life to consciousness is 
 inexplicable, it is only necessary to remark that the passage 
 from the inorganic to the living is none the less so. The 
 difficulty is then the same in the two cases, and it is illogi- 
 cal to maintain that a method that is legitimate in one case 
 is illegitimate in the other. 
 
 III. 
 
 An incontestable truth, resulting from tlie very nature 
 of the old psychology, is that it must remain a science of 
 pure observation. The new psychology, on the contrary, 
 has recourse, in a measure, to experiment. When psycho- 
 logical problems are put in the form we have indicated 
 above ; when the internal phenomenon, instead of being 
 looked upon as a manifestation of an uuknov/n substance, 
 is considered in its natural connection with a physical 
 phenomenon, it becomes possible to approach it by means 
 of this accompanying physical phenomenon ; for this 
 latter is, in most eases, under the hand of the experi- 
 menter, and he is able to measure its intensity and varia- 
 tions, to place it in definite circumstances, to submit it to 
 all the processes tliat constitute rigorous investigation. 
 Psychology thus becomes, in the proper sense of the word, 
 experimental. In fact, these processes are psycho-physical, 
 but, the external and the internal being strictly combined, 
 the object and final' results are psychological. We will not 
 attempt to give these here. The object of this book is to 
 set them forth at length. Vague and general phrases con- 
 vey no information. Suffice it to know that this method 
 
10 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 lias been employed, that it has borne fruit, and that, how- 
 ever difficult the task may be, the way has been opened. 
 
 To show clearly, in few words, the différence in the two 
 methods, we will refer to the theory of experimental 
 methods due to Stuart Mill, which has now become classic. 
 
 The old psychology employed in its process of investi- 
 gation only the method of agreement and the method of 
 difference. By this means it attained its principal object, 
 i. e., a natural classification of the " manifestations of the 
 soul," grouped under the names of the different faculties. 
 
 The new psychology also employs these two methods, 
 but it adds to them a third : that of concomitant variations. 
 Physics is not able, in studying heat, to drive it from body 
 and bring it back again. It proceeds in an indirect way. 
 It increases it, diminishes it, causes it to vary, and studies 
 these variations in their visible and tangible effects. It is 
 equally impossible to suppress and re-establish a form of 
 mental activity for the purpose of studying its nature and 
 effects ; but it is possible to vary it through the medium 
 of its physical condition. We capture the former through 
 the latter. Thus we study not the phenomenon of con- 
 sciousness, but its variations. Or, more exactly, we study 
 psychical variations indirectly by the aid of physical varia- 
 tions, that can be studied directly. It matters not if the 
 process be complicated, provided it be rigorous. Know- 
 ledge of natural facts is not easily obtained, and it is an 
 error of the old psychology to have confounded natural 
 knowledge of the facts of consciousness, which is direct, 
 with scientific knowledge of these facts, which is indirect. 
 Hence the simplicity of method that we have pointed out 
 in it; hence its powerlessness to pass much beyond the 
 level of common sense. 
 
 But we must not believe that experiment, with the pro- 
 cesses that constitute it, — measure, numerical determination, 
 etc., — has been applied to all the questions of psychology, or 
 
INTRODUCTION. ] 1 
 
 even to the greater number. So far there have only been 
 attempts, fragmentary investigations; but these attempts 
 mark the advance of psychology upon a new phase, the 
 passage of the descriptive period into the explicative. It is 
 no longer satisfied with being a natural history ; it claims 
 to be a natural science. This it is that explains the fact 
 that the English and the German psychology, despite their 
 community of end, has each its distinct characteristics ; that 
 one is systematic ; the other technical ; one rich in work as 
 a whole ; the other rich in work in detail. The best way 
 to show this difference clearly is to indicate the place that 
 each occupies in the evolution of psychical study. 
 
 Anterior to all science, the human spirit, as Wundt^ has 
 remarked, cannot collect the facts of experience without 
 mingling them with its own speculations. The first result 
 of this natural reflection is a system of general ideas, which 
 are translated into language. When science begins its 
 work, it finds these ideas already present. For example, in 
 the domain of external experience, heat and light are con- 
 cepts derived immediately from sensation. Positive physics 
 reduces these two ideas to a more general concept : move- 
 ment. But it has reached this result only by accepting at 
 first, and provisionally, the indications of common sense. 
 It is the same in the domain of internal experience. Soul, 
 spirit, reason, intellection, are ideas which preceded all 
 scientific study and made it possible. The mistake of the 
 old psychology has been that it accepted these creations of 
 the natural consciousness for definite truths. The soul, for 
 example, instead of being considered simply as a logical 
 subject, to which we attribute all the facts of internal expe- 
 rience as predicates, has become a real being, a substance, 
 manifested in " faculties." 
 
 The study of the facts of consciousness in themselves, in- 
 
 ^ Grundziige der Physiologischen Psychologie, p. 8. 
 
12 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 dependent of the general ideas that encumber language, 
 marks the first attempts at a new psychology, and dates 
 back almost two centuries. In the midst of much doubt 
 and uncertainty, Locke, and those who have followed his 
 tradition, go to an extreme, and reject all ideas already 
 formed as popular prejudices. But as their psychology was 
 still joined to metaphysics, no real progress was possible. 
 The break has come only in our day. 
 " Yet the first representatives of the new psychology gave 
 too large a part to verbal analysis and reasoning. They 
 did not enter sufficiently into the facts themselves. In 
 England, James Mill is the best example. Even Stuart 
 Mill, so eminent as a logician, so profoundly versed in 
 modern methods, though recognizing the utility of phy- 
 siological study, concedes to it too little. 
 
 It is in contemporaries, whom it would be superfluous to 
 name, that natural psychology attains complete self-con- 
 sciousness. Bain may be regarded as their chief represent- 
 ative, in that his method, entirely descriptive, free from all 
 hypothesis, evolutionistic or otherwise, rests in the order 
 of positive facts and gives no room whatever to criticism. 
 Questions are put in a natural concrete form. The internal 
 event is never separated from its conditions and its physical 
 effects. Physiology serves as guide. Pathological indica- 
 tions are used to profit. Each group of phenomena is 
 studied minutely and the laws induced — ^the law of associa- 
 tion and secondary laws — are given as the expression of 
 constant and general relations. 
 
 Such are the essential traits of contemporary English 
 psychology.^ It is, in the largest and best sense, a descrip- 
 tive study. In Germany, on the contrary, those who are 
 working to construct an empirical psychology accord little 
 
 ^We include under this title all doctrines that present the same 
 characteristics, to whatever country they belong. 
 
INTEODUCTIOX. 13 
 
 place to description. To characterize their worlc we mubi; 
 employ a term which has been much abused in our day, 
 but which is proper here, that is, 'physiological psychology. 
 Almost all of theni are physiologists, who, with their habits 
 of mind and the methods peculiar to their science, have 
 touched upon some points of psychology. 
 
 We have seen above that the psychical life consists of a 
 series of conscious states connected with physical states, and 
 that these begin with sensation and end with action. We 
 have also seen that in this uninterrupted series of psycho- 
 physical states those that are situated in the centre of the 
 chain form a group most difficult of access by means of 
 physical investigation. Ordinarily, German psychologists 
 have neglected this last group, or have studied it only cur- 
 sorily. But in the limited field to which they have restricted 
 themselves, they have given psychology a new impulse. They 
 have practised experiment. They have placed the psychical 
 phenomenon in definite conditions and studied its variations. 
 
 As the whole experimental method reposes definitively 
 in the principle of causation, physiological psychology has 
 two systems of means at its disposal : to determine effects 
 from their causes (for example, sensation from excitation) ; 
 to determine causes from their effects (internal states from 
 the actions that exhibit them). There is, moreover, need 
 that one at least of the two terms of this indissoluble 
 couple called the causal nexus be outside of ourselves, out- 
 side of consciousness ; that there be a physical happening as 
 such accessible to experiment. Without this condition, the 
 experimental method cannot be employed. In the order 
 of the phenomena that we call purely internal (the repro- 
 duction of ideas, their association, etc.), the cause and 
 effect are in ourselves. Although we cannot doubt that 
 the law of causality reigns there as elsewhere ; although, 
 in some cases, the cause can with certainty be determined ; 
 yet, as both causes and effects are in us, and give no exter- 
 
14 GEEMAlSr PSYCHOLOGY OF TO-DAY. 
 
 nal value, their physical concomitants being little known 
 or inaccessible, all experimental research in what concerns 
 them is necessarily impossible. 
 
 Indeed, some representatives of the German psychology 
 have thought that, even where experiment fails, we are not 
 driven to observation and description ; that we may yet 
 hope for more exact results. To reach them, they have 
 recourse to calculation. They have treated some questions 
 by a mathematical method. Assuming the principle that 
 every internal event has magnitude, and that it has, in 
 consequence, a mathematical character, they have tried to 
 proceed in psychology as in certain branches of mathe- 
 matical physics. They proceed on principles postulated as 
 probable hypotheses ; they deduce consequences by the aid 
 of reasoning and calculation, and compare the results with 
 those given in experience. For the success of this method 
 two conditions are necessary : that the principal hypotheses 
 be the product of induction and present indisputable signs 
 of probability ; and, following this, that the deductions that 
 are drawn from them be constantly compared with reality 
 and controlled by it. AVe will find in the course of this 
 work some attempts of this kind. New and ingenious as 
 they are, they certainly do not constitute the solid part of 
 German psychology. 
 
 From what precedes we may learn the essential traits of 
 the German psychology, and judge it in contrast with the 
 English. It presents, as a general characteristic, a greater 
 effort at precision; as special characteristics, the employ of 
 experiment; quantitative determination (experiment sup- 
 posing number and measure) ; a more limited field of study ; 
 a preference for monographs rather than extended works. 
 Many of these investigations, we shall see, pertain to very 
 modest questions, and it is probable that the partisans of 
 the old psychology will find the work too great for results 
 so small. But those who give allegiance to the methods 
 
INTRODUCTION. 15 
 
 of the positive sciences will not complain of this. They 
 know how much effort the smallest questions require ; how 
 the solution of small questions leads on to the solution of 
 great ones, and how barren of results it is to discuss great 
 problems before the small ones have been solved. 
 
 lY. 
 
 If we have succeeded in showing the place German 
 work occupies in the general evolution of modern psychol- 
 ogy, it is almost superfluous to add that instead of ex- 
 cluding the results of the purely descriptive method, it 
 supposes them. The two schools, descriptive and experi- 
 mental, have the same object : the latter marks a growing 
 tendency toward exactitude. But it is so far from being a 
 complete psychology, that it oJEfers us at present only at- 
 tempts. The future alone will be able to fix its true value, 
 and to say whether the scientific rigor to which it aspires 
 can be altogether attained. Thanks to the employ of ex- 
 periment and measure, it presents an original aspect : it is 
 our business to put it in relief. Meanwhile it would be 
 wrong to exaggerate the oppositions and difi^erences in the 
 results. It is only a branch of empirical, natural psy- 
 chology, which, in its true state, demands, in large part, 
 descriptive study. 
 
 Its great merit is that it has determined better than 
 vague definitions can what is properly a physiological 
 psychology. In consequence of a misconception that arises 
 in many minds, this term is often understood as applicable 
 strictly to the new psychology. This is not really true. 
 When psychology, realizing a progress that it does not 
 dream of now, succeeds in determining the conditions of 
 all mental action, of whatever sort, as well of pure thought 
 as of perception and movement, then psychology will be 
 entirely physiological, and it will be well indeed. For the 
 present there is an entire group of facts of consciousness 
 
16 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 whose study finds in the sciences of life only an indirect 
 and unstable support. The processes of the old psychology 
 — internal observation, analysis — find here their place; but 
 the new school employs them only in support of physio- 
 logical psychology, and to investigate two things : facts 
 and their relations. 
 
 The field and place of physiological psychology is defined 
 with sufficient clearness, as follows : 
 
 Its field, which ought to enlarge insensibly with pro- 
 gress in the physiology of the nervous system, embraces : 
 reflex action and the instincts ; detailed study of sensation 
 with questions relative to time and space in the limits of 
 experiment, movement, modes of expression and language ; 
 the conditions of the will and attention ; the forms of the 
 more complex feelings. 
 
 Its place is at the beginning of psychology. It studies 
 what the old school called the inferior faculties of the 
 soul ; but in it alone the study of the highest manifestations 
 finds a point of departure. It constitutes the most easily 
 accessible and the simplest part of mental science. 
 
 This simplicity is, moreover, altogether relative. To be 
 convinced of it one has only to read the books devoted to 
 the whole or to some parts of the physiological psychology. 
 In the presence of this constantly increasing mass of obser- 
 vations, experiments, measures, numerical determinations, 
 of facts based upon the physical sciences, upon physiology, 
 pathology, ethnology, of hypotheses and discussions varying 
 without end in the service of new discoveries, and which 
 denote a curiosity always on the alert on all points, always 
 alarmed at forgetting or neglecting something — one finds 
 himself in a new world, and he is not astonished that the dis- 
 ciples of the old school refuse to countenance a psychology 
 that resembles theirs so little. Add the weariness of tech- 
 nical details, a dry mode of exposition, from which all 
 literary adornment and oratorical effect are excluded, and 
 
INTEODUCnON'. ] 7 
 
 one will understand how it is that some good spirits find 
 themselves lamenting the psychology of the past, so simple, 
 so convenient, so tractable, and expressed in such beautiful 
 language. * 
 
 And yet, if it is permitted to judge the future, this com- 
 plexity is simple in comparison with that which will appear 
 one day,- when the domain of purely internal psychology 
 will be entered upon. Let us suppose the physiological 
 psychology, of which we have as yet only rough sketches, 
 already complete ; then only will it be possible to attempt 
 this new conquest, and to penetrate into the internal mech- 
 anism of spirit by the aid of processes that to-day we do 
 not suspect. What will this future science reveal ? This 
 no one can say, not even surmise ; but from the difficulty 
 of the work one can measure the enormity of the effort and 
 see beforehand that this psychology will resemble the old 
 as little as the physics of our day resembles that of Aris- 
 totle. 
 
 To confine ourselves to the present, the grandeur of the 
 task is of a nature to call forth the boldest conjecture. If 
 we cast a glance over the sciences of life, and consider the 
 number of laborers, and the questions at which they are 
 laboring, and the necessity for the untiring prosecution of 
 details which alone gives true science, we will conclude 
 that psychology should be in the same condition. The 
 old school, in regard to the small number of facts that it 
 demanded from the positive sciences, had set up the axiom 
 " that the knowledge of results was sufficient." It was a 
 rule of easy application but of little profit, for these results 
 and the propositions that express them are only formulas 
 without value for the man who does not know the facts by 
 which they are supported. 
 
 This pretended axiom rejected, we may see the time 
 approaching when psychology will demand the entire power 
 of a man, when he will be psychologist alone, as he is 
 
18 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 physicist, chemist, physiologist alone. In every science 
 that flourishes and is cultivated with enthusiasm, there is 
 a necessary division of labor. Each important question 
 becomes a field by itself. Will not the profound study of 
 perceptions alone, for example, be sufficient for the most 
 active mind ? Empirical psychology, united to the other 
 natural sciences by a tie of close connection, widens its 
 field ; the constant work of analysis enlarges the mass of 
 details. Where the last century had twenty facts to master, 
 we have twenty laws ; and next will come laws of laws, that 
 is, the generalization of more and more numerous facts. The 
 human brain has its limits, and is by necessity compelled to 
 concentrate itself upon a single study .^ 
 
 In fact, the number of those who are prepared for this 
 work is very small. The majority of physiologists know 
 too little psychology, and the majority of psychologists too 
 little physiology. We live in a period of transition, and 
 its difficulties are sufficient to tax the greatest courage. 
 There is no one who has the progress of the new psychology 
 at heart who does not feel, at all times, the lack of better 
 preparation. It will be necessary, to undertake this inves- 
 tigation with profit, to be versed in mathematics, physics, 
 physiology, pathology, to have material to deal with, instru- 
 ments to use, and especially the aptitudes of experimental 
 science. All this is wanting. In France especially, thanks 
 to the prevalent ideas that our early education has given us, 
 and the bad habits of mind that it has led us to form, the 
 second half of our life is spent in unlearning what we 
 learned in the first. 
 
 ^ It would be interesting to ask what philosophy, as a general con- 
 ception of the \70rld, will be, when the special sciences, in consequence 
 of their growing complexity, become in their detail too large for the 
 mind, and when philosophers will confine themselves to the most gen- 
 eral and necessarily superficial results. It is a question which we submit 
 to the thought of tlie reader. 
 
INTRODUCTION. 19 
 
 Psychology, in fact, has had the misfortune, hitherto, of 
 being left in the hands of metaphysicians. A tradition 
 has thus been formed that is difficult to break. In conse- 
 quence of matured' prejudice, men find it hard to admit 
 that the psychologist should be a naturalist of a distinct 
 kind. They persist in thinking of him as a "philoso- 
 pher" ; a title as inexact in this case as if it were applied 
 to the biologist or the chemist. 
 
 As long as this antiquated opinion persists, the word 
 psychology will have a very different meaning. This is 
 the reproach that the old school casts perpetually at the 
 new, that they know only the mechanism of mental life; 
 and this is true. But only metaphysicians can ask more. 
 If to know is to reveal an unknowable essence, then the 
 new psychology has taught us nothing. But if to know 
 is to study facts, to discover the conditions of their exist- 
 ence, and their relations, then it has done what it should 
 do ; and it is neither willing nor able to do anything else. 
 
 V. 
 
 It remains for us to indicate the object of this book. It 
 is not to give a history of contemporary German psy- 
 chology. In Germany, as everywhere, there is a spiritual- 
 istic psychology, which, under the different names of 
 anthropology and the science of man, exhibits the classical 
 traits of our current treatment of these questions.^ In 
 these works there are two constructive portions : the his- 
 tory and classification of positive truths, and their inter- 
 pretation. The latter is not new and varies only in insig- 
 nificant details. We will not treat of this psychology. 
 
 * The principal representatives of this psychology are at present : 
 Ulrici, Oott und der Mensch, 2 vols. ; Hermann Fichte, Anthropologie ; 
 Harms, Philosophie in ihrer GescMchte, tome 1, Psychologie ; Max Perty, 
 very numerous works, in particular, an Anthropologie, 2 vols. ; many 
 articles in the Zeitschrift fur Philosophie und philosoph. Kritik. 
 
20 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 We have excluded purely metaphysical theories, ideal- 
 istic and realistic. As large a part as they have taken in 
 psychology, they have nothing to teach us. Here, as in 
 all other departments of human knowledge, they deal only 
 with principles and general characteristics ; as for us, it is 
 particulars that we seek. 
 
 We have excluded also the interesting "theories of 
 knowledge," so numerous in Germany, due generally to 
 vigorous and subtle spirits that bear the mark of Kant. 
 They constitute a separate domain ; that of general criti- 
 cism. Their exposition would be a great task, and would 
 require a volume alone. 
 
 These exclusions made, there remains a very limited 
 field : it is the study of questions that are accessible at the 
 same time to observation and consciousness, and to scien- 
 tific investigation such as is practised in the laboratory ; 
 it is psychology considered as a natural science, stripped of 
 all metaphysics and based upon the sciences of life. But 
 our position is not as humble as it would seem, for these 
 phenomena serve as base and. point of departure for all the 
 rest. Physiological psychology, as it seems to us, pene- 
 trates through unforeseen openings into the loftiest ques- 
 tions of human knowledge, and modest experimenting 
 teaches more than volumes of speculation. 
 
 To estimate the spirit of contemporary German psy- 
 chology well, it is necessary first of all to remember that the 
 investigations that are to be presented are not the work of 
 philosophers, or of speculative thinkers. They are due to 
 scientists. German psychology presents us thus a particu- 
 lar and original character. While in England an unin- 
 terrupted tradition from Locke, through Berkeley, Hume, 
 Hartley, James Mill, confronts our contemporaries, in 
 Germany there is no tradition and no psychological school : 
 all is new. 
 
 Kant's successors were metaphysicians, and, in our day, 
 
LNTRODUCTION. 21 
 
 the critical school has succeeded them. Herbart alone, 
 among his numerous disciples, can be called a psychologist. 
 He sets out from a 'priori principles, gives little room to 
 facts, much to reasoning and mathematics ; but he had 
 some new and good conceptions, and especially an influ- 
 ence. Transformed by Beneke and developed by others, 
 his doctrine is becoming lost in rather vague speculations in 
 anthropology and ethnology. But, at the same time, the 
 true empirical psychology is growing, little by little, in 
 obscurity, taking its chances on occasion in works or 
 memoirs of physiology. 
 
 If a founder must be named, John Muller merits the 
 title. In his books he assigns large part to psychological 
 questions, and treats them fully. A disciple of Kant, he 
 wished, in his way, to give a physiological basis to the 
 theory of the subjective forms in intuition. 
 
 To each species of sensor nerve he attributed a specific 
 energy, in virtue of which each organ reacts in a manner 
 peculiar to it, whatever be the nature of the excitation 
 which it receives. He transformed the Kantian doctrine 
 of space in a physiological way, claiming that the retina 
 had a native feeling of its extension. This hypothesis, 
 taken up, modified, rejected, has given rise to a very lively 
 debate that is still in progress, and touches upon the noblest 
 problems of psychology. 
 
 After him, each order of sensation became the object 
 of profound research. Men studied their qualitative and 
 intensive differences. By penetrating deeper and deeper 
 into the knowledge of anatomical and physiological mecha- 
 nism, they were able to determine what, in sensation, is 
 simple, immediately given, and what is added by the work 
 of the mind (induction, deduction, the association of 
 images). Where consciousness, of itself, sees only an irre- 
 ducible fact, experiment shows many elements in combina- 
 tion. Going still further, Helmholtz shows, especially for 
 
22 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 sound, that a sensation called absolutely simple, free even 
 from the psychological conditions of which we have just 
 spoken, may be decomposed into elementary sensations that 
 consciousness fails to disunite. His experiments have 
 served as basis for the ingenious interpretations of Taine 
 and Herbert Spencer.^ 
 
 The same savant, preceded on this road by Dubois-Rey- 
 mond, and followed later by Bonders, Exner, Wundt, and 
 many others, attempted to determine the duration of 
 psychic acts. At first, sensations were studied ; later, acts 
 of a more abstract nature. This investigation continues, 
 has thrown light on the mechanism and conditions of con- 
 sciousness, and, as we may presume, will bring to light 
 unexpected results. 
 
 Outside of biological science, Fechner has pursued a 
 line of investigations aiming at the measurement of the 
 intensity of sensations in their relation to the excitation 
 that causes them. He has employed mathematics and 
 physics. His generalizations have given rise to a lively 
 controversy, and brought out verifications and counter- 
 experiments. A considerable number of works have al- 
 ready appeared, which, in accordance with the title chosen 
 by Fechner, are included under the name of psycho- 
 physics. 
 
 Such are the most general characteristics of the move- 
 ment that has arisen in Germany during the last thirty 
 years. Besides Miiller, its principal promoters have been 
 E. H. Weber, Volkmann, Dubois-Reymond, Fechner, 
 Lotze, Wundt. Several of them have contributed to the 
 progress of psychology without setting to themselves this 
 object. One will not be astonished, then, that their work, 
 as we. are going to present it, has a fragmentary character. 
 
 ^ Taine, De l'Intelligence, part 1, book iii. ; Herbert Spencer, Pnnci- 
 pies of Psychology, vol. i., part 2, ch. i. 
 
INTRODUCTION. 23 
 
 that they pursue different directions, and are engaged upon 
 different subjects. They are scattered workmen; not at 
 all resembling a school to the eye, that is to say, to the eye 
 of those who obey a common discipline and pursue a com- 
 mon tradition. But there are traits common to all of them, 
 and which distinguish them from every other group of 
 psychologists : the experimental sciences as point of de- 
 parture, a characteristic method, and a positive style of 
 treatment. 
 
 In most cases, it would have been impossible to proceed 
 here as with the English psychology. We ought often for 
 a monograph on a psychology to have substituted a mono- 
 graph on a single question, and to have mentioned also 
 works published elsewhere than in Germany. To our 
 mind, this necessity marks progress. According as psy- 
 chology, breaking its old metaphysical bonds, shall accus- 
 tom itself to the method of the sciences that touch it most 
 closely, will it carry less and less the imprint of one man 
 or one race, and become the common work of all lands. 
 
CHAPTER I. ' 
 
 BEGINNINGS : HEEBAET.* 
 
 I. 
 
 The first efforts toward a scientific psychology, in Ger- 
 many, are due to Herbart. They constitute a transition 
 from the pure speculation of Fichte and Hegel to the 
 unmetaphysical psychology. This explains the fact that 
 they are cited by such men as Helmholtz and Wundt, 
 that they have had an avowed influence upon them, and that 
 in other respects they have at present little more than an 
 historical interest. 
 
 Herbart has given us his psychology in two works under 
 the titles : Psychology as a Science, founded, for the first 
 time, upon Experience, Metaphysics, and Mathematics, and 
 Handbook of Psychology? The latter is much more con- 
 cise than the former, and is more difficult to read : it con- 
 sists, for the most part, in a resume of definitions and 
 formulas. 
 
 The point that concerns us at first sight is that Herbart 
 expects to found psychology on metaphysics. His point 
 
 ^ Herbart was born at Oldenburg, May 4th, 1776 ; he studied under 
 Fichte at Jena, was professor at Gottingen and at Konigsberg. He 
 died August 14th, 1841. 
 
 ^ Psychologie ah Wissensehaft, neu gegi-undet auf JErfahrung, Metaphysik, 
 und Mathematik, 1824-1825. — Lehrbuch zur Psychologie, 1815. — The 
 edition that we use is " the complete works of Herbart," by Hartenstein. 
 24 
 
BEGINNINGS : HEEBAET. 25 
 
 of departure lies "in being." The ontological principle 
 upon which all rests is " the unity of the real." 
 
 Being, for Herbart, is absolutely simple, without plu- 
 rality, without quaAtity; it is only a quale. He says 
 somewhere : " Being is absolute position ; its concept ex- 
 cludes all negation and all relation." And to pass from 
 considerations of being in general to being in particular : 
 " The soul," says he, " is a simple substance, not only 
 without parts, but with no plurality whatever in its 
 quality." ^ Its quality is unknown to us ; but its activity, 
 as that of everything else that is real, consists in conserving 
 itself (Selbsterhaltang). 
 
 If everything that exists is absolutely simple by nature 
 and by definition, whence, then, comes plurality ? It arises 
 from the determined relations that are established between 
 one real and other reals. In consequence of these recip- 
 rocal relations, the reals are engaged in strife ; and in con- 
 sequence of this strife, the Selbsterhaltung, which essentially 
 constitutes each of them, becomes a representation ( Vorstel- 
 lung). This is the hypothesis of Herbart. The represen- 
 tations (or, as contemporary psychology expresses it, the 
 states of consciousness) are then " only the efforts of the 
 soul to conserve itself." In other words, our sensations, 
 our ideas, our recollections, all that constitutes our psycho- 
 logical life, exist for us only as an effect of our tendency 
 to a self-conservation, which, through its relation to other 
 reals, is determined and specific. 
 
 This metaphysical début is very dangerous, and nothing 
 could be more just than the remark of Trendelenburg : ^ 
 The concept of the real, with Herbart, rests simply in 
 speculation, not in experience. 
 
 Although this be true, we will admit the hypothesis and 
 
 * Lehrhuch zur Psychologie, part 3. 
 ' Historische Beitrâge zur Philosophie, vol. iii. 
 3 
 
26 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 examine more explicitly the genesis of the states of con- 
 sciousness. We have now the matter of psychology, the 
 phenomena that it studies ; let us see how Herbart disposes 
 of them. It is certain that, in sj)ite of the marked taste for ■ 
 abstraction that he betrays in the misuse of metaphysics 
 and mathematics, he shows a true appreciation of real fact, its 
 evolution and its specific varieties. And one doubts this ! 
 the less because the tendency wliich is with him in a state ^ 
 of germ is developed in his disciples ; it is from the school 
 of Herbart that later, as we shall see, ethnic psychology 
 springs. 
 
 " The matter of psychology," says he, " is internal per- 
 ception, intercourse with other men of all degrees of culture, 
 the observations of the educator and the politician, the 
 recitals of travelers, historians, poets and moralists, experi- 
 ments on the insane, the sick, aud on animals." ^ Besides, 
 he remarks, " the man of the psychologist is the social and 
 cultured man who represents the history of his race, 
 arrived at its greatest height ; " but as actual facts do not 
 tell us what is primitive, it is necessary for this to have 
 recourse to the savage and the child.^ 
 
 To-day such views may seem common, they were not so 
 in Germany sixty years ago ; then, under the undisputed 
 reign of metaphysics, they would have been original almost 
 to paradox. I am inclined to think, however, that they 
 were not entirely original with Herbart, but were suggested 
 by the reading of Locke. 
 
 The taste for true fact in psychology has made Herbart 
 the most determined enemy to the hypothesis of faculties in 
 the soul. He . takes occasion to combat it continually. 
 Psychology has gone backward since Leibnitz and Locke, 
 and this is due to the separation of the faculties by Wolff 
 
 ^ Lehrbuch zur Psychologie, Introduction. 
 " Ibid., part 2, ch. I. 
 
BEGINNINGS: HEEBAET. 27 
 
 and Kant. The two first mentioned were wiser in letting 
 this hypothesis alone, for "when to the natural concep- 
 tion of what passes in us we add the hypothesis of faculties 
 which we have, psychology takes on the form of mythology." 
 Empirical psychology, says he in another place, reveals 
 to us three faculties : thought, feeling, desire ; to these 
 three faculties, as genera, it subordinates the others (mem- 
 ory, imagination, reason, etc.) ; then, under each species, it 
 subordinates varieties (memory of places, w^ords, etc. ; reason 
 theoretical and practical, etc.). But the real, the fact, is 
 individual ; it is not a genus, or a species. The general 
 can be derived from the individual only by abstraction, 
 according to rule ; and how attempt this abstraction when 
 the individual is imperfectly known, insecurely established ?^ 
 
 To this respect for reality that we find in Herbart, 
 although it very rarely touches upon individual facts, we 
 must add a clear apprehension of the scientific method. He 
 did not believe, as was then the fashion in Germany, that 
 it was possible to construct psychology by means of pure 
 deduction and logical argumentation. He proposed to 
 apply to psychology " something that resembled the inves- 
 tigation of the natural sciences" (welehe der Naturforschung 
 gleiche). Sometimes he even seems to say that psychology 
 can be constituted a science only on condition that a very 
 large part be relegated to the unknown, and that one con- 
 fine himself to phenomena. " Let experimental physics be 
 ignorant of the forces of nature, yet it has two means of 
 discovery, experiment and calculation. Psychology cannot 
 experiment on man : it has no instruments for that ; it 
 ought all the more to employ calculation." 
 
 It is not certain, now in our day, that experiment is 
 impossible in psychology, as Herbart maintained. The 
 researches of Fechner and his successors have shown the 
 
 ^ Psych, als. Wiss., Introduction. 
 
28 GERMAN PSYCHOLOGY OP TO-DAY. 
 
 contrary ; an entire order of psychological facts has become 
 accessible to experiment. But this is certain, that he had an 
 exact idea of the conditions of the science; he knew that it 
 could exist only with calculation, that is to say, with quan- 
 titative determination ; or, indeed, with experiment, that is 
 to say, with objective verification, and that in the absence 
 of these conditions, the use of the word science is an usur- 
 pation and an abuse. 
 
 n. 
 
 Psychology has some analogy with physiology. " Even 
 as the one constructs the body with fibres,* so the other con- 
 structs the mind with series of representations." Repre- 
 sentations or facts of consciousness whose laws can be 
 known — ^this is the matter of psychology. " But what we 
 seek is not a mere register of facts ; it is speculative knowl- 
 edge, reduction to law." For example, " psychology asserts 
 that the states of consciousness are associated in time and 
 space, and it has never come to consider time and space as 
 determinations merely that accompany this association ; 
 moreover, such a psychology is not vague, as the description 
 commonly given would have us believe, but follows laws of 
 strictly mathematical certainty." If we do not make use 
 of calculation, we must renounce all psychology as knowl- 
 edge. The internal sense, that pretended scientific instru- 
 ment of the majority of psychologists, has not for Herbart 
 " such easy prerogative and value in external experience, 
 whatever imagined superiority men have been able to dream 
 into it." 
 
 So far we know only one thing : the stat^ of conscious- 
 ness, according to the metaphysic of Herbart, are due to the 
 effort that each real makes to conserve itself^ when it enters 
 into relation with other reals. But is there nothing here 
 that resembles mathematical properties? Yes, for every- 
 
 * We would say in our day : vith anatomical elements. 
 
BEGINNINGS: HEEBART. 29 
 
 thing that is perceived withiu has properties that are gen- 
 eral ; that iSj it exhibits itself as going and coming, oscil- 
 lating and fluctuating, in short, as growing stronger and 
 weaker.^ Each teftn employed to express a representation 
 conveys a concept of magnitude. We must admit then 
 either that the facts of consciousness have no order, or that 
 they have a mathematical character, and are capable of 
 mathematical analysis. 
 
 Why has this analysis been for so long a time unat- 
 tempted? Herbart has given many reasons. The prin- 
 cipal reason is the difficulty of measurement. Psycholog- 
 ical magnitudes are variable quantities which can only be 
 estimated in an incomplete way. " But w' e can submit the 
 variations of certain quantities, and these quantities them- 
 selves, as far as they are variable, to calculation, without 
 determining them completely; upon this all infinitesimal 
 analysis rests. As long as the calculus of infinitesimals was 
 not invented, mathematics was too imperfect for this pur- 
 pose." It is now possible to use it in constituting psychol- 
 ogy as a science. 
 
 All our knowledge of internal facts is necessarily and 
 characteristically incomplete ; our mind, by a law peculiar 
 to itself, must complete it {Ergànzung)? But in most cases 
 the empirical data are so insufficient that this undertaking 
 can be conducted only in a speculative way ; and, for this, 
 it is necessary, first of all, to demonstrate the existence of 
 certain relations : that tw^o quantities are functions of each 
 other, that they are connected as a natural number and its 
 logarithm, as a differential and its integral, etc. 
 
 In short, with Herbart, psychology consists entirely and 
 alone in elaborating the facts of internal perception ; in 
 demonstrating the connection of the facts that perception 
 
 ^ Psych, cds Wiss., Einleitung. 
 
 ^ The word employed by English expositxus of Herbart to translate 
 
 Erganzung is elaboration. — Tr. 
 
30 GEEMAN PSYCHOLOGY OP TO-DAY, 
 
 indicates, by means that perception can not indicate; and 
 this according to general laws.^ 
 
 Inasmuch as the states of consciousness, without excep- 
 tion, according to Herbart, are representations, and rep- 
 resentations are forces, at least as far as they act in oppo- 
 sition to one another, he concludes that the task of 
 psychology consists in establishing a static and dynamic 
 of mind.^ 
 
 We enter here into the heart of the psychology of 
 Herbart. We must insist then upon its essential character- 
 istic : the employment of mathematics. 
 
 Every simple representation has a determined quality 
 which is invariable ; the percept red, for example, can never 
 become the percept blue. But every representation has also 
 a quantitative value which is variable, namely, its degree of 
 intensity, of force; or, more simply, its clearness.^ A com- 
 mon fact will show that our representations are really forces 
 that strive among themselves. Suppose, says Herbart,* that 
 a man speaks an unknown tongue to you ; you notice that 
 each word, if it is not pronounced very plainly, leaves your 
 memory immediately. The percepts produced in you by 
 these different sounds have, then, the property of chasing 
 
 * P^eh. ah. Wiss., p. 220. 
 
 ^ It must be noted well that Herbart says expressly that the states of 
 consciousness are not forces, but become so only in consequence of the 
 relations established among them ; just as the soul, as we have already 
 said, becomes conscious only by accident. The subject representing is a 
 simple substance properly called the soul. The representations are pro- 
 duced by external conditions, and are determined as to their quality as 
 much by these conditions as by the nature of the soul itself. The soul 
 is not, then, originally a representing (conscious) force ; but becomes so 
 from the existence of certain conditions. Further, the representations 
 taken in themselves are not forces, but they become so in consequence 
 of their reciprocal opposition. — {Psychologie aïs Wissenschaft, p. 31.) 
 
 '* Drobisch, Erste Grundlehren der Maihematischen Psychologie, p. 15. 
 
 * De attentionis mensura causisqae primariis, in the Sammtliche Werke, vol. 
 VII., p. 75, etc. 
 
begikn:ings: heebart. 31 
 
 each other out. Before we leam any language, every word 
 produces on us the same effect. As a result of custom, 
 the connection of the words has become easy ; we feel no 
 longer that each of them is an obstacle to the others; 
 but this antagonism continues none the less : it is a general 
 fact. 
 
 The principle that serves as support for all the rest is the 
 antagonism of representations. Herbart, who proceeds as a 
 mathematician, remarks that this hypothesis ought to be 
 taken from the first in its most simple sense. " We do not 
 deal with complex representations, designating objects by 
 their determinations in space and time, but of very simple 
 representations, such as red, blue, sour, sweet ; in a word, 
 of such as can be furnished by an immediate and instan- 
 taneous sensation." It is a metaphysical principle — ^the 
 unity of the soul — ^that explains at once the antagonism of 
 the representations and their association. As, in virtue of 
 the principle of contradiction, two contraries cannot exist 
 at the same time at the same place, so the contrary repre- 
 sentations arrest each other reciprocally. Without this 
 antagonism, all the representations would constitute only a 
 single act of a single soul ; and, in fact, they do constitute 
 but a single act as far as no obstacles whatever introduce 
 separation among them. 
 
 This antagonism between two states of consciousness does 
 not belong to either of the two taken alone ; it results from 
 a relation. " If we hear a c alone, it does not oppose itself 
 in our minds to a d. But if we hear c, d, at the same time, 
 or if these two representations co-exist in our consciousness, 
 then we perceive not only the sum c, d, but the antagonism 
 between them." 
 
 Moreover, among the representations, the antagonism is 
 very variable. " Let us take blue ; it is less opposed to 
 violet with its different shades than to red with its differ- 
 ent shades ; or, take c, it is more opposed to d than to 
 
,32 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 c sharp, to g than to e. The arrest that is the conse- 
 quence of the antagonism must vary with it." ^ 
 
 Let us admit, then, to place the problem in the most 
 elementary terms, that there are in the mind only two rep- 
 resentations, simple and contrary. Each has a degree of 
 force or intensity of its own : we know that as the result of 
 attention, or of some external cause, the intensity of a state 
 of consciousness may become very great. The intensive 
 magnitude of these two percepts can be represented by num- 
 bers. Let us call one of the representations A and the 
 other B ; designate by m and n their intensive magnitudes ; 
 then we can assert the relation A : B = m : w, although 
 there is no unit or common measure to which we can refer 
 A and B to determine their absolute intensive magnitudes. 
 The representations being contrary, it is evident that the 
 stronger will resist the more strongly. The resistance will 
 be in the relation -^. The more it resists, the less will it 
 undergo change ; consequently, the changes resulting from 
 the opposition will be = -i- : -i- = w : m. The decrease 
 in intensity which is brought about in this case is called by 
 Herbart an arrest {Hemmung), and the object of the calcu- 
 lation is to determine ; 1st. The sum of arrest {Hemmungs- 
 summe), that is to say, the total loss of intensity in the given 
 case ; 2d. The relation of arrest {Hemmungsverhaltniss), that 
 is to say, the way in which this total loss is apportioned to 
 each of the two representations, in proportion to its intensity. 
 To take an example, if we suppose two representations 
 whose intensity is in the relation = 3:2, the arrest pro- 
 duced will be = 2, because, following Herbart, if it were 
 greater than two, the more feeble representation would be 
 destroyed, which is impossible. From the other side, it 
 can not be less than two, because, in their internal shock, 
 each representation tending to lose the least possible, all 
 
 * Psychologie als Wissenschaft, p. 40. 
 
BEGINNINGS: HEEBART. 33 
 
 that is taken from the intensity of the one is added to the 
 intensity of the other. The total sum of arrest being = 2, 
 calculation shows that the loss for each is such that the 
 stronger representation becomes := V, and the feebler f \ 
 
 Such are the general principles on which the mathema- 
 tical psychology rests. We may sum them up in the follow- 
 ing propositions : 
 
 Representations become forces when they are in reciprocal 
 opposition. 
 
 Representations, in consequence of this antagonism, lose 
 a quantum of their intensity ; this is called, in the language 
 of Herbart, the arrest of the representation. 
 
 No representation can be destroyed ; the arrest, partial or 
 total, has no other eifect than to diminish its tension, and 
 cause it to pass from the state of real representation to 
 the state of simple tendency (Streben vorzustellen) ; (it is this 
 phenomenon that is called in ordinary language the passage 
 of the conscious into the unconscious). 
 
 Two representations are in equilibrium when each of the 
 two is sufficient to arrest the other. Each representation is 
 then in a state of tendency ; it is obscured ( Verdunhelung). 
 
 When the representation emerges from this point of " ob- 
 scurity," it gives rise to what Herbart calls a movement. 
 
 The calculation of this equilibrium and movement of 
 representatives is the object of the static and mechanic of 
 mind. 
 
 STATIC OF MIND. 
 
 It would be both outside our purpose and beyond our 
 ability to give a complete exposition here. It will suffice 
 
 ^ Here is the calculation of Herbart : 
 
 We have: (3 + 2): {|} = 2:|l| 
 
 Hence, the remainder of the stronger = 3 — | = igl. 
 The remainder of the feebler = 2 — f = f • 
 
34 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 to indicate the general characteristics of a question that has 
 now, besides, only an historical interest. 
 
 The static of mind has for its object to study the condi- 
 tions of equilibrium among representations, to submit their 
 reciprocal arrest to calculation, and to indicate all the vari- 
 ations they present in combination. 
 
 Representations form different classes, such as colors, 
 sounds, figures, etc., etc. Herbart calls each of these classes 
 a continuity. According to him, representations belonging 
 to the same continuity oppose one another ; those that be- 
 long to different continuities do not. Thus color produces 
 no arrest on a sound representation, etc. 
 
 Simultaneous representations are, by the very fact of the 
 unity of the thinking subject in which they are found, 
 capable of uniting, as far as the reciprocal arrest does not 
 forbid it. But it is evident that this uniting must assume 
 two very different forms, according as the two representa- 
 tions are of a different or of the same nature. In the first 
 case, they can unite totally ; in the second, they can unite 
 as far as the arrest permits. 
 
 Is^ Case. — This is the most simple case. The represen- 
 tations belong to different continuities ; " they can unite 
 totally in such a way as to form a single force, which 
 enters as such in the calculation." Herbart calls this a 
 complication or an entire complex (union of a sound and a 
 color). 
 
 The representations belong to the same kind ; there re- 
 sults a partial union due to the opposition that exists 
 between them. Herbart calls this a Verschmelzung, or 
 fusion (union of red and blue).^ 
 
 2c? Case. — Here the representations oppose each other 
 instead of uniting. Herbart reduces the problem to two 
 principal forms : 
 
 * Herbart distinguishes again complication and fusion as complete and 
 incomplete ; but we cannot give all the details. 
 
BEGINNINGS : HEEBAET. 35 
 
 1st. The two representations are in complete opposition, 
 and are of equal intensity. Let two states of conscious- 
 ness, A and B, have the same intensity=l, and oppose 
 each other totally, " as red and yellow." In order that the 
 arrest of A be zero, it wonld be necessary, as we have 
 seen, that B disappear entirely. But each of the represen- 
 tations tends to conserve itself, and both strive with equal 
 force. It results that each loses half of its original intensity. 
 
 2d. The two representations A and B are in complete 
 opposition, and are of unequal intensity. Let the inten- 
 sity of A = a, and that of B =^6, in such a way that «>6. 
 In this case, by the hypothesis of Herbart, the " sum of 
 arrest would be = 6, that is, equal to the intensity of the 
 feebler representation ; since, that there might be no further 
 contradiction,^ it would be sufficient that the feebler repre- 
 sentation be overcome." 
 
 3d. Three representations. A, B, C, are in complete op- 
 position, and their intensities a, 6, c, are such that we can 
 assert a^ b, b ^ e. In this case, the sum of arrest is = 
 6+c, that is, equal to the sum of the two feebler intensi- 
 ties, since, if their arrest were total, the representation A 
 would maintain its entire intensity. Herbart determines 
 by calculation how this sum of arrest 6-fc, is apportioned 
 among the three representations. According to him, more- 
 over, all cases are reducible to the three preceding, tiie 
 conditions, equality of antagonism and difference of inten- 
 sity, remaining the same. 
 
 ^ We give here, under a general form, the calculation, a particular 
 case of which Herbart has shown us above. The sum of arrest = 6 is 
 thus divided between two representations : A remains in consciousness 
 with the intensity : 
 
 ab a-\-b 
 
 ""(T+ô ~ a'+ab-^-b-'' 
 B remains in consciousness with the following intensity : 
 
 a6_ _ &•■' 
 
 a+6 a-|-6 ' 
 
36 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 In short, this equality of antagonism admitted, each 
 representation undergoes an arrest inversely proportional to 
 its intensity. 
 
 Herbart then examines two other cases : 
 
 1st. The intensities are supposed equal ; but the degrees 
 of antagonism are different. Then each representation 
 undergoes an arrest directly proportional to the entire 
 antagonism that exists between it and the other represen- 
 tations. 
 
 2d. The intensities are unequal and the oppositions un- 
 equal. For the solution of this case, very complicated 
 calculations are necessary.^ 
 
 Each representation, in consequence of the arrest that it 
 undergoes, can be chased from consciousness. But this 
 exclusion has degrees, and, in this passage from the state 
 of real representation to the state of simple tendency, it 
 has an important statical point that Herbart calls the 
 threshold of consciousness : " By threshold of consciousness 
 (Schwelle des Bewusstseins), I mean those limits that a rep- 
 resentation seems to overleap in passing from a state of 
 complete arrest to a state of real representation." Calcu- 
 lation can determine the conditions under which a repre- 
 sentation attains an infinitely small degree, while still a 
 representation ; under which, consequently, it touches this 
 limit.^ It is " below the threshold," when it has not the 
 force to fulfill these conditions ; and "above the threshold" 
 when it has attained a degree of real representation. In 
 other words, the threshold of consciousness is the limit at 
 which the intensity of a representation can be considered as 
 = 0. The " worth of the threshold " is the value a rep- 
 
 ' Let the intensities be a, b, e ; and the antagonism between a and 6 
 = m; between a and c = p; between 6 and e = n; the arrests will be: 
 m-\-p m.^n n-{-p 
 
 abc 
 
 ^ Psychologie oils Wissenschaft, p. 43, &c. 
 
BEGINNINGS: HERBART. 37 
 
 resentation must have to retreat just to the threshold of 
 consciousness. For example, if a = 1 and 6 = 1; c, at 
 the exact moment that it arrives at the threshold of con- 
 sciousness, will have a value = ^Z J or 0.707. 
 
 Below the threshold of consciousness, all perception be- 
 longs to the category of insensible perception of Liebnitz. 
 For Herbart, the simple representations are not infinitely- 
 small, but the complexes resulting from their fusion over- 
 leap the threshold of consciousness. " Thej are not," says 
 Drobisch, " diiferentials, but the integral of differentials. 
 Mathematical psychology can no more start with the study 
 of the insensible perceptions from which the simple per- 
 ceptions result, than physical mechanics with a theory of 
 molecular attraction. The concept then of simple repre- 
 sentation is as valid as that of the material point or of the 
 molecule ; it is a scientific abstraction, but it has its validity 
 none the less." ^ 
 
 MECHANIC OP MIND. 
 
 This section of psychology studies representations in 
 a state of movement. If we consider the state of each 
 representation as being produced in successive stages, there 
 is room to enquire with what quickness, constant or vari- 
 able, the obscurity will be produced, and in what time it 
 will be finished. 
 
 " The analogies between the mechanic of mind and that 
 of body, moreover, must not make us forgetful of their 
 points of difference. We do not deal here with angles, 
 sines, cosines, etc., etc., nor with infinite extension ; but every 
 movement of the representations is confined between two 
 fixed points : their state of complete arrest, their state 
 of complete liberty. Instead of the attraction that draws 
 bodies downward, we have here the natural and constant 
 
 * Erste GruncUehren, &c., p, 16. 
 
38 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 effort of all the representations to revert to their state of 
 complete liberty (absence of arrest)." 
 
 If we set out with a state of equilibrium, or, as is more 
 really the point of view of psychological experiment, with 
 that state of arrest in which the representations are, we see 
 that, as new forces intervene, the equilibrium is broken; 
 the sum of arrest decreases and a movement of the repre- 
 sentations begins. The mechanic proposes to apply calcu- 
 lation to the following questions : The diminution of the 
 sum of arrest ; the quickness of movement for each repre- 
 sentation ; the quantum of time during which it is exe- 
 cuted; the mediate or immediate awaking of representa- 
 tions. 
 
 We cannot enter here into an exposition. We will 
 only attempt to show how, by the aid of the " law of 
 reproduction," Herbart believes he can explain the for- 
 mation of general ideas, and, in particular, the notion of 
 space. 
 
 In consequence of this strife for existence among them, 
 each representation occupies the consciousness only a limited 
 time, and is changed into a simple tendency. Herbart 
 does not give us a very clear idea of the nature of this 
 tendency ; we can represent it, however, as a state of 
 equilibrium ; equal and contrary forces check each other 
 mutually. But when any circumstance occasions a diminu- 
 tion of arrest, the tendency becomes again a real represen- 
 tation ; it attains first the " threshold of consciousness," 
 the visible horizon, then mounts above the horizon {SteigeTi). 
 This ascending movement of a representation excites that 
 of analogous states, and thus the general idea is produced 
 in consciousness. It is due, then, not to a special power 
 that the soul exercises over the simple perceptions, but to a 
 mutual reaction of analogous perceptions ; the differences 
 are obscured in the mass of perceptions, and there remains 
 only what they have in common. 
 
BEGINNINGS : HEEBAIiT. 39 
 
 If we consider the notion of space, we will find that it 
 arises from a succession of sensations. Our states of con- 
 sciousness can be associated in different ways, whether it be 
 for the production of combinations or the formation of 
 simple successions. The successions themselves are of dif- 
 ferent kinds ; but there is one alone that suggests to us the 
 notion of space ; it is the succession that can he reversed, 
 that is, Avhose different terms read indifferently from A to 
 Z, or from Z to A. Movement (of an arm, a limb), con- 
 sidered as a real fact, plays for Herbart only a secondary 
 role in the acquisition of our notion of space ; it is the 
 occasion of this idea only as far as it produces in con- 
 sciousness a series of states that can be reversed. " During 
 the progressive movement," says Herbart, " the first repre- 
 sentations fall (below the threshold) successively, and are 
 fused gradually with those that follow. But upon the 
 least return backward, these earlier representations come 
 back en masse, are raised (above the threshold) by means 
 of those which are there added, and which resemble them. 
 It thus happens that each representation assigns its place 
 to all the others, since it must place itself beside and 
 among them." ^ 
 
 The notion of space arises then for Herbart from an 
 association amoug states of consciousness. Every other mo- 
 ment (feeling of muscular activity, resistance) is neglected 
 by him ; he takes account only of states of consciousness 
 and their relations. This has given occasion to Lotze to 
 object to this theory, that certain series (for example, the 
 musical scale) can be read indifferently, from up down or 
 from down up, without giving the least idea of space ; 
 and to other critics,^ who have maintained that this deriva- 
 tion of space itself previously implied the idea of space. 
 
 ^ Psychologie als Wissenschaft, pp. 119, 120. 
 ' Zeitschrift fur Philosophie (1866, vol. 1, 2). 
 
40 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 III. 
 
 We are not concerned with the study of the psychology 
 of Herbart in all its details ; what precedes contains the 
 essentials ; there remain only two points to detain us ; his 
 theories of sensation and the Ego. 
 
 To Herbart, all psychological facts, without exception, 
 are representations. The phenomena called feelings, affec- 
 tions, emotions, desires, passions, etc., do not constitute a 
 separate species opposed to ideas. The phenomena of feel- 
 ing, according to him, are not of an irreducible nature ; they 
 do not present essentially distinct characteristics ; they 
 should not form a separate group ; they do not represent a 
 second mode of psychic life. On the other hand, the feel- 
 ings are not representations. What are they then ? They 
 are simply relations. The particular states of the soul that 
 everybody calls feelings (with their varieties) are the rela- 
 tions between representations. This doctrine is found en 
 germe in Aristotle. It was early noticed that a group of 
 feelings — the aesthetic feelings caused by sound — depended 
 upon intervals, that is, upon relations between perceptions. 
 Herbart has generalized this theory and extended it to all 
 the feelings. 
 
 " Feeling {Gefùhî) arises when one representation remains 
 in consciousness in consequence of an equilibrium among 
 the forces that arrest it and those which tend to raise it." 
 This definition must be explained. When one represen- 
 tation overleaps the threshold of consciousness and is ex- 
 panded, a state is produced, which, in the common language 
 of psychology, is called an intellectual act. If, on the con- 
 trary, the sum of arrest is increased, the representation is 
 driven below the threshold; the intellectual act ceases. 
 But another case may arise : suppose that one representation 
 lies in consciousness ; if two other representations of equal 
 and contrary force tend, one to retire it, the other to increase 
 
BEGINNINGS: HEEBAET. 41 
 
 it, a state of equilibrium is produced. This state, result- 
 ing, as it seems, from a relation among the representations, 
 produces a feeling. Thus, says Lindner, one of the latest 
 disciples of Herbart,^ if we take a feeling such as affliction 
 caused by the loss of a friend, the idea of that friend is 
 caught " as in a vice " between two ideas : that of his death, 
 tending to produce an arrest, that of his benefits, tending to 
 a contrary effect. 
 
 Herbart praises highly the division (from Kant) of the 
 emotions into two classes : 1st. The exciting emotions (j-ils- 
 tige), such as joy and anger ; 2d. The depressing (schmd- 
 zende), as fear and sadness. He defines the first as " the 
 emotions that bring into consciousness a quantum of real 
 representation greater than it can contain ;" and the second, 
 as " the emotions that drive from the consciousness a quan- 
 tum of representation greater than that which ought, from 
 the nature of these representations, to be there." 
 
 In regard to the desires ÇBegehren) — of which Herbart 
 forms a group including the propensities, the passions, and 
 the will as desire reaching after a moral end — he defines 
 them as follows : "Desire is the predominance of a repre- 
 sentation that strives against obstacles, and thereby in this 
 sense determines the other representations." ^ 
 
 Every passion has for its foundation a dominant repre- 
 sentation; when the representation of the object desired 
 does not rule, there is no passion. The strength of passion, 
 its characteristic irresistibleness of tendency, consists in the 
 continued effort of the dominant representation — or, rather, 
 of the group of representations which pertain to the object 
 of the passion — against the continued arrest that it under- 
 goes in consciousness. Passion arises from a mass of im- 
 
 ^ Lindner, Lehrhuch der emph-ischen Psychologie, p. 117. 
 
 ''We do not give here the detailed classification of the emotions 
 according to Herbart; that would take us too far. See Lehrbuch zur 
 Psychologie, 2d part, chap. 1 to 4. 
 
42 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 moderately intense but connected representations, which 
 stand in opposition to the regular combinations of repre- 
 sentations. In metaphor, it is the antagonism of passion 
 and reason ; but, as we see, these are not two faculties, two 
 entities, opposed to each other. " Passions are tendencies 
 in the direction of desire, which have their foundation in 
 the interaction of representations. They are tendencies, and 
 not acts ; and this explains the fact that there are not only 
 passions but passionate natures. The absence of civiliza- 
 tion and education favors the development of such natures, 
 because the more isolated ideas remain, the more their union 
 is reduced to rule and order, the more powerfully will each 
 act for itself alone, and awake only ideas that can enter into 
 helpful combination with itself." 
 
 Thus everywhere in the psychology of Herbart we find 
 representations only. For him this fact alone explains all 
 the details of the mental life. It explains it as unity. The 
 Ego, or, if one prefer the other expression, the consciousness, 
 is not, in fact, for Herbart, a thing apart. While earlier 
 psychologists maintained that, for a representation to be 
 possible, it was only necessary that consciousness occupy 
 itself with it, with Herbart, and his school, on the contrary, 
 consciousness is only the sum of actual representations. In 
 short, it is an eifect and not a cause, a result and not an 
 original fact. Just as a thing or an object is the point 
 where different series of images meet, so the I is the point 
 where all the series of our representations meet ; and the 
 representation of the I, or the individual consciousness, is 
 produced only as we differentiate this point from the par- 
 ticular series that intersect there. 
 
 ly. 
 
 We cannot attempt here an extended criticism of the 
 psychology of Herbart. Such a study would necessitate a 
 profound study of details, and could be made only by one 
 
BEGINNIJS'GS : HEEBAET. 43 
 
 versed equally in psychology and mathematics. We will 
 attempt only to show wherein the originality of his effort 
 consists, what new conception he introduced into psychol- 
 ogy, and the nature of the movement that has arisen 
 from it. 
 
 At the first glance, his originality is striking. The 
 method of Herbart is neither the analytic method of 
 Locke, Condillac, and the ideological school that has fol- 
 lowed them ; nor the descriptive method of the Scottish 
 school ; nor the physiological method, seen dimly by Hart- 
 ley, and developed in our day. Conformably to its name, 
 it rests psychology on a threefold basis ; according little 
 to experience, more to metaphysics, and much to mathe- 
 matics. His method is, then, above all, mathematical. It 
 is surprising enough that a disciple of Kant should have 
 been the first to inaugurate it. Kant, indeed, ventured 
 to predict " that psychology could never be raised to the 
 rank of an exact natural science " ; and he gave two prin- 
 cipal reasons for this assertion : 
 
 1st. Mathematics is not applicable to internal phenom- 
 ena, because these phenomena are referred to one condition 
 only, time ; or, to give his words, " because the internal 
 intuition in which these phenomena must be construed has 
 only one dimension, time." 
 
 2d. Internal phenomena are not accessible to experi- 
 ment, that is, to observation made in circumstances that 
 are determined, that are variable at will, and that are 
 subject to the employment of measure. 
 
 To the first of the observations of Kant,^ i. e., that in 
 order to present internal facts in mathematical form, they 
 must have at least two dimensions, it has been answered 
 that this is actually the case, and the conditions insisted 
 
 ^ For this discussion, see, in particular, Wundt, Grundsiige der physir 
 ohgischen Psychologie, pp. 5, 6. 
 
44 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 upon are realized. Our sensations, perceptions, feelings, 
 are subject not only to the condition of time, but to varia- 
 tions of intensity. They are intensive magnitudes forming 
 a series in time. 
 
 As to the second point, although Herbart seems never 
 to have conceived the possibility of experiment, it is suffi- 
 cient to recall the work done later in psychophysics by 
 Fechuer, Volkmanu, Helmholtz, Wundt, Delbœuf, etc., 
 which is to be treated at length in this book. Doubtless, 
 our states of consciousness are undetermined magnitudes. 
 But is it impossible to determine them, that is, to submit 
 them to measure ? The essential condition of measure is 
 that there be a fixed relation between the measure and that 
 which is measured. Such a relation is that of effect and 
 cause. In the physical sciences, we measure variations in 
 cause by variations in eifect. In psychophysics, it is the 
 contrary ; the variations of cause measure the variations 
 of effect. The measurement of time offers a very old 
 example of this process. Let us measure the course of 
 our internal states by the aid of their external cause — the 
 movement of objects in nature — movement that itself occa- 
 sions the succession of our states of consciousness. It is 
 an analogous process, it seems to us, that psycho-physicists 
 pursue in employing the intensity of excitation (cause) to 
 measure the intensity of sensation (effect). Perhaps, in- 
 deed, it would be possible to proceed here exactly as in the 
 physical sciences ; to measure, as they do, the cause by the 
 effect, that is, the phenomenon of consciousness by the ex- 
 ternal action that it produces, i. e., by movement. But this 
 method has been hitherto little followed because it presents 
 great difficulties. To conclude, it is evident that the asser- 
 tion of Kant cannot be accepted without examination by 
 any one who has any acquaintance with the studies in 
 psychophysics which have been published in the last fifteen 
 years. 
 
BEGINNINGS: HERBAET. 45 
 
 Yet — and this brings us back to Herbart — experiment 
 has been applied to one group only of the states of con- 
 sciousness, to the perceptions. It would appear applicable 
 also to another group, to the states of consciousness con- 
 nected with motion, i. e., to the reactions that follow per- 
 ception. But these two groups are far from including the 
 totality of internal phenomena. Memory, abstract notions, 
 the logical processes, etc., appear to be outside of every ex- 
 perimental process. We might, indeed, calculate their 
 rapidity, their duration ; but their intensive variations 
 remain undetermined. Consequently, the only possible 
 attempt to proceed scientifically here consists in the em- 
 ploy of hypothesis and calculation. This is precisely 
 what Herbart attempted. He wished to apply through- 
 out the entire domain of psychology the method pursued 
 in the other sciences, such as mathematical physics. This 
 method consists in setting out with hypotheses that are 
 probable and based upon experience, in applying calcula- 
 tion to them, and finally, in verifying by experiment the 
 value of the theoretical results. Has Herbart followed it? 
 
 His point of departure is certainly hypothetical. We 
 will not speak of the threefold supposition that he urges 
 upon us from the first (unity of being, tendency to conser- 
 vation, fact of consciousness as its result) : it is perhaps a 
 necessity inherent in all psychology, even the experimental, 
 to set out with some metaphysical hypothesis. The true 
 hypothesis that serves as basis for his psychology is that 
 states of consciousness are forces that strive among them- 
 selves. This hypothesis, if it is not the best nor the only 
 possible one, rests at least on positive facts. But Herbart 
 adds to it a series of others that seem entirely arbitrary. 
 We have already noted many by the way, and it would be 
 easy to point out others. Thus he admits that the repre- 
 sentations have residues, by means of which they form a 
 combination ( Versohmelzung) ; but he adds that between 
 
46 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 each representation and the residues, there is a reciprocal 
 action that is directly proportional to the product of the 
 combined residues, inversely proportional to the intensity 
 of the representation." This hypothesis rests on no fact 
 of experience and on no mathematical necessity. Again, 
 in order to determine the absolute intensity of a represen- 
 tation, he posits the following hypothesis, which is entirely 
 arbitrary and improbable : if two representations, a and 6, 
 are in complete antagonism, and there arise a third, c, less 
 antagonistic, the antagonism between a and b ceases imme- 
 diately, and both fall on c, almost, says a critic of Herbart, 
 as two fighters might fall upon an innocent man. It is 
 certain, as Wuudt has remarked, that, if reciprocal arrest 
 belongs essentially to antagonistic representations, the in- 
 tervention of c ought simply to modify that antagonism, not 
 to suppress it ; just as the attraction between two bodies is 
 modified, but not suppressed, by the intervention of a tliird. 
 
 The common defect in the hypotheses of Herbart, is that 
 they are rarely based upon experience and supported by 
 previous induction. As for experimental verification of 
 results, it is completely wanting. Herbart does not appear 
 to have foreseen the work in psychophysics of which we 
 have spoken. And, moreover, this verification could only 
 have been done by physicists and physiologists, and Herbart 
 was a pure metaphysician with mathematical training. 
 
 His conception of psychology is that of a mechanic of 
 mind. He tried to pass from vague description of psychiq 
 phenomena to precise knowledge of the elementary states 
 that produce them. The phrase cited above : " Psychology 
 constructs the mind with representations as physiology 
 constructs the body with fibres," shows that he made 
 toward a revolution analogous to that of Bichat in anatomy. 
 Bichat substituted a much more philosophic study of the 
 organs for pure and simple description : the study of tis- 
 sues (later, anatomical elements). If Herbart had sue- 
 
beginnings: herbaet. 47 
 
 ceeded, he would have created a general anatomy of the 
 soul. But the very form of his attempt doomed him to 
 failure ; for if ever the reduction of the states of conscious- 
 ness to a mechanic become possible, it will not be by means 
 as simple as he imagined. Admitting, as is possible, 
 though there is nothing to prove it, that calculus can one 
 day be applied to psychology as to physics, it is certain 
 that this last phase of the science can be attained only 
 when, by successive reductions, psychology has been previ- 
 ously relegated to biology, biology to sciences less and less 
 complex, and finally to mechanics. Thus, in our day, it is 
 not to an abstract mechanic, that is, to abstract relations 
 between abstract forces, that psychology has recourse; it is 
 the nervous mechanism alone that concerns it, and this is a 
 sufficiently heavy task. It is better understood now than 
 fifty years ago, that the transition from psychology to 
 mechanics can not be made at once. 
 
 The judgment of one of the latest disciples of Herbart, 
 Volkmann von Volkmar, will serve us in conclusion. 
 Very favorable, as is natural, to the mathematical psy- 
 chology, it has, on the other hand, the advantage of fixing 
 its true meaning, and of determining the exact position 
 that we must assign him in the school. 
 
 " Mathematical psychology," says lie,^ "is not, as Fort- 
 lage would have it, ' an ingenious diversion in imaginary 
 magnitudes.'" It consists in submitting to systematic 
 exposition all the quantitative determinations that are 
 necessarily met in the psychological functions. The ideas 
 of action and reaction, the intensity of representations, 
 movement in the different states of consciousness, are met, 
 under one name or another, in all systems of psychology, 
 and even in common language. It is certain that these 
 facts have a more or less quantitative character. The 
 
 ^ Lehrbuch d. Psychologie, u. s. w., 2 vole., 1875-6, I, p. 476, etc. 
 
48 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 mathematical exposition differs then from the common ex- 
 position, only that it seeks to state with exactitude and 
 precision what common usage leaves undetermined. It is 
 unjust to confound the attempts of the school of Herbart 
 with the pretended mathematical philosophy that consists 
 only in an empty play of formulas, deductions, and arbi- 
 trary calculations. Mathematical psychology never pro- 
 poses to be the whole of psychology. It refrains from all 
 investigation of the nature of the soul, its relation to body, 
 the origin of representations ; it does not ajjply calculation 
 to simple states. Its only pretension — and it is a just one 
 — is to afford a method of finding the exact formula of the 
 general laws that rule the reciprocal relations of represen- 
 tations, and of attempting a mechanic of the intensive 
 states of the spiritual life. 
 
 " It is objected that it is impossible to find a measure for 
 psychic magnitudes : whence it is concluded that mathemat- 
 ical psychology is barren. The objection would be just, if the 
 effort were made to apply calculation to concrete states ; but 
 it is made only to determine relations, and never to measure 
 by a fixed standard the states of consciousness themselves. 
 
 " It is added that the relations with which psychology 
 deals are rather qualitative than quantitative and these lat- 
 ter can not be isolated. A remark that is true in many 
 respects, but is of value only against a system that tends to 
 absorb the whole of psychology in mathematics." 
 
 The author whom we have quoted understands that till 
 now attempts have taken as point of departure hypotheses 
 too simple and too systematic, that they have been too 
 dependent on the problems of pure mathematics, that cer- 
 tain difficult questions have been treated too lightly ; but 
 he maintains that the method of Herbart leads up to prob- 
 lems that are inaccessible by any other method, that here- 
 tofore this method has been developed too little, and its his- 
 tory has been too short for a fair judgment. 
 
CHAPTER II. 
 
 SCHOOL OF HERBART AND THE ETHNOGRAPHIC 
 PSYCHOLOGY. 
 
 I. 
 
 Was the effort of Herbart without precedent ? Follow- 
 ing Rosenkranz, the first systematic application of mathe- 
 matics to psychology was made by a physician of Vienna, 
 Niesley, who has been completely forgotten.^ Whatever 
 erudition may bring to light on this point, the effort of 
 Herbart belongs peculiarly to him, and he alone has founded 
 a school. As this book is not a history of German psy- 
 chology, it is not in point to enumerate his disciples. It 
 will suffice to show, at some length, that he originated a 
 great movement. 
 
 Drobisch (Moritz-Wilhelm), who is still professor in the 
 University of Leipzig, may be considered the oldest and 
 principal representative of the school. His psychology, 
 
 * On this point, see Volkmann v. Volkmar, work already quoted, vol. 
 I., p. 480. He cites a passage from WoljQF, little known, which shows that 
 this disciple of Leibnitz had conceived the possibility of a psychometry. 
 In his Psychologia empirica, § 522, after some demonstrations, he adds : 
 Theoremala haec ad psychrometriam pertinent, quae mentis human/B cog- 
 niiionem mathematicam tradit, et adhilc in desideratis est . . . Haec non alio 
 fine a me adducuntur quam ut intelligatur dari etiam mentis humance cog- 
 nitionem mathematicam atque hinc psycheametriam esse possibilem, atque 
 appareat animam quoque in ek quae ad quantitatem spectant leges mathema- 
 ticas sequi, veritatibus mathematicis, h. e. arithmeticis et geomeiricis in mente 
 humana non minus quam in mundo materiali permixtis. 
 
 5 49 
 
50 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 contained in two works, especially in the Erste Grundlehren 
 der Mathematisehen Psychologie (1850), is characterized by 
 remarkable clearness. "Mathematical psychology," says 
 he (work mentioned, p. 7), "is confined to the phenomena 
 of consciousness, and seeks to establish mathematical rela- 
 tions among them. To do this it must build upon hypo- 
 thetical concepts that are not given under color of fact ; but 
 it proceeds otherwise tlian mechanics, which supposes 
 impenetrable material points, forces in action, and a law of 
 inertia. Until it has succeeded in establishing mathemat- 
 ical relations among psychic phenomena, it leaves to meta- 
 physical speculation the task of interpreting these mathe- 
 matical facts in a sense that is materialistic, idealistic, in- 
 termediate, or any other." Further than this, Drobisch is 
 considered to have hastened the return to the philosophy 
 of Kant, a return in which all the German schools have 
 more recently joined.'^ Further, we will name Cornelius, 
 who is specially skilled in the physical sciences, but who, 
 besides his studies in electricity and molecular physics, 
 has published a Théorie des Sehens und Raumlichen Vor- 
 stellens (1861); Nahlowsky, who has studied feeling in his 
 Gefiihlsleben (1862) ; C. A. Thilo, who is the historian of 
 the school ; Rob. Zimmerman, at present professor in the 
 University of Vienna, who is its sesthetician. The in- 
 fluence of Herbart lives in some of the physiologists, as 
 
 ^ Vaihinger, Diihring, Hartmann u. Lange, p. 234. It is curious to no- 
 tice that, in 1850, that is before most of the contemporary English 
 works, Drobisch explained clearly the general nature of the law of 
 association in psychology. " Psychology shows that not only memory and 
 imagination, but judgment, reasoning, conscience itself, and in general 
 all higher activity and all development of mind rest upon the associa- 
 tion and reproduction of states of consciousness: that this explains 
 also the different variations of feeling, emotion, desire, passion, and 
 rational will. But these explications are supported by generalities that 
 have always an indeterminate character. This arises from their lack of 
 quantitative determination (Work cited, p. 3). 
 
SCHOOL OF HERBAET. 51 
 
 John Millier, and in one of Germany's greatest students of 
 insanity, Griesinger, who has even borrowed from Her- 
 bart his definitioij of madness/ The best idea, moreover, 
 of the influence Herbart has exerted on philosophy in gen- 
 eral can be obtained by a perusal of the Review of Exact 
 Philosophy," founded in 1860 by Allihu and Ziller, upon 
 which most of the Herbartians labored. But we propose 
 here another end, i. e.,to show that this school has produced 
 an ensemble of research which, in direct oj)position to the 
 simple and exact character of mathematical psychology, 
 presents a character singularly vague and complex. It is 
 the ethnographic psychology, represented by three disciples 
 of Herbart : Waitz, Lazarus, Steinthal. 
 
 At first sight it seems strange enough that so concrete a 
 form of psychology should attach itself to the school of 
 Herbart; but, in fact, the disciples have only developed 
 some of their master's views.- This point deserves attention, 
 for one would hardly suppose that the founder of the 
 mathematical psychology would have attached great import- 
 ance to such investigations. He maintains, however, that 
 psychology remains incomplete as long as it considers man 
 only as an isolated individual.^ He was convinced that 
 society was a living and organic whole, ruled by psycho- 
 logical laws that are peculiar to it. He has written a static 
 and mechanic of the state, as he made a static and mechanic 
 of ideas. Some of his disciples have developed what he 
 only indicated : thence has arisen a kind of work that psy- 
 
 ^ Griesinger, Traité des maladies mentales, French trans., p. 66. 
 
 " Zeitschrift filr die exacte Philosophie in Sinne des neueren Mealismus. 
 Among contemporaries we will mention the author of the History of 
 Materialism, A. Lange, who has himself published Die Grundlegung der 
 mathematischen Psychologie. Duisburg, 1865. 
 
 ^ Lehrbuch der Psychologie, 2d éd., p. 240. — For details on this point, 
 see Herbart : Allgemeine praktische Philosophie, ch. 12, and the two essays: 
 Bruchstucke zu einer Statik u. Mechanik des Staates ; TIeber einige Beziehun- 
 gen zwischen Psychologie u. Staatswissenschaft, 
 
52 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 chology did not know before and with which we will now 
 be occupied. 
 
 II. 
 
 " Do you want to understand the Greeks and Romans," 
 said a philosopher of the eighteenth century, "study the 
 English and French of to-day. The men described by 
 Tacitus and Polybius resemble the inhabitants of the world 
 that surrounds us." ^ In our day we think differently : we 
 believe that this abstract study, amounting to some general 
 characteristics, gives a knowledge of man but not of men : 
 we believe that all who share our common humanity were 
 not cast in a common mould, and we are curious about the 
 smallest of these differences. Hence a new conception in 
 psychology. 
 
 As long as naturalists confined themselves to a pure de- 
 scription of races and of species considered as permanent; as 
 long as historians, indifferent to the variations of the human 
 soul in the lapse of ages, spread upon all their recitals the 
 same uniform and monotonous varnish ; an abstract psy- 
 chology, like that of Spinoza and Cond iliac, seemed the only 
 psychology possible. Nothing else was thought of, and when 
 a very refined and subtle spirit was subjected to minute 
 analysis, it was said of this psychology : It has given us to 
 know man. 
 
 But when the idea of evolution was introduced into the 
 sciences of life and into historical study, stirring and renew- 
 ing the whole, psychology felt the impulse. The question 
 was raised : is this abstract study of man sufficient ? Does 
 it give more than broad traits and general conditions ; to be 
 simple and exact, does it not need completion ? The lower 
 forms of humanity have exhibited particular modes of feel- 
 ing and action, and the history of civilized peoples has 
 shown variations in sentiment, in social ideals, in moral or 
 
 ^Hume, Essays, VIII. 
 
SCHOOL OF HEEBAET. 53 
 
 religious conceptions, and in the languages that express 
 them. 
 
 Psychology has profited by it. It occupies, in fact, in 
 the structure of human knowledge a very exact place be- 
 tween biology below and history above. For if it is clear 
 that sensation, feeling, and thought exist only where there 
 are brain, nerves, and organism, it is also clear that social, 
 moral, religious facts, history entire, is only an effect of 
 which the human soul is the cause. Thus psychology 
 shoots its roots into the sciences of life and blossoms in the 
 historical sciences. Whatever comes to light in these two 
 groups of sciences concerns psychology and often modifies it 
 profoundly. 
 
 Of the two, biology has done more, and we may well be- 
 lieve that what it has given is little compared with what it 
 has in reserve. At the first, it took hold upon the very 
 sources of the psychic life : it contains the causes. Com- 
 plex as it is, it is much less so than history. It has, above 
 all, the advantage of a more precise and rigorous method, 
 in that it employs direct observation and experiment. 
 
 The deposits of history are less numerous and more vague 
 in character. The study of language, religion and custom 
 has led, however, to important results ; and if psychology 
 is to be no longer a tissue of abstractions, but is to force its 
 way more and more into reality, it must apply itself reso- 
 lutely to solve the problems of linguistics, morals, and 
 aesthetics, which are important parts of itself. If mathe- 
 matics owes its progress largely to the necessity of leav- 
 ing the domain of pure abstraction in order to explain 
 the complex phenomena of astronomy, mechanics, and 
 physics, is it not natural to suppose that this abstract 
 psychology which has been taken for a long time for psy- 
 chology entire, will find profit in the same, by applying 
 itself to the study of the varied facts of human nature in 
 history, custom, religion, literature, and language? The 
 
54 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 mental world has been so imperfectly explored only because 
 the science that attempts it has been shut up in itself, has 
 been entirely speculative, and has despised or neglected the 
 spontaneous and concrete manifestations of spirit. 
 
 We must be grateful, therefore, to all in Germany who 
 have attempted to contribute to the difficult work that has 
 been called ethnic psychology. 
 
 An early difficulty is to determine precisely what place 
 the representatives of the Volkerpsychologie occupy in the 
 present movement. Man is studied in so many ways by 
 anthropologists and historians, by the literary critic and 
 the linguist, that in this' body of efforts, which are often con- 
 tradictory, however they tend to the same end, one finds it 
 difficult to set himself right. "Without attempting here 
 anything like a classification, we are able to distinguish 
 three principal currents. 
 
 The most considerable of these, is that of the doctrine 
 of the transformists. By its very general character and 
 its preoccupation with the problem of origin, this doctrine 
 has a character as much philosophic as psychologic, although 
 it has brought some excellent ideas into psychology ; as that 
 of evolution and hereditary permanence. 
 
 The anthropologists form the second group. They are 
 especially given to the study of physical man, confining 
 themselves to vague generalities as to the psychological 
 varieties of the human race, its customs, sentiments, ideas. 
 
 Some others, on the contrary, have given themselves 
 entirely to these latter manifestations. Part, as Lubbock, 
 Tylor, MacLennan, Bachoffen, Herbert Spencer (in his 
 Descriptive Sociology), have investigated the natural history 
 of custom ; others have studied language and religious be- 
 liefs ; and others, finally, as M. Taine, have applied the 
 critical psychology to the exposition of literature and the 
 fine arts. 
 
 It is to this third group that the two men belong of 
 
SCHOOL OP HERBAET. 55 
 
 whom we wish to speak : Theodore Waitz and Lazarus. 
 While Haeckel, Fechner, Gerland, Peschel, develop, dis- 
 cuss, or transform the ideas of Darwin ; ^ while Vogt, Vir- 
 chow, SchaiFhausen, represent pure anthropology ; others 
 have attempted the psychological study of the races of man, 
 and, though their work has been modest, it is worth the 
 trouble of describing. 
 
 Although not known to us, Theodore Waitz has a dis- 
 tinguished place in contemporary German psychology, and 
 is often quoted in his own country. Born at Gotha, 
 March 17th, 1821, he studied under Drobisch, in the 
 University of Leipzig. At the age of twenty years, he 
 travelled in France and Italy, for the purpose of collecting 
 manuscripts, and of preparing a critical edition of the 
 Organon of Aristotle, which appeared in 1844. He located, 
 on his return, as privat-docent in the University of Mar- 
 burg, and never left that place. There he became a very 
 intimate friend of Ludwig, now Professor in the Univer- 
 sity of Vienna, and one of the greatest physiologists of 
 Germany. The two friends worked hard, instructing each 
 other mutually : Waitz gave Ludwig lessons in mathe- 
 matics, and Ludwig taught Waitz physiology and anatomy. 
 At that time Waitz published his Handbook of Psychology 
 
 ^ Fechner, in his work Einige Ideen zur Schopfungs u. Eniwickelungs- 
 geschichte der Organismus (Leipzig, 1873), undertakes especially to ex- 
 plain the relation of the organic to the inorganic. According to him, 
 the latter results from the former ; experience shows us this every day 
 in the decomposition of organic bodies, which are transformed into in- 
 organic elements. The processus in virtue of which nature is developed 
 in its infinite variety, results from the contrary action of two princi- 
 ples : stability and correlative differentiation. Gerland (Anthropologische 
 Beitrâge, Berlin, 1875), maintains that evolution can be explained by a 
 purely atomico-mechanical process, in which a "psychic principle," 
 recalling the monads of Leibnitz and Herbart, controls. Peschel has 
 published a Volkerkunde (Leipzig, 1874). Hseckel's works are well 
 known. 
 
56 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 as a Natural Science,'^ a book whose style and mode of 
 expression are remarkably clear and precise. And what 
 is not less worthy of our notice, it has a certain phys- 
 iological coloring that is very rare in the school of 
 Herbart, especially at that period. Waitz reports ex- 
 periments, discusses and interprets minor details in 
 optics and acoustics : the whole seems little to-day ; 
 but to be impartial we must carry ourselves back forty 
 years. Besides, we must not conclude that he was un- 
 faithful to his master, and proposed to exclude all meta- 
 physics from psychology ; ^ he proposed, on the contrary, 
 through the mediation of Herbart, to reconcile the two 
 parties then existing : one, that saw in psychic phenomena 
 only forms of body (the materialism of Feuerbach), the 
 other, that referred all to spirit (the idealism of Hegel). 
 
 Ten years after the publication of this treatise on psy- 
 chology, Waitz prepared the first volume of his great work. 
 Anthropologie der Naturvolker.^ He left it unfinished, and, 
 although now superseded, it is none the less a monument. 
 
 How did Waitz pass from abstract to ethnographic psy- 
 chology ? Even in the Handbook he was embarrassed by 
 frequent reappearances of the Naturmensch, and in particu- 
 lar by the way in which the external world was repre- 
 sented to him ; he seemed to have glimpses of the im- 
 portance of these concrete researches ; but we know by the 
 testimony of his pupil, George Gerland, that he was 
 
 ^ Leiirbuch der Psychologie ah Katurwissenschafl, 1849, Brunswick. This 
 book is a more matured form of the Grundlegung der Psychologie, pub- 
 lished in 1846 (Hamburg and Gotha). 
 
 ^ His book contains four principal divisions : 1st, Nature of the soul 
 and the general laws of thought ; 2d, Sensation ; 3d, Feeling ; 4th, 
 Intelligence. 
 
 3 Leipzig, vol. I (1859), II (1860), III (1862), IV (1864), V and VI 
 (1865-72). These last two were written or completed by George Ger- 
 land. A new edition of this work has been (1885-Tr.) published by 
 Gerland (Leipzig, Fleischer). 
 
SCHOOL OF HEEBAET. 57 
 
 drawn on by the study of religions. Waitz "desired 
 earnestly to unite the two poles of mental life : natural 
 science and religious faith." He proposed to write a phi- 
 losophy of religion. With this work in view, he studied 
 anthropology, to attain a solid foundation of fact, just as 
 he had studied anatomy before writing his Psychologie. 
 He found that this Anthropologie der Naturvblker, con- 
 ceived at first as preparatory work, served another end, 
 i. e., the natural history of uncivilized peoples. We must 
 indicate precisely the peculiar character of this work. 
 
 The vague title Anthropology may properly be applied 
 to investigations of many kinds. The study of man in his 
 physical, moral, social characteristics, in his development 
 and migrations, is an attempt so vast, so unlimited, that it 
 really absorbs all the human sciences. In fact, anthro- 
 pology rests upon an illogical and arbitrary conception. 
 Every exact science has for its object a group of determined 
 phenomena that it studies wherever it finds them. So 
 anatomy, physiology, psychology, ethics, proceed : they 
 pertain to certain facts and they pursue these facts in the 
 whole animal series, indeed, in all life. Anthropology, on 
 the contrary, is occupied not with a group of phenomena, 
 but with a species : its unity is factitious, inasmuch as it 
 exists only for man and by man : it is not as much a science 
 as a body of facts drawn from other sciences. Thus books 
 on anthropology treat only a small part of that which their 
 title promises. They are only treatises on the comparative 
 anatomy of the human races : all the rest is treated inci- 
 dentally or omitted. Waitz — and this it is that characterizes 
 him — labors especially on the psychological side : he has 
 put in the first place what other anthropologists mention 
 only incidentally or not at all. 
 
 We cannot deny that his work has been in part super- 
 seded ; especially is this the case with the first volume, which 
 is devoted entirely to general questions, and which had the 
 
58 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 misfortune to appear a few months before the Origin of Spe- 
 cies. The psychological part of this volume (p. 296, etc.), 
 although very extended, is now equally out of date. For 
 Waitz, two principal problems arose : Has man a specific 
 character? Are there specific diiferences among the races ?^ 
 
 To the first question, Waitz replies that the psychological 
 characteristics peculiar to man can not be expressed in any 
 one of the proposed formulas, such as that of perfectibility. 
 He makes of them four groups : man subdues nature to him- 
 self by work ; he employs articulate speech ; he has emo- 
 tions that serve as the basis of his social life ; he has relig- 
 ious conceptions. 
 
 On the second point, Waitz studies at length the psy- 
 chological variations of the human races by means of varia- 
 tions in the skull ; he finds no profit in this and concludes 
 that, for psychology, there are no specific differences among 
 the human races (class es keine specifischen Untersohiede der 
 Menschenracen in Hilcksicht des geistigen Lehens gibt, vol. I, 
 p. 393). Whence, then, does it arise that there are such 
 great differences among them in matters that pertain to gen- 
 eral culture and civilization ? For if we decide that differ- 
 ences are not original we must inquire how they are 
 acquired. — For Waitz, all is explained by climate, migra- 
 tions, and religious ideas ; but above all by climate, which 
 is the only first cause : the primitive difference from which 
 all other differences, of food, dwellings, occupations, political 
 affairs, etc., logically proceed. 
 
 Without going farther, one sees that most of these asser- 
 tions could not be maintained to-day, or, at least, that the 
 facts tend the other way. The five volumes devoted to descrip- 
 tive anthropology, on the contrary, remain still the finest col- 
 lection that exists, excepting monographs, for the study of 
 
 ^ It must be added that this concerns Waitz only from a point of view 
 purely psychological. 
 
SCHOOL OF HEEBAET. 59 
 
 the races in a state of nature. Special publications have com- 
 pleted or corrected the work of Waitz in many points ; but 
 no work has superseded it as a whole. His second volume 
 is devoted to the negroes and kindred races (Nubians, Abys- 
 sinians, Gallas, Malgaches, Caffres, Samalis), their material 
 culture, family life, political organization, customs, religion, 
 intellectual qualities, temperament, and character.^ A 
 similar study (vol. Ill, 1 0-I Y) is devoted to the aboriginal 
 races of America from the Esquimaux to the Araucans and 
 the semi-civilized peoples of Mexico, Peru, and Central 
 America. The last two volumes are devoted to the Oceanic 
 races. They are in great part the work of Geo. Gerland, 
 Waitz having died at the age of forty-three years. May 21st, 
 1864, leaving his work unfinished. 
 
 Waitz visited none of the peoples that he described ; but 
 drew his data from travellers in these countries. No one, 
 moreover, ever had a more lively feeling of the greatness 
 and difficulty of his task. He coveted for the accomplish- 
 ment of his work, says Gerland, the combined powers of the 
 zoologist, geologist, psychologist, and linguist. His critical 
 judgment throws light everywhere. He understands that 
 the accouuts of travellers may often be unreliable ; that the 
 psychological investigation of the inferior races has been 
 conducted entirely from a standpoint of conjecture. 
 
 We commit the geological study of a country to a geol- 
 ogist, the study of its flora to a botanist, the anatomical 
 study of a race to an anatomist ; but for the study of the 
 psychological characteristics and customs of a tribe it seems 
 to many men that there is no need of preparation or special 
 faculties of observation. And yet no investigation is more 
 difficult. It is necessary, through the medium of languages 
 rude and unfamiliar, to interpret feelings entirely different 
 
 ^ See especially a very good description of the negro with his sudden 
 and violent passions, p. 202, etc. 
 
60 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 from ours ; it is necessary to resist the impulse — natural to 
 amateurs — to ascribe to these races our own customs of 
 thought and feeling ; it is necessary to separate their true 
 religious beliefs from the mysteries with which they are 
 entangled : in short, it is necessary to translate continually 
 from a text whose every word suggests an opposite mean- 
 ing. 
 
 III. 
 
 Waitz collected facts, but did not arrive, as it would 
 seem, at a clear conception of the psychology of the races. 
 He studied especially the lower forms of human develop- 
 ment, a study that will be, perhaps one day, as fruitful as 
 that of the lower organisms has been in zoology. And 
 it is safe to say that a premature death prevented his going 
 farther. Others, after him, have digged in the same furrow : 
 Lazarus and Steinthal. These may be considered the true 
 founders of the ethnic psychology. 
 
 Steinthal is known by works on the languages, in which 
 he shows discouraging metaphysical tendencies. He has 
 written on their origin, development, classification, on the 
 relations of grammar to psychology and logic. He is every- 
 where convinced of the existence of an AUgeist, a collective 
 spirit, the condition and support of all society and the basis 
 of moral life, whose law is to be sought not in the indi- 
 vidual soul, not without, nor above humanity. Lazarus, 
 to judge him by his principal work,^ has less the manner of 
 a psychologist than that of a moralist, using the word in 
 the sense that the literary critic with us has given it. This 
 book is a series of elegant essays containing fine remarks 
 on humor as a psychological phenomenon, on tact^, honor, 
 
 ' Das Leben der Seele, in Monographieen uber seine Erseheinungen u. 
 Gesetze, 2 vol. The first edition appeared in Berlin (Schindler) in 1856- 
 57. A new edition lias since appeared (Berlin, 1876-1878-1882, Diimm- 
 ler). We will mention also liis Idéale Fragen, 1878, and his monograph 
 Ueber die Reize der Spide, 1883. 
 
SCHOOL OF HEEBAET. 61 
 
 and glory, on the relations of the arts among themselves, 
 on education and science, on language in its relation to 
 thought. We find deep erudition in it, agreeable traits 
 borrowed from the romancers and poets, but nothing that 
 resembles a rigorous scientific method, no classification of 
 facts or earnest search for laws. 
 
 These two men, however, have fixed the object and de- 
 termined the sphere of ethnic psychology. They have 
 founded, even, a special Review, to furnish its documents 
 and constitute its literature. Established in 1859, the Zeit- 
 schrift fur Volkerpsychologie und Sprachmssenschafi, is in 
 its tenth volume — very little for nineteen years. It pro- 
 poses to publish essays toward the discovery of the laws of 
 ethnic psychology, and reports of historical, ethnological, 
 geological, and anthropological facts; to study language, 
 *'not as the philologist or the empirical linguist, but in order 
 to discover, with the aid of physiology, the psychological 
 laws of language." This Review has fulfilled its promises. 
 
 Three essays of the first importance explain under dif- 
 ferent forms the conception of the ethnic psychology.' 
 
 In addition to ordinary psychology, w^hich deals with 
 individual man, there is room for another science, devoted 
 to social man, or, more exactly, to groups of men ; it is 
 ethnological psychology. That this may have a real ob- 
 ject, that it may not be merely words without sense, a 
 " simple form of speech," it must be proved that the 
 study of the individual is not sufficient. At first sight, 
 we may say : Every social group is composed of indi- 
 vidual elements ; study these elements — which is the end 
 of psychology — and all will be explained. This is a 
 very simple thesis, but it does not deceive by an ap- 
 pearance of clearness. If it be true that the social 
 
 ^ Zeitschrift, etc., Vol. I, Int. ; vol. II, Verhaltniss der Einzelnen zur 
 Gesammtheit (republished in Das Leben d. Seek, 2d Ed.) ; vol. Ill, 1st 
 art., Einige synthetische Gedanken zur Volkerpsychologie. 
 6 
 
62 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 whole is something else than a simple addition of indi- 
 viduals, if the formation of groups gives birth to new 
 relations, to new forms of development; briefly, if the 
 whole be not an arithmetical sum of units, but a chem- 
 ical combination differing from its elements, it must be 
 admitted that Volkerpsychologie has a province exclusively 
 its own. And this is the truth. The social whole dif- 
 fers as much from each of its parts as the laws of polit- 
 ical economy differ from the principles of domestic 
 economy urged by a father upon his son, by a teacher upon 
 his ward. Take a single tree, says Lazarus; it consti- 
 tutes an object of study for the botanist : but plant some 
 square leagues with fifty thousand trees ; it is a forest, and 
 this forest, as forming a whole, becomes the object of another 
 science; that of forestry, a science which rests without doubt 
 on the physiology of plant life, but which has, nevertheless, 
 an end and means of its own. 
 
 The people taken en masse — in an assembly, a public 
 gathering — have certain peculiarities of life that each indi- 
 vidual alone has not. Whence do they come? Are they 
 born of the mutual relations of individuals? Are they 
 infinitely small increments manifested only in the inte- 
 gral ? History shows us likewise that a people may 
 differ in character from the individuals that compose it. 
 " Note the Spaniards. Individually, they have an in- 
 genuous good-nature, as we see in their romances ; they 
 are capable of nobility, and even of sublimity of char- 
 acter; but as a nation they have shown themselves desti- 
 tute of the sentiment of justice and cruelly fierce. As a 
 nation, they have devastated and depopulated America and 
 the Netherlands ; they have ruined themselves through their 
 political and religious prejudices. Their nationality is 
 embodied in Pizarro and the Duke of Alba. A nation 
 is then quite a different thing from the ensemble of its 
 individual members." In whatever way we explain this 
 
SCHOOL OP HEEBART. 63 
 
 difference, it exists, and the single fact that it exists affords 
 ground for the psychology of races. 
 
 What is the nature of this Volkgeist, of tliis spirit of a 
 people, thus presented for study? Lazarus and Stein- 
 thal reply in a rather mystical style, " that it is not a sub- 
 stance, but a subject"; that it is "a monad that pene- 
 trates and combines individuals"; that it is an "objective 
 spirit." In other words, whenever men form a group, 
 live together, constitute a society, there arises from the 
 consensus of individual (subjective) spirits a common (ob- 
 jective) spirit, " which becomes at once the expression, the 
 law, the organ of the subjective spirit." Let us take, for 
 example, one of the elements of the Volkgeist, language : 
 it is at first an individual product ; but it soon becomes the 
 objective expression of individual thought ; its lav), because 
 it is the given form of thought, and further, its organ, be- 
 cause it is the instrument of all subsequent progress in 
 language. The same remark may be made concerning all 
 the other elements of the social spirit. From the con- 
 sensiis of these different elements, from their action and- 
 reaction, results the formation of a physico-psychical type 
 which is the national resume. 
 
 This "objective spirit" has a support (Ty-a^er). Is it 
 the totality of individuals ? To Lazarus, it is simply their 
 mean. In a nation, it is necessary, at first, to exclude 
 children, for in them the development is not complete ; on 
 the other hand, to exclude exceptional geniuses ; in short, 
 whatever is too low or too high. The mean that remains 
 is the support of the objective spirit. 
 
 A point treated with clearness by Lazarus and Steinthal 
 is the determination of the elements that constitute the 
 Voll-geist. These elements are language, mythology, reli- 
 gion, culture, popular poesy, writing as the basis of the 
 historic consciousness, art, practical life, customs, statute 
 law, occupation, family life, and finally, the reciprocal 
 
64 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 action of these different manifestations. The study of 
 these constitutes the work of the psychology of races. Its 
 concern is to arrive at psychological knowledge of a people 
 in its spirit and action, "to discover the laws according 
 to which, its ideal activity — in life, science and art — de- 
 velops, extends, or contracts, rises or falls, is refined and 
 vivified, or is weakened and benumbed. To embody reality, 
 the psychology of the races may not give a vague and 
 arbitrary table of the internal (psychical) qualities of a 
 people, but must discover the source whence they all flow. 
 It must lay hold not upon such and such particular and 
 accidental directions of its development, but its totality, 
 with the laws that rule this development " {Lehen der Seele, 
 vol. I, pp. 337-338). It must explain especially the forma- 
 tion of races, determine the causes that have broken the 
 human family into different peoples, and show, teleologi- 
 cally, what profit the spirit of man has derived from its 
 development (Ibid., p. 335). 
 
 The natural sciences set out from natural history. By 
 an analogous process, the history of man can be raised to 
 the rank of a science, and the process of transformation 
 ought to be the same in the two cases. Psychology is to 
 history what biology is to zoology and botany. The laws 
 of biography, that is, of the development of the individual 
 mind, ought to be exhibited in the psychology of the in- 
 dividual mind ; so the laws of history, which we may call 
 the biography of nations, ought to be exhibited in a com- 
 parative psychology which constitutes the true science of 
 history. 
 
 Here is a noble program, well defined. The Zeîtschrijïfûr 
 Vôlkerpsyehologie proposes to fulfill it. Up to the present, 
 we cannot say that it has succeeded. It has furnished a 
 number of documents ; but we seek in vain for exact results. 
 The articles that it has published in the nineteen years of 
 its existence seem to be capable of the following classifi- 
 
SCHOOL OF HEEBAKT. 65 
 
 cation : history of religions, literary criticism, linguistics, 
 anthropology, history of customs, law and politics, pure 
 philosophy/ Judging from their titles, many of them are 
 attractive, but they are treated in a manner as much lit- 
 erary as scientific. Often they appear too general for this 
 kind of investigation, stripped too far of peculiarly philo- 
 sophic conceptions. Without doubt, the task undertaken 
 is so great, and the problem to solve so difiScult, that twenty 
 years of effort is very little; but is it unreasonable to 
 ask that some generalizations, at least provisional, on 
 particular points, should have been established by these 
 
 ^ We give tlie titles of the principal articles ; they are better than 
 any commentary in helping the reader to understand the spirit of the 
 magazine. 
 
 The original form of the myth of Prometheus. — The myth of Sam- 
 son and the myth of Hercules. — Relation of religion to mythology. — 
 Origin of myths among the Indo-Germanic peoples. — Mythological 
 representations of God and the soul. — Popular poetry in Italy. — The 
 theatrical nature of French art. — The Gothic style and the nations. — 
 Hungarian poetry. — The rise of subjective poetry among the Greeks 
 (Archilochus, according to the author, was the first subjective poet). — 
 Homer and the Odyssey. 
 
 Articles on linguistics are very numerous ; notice, Assimilation and 
 attraction in language. — Idealism in the science of language (Lan- 
 guage is the conception of the world peculiar to a people). — The Coptic 
 language. — Pott vs. Steinthal on the subjectivity of language. — The duel 
 among the Shemetic peoples. — Outline of a comparative syntax. 
 
 The centre of civilization in antiquity. — Geography and psychology. 
 — The language of gesture. 
 
 The origin of customs (Lazarus considers them a result of social ex- 
 istence). — Ideas in history. 
 
 On nationality. — Influence of dwellings on moral conduct, based on 
 statistics. — The legal condition of woman in the ancient Roman and 
 German law. — The principle of nationalities in Italy. — ^The ancient 
 German empire. 
 
 Plato's theory of ideas. — The controversy between Trendelenburg 
 and Kuno Fischer. — Poetic imagination and the mechanism of con- 
 sciousness. 
 
 The principal co-laborers, besides Lazarus and Steinthal, are Del- 
 briick, Tobler, Cohen, etc. 
 
66 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 researches ? Is it not the first duty of the promoters of 
 this work, to make out from time to time balance sheets 
 of their results ? 
 
 The English anthropologists, with whom we are not 
 further concerned here, appear to have apprehended better 
 the conditions of a psychology of the races. They have 
 sketched it in monographs. Anxious, above all, to collect 
 facts, they have yet drawn interesting conclusions. Thus 
 Lubbock and MacLennan have studied the primitive 
 family; Tylor attempted to prove that the first stages 
 of civilization are always uniform, whatever be the race, 
 time, or country. We advise some laborer on the Zeitschrifi 
 fur Volkerpsychologie to employ similar materials in the 
 Review. 
 
 Stuart Mill, in the book that he devotes to the logic 
 of the moral sciences,^ treats of the method of ethology, 
 that is, of the science of character, including in it the 
 formation of national or collective character, as well as 
 individual. He makes it entirely a deductive science. 
 According to him, psychology founded on observation 
 and experience, discovers the fundamental laws of mind ; 
 ethology determines the nature of this product, con- 
 formably to these general laws, in a body of moral and 
 physical circumstances. It would be interesting to know 
 what the representatives of the Volherpsychologie think 
 of this method ; for, though they are explicit enough as to 
 the object, the end, and the elements of their science, 
 they have not been sufficiently explicit as to the method. 
 They seem to have aimed especially at the collection of 
 data, and in this they have shown themselves more 
 empirical than Stuart Mill himself. But we must not 
 censure them : these studies of detail will have their use; 
 they deserve to be continued, and their promoters have 
 
 "I 
 ? System of logic, book VI, ch. 5. 
 
SCHOOL OF HERBAET. 67 
 
 an assured place in the history of contemporary German 
 psychology.^ 
 
 ^Among the representatives of the Volkerpsychologie, we may further 
 mention Bastian, who has written many works on this subject. Yet his 
 Mensch in der Geschichte (3 vol, Leipzig, 1860) is as much a book of an- 
 thropology. As for his Beitrage zur vergleichenden Psychologie, Zur natur- 
 wissenschnfilichen Behandlungbweise der Psychologie, and other works, they 
 are far from giving what their titles promise. They consist of a col- 
 lection of essays on the worship of ancestors and manes, on the different 
 conceptions of the spiritual principle among primitive peoples, on prop- 
 erty, priests, medicine-men, etc. It is an inextricable medley of facts, in 
 which the beliefs of all the savage races, and of all the ancient nations, 
 are often heaped up upon the same page. 
 
CHAPTER III. 
 
 LOTZE. 
 
 The Theory of Local Signs, 
 
 I. 
 
 In a study of empirical psychology in Germany, it is 
 equally impossible to pass Lotze in silence and to treat 
 him with thoroughness. In general character and in 
 tendency, he is above all a metaphysician ; in educa- 
 tion and profession, he is familiar with physiological re- 
 search. At the age of twenty-two, after having studied 
 philosophy and medicine with equal enthusiasm, he was 
 charged, as privat-docent, with this double instruction in 
 the University of Leipzig (1839). In the years that 
 followed, his publications showed marks of this double 
 course of study. He contributed to a dictionary of physi- 
 ology {Handwbrterhuch der Physiologie of Wagner) im- 
 portant articles, quoted to-day ; he published a Treatise on 
 Pathology and General Therapeutics (1842), a Physiology 
 of the Physical Life (1851). And at the same time he made 
 ready a Metaphysics (1841), a Logic (1843), and a Medical 
 Psychology (1852). From that time metaphysical tenden- 
 cies seemed to prevail more and more with Lotze, as is 
 seen in his Microcosm, now in its fourth edition,^ his 
 
 ^MikroJcosmus: Versuch einer Anthropologie, 3 vol., Leipzig, 1856-64; 
 
 2d edition, 1869-72 ; (3d éd., 1876-80. The first volume only of the 
 
 . 4th ed. has appeared, 1884. — Tr.). The divisions of the work are : body, 
 
LOTZE. 69 
 
 History of esthetics in Germany and the System of Phil- 
 osophy, devoted to logic and metaphysics.-'^ 
 
 The greater par^ of his work then is entirely outside 
 of our subject, and we have nothing to say of it here. His 
 psychology itself falls only half within our plan. Lotze, 
 in fact, although employing experience largely, never sep- 
 arated psychological researches from metaphysical hypothe- 
 ses, and we can say without hesitation that the " psychol- 
 ogy without a soul," which has gained a goodly number of 
 adherents in Germany, in later years, never had his entire 
 allegiance. It is, jet, in truth, a physiological psychology 
 that he has attempted under the rather singular title of 
 Medical Psychology, and, such as it is, at twenty-six years 
 from the date of its appearance, it remains the book that 
 acquaints us best with Lotze as a psychologist, and assigns 
 him a place in the contemporary movement that we are 
 discussing. 
 
 Of the three volumes of this work, the first is de- 
 voted to pure metaphysics.^ Of the rest, much has grown 
 old ; the author, we believe, would not hesitate to admit 
 it. Not to speak of the physiology of the nerves, very 
 different now from what it was thirty years ago, the 
 manner of approaching or stating different problems is 
 entirely different since Fechner, Wundt, Helmholtz, have 
 treated them. An analysis of the lledical Psychology 
 would be out of place. We will present only that portion 
 of the work which is now most valuable. Let us lay aside 
 
 soul, life, man, spirit, course of the world, history, progress, connection 
 of things. In this body of questions so different, the problems of psy- 
 chology are as often touched upon as treated. (English translation by 
 Eliz. Hamilton and E. E. C. Jones, London, 1885. — ^Tr.) 
 
 ^ Theil I, Logik, drei Bûcher von Denken, 1880 ; II, Metaphysik, 1879. 
 (English translation under supervision of Bosanquet, Oxford, 1884. — 
 Tr.) 
 
 * Translated into French by M. Penjon under the title, Principes de 
 Psychologie physiologique {Bibl. de Phil, contemp.). 
 
70 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 the metaphysics of the author. We will omit also the 
 studies on sensation, feeling, will, which are necessarily- 
 found in every psychology, and which have since been 
 presented in a larger form in Germany and elsewhere. 
 These questions excluded, we will enquire only into a 
 single point and examine its details : the theory of local 
 signs and the perception of space. This is really the most 
 original part of the Psychology of Lotze, the part that still 
 lives, accepted, or at least discussed, by the best thinkers, 
 and whose influence is to be found in all contemporary 
 discussions. Wundt has admitted it by modifying it; 
 Helmholtz ^ considers it the first decisive step toward bring- 
 ing physiologists to the opinion that the perception of ex- 
 tension is not inborn, but arises from experience. 
 
 It is the exposition of this unique question, then, to 
 which we now turn. Yet, inasmuch as it is difficult to 
 separate entirely the experimental study from the meta- 
 physical hypothesis in the Psychology of Lotze, and inas- 
 much as his phraseology presents an ontological character, 
 and cannot be changed without altering his teaching, it is 
 necessary that his method, which is neither purely specu- 
 lative nor purely empirical, be explained to the reader. 
 
 What strikes us at first sight in Lotze is his profoundly 
 metaphysical turn of mind. Nowhere does he treat psy- 
 chology as a science of the simple phenomena of the soul. 
 He reckons of only second importance the investigations 
 peculiar to the sciences of nature, that are concerned only 
 with the outside of things. " We have," says he, " two 
 kinds of scientific knowledge. We know, on the one hand, 
 nature, the essence of the object studied ; on the other 
 hand, we know only the external relations that are possible 
 between it and other objects. In the first kind of know- 
 ledge, there is a possible question of a cognitio rei only 
 
 * Op%MeP%8^o?ogr^g'we, French trans., p. 758. (German ed. p. 595 — Tr.) 
 
liOTZE. 71 
 
 when our intelligence apprehends an object, not simply 
 under the form of external being, but in an intuition so 
 immediate that we are able, by our senses and ideas, 
 to transport ourselves into it, to penetrate its peculiar 
 nature, and consequently, to know what ought to be, ac- 
 cording to its internal and specific essence, the order of 
 such a being. On the contrary, the other scientific kind 
 of knowledge, the external, cognitio circa rem, does not 
 penetrate to the essence of things, but consists mainly in a 
 clear and precise apprehension of the conditions under 
 which the object manifests itself to us, and under which, 
 in consequence of its variable relations to other objects, 
 it is regularly transformed." ^ 
 
 There is no one who does not admit with Lotze that 
 knowledge of the essence of things is more valuable than 
 knowledge of the internal or external events that manifest 
 them. But unfortunately, we do not see that we are any- 
 where given the means of attaining it. It would have 
 been remarkable, indeed, if Lotze had been able to show to 
 the supporters of the psychology based upon phenomena 
 alone, not that their knowledge is limited — this they know 
 very well — but that another kind is possible, and that the 
 hypothesis of a soul considered as a substantial principle 
 adds something or other to our knowledge, and to the in- 
 telligibleness of internal phenomena. In psychology, if the 
 cognitio rei consists in the affirmation ever repeated, but never 
 established, of a principle that feels, thinks, desires ; better 
 still is the cognitio circa rem. To cope with the empirical 
 psychology, Lotze must be able to prove that a science 
 worthy to bear this name — that is, something else than 
 mere opinion, individual taste, feeling, desire of the heart — 
 can be more than a statement of simultaneities and suc- 
 cessions of relations among states of consciousness ; he must 
 
 ^ Medicinische Psychologie, vol. I, p. 50. 
 
72 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 be able to show that it is not the so-called cognitio circa 
 rem that constitutes alone what is generally known as scien- 
 tific knowledge. 
 
 This proof he has not given, and he himself recognizes 
 the equivocal nature of his position when he says " that 
 we are able^ to attribute to ourselves, almost with equal 
 reason, the most profound knowledge of the soul, and, 
 from a scientific point of view, the most complete ignor- 
 ance," and when he attempts to place himself in turn at 
 two contradictory points of view for constructing psy- 
 chology. We find everywhere in him a powerful and 
 fruitless eifort to reconcile two irreconcilable tendencies ; 
 one of which consists in employing rigorously a scientific 
 method, relying upon the results of physiology, and follow- 
 ing them as a conducting thread ; the other, in abandoning 
 this method entirely and postulating an entity, " the soul," 
 under the claim of faultless evidence, absolute certainty, 
 as a truth known immediately, and thereby placed above 
 all proof. As we would expect from a mind so profoundly 
 metaphysical, it is the nature of this mysterious entity that 
 is all important in his eyes. The rest, subordinate and 
 accessory, is of value only in proportion as it assists us 
 here. If we compare the work of psychologists to a voy- 
 age of discovery, we may say that, for Lotze, the true 
 continent is the undiscovered one. 
 
 " If we wish to present, in our way of thinking," says he, 
 " the ideal of the science, we must consider psychology the 
 science of the essential principles of all being and all action ; 
 physics, on the contrary,^ as the science of the forms the 
 spiritual life assumes in its development in the domain of 
 the relations of time and space. But if we wish really to 
 contribute to the progress of the science, we must content 
 
 ' Work quoted, trans. Penjon, p. 52. 
 
 ^ Physics is, for Lotze, the type of the cognitio circa rem. 
 
LOTZE. 73 
 
 ourselves, as too often the gaps in human knowledge neces- 
 sitate, with possessing this principle in part, and in part 
 submitting the great diversity of empirical phenomena forth- 
 with to the highest laws that abstraction can obtain, to pre- 
 pare, little by little, for the moment when it will be possible 
 to deduce these phenomena from the true principle, the 
 loftiest of their existence." ^ 
 
 This passage, so strange for a psychologist, signifies, if 
 we understand it, that the ideal of psychology would con- 
 sist in becoming pure ontology, but that for the present it 
 must be content to explain the known by the unknown, the 
 given by the supposed, the real by the imaginary ; in short, 
 that the laborious results of empirical psychology are an 
 illusion and a snare unless they borrow their light from 
 this " reality known immediately," which for Lotze and his 
 followers is a source of revelations inaccessible to the rest 
 of us. 
 
 Without going further we see what embarrassment results 
 in the construction and exposition of a doctrine of psychol- 
 ogy from the employment of such a mixed method, as we 
 have called it above. We might define it still better thus : 
 a process that consists in part of employing the scientific 
 method, in part, under pretext of doing better, of neglect- 
 ing it altogether. Lotze oifers us the spectacle of a man 
 caught continually between his science and his tendencies, 
 between his positive knowledge and his habits of thought. 
 He puts metaphysics very high without being willing to 
 renounce facts ; he lays much stress on facts, but subor- 
 dinates them to " metaphysics : and he never succeeds in 
 uniting these two dissimilar elements, which, in whatever 
 way he attempts to join them, demand only that they be 
 separated. 
 
 He is, however, a vigorous and penetrating thinkerj and 
 
 ^ Medioinische Psychologie, loc. cit., p. 58. 
 
L 
 
 74 GEEMAN PSYCHOLOGY OP TO-DAY. 
 
 it is only just to do him rightful homage. To sift a ques- 
 tion, turn and return it on all its sides, to perceive all pos- 
 sible hypotheses, and discuss their degrees of probability, 
 he is without an equal. His manner of writing shows it. 
 A dialectician of marvellous subtlety, he distinguishes and; 
 divides to excess, recalling at times the method of the scho- 
 lastics, sometimes also advancing in phrases that are vague, 
 general, of noble swing, after the manner of the French 
 spiritualists ; but we constantly regret the scarcity of facts 
 and examples. 
 
 When he is concerned with a definition of the "essence of 
 the soul," a question that is very dear to him, he spends so 
 much time warning us of false solutions, bad methods, mis- 
 taken points of view, the custom of speaking of the spirit 
 as we speak of matter, in combatting opposing definitions, 
 that what he himself says on the point is reduced to very 
 little, and the result of a great eifort is merely a negative 
 impression. He puts us in mind more than once of the 
 saying of Montaigne of one of the ancients : " What juice 
 and marrow he has in him are dried out in the process of 
 cooking." 
 
 We have tried to show that the psychology of Lotze is 
 embarrassed at each point by his metaphysics. It would 
 be outside our purpose to explain his metaphysics at length : 
 some lines will suffice. Lotze can be looked upon as a rep- 
 resentative of the doctrine called in Germany Idealrealismus, 
 a term that is applied to the schools holding a mi4dle place 
 between idealism and realism. If we consider Schelling 
 and Hegel typical idealists, and Herbart and his disciples 
 typical realists, we will notice that their fundamental point 
 of divergence is this : Is the original element the idea or 
 the thing f Does thought regulate things, or do things 
 regulate thought? Ideal-realism considers the solution 
 false that is committed to either the one or the other of 
 these alternatives. It postulates parallelism between thought 
 
LOTZE. 75 
 
 and being, but not identity. It admits facts as foundation 
 and point of departure ; but, advancing upon this, it aspires 
 to the conclusions of idealism. Lotze occupies a position 
 of this kind in German speculation. A naturalist and 
 physician by education, a poet and artist in disposition, 
 he sets out with facts, but allows himself to be carried 
 away by his aspirations after the ideal, beyond the limits 
 of the physical world. He distrusts the purely idealistic 
 solution, but fears materialism and a mechanical explana- 
 tion of the universe still more. Besides, in his metaphysic, 
 feeling, sesthetic taste, and religious convictions, play a 
 great role : among all hypotheses he accords undisputed 
 prerogative to that which satisfies most of our moral needs.^ 
 From this ensemble results a doctrine a little vague in out- 
 line and difficult to reduce to system, yet clear enough in 
 its general impression. 
 
 II. 
 
 The Psychologie of Lotze, setting aside the first part, 
 which is devoted entirely to insoluble questions of meta- 
 physics, and the last chapters, in which the psychology of 
 disease is rather touched upon than treated, embraces the 
 following questions : the study of simple sensation, feeling, 
 moTement, and instinct ; the rise of the intuition of space ; 
 consciousness, its different states and the conditions of its 
 development. As we have said above, we wish here only 
 to examine a single point. 
 
 It is necessary from the first to understand well the ob- 
 ject that Lotze sets before him in his chapter on the ramn- 
 lichen Anschauungen. He does not propose to explain the 
 notion of space, considered as an» original and irreducible 
 
 ^ Wo zwei Hypothesen gleich moglich sind, die eine ubereinstimmend mU 
 tnoralischen Bedurfnissen, die andere mit ihnen streitend, kann Nichts die 
 Wahl zu Gunsten der letztern lenken. {Median. Psych., p. 36.) 
 
76 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 form of the mind. He declares himself very clearly on 
 this point. We can reproach him only for not having 
 shown in the beginning of his exposition, this important 
 distinction which is manifest throughout, and which takes 
 the form of remarks in the course of the discussion. It is 
 a fault of composition that is very embarrassing; for, as a 
 result, some uncertainty arises in the reader's mind as to 
 the object the author proposes. At first glance he seems 
 to be engaged upon a " deduction " of space, upon an ele- 
 mentary analysis whose object is the reduction of space to 
 a simpler notion — a reduction that some of the empirical 
 schools have attempted. But not so. " It is not at all our 
 project," says Lotze,^ " from these local signs to deduce the 
 soul's faculty of perceiving space in general, nor the neces- 
 sity it is under of apprehending the thing felt in this no- 
 tional category. We presuppose, on the contrary, that there 
 are in the nature of the soul grounds by reason of which 
 it is not only capable of a notion of space, but is further 
 compelled to apply this notion to the content of sensation, 
 and we seek to explain by hypothetical physiological rela- 
 tions, between the local signs, neither this faculty nor this 
 compulsion. Yet, while we accept and hold as a fact to 
 be recognized from the first, that the soul is able to form 
 these ideas of space and consents to it; it remains to ask 
 further on what principle, in this general idea of space, its 
 discrimination is guided in assigning one sensation to 
 such a place and another to another, and how it is led to 
 regard the sensations a and b as contiguous, the sensations 
 a and c as remote in their relation to each other.'' 
 
 The general intuition of space is then assumed as an 
 original fact and placed above all explanation. Yet it is 
 not to Lotze a kind of entity prior to experience. " We 
 must not imagine that, before the soul receives external 
 
 * Medidnische Psychologie, book II, I 292. 
 
liOTZE. 77 
 
 impressions, it spreads out, like a net ready to catch any- 
 thing that falls into it, the intuition of infinite space of 
 three dimensions entirely formed and already complete. 
 The question would* arise again, how do we get impressions 
 to enter a net like this spread in a world where as yet 
 they are not. The power of responding to the action of 
 luminous waves by the sensation green or red is ex- 
 plained only as a manner of reaction peculiar to the nature 
 of the soul and innate, aflPording room for no deduction 
 whatever. After having experienced these sensations, we 
 construct the general idea of color. It is the same with 
 space. We do not have at first the vacant intuition into 
 which the images of things that affect us are to be subse- 
 quently placed ; but, reacting according to the laws of our 
 nature against excitations already experienced, we commence 
 by localizing an impression p near another q, by imagining 
 a line mn that can be called an element of the future space, 
 but not a line in space, for the entire space in which it 
 would then be traced does not yet exist. It is later, upon 
 observing what we have done, or what is done in us, that 
 we conceive of the possibility of uniting two of these lines 
 pq, rs, by two others, pr, qs, and that, by continuing our 
 observations, we acquire the conviction that the possibility 
 of thus connecting two given points has no limit. So the 
 intuition of infinite space is formed ; it is the result of the 
 combination of elementary reactions native to the soul and 
 belonging to it, as is said, a priori." ^ 
 
 It is then well understood that Lotze does not attempt 
 to explain the empirieal genesis of the intuition of space. 
 
 . ^ Revue philosophique, Nov. 1887, vol. II, p. 345. Lotze has given a 
 more extended exposition and resume of his theory of local signs in the 
 Medicinische Psychologie. In the article from which this passage is 
 taken, he replied to various objections that his theory had called forth. 
 Another résumé is given by Lotze, in an appendix to the work of Stumpf, 
 of which we will speak in Chap. V. It was published in 1873. 9 pages. 
 
78 GERMAN PSYCHOLOGY OF TO-PAY. 
 
 In order that our visual and tactile sensations appear to us 
 extended, it is necessary and it suffices that there be within 
 us the possibility and the necessity of co-ordinating them in 
 a certain way. This admitted, what is experimentally the 
 disposition that favors such a co-ordination ? 
 
 The great, almost inevitable error, that is inherent in 
 almost every theory of space, and against which Lotze 
 wished to guard himself, consists in confounding the solu- 
 tion of the problem with its data. We never free ourselves 
 from a petitio principii; to explain space, we always 
 employ elements that contain this idea. The grossest 
 form of this mistaken solution is the old hypothesis of 
 idea-images. It is not sufficient to detain us, and no 
 one would be willing to discuss seriously whether or not 
 small copies of objects enter the "soul" from without. 
 Yet this doctrine, in a much more refined and subtle form, 
 indeed, meets us still everywhere. All the theories of 
 space, in fact, admit more or less, that the form under 
 which a quantity of simultaneous excitations of the ner- 
 vous system follow one another in space, affi)rds immedi- 
 ately the reason for a similar disposition of sensations in 
 space. 
 
 To illustrate the critique of Lotze by an example, sup- 
 pose the end of a rule be laid on the hand ; a certain 
 number of nerve extremities are excited, and the excita- 
 tions are transmitted by the nerves to the sensorium. It 
 is generally held that these excitations are then repro- 
 duced, not to say where or how, in the same order as the 
 impressions received, in such a way that the series A, B, 
 C, . . . Z, of cutaneous impressions, becomes a series 
 a, 6, c, . . . z, of internal states, the form of the first 
 series giving the form of the second. It is thus implicitly 
 maintained that each point of the hand touched by the rule 
 is represented in the sensorium by an analogous equivalent. 
 For visual impressions, consisting of images painted on the 
 
LOTZE. 79 
 
 retina, there is a similar hypothesis, which it is needless 
 to develop. In short, it is admitted that that which per- 
 ceives in us — soul or brain — by whatever term it be desig- 
 nated, presents a* reproduction of external impressions, 
 modified, reduced, transformed; that each element of 
 extension is perceived as extended. 
 
 Whatever metaphysical solution we adopt, whether we 
 suppose with materialists that the soul is extended, or with 
 idealists, that the soul is not extended, matters not, since 
 the same error is always committed. In order to get rid 
 of this perpetual illusion, it is necessary from the first to 
 understand that our visual and tactile impressions can he 
 'perceived only under the f orra of intensive states. What each 
 point touched transmits to " the soul " is not an extended 
 image of that point, but an intensive modification, vary- 
 ing with the nature and energy of the impression. In 
 order to perception the impressions of the rule placed on 
 the hand must be wholly transformed, completely changed 
 in nature : a totality of given extensives must become a 
 totality of given intensives, and thus furnish to the soul the 
 material of a reconstruction, a transformation anew of the 
 intensive into the extensive. " The great advance here 
 consists in no longer detaching from things their objective 
 images, but introducing, in their stead, immediately into 
 consciousness, subjective figures of excitation, with their 
 special contour. Undoubtedly there must be supposed also, 
 in the transmission of these figures to the soul, a point 
 where their geometrical form disappears, leaving no traces, 
 and where it is replaced in the soul by a sum of iintensive 
 excitations, which, like the pitch of sound, contain no in- 
 dication of extension or of position in space. If, con- 
 sequently, we obtain a notion of the position of external 
 objects, it cannot be by means of perception, but by 
 means of the new reproduction of space. In general, the 
 extensive is transformed into the intensive. It is thus that 
 
80 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 the soul must first reconstruct, within, a new world of space, 
 in which the images of external objects find a correspond- 
 ing function. Just as a variable magnitude can decrease to 
 zero, and setting out thence take a new increase ; so it is 
 absolutely necessary that the regular geometrical impres- 
 sions disappear at a point where there is no longer space, to 
 be reproduced again on the other side. Just as, further, 
 a variable magnitude is developed anew, not because it re- 
 serves its former positive values to place them, so to speak, 
 under the value zero, but because the law of its variation is 
 applied in the temporary destruction of its positive value ; 
 so also the impressions conveyed to the soul are developed 
 in a new world of space, not by obscuring in consciousness 
 the concealed quality of space, but by exhibiting their 
 capacity of maintaining in the extensive excitations of the 
 soul, which have produced them, relations whence result 
 anew, through the constitutive faculty of nature, images of 
 the objects in question."^ 
 
 If it be admitted that, when the peripheral impression, 
 transmitted by the nerves, becomes a state of consciousness, 
 it ceases to present an extensive character, it still remains 
 to explain how each of the elements that constitute this 
 impression conserves its peculiar character and its relations 
 to the other elements ; how it is differenced from them and 
 associated with them : for, without such conditions as these, 
 
 ^ Medidnische Psych., vol. II, f 287. Lotze farther compares the soul 
 to a lens that focuses at an indivisible point all the rays reflected from a 
 colored surface. At this point it would be no longer possible to dis- 
 tinguish the relative position of the rays, since they are condensed in a 
 general glare. But beyond this point the rays diverge again and spread 
 out on an inverted scale, a copy of the given surface. In this comparison, 
 the convergent rays represent the nervous movements caused by an ex- 
 ternal impression ; the point of concentration corresponds to the unity 
 of consciousness ; and the bundle of divergent rays represents the recon- 
 struction in the soul of the previously destroyed relations of space. 
 {Revue philosophique, vol. IV, p. 347.) 
 
LOTZE. 81 
 
 no reconstruction of space is possible. To this tlie Iiypo- 
 tbesis of local signs affords a reply. 
 
 Tactile and visual sensations are the only sensations 
 that imply — at least, in a clear and indubitable way — the 
 notion of extension. Hence a great difference between them 
 and sensations of hearing, taste, and smell. A sound, a 
 taste, an odor produce modifications of our organs, that 
 vary according to the specific character of these sensations ; 
 but they produce nothing more. Between a single somid 
 and several identical sounds that affect us simultaneously, 
 there is a difference only of intensity : each sound blends 
 with those like it, without preserving its individuality ; the 
 intensity only of the sensation is reinforced. In the same 
 manner, between the odor produced by one odorous mole- 
 cule and the odor produced by thousands of similar mole- 
 cules, between the taste produced by one sapid molecule 
 and the taste produced by thousands of similar molecules, 
 there is a difference only of less and greater. Such is the 
 case with all the intensive sensations. 
 
 With extensive sensations, the conditions change, and 
 the phenomenon becomes more complex. Without doubt, 
 there are also variations in intensity here (compare, for 
 example, a luminous point with a luminous body, a red 
 point with a red cloth, contact at a point with contact of 
 the whole hand) ; but a new character of the first import- 
 ance is added to that of intensity : extension. Let us ex- 
 amine this new character. 
 
 To reduce the problem to its simplest terms, we will ex- 
 clude all complication due to pain and pressure, and suppose 
 that the head of a pin touches the skin, that a red point is 
 painted on the retina. As in the case of intensive sensation, 
 a movement of the corpuscles of touch and of the rods of 
 the retina, a transmission of this movement, by the nerves, 
 to the sensorium, is occasioned ; but this tactile or visual 
 sensation does not appear to us as a simple modification of 
 
82 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ourselves ; it is referred to a point of our body or to an ex- 
 ternal object ; it is placed in space. In a word, there is 
 here more than a sensation felt, tiiere is a sensation localized. 
 
 The différence between intensive and extensive sensations 
 becomes more striking still if, in place of a single point, many 
 points of the skin or retina, as is most ordinarily the case, 
 are simultaneously affected. There is produced no longer 
 a fusion of sensations in a sensation more intense ; but each, 
 preserving its individuality, is co-ordinated with others and 
 forms the continuity that we call extension. 
 
 If all the points of the skin in a case of contact, and all 
 the points of the retina in the case of a colored surface, felt 
 identical impressions in an identical way, it would be natu- 
 ral to admit that there is produced here, as in the case of 
 intensive sensations, a fusion, and not a co-ordination of 
 sensations. But as, in fact, there is no such fusion, it must 
 be admitted that each point of the skin, each point of the 
 retina, feels after its kind, that is, imposes upon the impres- 
 sion received a particular mark, as indistinct as you will. 
 This special mark which differentiates each impression from 
 others is the local sign. 
 
 How are we to conceive these local signs ? " We are able 
 at the outset," says Lotze, " to represent them, in general, 
 under the form of a physical nervous process, associated con- 
 stantly, in each part of the nervous system, with a variable 
 nervous process, which at the same point, serves as basis for 
 the qualitative character of the sensation." Leaviug these 
 generalities for a more exact determination : " We are able," 
 says he, " in two ways to conceive a system of local signs 
 from which a clear and geometrical idea of space would 
 result : 1st. It could be made up of muscular sensations. Not 
 only every position of a limb, but further every contact of 
 one of its parts could be distinguished from that of another 
 part by a particular combination of those light accessory 
 sensations which are provoked at the points of special con- 
 
LOTZE. 83 
 
 tact by the transmission of the excitation. 2d. Still, what 
 would permit a much more complete and easy determination 
 of magnitudes mathematically comparable, would be a system 
 of movements, produced, perhaps, by the passage of the ex- 
 citation, or, at least, by a tendency developing in the sense 
 aifected. Let us conceive some very sensible organ, so mobile 
 that by the action of an appropriate muscular system, any 
 one of its sensible points can be turned toward any and all 
 directions of space ; and suppose, further, that the influence 
 of the excitation always awakes in some way these tendencies 
 to movement : we see that each portion of the organ will 
 have the power of attributing to its excitations a mathematic- 
 ally determined local sign, in a complete and entirely special 
 way. Indeed, each portion would have the power of awak- 
 ing a tendency to movement, determined not only in magni- 
 tude, but also in direction, in correspondence with the three 
 co-ordinates of space : a tendency which does not recur ex- 
 actly for any other portion, and which, however, in relation 
 to every other similar tendency to movement, sustains a cer- 
 tain degree of resemblance, or difference, of elevation or op- 
 position. These considerations lead us at once to seek the 
 local signs not in the accessory passive states alone which 
 each portion of the nervous system experiences in addition 
 to the sensorial excitation, but rather in the movements 
 which the same portions tend to provoke through their con- 
 nection with the rest of the nervous system. The eye, as 
 well as the sense of touch, will give us occasion to test the 
 value of this hypothesis in explaining the notion of the 
 world." ^ 
 
 To make these general considerations upon the local 
 signs complete, it remains to ask what relation they sustain 
 to consciousness. Although Lotze is not disposed, in general, 
 to overestimate considerations based upon the unconscious, 
 
 ^ Medicinische Psychologie, book II, ibid., § 291. 
 
84 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 he is inclined nevertheless to assign them an important role ; 
 and one is not astonished that Hartmann has considered this 
 theory of local signs ^ as proof of his doctrine. When we 
 determine trigonometrically the position of distant points 
 from the angle that the visual rays from ourselves to these 
 points include, we make a perfectly conscious use of our local 
 signs. In ordinary life when we refer a cutaneous excita- 
 tion to a given point on the skin, by virtue of an associa- 
 tion founded on experience, we have still a clear conscious- 
 ness of the local sign. But, in most cases, it is not so. 
 " When in the sphere of vision we localize colored points 
 perceived simultaneously, the reason of this localization lies 
 entirely outside of consciousness, and the local signs that we 
 still postulate perform their functions unconsciously." The 
 case is analogous to that of reflex movements, which enter 
 consciousness only as accomplished facts. " Localization, 
 in space, then, belongs to the unconscious product of the 
 soul's action through the mechanism of its internal states." ^ 
 Lotze has recently declared that he could not subscribe 
 to the opinion of those who maintain that, his theory admit- 
 ted, it is possible to verify the hypothesis of local signs by 
 reflection and internal observation. " We do not forget," 
 says he, " the uncertainty and arbitrary character of every 
 hypothesis upon which phenomena are supposed, which 
 exist in the soul, but exist unconsciously. We certainly 
 have not the right to admit such unconscious states, at 
 least to compare them with forgotten and reproduced 
 ideas, the only examples of the persistence in the soul 
 of that which persists no longer in consciousness. But 
 in the case in hand I believe we have this right." ^ The 
 skilled musician executes unconsciously acts that were at 
 first conscious. " We are persuaded that it is the same with 
 
 ^Philosophie d. Unbewussten, trans. Nolen, I, p. 371, etc. 
 ^ 3fedicinisehe Psych., ibid., g 294. 
 ^ .Eemie philosophique, loc. cit., p. 360. 
 
LOTZE. 85 
 
 the localization of our sensations. It seems at present to 
 take place suddenly, at the very instant that we open our 
 eyes ; but at the dawn of life this power is developed only 
 by means of a series of experiences, which, if we could re- 
 produce them, would enable us to see, as in so many of the 
 states of consciousness of the child, all those intermediate 
 states which have become imperceptible to the consciousness 
 of the adult." 
 
 III. 
 
 After these general considerations upon the local signs, 
 let us study, in order better to understand their nature, 
 the role that they play in the formation of visual and tac- 
 tile perceptions. 
 
 VISUAL LOCAL, SIGNS. 
 
 Setting aside the numerous questions that attach to 
 vision : estimation of distance, direction, right vision, 
 union of images in one, etc., etc., — we will consider a 
 single point : the formation of the image on the retina. 
 In this we follow the example of Lotze, who treats the 
 other questions as mere accessories. 
 
 The excitation of any portion of the retina produces in 
 " the soul " two corresponding states, the one determined 
 to a color, the other to position relative to the point excited, 
 whicli latter is itself relatively allied to that portion of the 
 retina among its surrounding portions. Let us not forget, 
 moreover, that this second state (that which corresponds to 
 position) can present only an extensive character. The 
 sensation corresponding to color cannot have even the form 
 of a point ; for, being without extension, it cannot be con- 
 ceived as the negation of extension in space, that is, as a 
 point; it is perceived only as quality, having neither a posi- 
 tive nor a negative relation to a development in space." ^ 
 
 1 Loc. cit., \ 310. 
 
86 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 The local sigu, that concomitant of the sensation of color 
 which prevents its losing its individuality, consists, as we 
 have said, in a system of movements. To understand it, 
 let us suppose that the image of a brilliant point is formed 
 on one side of the retina : at the same time a movement 
 of the eye takes place, by which the centre of clearest 
 vision is placed beneath this image. We know, in fact, 
 that there exists in the retina a small portion at the centre, 
 which has a visual sensibility very superior to any other 
 part. We know, also, that in virtue of a physiological 
 contrivance, whose causes and origin it is not here our 
 business to investigate, the excitation of any point of the 
 retina occasions a deviation of the axis of the eye, in such 
 a manner that the point of clearest vision is directed toward 
 the exciting object. 
 
 This understood, let us call this point of clearest vision v, 
 and suppose that three other points of the retina, a, b, and 
 c are excited. The image formed at a will give rise to a 
 certain movement, necessary to produce the image at v. The 
 image formed at h will give rise to a movement different from 
 av. The image formed at c v/ill give rise to a movement 
 différent from av and vb. Whatever positions we assign to 
 a, 6, c, it is easy to see that, in any case, the movements 
 v/ill not be identical, that each will have a character pecu- 
 liar to itself. Indeed, if we suppose that a, b and c are 
 situated in the same line, or rather, in the same circular 
 arc, the segments va, vb, vc, of this arc must have different 
 magnitudes, and, as the eye must pass over them to bring 
 in turn the images a, b, c, in the direction of clearest vision, 
 there will necessarily arise muscular movements that are 
 different in magnitude, though analogous in other respects. 
 If we suppose a, b, c to be situated on the circumference 
 of the same circle whose centre is v, then vb, va, vc, will be 
 equal, but in different directions. Finally, if we suppose 
 that a, b and c are situated neither on the same line from 
 
liOTZE. 87 
 
 V, nor on the same circumference whose centre is v, then 
 va, vb, ve, will be at the same time unequal in magnitude 
 and in different directions. " If we desio^nate the sum of all 
 these movements by S, this sum is for each point of the 
 retiua an unchangeable and definite combination, and so we 
 believe that we have in it a local sign that differences the 
 excitation at each point from the excitation at any other." 
 
 In the case that we have just examined, we supposed a 
 lively impression produced at a point of the retina, and 
 followed by a real movement of the eye. But, in cases 
 where there is not a single predominating impression, each 
 excitation of the retina continues none the less to determine 
 a similar tendency to movement in connection with the point 
 affected. " We may further admit that this tendency has 
 at first for its end only the production of the automatic 
 movements of the eye, but that it afterward produces a 
 change in the state of the soul — an impression ; and, to my 
 mind, it is by means of these impressions, in accordance 
 with their gradual and exact determination and the degree 
 of their inter-relation, that the soul develops in space the 
 perception of colored points, in such a way that their dis- 
 tance in the field of vision, and all their relative positions, 
 correspond to the distances and positions of tlie nervous 
 points excited. It is not necessary to require that these 
 impressions be transformed into conscious representations. 
 Although this is a fact in certain cases, we must consider 
 the initial localization of the colored points an absolutely 
 unconscious operation of the soul." Later, in consequence 
 of habit, the colored points seem to be placed, of them- 
 selves, in determined positions, and their localization is not 
 the result of a sensation antecedent to conscious movement, 
 still less of real movement.^ " Thus," says Lotze, " it is 
 
 ^ Lotze returns many times to this point ; that we attribute, according 
 to him, to real movements of the eye, an exaggerated influence in the 
 development of the notion of space. See in particular loc. cit., § 328. 
 
88 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 neither to real movements nor to their conscious sensations 
 that we refer the co-ordination of points in the field of 
 vision. The first localization, entirely unconscious, rests 
 in the connection between the sensor and motor nerves, 
 and it is the excitation of these latter at their central ter- 
 minations that gives to each impression of color its peculiar 
 local sign."^ 
 
 We will sum up in a few words the exposition given. 
 The formation of the field of vision is possible only by a 
 body (ensemble) of local signs. These local signs can arise 
 neither from movements of the motor muscles of the 
 eye, nor from the histological constitution of the retina 
 alone, even allowing that each feeling point presents a 
 structure slightly different from that of the surrounding 
 points. The cause of distinction among the excitations 
 of the particular points of the retina can be found only 
 in their relations with the motor train. Each impres- 
 sion for each point gives rise to a particular movement (or 
 tendency to movement), which produces a certain psychic 
 state; this state constitutes peculiarly the local sign. 
 Lotze attributes to these acts a character in general uncon- 
 scious, but without disguising the difficulties inherent in 
 such a hypothesis. Finally, when the excitation, the move- 
 ment, and the psychic impression that follows, have been 
 repeated a great number of times, there results a complete 
 knowledge of the topography of the retina, of the position 
 of all the points ; this makes an immediate localization 
 possible, even when the eye is in repose. Tliis process ap- 
 proaches very near the reflex processes in its origin (exci- 
 tation), its end (motor reaction), its automatism, and its 
 unconscious character. To conclude with the words of 
 Lotze himself : " It is from the combination of the excita- 
 tions of the retina with those unconscious impressions 
 
 ^ Medicinische Psychologie, he. cit., | 343. 
 
LOTZE. 89 
 
 which associate with ihem, in the soul, tendencies to move- 
 ment, that we may deduce the co-ordinatiou of points in 
 
 the field of vision."^ 
 I 
 
 TACTILE LOCAL SIGNS. 
 
 It will be useless to dwell as long on this point as on 
 the preceding. It will suffice to note wherein the two 
 cases differ. 
 
 The corpuscles of touch play a role analogous to that of 
 the cones and rods in the retina. There are differences in 
 structure between them, at the outset, three kinds being 
 distinguished (corpuscles of Pacini, of Meissner, and of 
 Krause). Moreover, they are spread out or grouped in a 
 very different way at different points of the skin. These 
 facts in themselves are sufficient to explain the fact that 
 the same excitation may vary according to the cutaneous 
 region that it affects ; but they do not explain localization. 
 Qualitative differences do not explain the fact that the 
 impressions are referred to certain points of the skin, and 
 are co-ordinated in space. 
 
 These anatomical differences, then, are only the first con- 
 ditions of localization in space. A second fact to which 
 Lotze attaches great importance, is the phenomenon called 
 " the wave of accessory sensations." As the skin forms a 
 continuous surface, no excitation, however small, can be 
 assigned to a point where it originates. It always occa- 
 sions tension, pressure, displacement, small or great, in the 
 neighboring parts. But the structure of the skin is not 
 everywhere the same; it varies in thickness, flexibility, 
 rigidity. The contact varies according as the affected part 
 adheres to an osseous surface, or covers a cavity, or rests 
 on the soft mass of the muscles. "Thus the sensation re- 
 sultmg from the excitation of a point A, is encircled by a 
 
 ^ Medicinische Psychologie, loc. cit., | 328. 
 
90 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 wave of accessory sensations, determined by the form of this 
 point, its extent, the composition of its elements, and differing 
 in these particulars from the wave that accompanies the 
 excitation of any other point B." It suffices to recall the 
 celebrated experiments of Weber, to see that the tactile sensi- 
 bility varies with the regions of the skin. At the end of 
 the tongue and at the ends of the fingers, two points can be 
 distinguished, and consequently present local differences, at 
 as short a distance as one and two millimeters ; on the back, 
 the shortest distance is two to four centimeters. But we 
 must not be deceived here : the waves of accessory effects, 
 in spite of the important role they play in tactile percep- 
 tion, do not fulfill the conditions necessary to true local 
 signs. They afford means of distinguishing two sensations, 
 A and B ; they do not suffice to distinguish them in space ; 
 i. e., to construct a line of which A and B are the extremi- 
 ties. 
 
 There remains a third element : movement and the mus- 
 cular sensations that accompany it. While recognizing the 
 important, capital, role that this last element plays in the 
 localization of the tactile perceptions, Lotze insists upon it 
 less than his followers do,' and thinks that we cannot find 
 in it a complete solution of the problem in hand. 
 
 To sum up, the skin is a continuity, varying in its sur- 
 face, in consequence of differences in anatomical structure, 
 of direct impressions and the auxiliary impressions that 
 they produce, of movement and accompanying muscular 
 sensations. In order that we may decide, says Lotze, 
 whether an impression is produced on the right or on the 
 left, it is necessary that the excitation of the sides of the 
 body produce different sensations in consciousness. Beings 
 of a completely symmetrical constitution would be incapable 
 
 ^ According to researches of which we will speak later, it is maintained 
 that the delicacy of the sense of place is proportional to the mobility 
 of the part of the body affected. See the chapter on Wundt below, § III. 
 
LOTZE. 91 
 
 of distÎDguishing between the right and left, and in gen- 
 eral, between corresponding parts of the body.' There 
 are differences of structure, of movement in the members, 
 of muscular sensation, that make the differentiation pos- 
 sible. We remark finally with the author — ^and this fact 
 shows the importance of movement — ^that, if the extremities 
 of the fingers be fixed upon the end of a rigid rod, all 
 delicacy of localization disappears : each excitation instead 
 of affecting a particular point, seems to be diffused through- 
 out a homogeneous medium. 
 
 We must not forget, then, that to Lotze, neither differ- 
 ences of structure, nor accessory waves, nor movement, nor 
 muscular sensations, explain the localization of tactile 
 impressions. For such localization, a synthesis is neces- 
 sary : " it is necessary to possess already a geometrical 
 image of the contour of the body and to have learned by 
 experience to what point the sensations A and B are to be 
 referred, according as they are affected with the local signs 
 a and /3." 
 
 A very natural objection arises here : the case of persons 
 born blind, who acquire the notion of space by touch with- 
 out the aid of sight. From the first, Lotze admits that the 
 cutaneous sensations taken alone, though they do not give 
 us the distinct idea of space, nevertheless give rise, in cer- 
 tain cases, to the obscure idea of a certain largeness which 
 is not without some remote analogy to the idea of space. 
 Further, when the sense of touch exists alone, the necessary 
 conditions of localization are found in it, in virtue of the 
 movements that accompany impressions ; but these move- 
 ments having neither the fullness nor delicacy of those 
 that accompany the visual impressions, the localization 
 is ruder and more imperfect. "The skin is possessed 
 of innumerable sensitive points, but the movements neces- 
 
 ^ Medicinische Psych., loc. cit., ^ 340. 
 
92 GERMAN PSYCHOLOGY OP TO-DAY. 
 
 sary to estimate position are not immediately possible at 
 these points, as they are at those of the retina, and it is 
 necessary that the movable organs combine to supply this 
 defect. The hand sliding over the surface of a body re- 
 ceives, like the retina, a great number of impressions at 
 once. When it loses one p, it does not lose all ; the others, 
 Ç, r, s, persist, and a new impression t joins them :^ thus 
 it is that groping, together with the sensibility of the skin, 
 serves to form for the blind a notion of space ; but is perhaps 
 not entirely identical with that which sight makes possible." 
 Lotze, in effect, remarks that the faculty of differentiation, 
 being much less fine in touch than in sight, the space of 
 a square inch must offer to the blind fewer differentiable 
 points than are discerned by the man who sees. It is concluded 
 that, to the blind, objects ought to appear smaller than to 
 one who sees ; and, in fact, those born blind, when operated 
 upon (among others the case of Cheselden), have many 
 times expressed their astonishment at the unexpected size 
 of objects. 
 
 Lotze completes his theory of local signs with an inquiry 
 into the genesis of the notion of externality. We will say 
 nothing upon it, as this question is to be examined else- 
 where. Our object was only to discuss a single point in 
 the doctrine of Lotze : that which gives him true originality 
 as a psychologist. 
 
 This doctrine of local signs has been adopted in Germany 
 by a number of authors : admitted without reserve by some, 
 modified by others. 
 
 The first merit that we must allow him is that he has 
 brought to light all the difficulties inherent in the prob- 
 lem. No one has shown better than Lotze the petitio 
 
 ^ We must remark with Lotze that the persistence of each impression 
 alone renders the notion of space possible. If, in the passage from p to q, 
 no trace of the former persisted, we could not establish those relations 
 which constitute space. 
 
LOTZE. 93 
 
 prineipii of the ordinary solution. By an almost un- 
 conquerable tendency of the human mind, we are wont 
 to explain space by means of images that presuppose it. 
 We see objects reflected in the retina as in a mirror, or 
 imprinted upon the tactile organs as the stamp upon wax, 
 and we think that these external images ought to be 
 reproduced in our consciousness under forms more or less 
 analogous. Reflection, however, teaches us that knowl- 
 edge of these images supposes anterior knowledge of our 
 body, of its parts, of their positions, in short, knowledge 
 of relations in space, and that this knowledge can be itself 
 derived only from states entirely internal. Lotze sees but 
 one way of resolving this difficulty : we must refer the 
 perception of extension to a perception of qualitative diifer- 
 ences, which by a new reconstruction of the mind become 
 relations of extension. 
 
 His hypothesis is natural and scientific ; he has devel- 
 oped it in metaphysical language, which we have scrupu- 
 lously respected for the sake of exactness. It is based 
 on facts and is offered as their only probable explanation. 
 Lotze undertakes to show that the anatomical disposition 
 of the visual and tactile organs affords solid support to his 
 hypothesis. " If we find," he says, "such a disposition 
 as will assure the action of external excitations upon the 
 nervous system, according to geometrically prescribed rela- 
 tions, this disposition will afford much reason for the be- 
 lief that nature intended to deduce from these relations 
 something for consciousness : this in itself, however, explains 
 nothing." To our mind he has not insisted sufficiently 
 upon this point. It is true that at the time the Medical 
 Psychology was written the arrangement of the terminal 
 organs for the visual and tactile nerves was not as well 
 known as to-day. But, taking the question up again quite 
 lately, Lotze has not insisted further upon these anatomic 
 details. Physiologists seem now to admit that the structure 
 
94 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 of the peripheral nerve terminations plays a great role in 
 the reœptiou of impressions from without, and this position 
 has some analogy to the hypothesis of local signs. 
 
 We have seen the important place that Lotze assigns to 
 movement, in the formation of visual or tactile space, 
 especially to unconscious movement, or, as he sometimes 
 expresses it, to tendencies. This position invites criticism, 
 especially from those who, ridding themselves of the uncon- 
 scious, rest as much upon induction as upon well-established 
 facts. " For the sake of brevity," says Lotze, " we will some- 
 times use the expression tendencies to movement, to desig- 
 nate the local signs. This expression has been criticised as 
 ambiguous and incompatible with the precision that notions 
 in a mechanic of psychic phenomena should have." This 
 criticism leads Lotze to define his thought and to speak of 
 the local sign as a purely psychic state of which movement 
 is the occasion. " That which passes in the nerves can 
 give only a rotation of the eye, i. e., a phenomenon of the 
 physical world : the psychic affections that issue from it can 
 alone bear the name local signs, for they alone produce 
 localization, and localization is an act of representation with 
 no relation of resemblance to any movement whatever, and 
 cannot be in any way estimated in terms of the notions 
 employed in a mechanic of body." Here again we fall into 
 the difficulty of admitting as the last ground of our expla- 
 nation a state which is considered at once psychic and un- 
 conscious. Yet it must be remembered that Lotze does 
 not cease to repeat that his theory is presented only as an 
 hypothesis. 
 
 Is this hypothesis true ? To reply in the affirmative we 
 must be able to show that it is the only hypothesis possible : 
 now it is probable that Lotze himself would not maintain 
 this. Besides, there is a difficulty involved in the whole 
 discussion of space, i. e., the role that is played by the ulti- 
 mate or a priori element, which he mentions only in pass- 
 
I.OTZE. 95 
 
 ing, but which remains, nevertheless, the basis of all the 
 Avork of mental reconstruction. 
 
 To sum up, his theory holds a middle place between the 
 attempts which the English school have made to explain 
 entirely, and by experience alone, the genesis of the idea of 
 space, and the complete absence of explanation which has 
 prevailed ordinarily among the defenders of an a priori in- 
 tuition. The continued investigation to which the science 
 is subjecting this notion, in the light of new theories and 
 experiments, will determine its relative value. Whatever 
 become of the solution of Lotze, it will remain the work 
 of an ingenious and penetrating mind, one that is extremely 
 apt, especially, in stating the difficulties of the problem.^ 
 
 ^In an article recently published in the Revile philosopldque (Sept. 
 1878, vol. VI, pp. 217-231), Wundt criticised very profoundly Lotze's 
 theory of local signs, which he calls the hypothesis of simple local signs, 
 in opposition to his own, the hypothesis of composite local signs. He 
 reproaches Lotze for putting the question under a metaphysical form 
 (hypotliesis of the soul), and for deciding, in virtue of this hypothesis, 
 that our retinal and cutaneous sensations cannot possess extension. He 
 attempts, on the contrary, to show : 1st. That there are optic and other 
 experiments that justify our refusing to the retinal and cutaneous sensa- 
 tions, taken in themselves, an extensive character; 2d. That the con- 
 ditions that must be added to these sensations to place them in the cate- 
 gory of extension are those of movement. 
 
CHAPTER IV. 
 
 ORIGIN OF THE NOTION OF SPACE. 
 
 Debate of the Nativists and Empiricists. 
 
 We have just studied with Lotze, in detail, a particular 
 element of sensible cognition. Without leaving this prob- 
 lem, we must notice the debate of a question of much more 
 general character, that concerns the very foundations of 
 human knowledge. 
 
 Is the knowledge of extension and its determinations, 
 length, breadth, thickness or distance, position, form, inborn 
 or derived from experience ? This is a question that has 
 been asked and answered differently, especially by physiolo- 
 gists, and has given rise to numerous theories. Helmholtz, 
 I believe, was the first to classify them as native and empir- 
 ical. Doctrines on this subject really date back to the first 
 attempts in psychology ; but it is only in our day that they 
 are constructed with a clear knowledge of the problem in 
 hand, of the possible solutions, and with the substitution 
 of reasons of fact, drawn from the natural sciences, for 
 metaphysical deductions. The issue is joined particularly 
 on the question of visual space. This was to be expected 
 from the fact that sight is the most delicate of the senses, 
 the richest in its reports of the external world, and the 
 most open to nice experiment. The same question is raised, 
 however, as to tactile space, and although we cannot cite on 
 this point as many attempted expositions or debates as bril- 
 liant as those of Hering and Helmholtz on sight, the solu- 
 96 
 
ORIGIN OF THE NOTION OF SPACE. 97 
 
 tions are fundamentally the same. On this side the struggle 
 between the nativists and empiricists, to which I will first call 
 attention, has been less deadly and there is much less to say 
 than on the question of visual extension ; but for the reason 
 that it is simpler the debate is more instructive. 
 
 We will expound the different doctrines, and then exam- 
 ine the theoretical question. 
 
 I. 
 
 TACTILE SPACE. 
 
 Reduced to their common content, the theories of nativism 
 maintain that the order of tactile sensations has its basis in 
 the constitution of the organism, that it is given originally 
 with the organism, and is consequently innate. This hypo- 
 thesis is the more natural, the simpler, and arises first in 
 the mind. Any one who has not betaken himself to reflec- 
 tion or the thought of others adopts it confidently. It is 
 a spontaneous belief, one of those predications that the 
 Germans call " a product of the natural consciousness." It 
 has been everybody's solution in all time. 
 
 The great physiologist, John Millier, seems to have been 
 the first to give it a scientific form. It is generally admit-^ 
 ted that he constructed his theory under the influence of the 
 philosophy of Kant. Historically this influence is indis- 
 putable, although, in our opinion — we will attempt to show 
 it later — the Kantian critique has no coniiection with this 
 debate. Muller observed with reason " that the notion of 
 objects of touch rests, in the last analysis, upon the pos- 
 sibility of distinguishing the diflerent parts of the body as 
 occupying each a difierent place in space ; " but, according to 
 him, if the optic and the tactile nerve alone among the 
 sensor nerves, convey to the sensmnum an impression of ex- 
 tension in space, it is because " they alone are capable of 
 feeling their own extension in an exact Avay." " Since 
 9 
 
98 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 entire members, indeed the majority of the parts of the 
 body, have sensor nerves, it results that the sense of touch 
 is capable of apprehending, in all dimensions, the ex- 
 tension of the body ; for each point at which a nerve fibre 
 terminates is represented in the sensorium as an integral 
 portion of space (vol. II, pp. 271-272). 
 
 The well-known investigation of E. H. Weber deter- 
 mined more exactly the role of the nerve terminations. 
 He showed, using compasses with blunted points, that 
 tactile sensibility varies extremely from one part of the 
 body to another ; that in order that two points be distin- 
 guished on the end of the tongue, a separation of a milli- 
 meter is sufficient, while on the back it must be from four 
 to six centimeters. In this way he divided the surface of 
 the body into a great number of regions, called circles of 
 sensation, which vary extraordinarily in size and form. At 
 first, Weber considered each of these circles, that is, each 
 portion of the skin provided with a single nerve thread, as 
 an unit of space. Later, replying to the different objections 
 called out by his theory, he maintained that the circles of 
 sensation must be such that there may be many between 
 two points felt to be distinct ; in this way he explained the 
 space intervening in sensation between the two points. He 
 gave to experience and habit a considerable role, admitting 
 that they diminished the number of circles necessary to the 
 perception of the interval between two points of the body. 
 In so far he approached the empirical theory. 
 
 Other authors, among them Czermak and Meissner, 
 made various modifications. But the one who has been 
 more recently the most intrepid champion of the nativist 
 theory, while pretending to reconcile it to its rival, is 
 Stumpf. In his Psycliological Origin of the Notion of 
 Space^ he maintains that we have innate knowledge of three 
 
 * TJeber den psychologisehen Ursprung der Haumvorsidlung, Leipzig, 1873. 
 
OEIGIN OF THE NOTION OF SPACE. 99 
 
 dimensions. At first, in all contact, we feel necessarily and 
 immediately a certain extension; we localize the tactile 
 impression in a definite place, needing no other condi- 
 tion than the contact itself. Thus we have intuitive 
 knowledge of a surface touched. But it is curious to see 
 the way in which he establishes his position for the third 
 dimension. He says if the surface (length and breadth) 
 be perceived immediately, depth must be also. In fact, 
 the surface that we feel in contact with any part of our 
 body must be either plane or curve ; these are the two 
 possible cases. Now, these two kinds of surface imply a 
 third dimension, "for they report something that is re- 
 lated to depth : the presence or absence of an inclination 
 {Aushiegung) toward depth. It cannot be objected that 
 this is true only of curved surfaces, and that the plane 
 surface is, on the contrary, a negation of depth ; for a nega- 
 tive concept contains all the content of a positive concept, 
 plus a negation " (p. 177.) With such reasoning, the 
 weakness of which is too apparent, Stumpf maintains that 
 the new-born babe, when its body is encircled with a band, 
 must have the idea of a curved surface, and consequently 
 of three dimensions (p. 283.) He concedes, however, that 
 this new-born babe has not all our notions of mathemat- 
 ical relations; but its primitive representation virtually 
 contains them. 
 
 The empirical or genetic theory maintains a psychological 
 evolution. Relying particularly upon the influence of asso- 
 ciation and habit, it refers the fact of tactile localization to 
 experience, in accounting both for its completion and its 
 orip-in. 
 
 The first hints of this doctrine are to be found in Locke, 
 Condillac, Berkeley especially, and in general in those who 
 are inclined to give as large a role as possible to experi- 
 ence. In this century, Herbart, for reasons purely meta- 
 physical, referred, as we have seen above, the notion of 
 
100 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 space to a sucœssion of states of consciousness that can be 
 reversed, that is, read indifferently from A to Z, and from 
 Z to A. He wished by this to explain the fact that the 
 soul, supposed by him to be absolutely simple and unex- 
 tended, can perceive objects that have extension and form. 
 The movement of a limb produces in consciousness a series 
 of states ; it is this series that, as far as it can be reversed 
 (not the movements themselves), suggests to us the notion 
 of space. 
 
 In 1811, an author little known to-day, Steinbuch, in 
 his Beitràge zur Psychologie der Sinne, submitted that 
 movement alone could furnish the notion of space. His 
 theory, applied by himself mainly to vision, deserves to be 
 recalled ; it contains in germ the doctrine maintained later 
 with so much fullness and assurance by the English psy- 
 chologists, especially Bain. We will notice it further on 
 under the head of visual space. 
 
 But Lotze first transformed the empirical hypothesis into 
 a profound and elaborate theory ; it will suffice to notice 
 it again in a few words. Each feeling point of the body 
 has its local sign. This term implies no original localiza- 
 tion or extension ; it means simply that each tactile impres- 
 sion presents a particular character (nuance) that serves later 
 to localize it at a certain point of the body. At first, these 
 impressions are purely intensive, and present no special 
 determination of any kind. Later, the mind, by virtue of 
 laws peculiarly its own, transforms these intensive data into 
 extensive quantities, and produces a "reconstruction of 
 space." A psychological process plays the capital part in 
 the genesis of the notion. 
 
 The most recent of the genetic theories is that of Wundt. 
 He accepts the theory of local signs, but judges it insuffi- 
 cient : for how can a graduated series of qualitative local 
 signs be transformed into a succession in space? Lotze 
 explains this only by admitting the presence of a priœ^i 
 
ORIGIN OF THE NOTION OF SPACE. 101 
 
 laws of mind. But, says Wundt, the different impressions 
 are accompanied by movement, and thence results a feeling 
 of innervation. These two elements — local signs and 
 movement, with accompanying sensations — explain locali- 
 zation in space. Neither local impressions alone nor 
 movement alone could give it ; but the two, united in our 
 mental chemistry, form, by a psychological synthesis, a com- 
 bination which is the notion of space. The originality of 
 Wundt's solution, then, consists in the idea that the notion 
 of space is a synthesis of given elements ; but each of 
 these elements no more resembles space, the result of their 
 combination, than oxygen and hydrogen resemble water. 
 
 II. 
 
 However dissimilar these theories may be, they have one 
 result in common — they exhibit the problem in all its 
 aspects, and enable us to state it more clearly. Setting 
 aside the general considerations of the metaphysicians, the 
 majority of the authors mentioned proceed by the exami- 
 nation of details ; for an abstract discussion, they have 
 substituted concrete discussions ; instead of seeking for 
 the origin of space, they endeavor to show by observation 
 and reasoning the genesis of the ideas, length, breadth, 
 distance, form, position, direction — in a word, all the de- 
 terminations of extension. Their method is directly op- 
 posed to that of the metaphysicians.^ Here is a fact to 
 
 ^A good example of the opposition between the two methods is seen 
 in the discussion of Stuart Mill with his opponent Mahaffy. Mahaffy 
 maintains that direction cannot be used in an analysis of extension, 
 " because direction implies space, and space cannot be used to explain 
 itself." Mill replies : " Instead of direction implying space, it would 
 be more proper to say that space implies direction. Space is the con- 
 nected whole of directions, as time is the connected whole of succes- 
 sions ; consequently, to postulate direction, is to postulate, not space, but 
 the element from which the notion of space is formed." — Examination of 
 Hamilton. 
 
102 GEEMAN PSYCHOLOGY OP TO-DAY. 
 
 which, in our opinion, sufficient attention has not been 
 given; many physiologists do not seem to have seen it 
 clearly, though their habits of mind have nevertheless led 
 them aright in their ignorance. 
 
 It may be objected that all this has no value ; that these 
 terms, length, direction, etc., convey a meaning only as they 
 exist already in the notion of space, and this notion alone 
 renders them intelligible. But even though this be granted 
 — as it is by most writers — ^the position remains good. The 
 questions we are dealing with rest upon problems of ex- 
 perience, not upon transcendental questions. We wish the 
 empirical genesis of the notion of space ; it is right, then, to 
 go to experience for the solution. 
 
 If the study of the abstract notion of space be substituted 
 for the concrete study of its elements, it becomes impossible 
 to proceed analytically. The most determined adversaries of 
 the physiological method cannot deny that, in this respect, it 
 has done great service. Physiologists, indeed, resting upon 
 experiment, the data of pathology, and cases rare enough 
 to be instructive, have studied the role of each of the ele- 
 ments of tactile perception taken alone, have separated 
 visual space from tactile space, touch proper from its accom- 
 panying sensations, and have determined the functions of 
 muscular movement, and of the feeling of innervation. 
 We will show this in more detail. 
 
 When we attempt to solve the question, " Does the no- 
 tion of tactile space result from mechanism, or is it innate ? " 
 the difficulty of separating what is due to visual sensations 
 arises at once. Sight and touch are two languages that we 
 employ simultaneously from our birth, and they become so 
 confused with each other that they seem but one. Further, 
 the reports of sight tend by their superiority and richness 
 of information to conceal those of touch. Recourse is left 
 us to those who are born blind, and if some such were 
 found endowed with talent for psychological analysis, they 
 
OEIGIN OF THE NOTION OF SPACE. 103 
 
 could give us a great deal of information. Yet they would 
 misconstrue us, since terms \yould not have the same signi- 
 fication for them. This renders the observations of Platner's 
 blind man, of whom we will speak later, sometimes very- 
 vague. Still many good observations could be made by 
 critical examination. The study of operations upon those 
 who were born blind has been very instructive. Since 
 Cheselden there have been about a dozen cases, of which 
 hardly half were adults. Despite contradictions in detail, 
 these observations have shown that the patient knew neither 
 the form nor distance of objects, and, consequently, that the 
 data of tactile space are not the same as of visual space. 
 It is known that Locke in reply to Molyneux drew the con- 
 clusion that if a man born blind should recover his sight, 
 he would not be able to distinguish a sphere from a cube : 
 but what was to him only an opinion, a probable conjecture, 
 has now become, thanks to objective observation, an estab- 
 lished fact. 
 
 Having thus established the point that touch has its 
 peculiar way of arriving at the different modes of extension, 
 we can go a step further and distinguish contact proper 
 from sensations of temperature, pleasure, pain, etc. It is 
 established that in certain diseases the patient is sensitive 
 to the slightest touch, the tip of a feather, a breath, etc., but 
 does not feel the pricking or cutting of the skin. Others, 
 on the contrary, are very sensitive to pain, but cannot local- 
 ize it, and do not feel touch. If the leg is pinched, they 
 refer the pain to the hip, or even to the other leg. Sensa- 
 tion of temperature may be entirely wanting, the two other 
 kinds of sensation remaining intact. Touch, then, can be 
 considered as a complex sense ; or rather as the union of 
 many senses, of which contact alone concerns us. 
 
 Considering touch as contact simply, there is yet another 
 element of capital importance to be considered — movement. 
 
 The different parts of the body are movable, and the 
 
104 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 parts most easily moved are most sensitive to contact, for 
 example, the hand. It is hardly necessary to remark that 
 the possibility of moving the tactile organ in each of the 
 senses makes it possible to know the form and dimensions 
 of objects. The paralytic who feels but cannot move is 
 incapable of active touch. By touch, in ordinary language, 
 we understand, besides contact proper, the accompanying 
 movement. Moreover, reflex and voluntary movements do 
 not serve for the perception of external objects only ; they 
 give us from the first knowledge of the different parts of 
 the body : those parts that move most easily, as the end of 
 the tongue, the lips, the hands, possessing the power of finest 
 localization. 
 
 But in touch, movement has a double function. It is 
 not only a precise means of varying and multiplying points 
 of contact ; it is in itself a source of knowledge, because it 
 is the source of psychic states that constitute a true muscular 
 consciousness. Each movement has its own modality ac- 
 cording to the nature of the muscles put in play, their state 
 of vigor or fatigue, the direction of the movement (flexion, 
 extension, rotation, etc.), its duration, intensity, and the 
 degree of effort and resistance. Experiment shows that all 
 these variations are transmitted — or may be — ^to conscious- 
 ness. 
 
 Physiologists have differed much as to the seat and 
 conditions of this muscular sensibility. These theoretical 
 controversies are of little consequence : one thing is certain, 
 and this is that we have a feeling of the state of our muscles. 
 Pathology, further, through the study of cases in which this 
 is wanting, testifies to the importance of this faculty. In some 
 diseases the patients do not know the position, or even the 
 existence of their limbs, when they no longer see them ; they 
 do not know whether they are extended or bent, and think 
 they are without weight. In other cases, still more instruc- 
 tive, only the muscular sensibility remains. " In the case 
 
OEIGIN OF THE NOTION OF SPACE. 105 
 
 of a workman," says Landry/ " whose fingers and hands 
 were insensible to all contact, pain, and temperature, the 
 sense of muscular activity was everywhere alert. If I made 
 him shut his eyes and placed a large object in his hand, he 
 was astonished that he could not shut it ; but his only idea 
 was that there was some obstacle to the movement of his 
 fingers. I secretly tied to his wrist a kilogram weight ; 
 he thought some one was pulling him by the arm." The 
 only remaining state of consciousness was that of effort, 
 under the form of resistance and traction. 
 
 A rarer case is the loss of the muscular sense, while sen- 
 sibility to contact remains. Yet Landry (work quoted, p. 
 195) speaks of "persons who had lost the feeling of weight, 
 resistance, and the different muscular movements, while 
 sensibility to touch was normal." 
 
 We have now briefly enumerated the elements that 
 unite to form our knowledge of tactile extension. By 
 some examples, chosen from many, we have shown the 
 function of each of these elements, and the result when they 
 are deranged. This analytical process shows the complex- 
 ity of the problem ; it remains to study the genesis of the 
 notion of space. 
 
 A general fact, underlying all physiology of feeling, 
 seems at first sight to be capable of interpretation in favor 
 of the empirical or genetic theory. And truly so, if it is 
 well established, viz. that all sensation is really felt at the 
 nerve centres and not at the point in contact. Tactile 
 sensations, at tlie outset, are not transferred to external 
 objects nor even to the periphery of the body. They are 
 very probably felt as vague internal sensations and as 
 obstacles to movement. It is not till later that they are 
 localized at the point touched. Physiologists designate this 
 general fact by the name "law of eccentricity of sensa- 
 
 * Traité des paralysies, p. 199. 
 
106 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 tion " ; meaning that what occurs really at the centre is 
 projected to the extremities. This fact seems to support 
 the fundamental position of the empiricists, as Helmholtz 
 has formulated it : " Sensations are signs in consciousness 
 which it is the function of the intelligence to interpret." 
 It seems true, in fact, that localization here results from 
 the interpretation of primitive data. But the question is 
 not decided even then, for the defenders of nativism may 
 maintain either that the localization is immediate and the 
 repetition only defines it, or that the operation whereby 
 the impression is referred to the extremities is not interpre- 
 tation, but mechanism pre-established and inborn ; and this 
 is the foundation of their doctrine. 
 
 Yet it cannot be denied that if it were established that 
 tactile localization is not immediate, their reasoning would 
 have less weight than that of their adversaries. Is this 
 immediate localization a fact ? The first difficulty in re- 
 plying to this question is to find tactile perception at work 
 alone. Visual perception precedes it. Some hours after 
 birth the child follows the movement of a light a short 
 distance away with its eyes. It begins to feel later. 
 There is reason to believe that the first attempts at tactile 
 localization are greatly assisted by sight. This, in the 
 present case, would afford little support to the nativist 
 theory ; for if the child localize contact at a certain point 
 of its body, because it sees something special there (for 
 example, a hand or an object approaching), this fact seems 
 to be an interpretation. If we rule out this foreign element, 
 sight, and confine ourselves to tactile perception alone, we 
 are immediately arrested by the lack of observations. 
 Darwin, in his interesting study. Biographical Sketch of an 
 Infant (Mind, July, 1879), says that the seventh day, 
 when he touched the sole of the child's foot with a piece 
 of paper, " it drew back the foot quickly, and bent the toes 
 under, as an older child does when tickled." But we can 
 
ORIGIN OF THE NOTION OF SPACE. 107 
 
 see in this only a very vagiie localization, since the move- 
 ments of reaction can probably be considered, in this case, 
 only reflex acts. Is localization immediate in some less 
 movable part of the body, as the chest ? If so, this would 
 prove the nativist theory ; but this has never been estab- 
 lished. 
 
 The capital defect of this theory is its extreme sim- 
 plicity. By reducing all to an immediate localized con- 
 tact, it gives an insufficient role to muscular sensation in 
 the acquisition of the tactile notion. The supposition that 
 each point of our body feels immediately its position in 
 space, for the reason that every sensation is related, by 
 virtue of a law of our organization, to the peripheral ex- 
 tremity of the nerve affected, postulates, really, the point 
 in discussion ; for the excitation of a nerve extremity itself 
 affords no data in extension. The empirical theory main- 
 tains, on the contrary, that the idea of the position of a 
 certain point of the body (to the right, left, above, below), 
 results only from the play of certain muscles, different in 
 each case, which awake determined muscular sensations in 
 consciousness ; in such a way that the directions which call 
 the same muscles into play are the same, that is, the play 
 of different muscles gives different directions. 
 
 The empirical theory, then, is characterized by the domi- 
 nating, almost exclusive role given to raovemeut and mus- 
 cular sensibility.^ If it does not surmount all the difficul- 
 
 ^ The exposition of this theory does not fall within our province. 
 Bain has developed it most thorouglily. Yet it may be helpful, for 
 clearness of treatment, to point out its distinguishing characteristics. 
 The fundamental proposition is this : The state of consciousness which 
 accompanies certain modes of muscular movement is the original datum 
 of our perceptions of length, height, breadth, form, position, direc- 
 tion, that is, all the determinations of space. If we move one of our 
 limbs freely, we have the feeling of a longer or shorter muscular move- 
 ment, nothing more. If this movement is arrested at its two limits by 
 an obstacle (as the arrest of the hand by the two sides of a box), the 
 
108 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ties^ it does take account of all the facts, at least, and deals 
 with the problem in its complexity. It is the spirit of this 
 method to press forward as far as may be in its efforts at 
 explanation, and to attempt the analysis of the simplest 
 elements, instead of assuming extension as an ultimate fact ; 
 it reduces the idea to a more general and consequently more 
 simple notion, simultaneousness, and reduces simultaneous- 
 ness to a notion yet more simple, succession. 
 
 It is remarkable that in establishing their position, 
 which contradicts absolutely the position of the nativists, 
 empiricists appeal especially to tactile extension ; they main- 
 tain that touch, and not sight, must be considered, to under- 
 stand properly the genesis of the notion of space. " The 
 part played by the eye," says Stuart Mill, " in our actual 
 notion of extension, alters its character profoundly, and 
 gives rise principally to the difficulty we find in believing 
 that extension, in its ordinary signification, is a phenome- 
 
 first determination results. In the same way, if we pass the hand or 
 finger over a surface, and say that two points, A and B, are separated 
 by space, we mean, at first, simply that a series of muscular sensations 
 is experienced between the moment that the hand leaves A and the 
 moment that it arrives at B. It is then the sensation of the longer or 
 shorter duration of muscular effort that gives us extension. The no- 
 tion of length in space is reached from the notion of length in time. 
 What has been said of length is true also of distance, direction, form. 
 
 It remains, however, to explain how this series of successive muscular 
 contractions, translated into successive states of consciousness, gives the 
 idea of simultaneousness. Here a second element enters : tactile im- 
 pressions. In the case cited above, when we pass the hand over a fixed 
 surface, Ave have, besides sensations of movement, a succession of tac- 
 tile sensations. Here is the co-existence of two successions. This co- 
 existence becomes still more apparent when we reverse the movement, 
 and cause the tactile series also to be inverted. Further, we easily 
 perceive that the order of tactile sensations does not vary with the 
 rapidity of the movement. If the hand moves more quickly, the 
 series develops more rapidly; if more slowly, the. same series is reached 
 more slowly. Consequently, the order of tactile sensations may be 
 considered independent of their succession in time and as arranged 
 
OEIGIN OF THE NOTION OF SPACE. 109 
 
 non, not of synchronism, but of succession." For the man 
 , who sees, visual extension is first. Now, by its very nature, 
 sight gives at a singly glance a prodigious number of sensa- 
 tions, and thus communicates to its impressions a character 
 of simultaneousness. The peculiar and immediate object 
 of sight is color : sensations of color have grown to be for 
 us representative of the tactile and muscular sensations we 
 would otherwise experience from touching the colored 
 object. The eyes receive in the rough a great nuDiber of 
 sensations of color, and the result is the same as if we had 
 received in the rough a great number of tactile and muscu- 
 lar sensations, i. e., the perception of extension. Visual 
 perceptions, as Herbert Spencer has ingeniously said, 
 become symbols of tactile and visual impressions, and play 
 a role analogous to that of formulas in algebra : they replace 
 and simplify. 
 
 It would add greatly to the strength of the empirical 
 
 simply one with another. Extension, or space, as far as it is a state of 
 consciousness, has no other origin or meaning ; it is simply an association 
 of muscular with tactile (or visual) sensations. " The union of sensa- 
 tions of touch (or sight) with the feeling of the expenditure of motor 
 force explains the whole notion of extension or space" (Bain). Space 
 is thus merely a particular case of simultaneousness. A series of mus- 
 cular sensations accompanying motion from one object to another, this 
 is the only feature of distinction between simultaneousness in space and 
 the simultaneousness of a taste and a color, or a taste and an odor. 
 
 If it be objected that the close association of these two elements — 
 muscular and tactile sensation — does not account entirely for the com- 
 mon conception of space, it may be replied that it is only by a pure 
 metaphysical prejudgment that space is made an indepen^lent phantasm. 
 These elements account for all ; what remains is imaginary. These ele- 
 ments serve for the explanation, and we have no ground for believing 
 that space or extension is more than that which their composition affords. 
 
 For a detailed exposition of this doctrine, see, in particular. Bain, 
 Senses and Intelket,-2d éd., p. Ill, etc.; Stuart Mill, Exam, of the Phi- 
 losophy of Hamilton, ch. XIII ; Wundt, Physiolog. Psychologic, p. 480, 
 etc. Wundt accepts the theory only with the additions we have already 
 mentioned, and charges it with the omission of local signs, pp. 495, 496. 
 10 
 
 I 
 
110 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 position, if extended observations were made on those who 
 are born blind. What we have is neither clear nor suffi- 
 cient on many points. The most curious, from Platner, 
 a doctor philosopher of last century, brought to light by 
 Hamilton, furnish support to the empirical position. Atten- 
 tive observation, says Platner, has convinced me that the 
 sense of touch in itself, is utterly insufficient to give us the 
 notion of extension or space ; that a blind man considers 
 the world as something active merely, something contra- 
 dicting his notions of rest ; that for him time takes the 
 place of space ; that nearness and distance signify only a 
 shorter or longer time, the smaller or greater number of 
 sensations he finds necessary in passing from a given sen- 
 sation to another. In fact the man who is born blind 
 knows things only as existing, one distinct from another : 
 if parts of his body or objects touched by him did not 
 produce on his sensor nerves diffiîrent Jcinds of impres- 
 sions, he would take all external objects for one and the 
 same thing. " In his own body, he did not distinguish his 
 head and foot by their distance, but by the difterence in the 
 sensations they caused — a difference which he perceived with 
 incredible delicacy — and especially by means of time."^ 
 These remarks were made, it is true, previous to the rise 
 of contemporary theories : they bear the date 1785. It is 
 to be desired that other observations be made, and be made 
 with method, expressly to clear up this question. All 
 observation presents a mass of confused details : to see 
 clearly, one must attend exclusively to the object of his 
 search. The debate of the nativists and empiricists has 
 defined the problem but has not solved it ; we may hope 
 that new research will give a complete solution. 
 
 The considerations which we have been estimating in favor 
 of the empirical hypothesis, rest on a physiological and 
 
 ^ For details, see Hamilton, Lectures on 3Ietaphysics, &c., II, 174. 
 
ORIGIN OF THE NOTION OF SPACE. Ill 
 
 psychological analysis of tactile perception. There are 
 others to be drawn from pathology, and it seems surprising 
 that so little use ha| been made of them hitherto. Every 
 one is familiar with the illusions of those who have had 
 limbs amputated ; for a long time they seem to have sensa- 
 tions in the arm or leg which has been removed, and these 
 sensations are nicely localized in the fingers and toes. 
 
 Weir Mitchell, in his Lesions of the Nerves, says he 
 has seen maimed men who endeavored to extend or bend 
 their fingers or spread them out : they would say, " My 
 hand is open ; now it is shut. I am touching my thumb 
 with my little finger," &c. They were convinced that the 
 movement they willed took place, and had a clear idea 
 of the extent and force of this movement. These facts, 
 which have given rise to much discussion, prove, at least, 
 that muscular activity has an important function in per- 
 ception. 
 
 There is another important question. These illusions 
 persist a long time — this can not be doubted ; but do they 
 persist permanently? or do they disappear entirely after 
 some years ? 
 
 Among nativists, Miiller alone sees the import of this 
 question, and insists strongly on the negative (Vol. I, 
 p. 643, &c.) : " It is generally said that the illusions of 
 the maimed last some time, until the wound has healed 
 and the patient no longer needs a physician. But the truth 
 is these illusions are permanent and preserve the same 
 intensity throughout life." In support of this assertion 
 he cites nine examples, some of which are in detail. 
 
 The contrary is held by many writers.^ The illusions 
 of the maimed, say they, do not persist, but in time dis- 
 appear completely. 
 
 ^Vulpian, Diction, encycl. des sciences med., art. Moelle êpiniere, p. 523; 
 Carpenter, Mental Physiology, p. 150 ; Spring, Symptomatologie, vol. II, 
 p. 82. 
 
112 GERMAN PSYCHOLOGY OP TO-DAY. 
 
 What is the bearing of these facts upon the question be- 
 fore us? Evidently the illusion of the maimed, such as 
 arises just after amputation, is at least as easily explained 
 on the empirical hypothesis as by the contrary doctrine. 
 It proves, in fact, the strength of an acquired association. 
 Certain states of the nerves, transmitted to the centres, con- 
 tinue to awake in these centres old associations according to 
 which a feeling of pain or muscular activity is localized in 
 its accustomed place ; that is to say, in consequence of habit, 
 a state of consciousness (the initial excitation) awakes a 
 group of consecutive states invariably connected with the 
 first. The nativist theory holds that " each point of the 
 body at which a nerve fibre emerges is represented in the 
 sensorium as an integral part of space : " it seems that, in 
 this view, impressions ought to be projected to the actual 
 surface, that is, to the stump of the amputated limb. Really, 
 nativists avail themselves of the fact that, since the sen- 
 sation arises in the nerve centres at which each point 
 of the surface is represented, it is not surprising that sen- 
 sations persist permanently in an absent member, for the 
 psychic representation of this member permanently persists. 
 
 But admitting this point — ^though it grants too much to 
 the nativists — it must be proved that this illusion lasts 
 through life : that no habit newly acquired can replace the 
 old state that we are supposing inborn. Miiller seems to 
 have seen this when he endeavored to prove that the illu- 
 sion is permanent. Unhappily for him, the facts seem to 
 contradict his position ; and as the final removal of the illu- 
 sion can be explained only on the supposition that the 
 psychic representations are removed also, it is difficult to 
 see how a capacity that disappears when its conditions are 
 changed can be called innate. In this fact, also, M. Vul- 
 pian sees " proof that notions of the position of different 
 points of the skin result from experience and are not facts 
 of graduated innervation. As far as impressions from the 
 
OEIGIN OF THE NOTION OF SPACE. 113 
 
 stump can replace wholly or in part those that existed be- 
 fore in the skin of the limbs that are lost, these notions per- 
 sist more or less distinctly. But if these extremities cease 
 to bear impressions to the spinal cord, notions of position 
 are gradually lost." ^ 
 
 An analogous case is found in autoplastic operations. 
 When a piece of skin is brought down from the forehead 
 to the trunk of the nose, all contact with its surface is re- 
 ferred by the patient to his forehead, as far as the connec- 
 tion of the nerve fibres between the forehead and nose is 
 maintained. When the connection is cut, new connections 
 are established and the error of localization corrected. The 
 illusion at first may be explained by either hypothesis : for 
 empiricists it amounts to this, that an experience of long 
 standing cannot be immediately modified by new experiences : 
 for nativists, it amounts to this, that every impression is 
 referred by the sensorium to the peripheral extremity of a 
 nerve, whatever be the situation of the extremity. The 
 adjustment later seems explicable only on the empirical 
 hypothesis : according to repeated experiments, impressions 
 of contact become constituent parts of a new group ; they 
 enter into relation with new elements and finally constitute 
 with them a stable association. A new localization results 
 from new conditions. 
 
 On a comparison of the two theories, the balance of prob- 
 ability seems to be in favor of the genetic. Topographical 
 knowledge of our own body — and this knowledge conditions 
 that of the external world — is the result of repeated efiPort. 
 Localization is automatic for the adult, but this automatism 
 is not congenital : it must have been acquired. The young 
 child cries when ij; is in pain, but does not show by any sign 
 that it refers the pain to a particular spot. When we 
 awake with a feeling of uneasiness and discomfort we can 
 
 * Vulpian, cited above. 
 
114 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 not give it immediately a precise local origin. More than 
 half of the facts, ordinary or exceptional, favor the empiri- 
 cal position. 
 
 It must be remarked, moreover, that neither of the two 
 theories is exclusive, or can be. Nativists recognize the 
 function of experience, but make it secondary. On the 
 other hand, no empiricist can doubt that there are ana- 
 tomical and physiological conditions which are inborn and 
 predetermined. Nativists, as their method would lead us 
 to expect, stop too soon in their explanation, innateuess 
 being the ultimate fact. Empiricists are indeed free from 
 this fault, but they fail in their allotted task of interpreting 
 all the phenomena in terms of experience. Many points 
 still remain obscure forwant of observations both in number 
 and in quality. 
 
 III. 
 
 VISUAL SPACE. 
 
 In visual perception, the same problem arises and in the 
 same form : but here, the conflict between the two theories 
 is more severe, and attempts at solution more numerous. 
 It will not be out of place to speak with some detail. More- 
 over, the exposition will offer a somewhat dogmatic as well 
 as historical interest, since it seeks to present the question 
 in all its aspects and helps us to enter into its difficulties. 
 
 Millier was the first for sight as for touch to maintain 
 the doctrine of nativism from a scientific standpoint. " The 
 retina," says he, " feels its own extension and position, when 
 not in the least affected by the world without. It feels 
 them as darkness before the eyes." This immediate know- 
 ledge of its own dimensions serves as the measure of 
 visible objects : it finds in itself its unit of measure. Yet 
 Millier attributes to it only a single inborn property : the 
 perception of surface or extension in two dimensions. All 
 
OEIGIN OF THE NOTION OF SPACE. 115 
 
 that the adult possesses in addition to this original percep- 
 tion is for Millier the result of experience : " The power 
 to know simple forms is not the result of education ; but 
 that of judging the* different dimensions of body from its 
 image requires exercise, since the visual intuitions are 
 originally of surface only, and since to arrive at the repre- 
 sentation of a body, the judgment must add to it the differ- 
 ent aspects seen when it is placed in other positions. Thus 
 we reach the representation of depth in the visual field ; 
 it is an idea and not a sensation." Miiller does not admit 
 that the fact that objects are inverted upon the retina con- 
 tradicts his hypothesis of the intuitive perception of sur- 
 face. Direct vision does not need explanation because we 
 see everything inverted and not a single object among 
 others ; nothing can be inverted when nothing is straight ; 
 the two ideas exist only by opposition. Finally, to explain 
 the fact that the two eyes, have each its distinct impres- 
 sion and yet perceive a single object in one and the same 
 position, Miiller admits that corresponding points of the 
 two retinas have the same perceptipn of space, because at 
 the chiasma, each nerve fibre from the brain divides into 
 two which emerge at identical points : whence results a 
 union of the two impressions in a single perception.^ 
 
 The doctrine of Miiller has been called the hypothesis of 
 subjective idemtity. It was early abandoned because it in- 
 volved too many difficulties, ^nd was contradicted by well- 
 established facts : for example, we see as simple, objects which 
 are not reflected on the same retinal points ; this fact alone 
 contradicts the doctrine, and the auxiliary hypotheses of 
 Briicke and others have not explained it. 
 
 A second form of the nativist theory has been called 
 the hypothesis of projection.^ It has been maintained by 
 
 ^ Lehrhuch d. Physiologie, vol. II, pp. 351-358. 
 
 * The name was attached to it by Wundt : Grundzuge, p. 632. Helm- 
 lioltz takes it in another sense. See Physiolog. Optik, p. 442. 
 
116 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 Tourtual (1827), Yolkmann (1836), admitted in part by 
 Donders and Nagel (1861). According to this hypothesis 
 the retina is capable of projecting its impressions outward, 
 in given lines of direction or of sight.^ These writers insist 
 upon an immediate projection ; while, according to Millier, 
 objects are not projected in external space, but are referred 
 for special determination to extension within. As has been 
 remarked, this hypothesis is implicitly admitted in most 
 physiological research. Impressions are generally consid- 
 ered as projected into space along the lines of vision. On 
 the hypothesis of projection, it is not difficult to explain 
 the fact that impressions at points which are not identical 
 in the two retinas give a simple perception. On the other 
 hand, it does not explain the double images of binocular 
 vision. If, in fact, images are projected along the lines of 
 direction or sight, we ought to see everything simple, since 
 the rays that belong to a luminous point cut each other at 
 that point. Yet Donders maintains that this hypothesis 
 explains the majority of cases. 
 
 The theories of which we have spoken have been vari- 
 ously modified — the last especially — in view of the expla- 
 nation of new facts. Nagel, among others, in his book on 
 binocular vision {Das Sehen mit zwei Augen, &c.), has con- 
 tributed to it.^ Independently of the difficulties we have 
 
 ^ It may be of service to define the terms used in the exposition : 
 
 Identical (Miiller) or corresponding (a terra more used in our day) 
 points in the two retinas, are upon corresponding horizontal and verti- 
 cal meridians. Points that do not correspond are called disparates. 
 
 Lines of direction pass from luminous points in the retinal image 
 through the nodal point of the eye. Lines of sight pass through the centre 
 of the retina, the centre of the pupillary image, and a point in space. By 
 tracing lines of direction, we obtain the retinal image of an object ; but 
 these lines do not coincide with those by which we project the retinal 
 image without. In fact this projection is in the direction in which we 
 see. For more details see books on Physiology. 
 
 * Nagel supposes that the two retinal images are projected on the 
 different spherical surfaces which have as centres the point of inter- 
 
ORIGIN OF THE NOTION OF SPACE. 117 
 
 pointed out, these theories have a grave defect : they can 
 explain the perception of surface only on the nativist 
 hypothesis ; the notion of depth, in spite of additional 
 secondary hypotheses, is in fact derived from experience. 
 It was natural, then, that the eifort should be made to 
 render the nativist doctrine complete and consistent, by 
 explaining through innateness alone the totality of visual 
 phenomena. This Panum and Hering have done. 
 
 Panum borrowed the elements of his theory from the 
 two doctrines we have spoken of, but modified both. 
 Since it is not possible, without contradiction, on the 
 hypothesis of identity, for impressions at disparate points 
 of the retina to give a single and separate notion of exten- 
 sion, Panum supposes that each point of either retina is 
 co-ordinated, not only with the corresponding point of the 
 other, but with a " circle of sensation." There is a neces- 
 sary fusion of the image of a point a (right retina) with 
 the image of a point a' (left retina) ; there is a possible fusion 
 of the image a (right retina) with the corresponding sensi- 
 tive circle A (left retina). Panum makes this difference, 
 then : in the first case, the two images must be fused 
 into one ; in the second case, they may be fused into one. 
 That this fusion may take place, it is necessary that at some 
 point of A, an outline be formed analogous to that deline- 
 ated at a. Panum has strangely complicated the theory of 
 projection with secondary hypotheses. He assigns to the 
 eye three specific energies : 1st. A " synergy of binocular 
 parallax;"^ which gives the perception of depth (third 
 
 section of the visual lines. The process of projection is called by him 
 " a constructive operation," and in this process he gives an important 
 function to muscular sensation. Volkmann also attributes to these sen- 
 sations a great influence. In this they ally themselves to the empirical 
 school. Wundt, with Classen, assigns these writers an intermediate 
 position between nativists and empiricists. 
 
 ^ Panum has given his doctrine in his Phydolog. TJntermchungen vber 
 das Sehen mit zwei Augen, Keil, 1858, and in his memoirs published in 
 
118 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 dimensiou) ; 2d. A " binocular energy for the combination 
 of colors," by which colors seen with two eyes combine and 
 are seen as one ; 3d. A " binocular synergy of alternation," 
 by means of which colors seen with two eyes may be kept 
 distinct. As a critic has remarked,^ Panum enriches the 
 retina with so many inborn powers that he may be called 
 the most logical and courageous representative of the nativ- 
 ist hypothesis. 
 
 His theory served as basis for that of Hering, who, it is 
 agreed, gave to nativism its profoundest and most logi- 
 cal form, in his Beitrdge zur Physiologie (1861-1864). 
 Hering attributes to the different points of the retina feel- 
 ings of extension (Ro.umgefûhle) of three kinds : length, 
 breadth, thickness. Each point has its own value in breadth 
 and length ; this value increases in proportion as it is distant 
 from the centre of the retina, and points situated on the 
 right and left, above and below the centre of the retina have 
 opposite values. By means of these feelings, the retina 
 arranges its impressions in two directions. The third feel- 
 ing, giving depth, is of a particular nature : it must have, 
 says Hering, equal values, but contrary signs, for identical 
 retinal points ; equal values and the same sign for sym- 
 metrical points. The feeling of depth of the two outer 
 halves of the two retinas is positive : it answers to greater 
 depth. That of the inner halves is negative, and answers 
 to lesser depth. Since identical points (that is, points 
 having the same latitude and longitude) have, as has been 
 said, feelings of depth of equal value, but of opposite sign, 
 it results that for these points the perception of depth is 0. 
 These points seem to form a plain which is the principal 
 
 the Archiv Reichert, 1861. The angle in which an object is seen from 
 a given distance is called the parallax. In binocular vision, two points 
 not symmetrically situated in reference to the observer's median line, 
 form paralaxes differing more or less for the two eyes. 
 ^ James Sully, Mind, No. X, p. 171. 
 
OEIGIN OF THE NOTION OF SPACE. 119 
 
 surface of the visual field {Kernflache des Sehraumes). At 
 first, the distance of this surface seems undetermined : it is 
 neither near nor far. It is only by experience that the 
 observer assigns position to it in reference to himself. Our 
 body, since it is always in the field of vision, serves as 
 point of departure in determining the distance. Impres- 
 sions on the outer halves of the two retinas are placed 
 beyond this principal surface; impressions on the inner 
 halves, within. The entire impression resulting from the 
 binocular fusion of the two impressions takes the mean 
 value of the feelings of length, breadth, and thickness. 
 
 The theory of Hering has one merit at least : it is logi- 
 cal. The perception of the third dimension, as well as of 
 the other two, is deduced from capacities innate in the 
 retina. Hering allows to experience only what every in- 
 tuitive hypothesis must; he denies entirely the function 
 of muscular sensation. 
 
 In the book already cited, Ueber den psi/chologischen 
 TJrsprung der JRaumvorstellung, 1873, Stumpf, in the gen- 
 eral characteristics of his theory, can be called a nativist. 
 Although he does not hesitate to criticise his predecessors, 
 and believes that he can reconcile the two theories, still in 
 reality he gives to intuition the leading place. His theory 
 is not presented in systematic form, as those of which we 
 have already spoken. He is not a physiologist, moreover : 
 his principal object is to examine the psychological value 
 of the different solutions, and exhibit their strength or 
 weakness. His book, the work of a skilled reasouer, in- 
 cludes as well the solutions of the Scottish school (Hamil- 
 ton, Mill, Bain), as those of his countrymen. His funda- 
 mental principle is that " the notion of space rests in its 
 elements upon sensation, and in its development upon 
 association." He is driven to maintain that extension 
 and its content (light, color, etc.) are inseparable, and con- 
 sequently, with the first sensation of light or color, the 
 
120 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 notion of space of two dimensions is given. Thus it be- 
 comes intuitive, although external excitation is the occa- 
 sional cause.^ In regard to the third dimension, Stumpf 
 reasons the same for sight as for touch ; a few words will 
 suffice to characterize it. Surface extension is given im- 
 mediately in sight ; now every surface is either plane or 
 curved. These two species imply the third dimension, 
 for they imply the presence or absence of an inclination 
 outwards toward depth. 
 
 These are the principal forms of the nativist theory. 
 They are as complex and scientific as those we have men- 
 tioned on touch, but in a different way. Yet, as Helm- 
 holtz justly remarks, their fundamental characteristic is 
 always the same; i. e., "they make the localization of 
 impressions in the field of vision innate, whether it be that 
 the soul has direct knowledge of the dimensions of the 
 retina, or that the excitation of given nerve fibres gives 
 rise to representations of space by means of a pre-arranged 
 mechanism that cannot be understood more precisely." 
 It remains to consider the empiricists in their turn. 
 
 Although we are dealing with German thinkers, we must 
 mention Berkeley as the first systematic representative of 
 empiricism. The debate had not begun in his time, but 
 his position is clear notwithstanding. In his first work, 
 published in 1709 {An Essay toward a new Theory of 
 Vision), he maintained that the peculiar and exclusive ob- 
 ject of sight is color ; that visual sensations are arbitrary 
 signs suggesting to the mind the idea of externality. In 
 his other works he also took this position. " We perceive 
 distance not immediately, but by mediation of a sign which 
 hath no likeness to it, or necessary connection with it, but 
 
 ^ Ueberhorst, in his book Die Entstehung der Gesichtswahrnehmung 
 (Gottingen, 1876), has shown the importance of the position that sen- 
 Bations of color can not have originally any determination as to space. 
 
ORIGIN OF THE NOTION OF SPACE. 121 
 
 only suggests it, from repeated experiences, as words do 
 things.^ Finally, he considers tactile sensation an indis- 
 pensable auxiliary to visual sensation, a point common to 
 most of the empirical* theories. 
 
 Yet the position of Berkeley is connected with the more 
 general doctrine of " immaterialism." Steinbuch, a writer 
 already mentioned in connection with touch, put the ques- 
 tion in an experimental form. Movement alone, said he, 
 can give us the notion of space. The retina has no power 
 of perceiving relations of contiguity or position among 
 its parts ; this perception is due to movement of the mus- 
 cles of the eye. An illuminated point of the retina be- 
 comes a luminous line by the conscious contraction of a 
 muscle, and this contraction has degrees for different parts 
 of the retina. Thus, by the contractions necessary to 
 expose different parts of the retina in turn to the same 
 rays, difference of space in the retina becomes difference 
 of time. Each point of the retina has its degree of 
 muscular contraction ; and it results that, as the result 
 of education, the luminous sensations at particular points 
 are tacitly connected in consciousness with the degrees of 
 contraction that belong to these points. Miiller, after ex- 
 plaining this theory, remarks "that, if points in the retina 
 are not different in nature, we have no means of knowing 
 them as distinct, and that, without a qualitative difference 
 in the sensation, it is impossible for any quantum of con- 
 traction to unite, in memory, with a point of the retina " 
 (II, 540). This remark is just; and it can be further said 
 that the hypothesis of Steinbuch suggested the theory of 
 local signs, i. e., of a peculiar characteristic for each point 
 of the retina. 
 
 As we have seen, this hypothesis of local signs was 
 developed by Lotze. His theory has been already treated 
 
 ^ Alciphron, or the Minute Philosophers, 4th Dialogue (IT, p. 148-Tr.). 
 11 
 
122 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 at length. Yet it must be added that he has had a 
 great influence in the way of reaction in favor of the 
 experimental position and against the uativist, which,, 
 before him, was blindly accepted by physiologists. 
 
 Wundt, in his Memoirs, published 1858 to 1862 ini 
 the Zeltschrift fur rationelle Medicin, was the first to show 
 in a manner at all complete that the formation of the field of 
 vision can be sufficiently explained by means of two classes 
 of data : local differences of sensation in the retina, and 
 movements of the eye. He has studied the latter element 
 carefully, and deduced the estimation of distance in the 
 field of vision, from the conscious muscular effort necessary 
 to sweep the field with the eye. He maintains that for 
 sight as for touch the notion of space cannot result from 
 the simple association of the two primitive elements (reti- 
 nal inipression and movement) ; it can result only from 
 synthesis, a combination of such a nature that the result 
 shall differ from either of the two elements.^ 
 
 The leading representative of the empirical position is 
 Helmholtz. Not to speak of his important work as a 
 scientist, he has given in his Physiologische Optik and Pop- 
 uldre wissenschaftliche Vortrdge a very elaborate psycho- 
 logical theory of tlie genesis of visual space from experience 
 alone. Two physiological elements serve as basis for his 
 explanation : 1st. Signs furnished by sight. They are dis- 
 tinguished from one another by three characteristics : in- 
 tensity, quality (color), locality, the last depending upon the 
 portion of the retina excited. 2d. The degree of innervation 
 felt by us and referred to the nerves of the muscles of the 
 eye. These elements serve as basis for the higher mental 
 operations by which the notion of space of three dimensions 
 is afforded. 
 
 Helmholtz's fundamental position, as we have already 
 
 * For a detailed exposition of Wundt's theory, see the chapter devoted 
 to him, I IIL 
 
ORIGIN OF THE NOTION OF SPACE. 123 
 
 said, is this, that sensations are signs to be interpreted. Our 
 representations are necessarily symbols of objects only : we 
 learn to use them to regulate our movements and actions. 
 " When we have learned to interpret these symbols cor^ 
 rectly, we are able with them to direct our actions to the 
 result desired, that is, to bring about new sensations." The 
 truth of our representations, then, is entirely practical in its 
 nature, and to ask whether they are true to their objects is 
 nonsense ; and " the search of nativists for a pre-existing 
 harmony between the laws of thought and the laws of 
 nature rests upon a misconception." Yet these signs, given 
 us for interpretation, appear as effects of which objects are 
 the causes. We believe this, because repeated experiment 
 upon objects has shown that the modification of our sensa- 
 tions rests in part in the will, but is imposed upon us partly 
 also from without, independently of all internal action, 
 " Thus we come to recognize in sensation a cause indepen- 
 dent of our will and imagination, i.e., an external cause ;" 
 and thus the idea of cause is introduced as a regulating 
 principle in the order of perception. 
 
 This admitted, the psychological mechanism by means 
 of which we form a representation of space, or to speak 
 more correctly, by means of which we look upon an object 
 as extended, that is, as having such a form, position, direc- 
 tion in the field of vision, etc., can only be a process " of 
 unconscious reasoning." If this expression, says Helm- 
 holtz, is objected to it is because we are accustomed to con- 
 sider reasoning the highest form of intellectual activity. 
 But the processes of reasoning of which we now speak, 
 although they can never be put in logical form, are identical 
 with our ordinary processes — a mental operation and pro- 
 duct. " The difference between the reasoning of logicians 
 and the unconscious reasoning upon which our knowledge 
 of the external world rests seems to me very plainly to con- 
 sist in this : that the former can be formulated, and the 
 
124 GERMAN PSYCHOLOGY OP TO-DAY. 
 
 latter cannot, in that it is made up not of words, but of sen- 
 sations and tlie memory of sensations." ^ If these processes 
 were translated into the analytical terms of formal logic, they 
 would seem to be inductions. They would really have, as 
 a starting point, propositions established by experience, 
 that is, as Stuart Mill remarks, a register of facts, gathered 
 into a simple formula, which, although adding nothing to 
 our knowledge, is of great practical importance, since it 
 gives a conclusion for all cases in which the data are the 
 same. An example will make this clearer. When we feel 
 an impression on the right side of the two retinas, we know 
 from experience repeated in many cases that there is a 
 luminous body at our left. We have ascertained that the 
 hand must be stretched out to the left to hide or seize the 
 light, and that we must go to the left to approach it. If, 
 in cases of this kind, we do not reason consciously, we have 
 none the less the essentials of ratiocination and have reached 
 a conclusion : the work has been done by unconscious pro- 
 cesses of association of ideas residing in unexplored parts 
 of the memory.^ 
 
 To sum up, the operation, as Helmholtz conceives it, is 
 this : every impression on a given part of the retina pro- 
 duces, by means of local signs and muscular movement, a 
 given modification of the sensorium (first group of facts). 
 By the aid of touch, movements of the body, and various 
 experimental contrivances, we determine the cause of this 
 modification (second group of facts). These two groups of 
 facts, when repeated a sufficient number of times, become so 
 closely associated, that, when I press my eye to the right, I 
 invariably see a light to the left, and only objective verifica- 
 tion teaches me that it is an illusion, and that the second 
 group of facts is wrongly deduced. Our knowledge of the 
 
 * Popuiare vdssenschaftliehe Vortrdge, III, 
 
 * JPhysiolog. Optih, p. 449. French trans., p. 58S. 
 
ORIGIN OF THE NOTION OF SPACE. 125 
 
 field of vision, which consists of a sum of representations, is 
 acquired, then, only when each excited point of the retina 
 has become capable of associating to itself a group of cor- 
 responding facts. »It is evident that Helmholtz meant 
 under the name unconscious reasoning what the Scottish 
 school call " inseparable association." And he expresses 
 himself exactly as Mill or Bain, when he says : " The only 
 psychic act necessary to this result is the regular repetition 
 of the association of two representations that are once asso- 
 ciated, and this association has more force and necessity 
 according as it occurs oftener." ^ 
 
 Such are the general principles of the theory of Helm- 
 holtz. We will briefly indicate some details. Our knowl- 
 edge of extension of two dimensions from monocular vision 
 is reached by means of movement. The author presents no 
 hypothesis either as to the nature or anatomical disposition 
 of the local signs. He admits that these signs may be scat- 
 tered at random upon the retina : this would not change 
 his theory at all ; except that the habitual association would 
 be more difficult. It is by means of movement that the eye 
 learns the order of the points of the field of vision, that is, 
 the local signs that belong to points in immediate proximity 
 to one another. This relates the localization of impressions 
 to certain other impressions which are connected in a definite 
 way with the excitation of certain fibres. As for the third 
 dimension, we have already seen how Helmholtz explains 
 the notion of distance and externality. The binocular per- 
 ception of relief rests entirely upon the fact that we are 
 simultaneously conscious of two different images. The 
 sensations of the two retinas are perfectly distinct from each 
 other: they arrive in consciousness without fusion. They 
 are combined in a simple representation, when in con- 
 sequence of repeated association, they become signs of one 
 
 ^ Physiohg. Optik, p. 798. French trans., p. 1002. 
 
 I 
 
126 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 and the same object. " Their fusion into a single notioD of 
 the external object is not accomplished by a pre-arranged 
 mechanism (as the nativists maintain), but by a psychic 
 act." 
 
 Such are the principal forms of the empirical theory. 
 Wundt makes of them two classes : 1st. Logical theories, 
 which are of two kinds ; the one, as Berkeley and the first 
 representatives of empiricism, holds that notions of exten- 
 sion are the result of a conscious reasoning process ; the 
 other introduces an unconscious activity; 2d. Association 
 theories, whose principal representatives are in England. 
 This classification is not exhaustive, since Helmholtz does 
 not belong to either class.^ 
 
 We have already compared the two rival theories on the 
 subject of touch, and indicated, in a general way, the merits 
 and defects of each. We will now confine ourselves to the 
 special question of visual space. And this must be viewed 
 only in its psychological aspect. Intuitionism and empiri- 
 cism do not propose simply to give a metaphysical expla- 
 nation of the notion in the abstract ; they must interpret 
 experience also, and give an account of the varied phenom- 
 ena of visual perception. These physiological problems 
 have been discussed by men skilled in experiment, who have 
 devoted years to such investigations ; we have named them 
 already. Their results, even in questions of fact, do not 
 agree. Although the empirical theory suffices to explain 
 the majority of cases, and offers the greater probability, yet 
 it is not established, and many of its experiments are dis- 
 puted. It is not strange that the discussion is not yet closed 
 upon a question that is so delicate from a psychological 
 standpoint and involves a critique of the fundamental 
 notions of the intelligence. 
 
 What is the peculiar object of sight ? This very simple 
 
 ^ Wundt gives his own theory the name " synthetic." 
 
ORIGIN OF THE NOTION OF SPACE. 127 
 
 question sums up the debate. If we reply : Color, we are 
 empiricists. If we reply : Colored extension, we cast our 
 lot with the nativists. 
 
 One of the merife of Stumpf is that he sees that the 
 whole question lies in germ here, and had he proved that 
 color and extension are inseparable, nativism had won the 
 day. Before him, Hamilton employed the resources of his 
 subtle dialectic to show by reasoning alone that distinction 
 of color necessarily implies distinctive determination in 
 extension ; but the reply which Stuart Mill made to him 
 seems to us final.^ We refer the reader to it. 
 
 It will be remarked that the theory of local signs, 
 although developed especially by the empiricists, is really 
 common to the two schools. The perception of local differ- 
 ences in the field of vision is a fact, and it can be explained 
 only on the hypothesis of local signs. But when it comes 
 to a determination of their nature, the two schools differ. 
 
 According to the empirical theory they are any distin- 
 guishing signs whatever : only that their significance rela- 
 tive to the perception of the external world is the result of 
 experience. It is useless to suppose any agreement further 
 than this, between the local signs and the local differences 
 that correspond to them.^ 
 
 According to the nativist theory, on the contrary, 
 they give an immediate notion of local differences, of their 
 nature, magnitude, and relative position : being at once 
 organs of sense and elements of space. From a philo- 
 sophical point of view, as Helmholtz has remarked, this 
 theory supposes a pre-established harmony between thought 
 and the laws of nature. 
 
 The nature of the local signs, then, is not a point on 
 which either of the two schools can be profitably attacked, 
 
 ^ Exam, of the Philos, of Hamilton, p. 277. 
 
 ^ Helmholtz, Popular, wissenschajt. Vortrdge, III. 
 
128 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 since each presents, in its own way, a plausible expla- 
 nation. 
 
 Pursuing our comparison to the question of visual space 
 considered as simple surface, we find that the two theories 
 are about equally credible. There are still, however, for 
 the nativist hypothesis, some points of stumbling. 
 
 1st, The inverted position of the retinal image presents 
 no difficulty on the empirical hypothesis; this image is 
 simply a matter for mental elaboration, a datum for expe- 
 rience to interpret ; its position is a matter of secondary 
 importance. But not so to the nativists. This fact has 
 embarrassed Miiller and others ; they have derived it only 
 by involved and inadmissible explanations.^ 
 
 2d. Despite the intervention of retinal images, we see 
 simple in the majority of cases. In fact, nativists maintain 
 that impressions' received at corresponding or identical 
 points give simple vision ; and impressions at disparate 
 points, double vision. But Helmholtz has shown that 
 images at corresponding points sometimes give double 
 vision, and, vice versa, images at disparate points sometimes 
 become fused. 
 
 When we pass from the notion of surface or two-dimen- 
 tioned space, to cases in which the third dimension enters, 
 the debate is very warm. It is on this field, over the solu- 
 tion of this problem, that the great battle between the two 
 schools has been joined. We may say that empiricism has 
 gained from day to day, while most of the discoveries have 
 brought new embarrassment to the nativists. We have 
 seen in the earlier exposition that the empirical explanation 
 is simple, that it is based on physiological and psychological 
 facts, that it invents no faculties and avoids all useless 
 hypotheses. Nothing, on the contrary, can exceed the 
 
 ^ Fick, for example, supposes that the nerve fibers, at their entrance 
 to the brain, establish impressions of above and below, right and left, 
 as they really are — an hypothesis which has no anatomical foundation. 
 
OEIGIN OF THE NOTION OP SPACE. 129 ' 
 
 complexity of the theories of the nativists. We may give 
 to the retina au innate perception of its extension, with 
 Millier, or clothe it^ with Panum, in the attire of intuitiv^e 
 cognition ; we may suppose, with Hering, a principal sur- 
 face of the field of vision, undetermined as to its distance 
 from the eye ; all these hypotheses have one disturbing 
 characteristic : they are invented simply to explain the 
 facts ; they are the work of the imagination, not scientific 
 solutions. In any case it is wrong to have recourse to 
 them, if there are facts and known laws sufficient to solve 
 the problem. Besides there are other data which we can 
 not deal with here (the perception of relief, lustre, &c.), 
 which may easily be explained on the empirical hypothesis, 
 but are very embarrassing on a theory of predisposed 
 mechanism. And pathological facts may be cited against 
 such predisposition : for example, in the case of paralysis 
 of the abductor muscle of the eye, the patient sees objects 
 further from him than they really are. The distance seems 
 too long because the muscular contraction must be greater 
 to execute the same movement. The patient grasps space 
 only when he experts to take the object. A stone-mason 
 afflicted with this disease, struck his hand with the hammer, 
 instead of hitting the stone (Wundt). But little by little 
 the disease accommodated itself to his movements, though 
 it cost him the greatest effort in the part affected. This 
 successive accommodation of pathological states throws light 
 on the way in which a derivation often passes for an original. 
 If, when the conditions are changed we can come to estimate 
 anew the position of an object, it seems natural to say that 
 originally the idea of direction arose from a relation between 
 the muscular sensation and the point in the retina which 
 experienced the external excitation. Still other arguments 
 are found in certain cases of squinting ; ^ but, not to insist 
 
 * See on this point Helmholtz, Physiol. Optik, French trans., p. 882. 
 
130 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 further upon it, this is the chain of facts that inclines us 
 necessarily toward the empirical theory. We borrow from 
 Helmholtz the resume of reasons which lead us to conclude 
 in its favor: 
 
 1st. The theory of nativism seems to introduce an un- 
 necessary hypothesis. 
 
 2d. Its results give, in accounting for space, notions 
 that rarely accord with fact. The advocates of this theory 
 are obliged to admit against themselves that their original 
 sensations of space may be modified, or, indeed, replaced by 
 knowledge furnished in experience. 
 
 3d. It is hard to see that these original sensations of 
 space can contribute anything to the explanation of visual 
 perception, since the advocates of this theory are compelled 
 to admit that, in the great majority of cases, these sensa- 
 tions must be supplemented by very profound experi- 
 ential knowledge. If this is necessary, it seems simpler 
 and easier to admit that all notions of space are furnished 
 by experience only, without having first to combat innate 
 notions which are false in most cases.^ 
 
 It remains to estimate some considerations against the 
 empirical theory which cannot be passed over in silence. 
 
 The first of these objections rests on a well-known fact. 
 Bailey, in England, first used it in his attack on Berkeley's 
 doctrine of sight, and it has been renewed later by other 
 nativists.^ The chicken just hatched, still carrying a 
 fragment of the shell upon its tail, catches a fly on the 
 wdng. The little calf makes the necessary movements to 
 suck its mother. The crocodile, hatched with no parental 
 incubation, starts directly for the water, bites a stick that 
 is held out to him, etc. We cannot deny that these facts, 
 though they may be modified by the name instinct — which 
 
 ^ Helmholtz, Physiol. Optik, p. 442 ; French trans., p. 578. 
 " Stumpf, work cited, p. 295. The best collection of facts of this kind 
 is to be found in Abbott, Sight and Touch, p. 178, etc. 
 
OEIGIN OF THE NOTION OF SPACE. 131 
 
 explains nothing — favor the nativist theory, since they 
 show that animals, " as soon as they see the light, see depth 
 also." 
 
 Helmholtz, who has discussed this objection (in his 
 Pop. wissenschaft. Vortrdge, 2d series), replies : " It is said 
 that the calf sees the udder of the cow and seeks for it. 
 It is a question whether it does not smell it merely, and 
 make movements in the direction of the odor. The chick 
 picks about to find grains ; but it has picked in the shell 
 before, and seems to pick at first at haphazard, as it 
 follows the example of the hen. After it has found some 
 grains by chance, it learns their appearance ; and this it 
 must learn the more quickly as its life is so extremely 
 short." — " It would be desirable that new observations be 
 made in this connection, especially to throw light upon this 
 question. Observations made hitherto seem to me to prove 
 no more than that animals have at birth certain tendencies; 
 and it is certain that in the case of man these native ten- 
 dencies are reduced to very few." 
 
 The second objection is based upon theoretical consider- 
 ations. It was formulated by Wundt, though he rejects 
 the intuition hypothesis notwithstanding. The genesis of 
 our ideas of space is referred by Helmholtz to processes 
 of reasoning from analogy. Thus, according to him, we 
 place on the right in space impressions that aifect the retina 
 on the left ; because, in a great number of previous cases, 
 experience has taught us that the object is really in that 
 direction. But, objects Wundt,^ this reasoning from anal- 
 ogy does not apply to primitive experiences, to those which 
 are first in order, and serve as basis for all the rest. In 
 truth, Helmholtz escapes this objection by maintaining 
 that primitive representations of space are formed by means 
 of touch, agreeing in this with the founders of the em- 
 
 1 GrundzUge, pp. 638-640. 
 
132 GEEMAN PSYCHOLOGY OF TO-DAY. ' 
 
 pirical theory, Berkeley and Condillac. Still the objection 
 is only removed further back, as the same difficulty 
 arises in the case of touch. Helmholtz admits, in the law 
 of causality, an element that is not given in pure experi- 
 ence, and which does not help the explanation of primitive 
 notions. Wundt also has recourse to the synthetic theory, 
 of which we have already spoken. 
 
 We now have an impartial statement of the question. 
 We must say that these objections are not without weight ; 
 otherwise, the victory of the empirical theory would be 
 complete, and the rival position would belong to history 
 only. Whatever opinion we adopt, the debate affords a 
 fine example of analysis applied to a notion which has passed 
 as simple and ultimate, and this analysis is not merely 
 verbal and ideological after the manner of eighteenth cen- 
 tury discussions ; but conducted, as far as possible, with 
 the help of objective observation and experiment. Beside 
 the experimental difficulties that impede the physiologist at 
 every step, there is a psychological difficulty throughout 
 the whole debate. At first sight, it seems very easy to 
 say : this is primitive, this is acquired, this is a fact, this 
 is an induction. Yet the reader has seen how difficult it 
 is to be sure in such cases. The perception of distinct 
 color, red, green, seems to be an act of immediate cogni- 
 tion, with no possible error when the eye is normal. Yet 
 the facts of simultaneous contrast (modifications which the 
 colors undergo when placed in juxtaposition) seem to show 
 that there is here a cerebral process more complex than 
 simple perception — and this is the beginning of an inter- 
 pretation.^ How much more difficult is it to separate sen- 
 sation and inference in cases so complex ! 
 
 * Helmholtz, Optik, \ XXIV, in particular, p. 543. Yet it must be 
 remarked that Hering, and other more recent writers with him, believe 
 that they have explained different optical phenomena, especially simulta- 
 neous and successive contrasts, consecutive images, etc., by a purely 
 
ORIGIN OF THE NOTION OF SPACE. 133 
 
 We will add, in closing, that it would be wrong to 
 attribute to either of the two schools an invariable phil- 
 osophical tendency. , In fact, nativism is as likely to be ma- 
 terialistic as idealistic. In the former case, the innateness 
 of space is referred to the anatomical constitution of the 
 organs only : in the latter, the idea of space is considered 
 innate in consciousness. In the same way, empiricism may 
 maintain that impressions are signs of things, interpreted 
 according to our earlier experience ; or, with Helmholtz, it 
 may admit a regulative principle, as causality. Nativism 
 supposes a pre-established harmony between the laws of 
 thought and the laws of the external world. Empiricism 
 seeks to deduce from experience the agreement that exists 
 between the external world and our ideas. 
 
 It is evident aiso that Kant's doctrine of space and the 
 theories we have discussed deal with problems of an en- 
 tirely different order. Whether we consider space an a "pri- 
 on form of mind, or an objective reality, or an abstraction, 
 the question of its genesis in the human mind remains 
 unanswered. So nativists have no right to make use of the 
 name of Kant. In the words of this philosopher, they con- 
 found a question of the phenomenal order with a problem 
 of the transcendent order, the ultimate origin of the notion 
 of space. The discussions of which we are speaking cannot 
 depart from facts and their immediate interpretation : this 
 is the point we wish to emphasize.^ 
 
 pliysiological process, i. e., assimilation and dissimilation of matter in 
 the visual substance. Bering's work has been published in the Reports 
 of the Academy of Science of Vienna, 1872-1874. 
 
 ^ A very complete exposition of the nativist and genetic theories is to 
 be found in the work of Cesca : Le teorie nativistiehe e genetiche della local- 
 izzazione spaziale, 1882 (Drucker et Tedeschi, Vérone, Padoue). The 
 author has classified and explained them with method, comprising, as 
 we have not been able to do here, the theories of Spencer, Bain, Taine, 
 Delbœuf, etc. 
 
 12 
 
CHAPTER V. 
 
 FECHNER AND PSYCHOPHYSICS. 
 I. 
 
 In the domain of experimental psychology, few men have 
 published researches as original and as warmly debated as 
 Gustav Theodor Fechner, now honorary professor in the 
 University of Leipzig. From the year 1836, the date of 
 his first work, The Life after Death, to the last months of 
 1877, the date of his last book, In Sachen der Psychophysik, 
 Fechner has touched upon all the philosophical problems, 
 and has taken part in all the great discussions that they 
 have raised in Germany. The list of his works shows it : 
 they comprise metaphysics, morals, religious questions, the 
 doctrine of evolution, œsthetics.^ We fiud here a great 
 number of new thoughts and enticing hypotheses. In 
 sesthetics especially, or at least in the study of its physical 
 aud physiological conditions, Fechner has shown a rigor of 
 method very rare among German sestheticians. But it is 
 not our object to examine these different publications : the 
 true glory of Fechner is elsewhere ; in his work in psycho- 
 
 ^ Das Buchldn von Leben nach dem Tode, 1836. Ueber das hochste Gut, 
 1846. Nanna oder uber das Seelenleben der PJlanzen, 1848. Zsnddavesta 
 oder uber die Dinge der Himrnds u. der Jenseits, 1851. Die physikaliscke u. 
 philosophische Atomenlehre, 1855. Ueber die Seelenfrage, 1861. Die drci 
 Motive and Griinde des Glaubens, 1863. Einige Ideen zur Schopfungs u. 
 Entwickelungsgeschichte der Organismus, 1874. Vorschule der JEsthetik, 
 1876, etc., etc. To these works those which treat of psychophysics must 
 be added. 
 
 134 
 
FECHNER AND PSYCHOPHYSICS. 1S5 
 
 pliysics. In 1860 the Elemente der Psychophydk^ appeared, 
 a large book, full of experimeuts, tables, figures, calculations 
 and philosophical ^generalizations. This work has served 
 as basis for all the debates which have arisen for twenty 
 years. Fechner has replied to his critics only incidentally 
 in memoirs or articles.^ Taking the offensive again in 
 1877, in his In Sachen der Psychophyidh, he met ail his 
 critics and maintained his first conclusions against them. 
 
 If psychophysics endure under one form or another, it 
 will be his work, and he can be called its founder, altliough 
 he has always refused this title and in his historical résumé 
 of the question (Kemente der PsyehophysiJc, book II, pp. 548- 
 560), gives the honor especially to Weber. We will speak 
 later of Weber's work. It is certain that before Fechner 
 there existed only fragmentary works without general range : 
 he was the first to publish a complete and systematic book. 
 It is against him, therefore, that all attacks have been 
 directed. 
 
 In the account which we will give of this question, we pro- 
 pose, after having shown in some words the object of psy- 
 chophysics, to explain the experiments on which it is based, 
 and the law which has been adduced from them ; finally to 
 state the objections which it has encountered. 
 
 " I understand," says Fechner, " by psychophysics, an ex- 
 act theory of the relations of soul and body and, in a general 
 way, of the physical world and the psychical world." The 
 sciences of nature, long since in possession of their prin- 
 ciples and method are upon a road of continuous progress. 
 On the other hand, the sciences of spirit — ^psychology and 
 logic at least, have also had their foundations in a measure 
 laid. On the contrary, the science of the reciprocal relations 
 of body and spirit is far less advanced than the two groups 
 
 ^ Two volumes in 8vo : Leipzig, Breitkopf u. Hiirtel. 
 * Memoir agaiust Aubert in Beriehte der Sachs. Societal., 1864. Article 
 against Delbœuf, Jen. Literat. Zeitung, 1874, No. 28. 
 
136 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 of sciences just named, between which it occupies an inter- 
 mediate position. So far it consists only of theories with- 
 out proof, or a collection of facts without precision and 
 order. Fechner's object is to inaugurate a positive era in 
 this kind of research, or more exactly to build up a science 
 resting upon experiment, calculation, and measure. 
 
 In principle it places the new science outside of all meta- 
 physical hypothesis. This fact deserves mention the more 
 because, in the various works of which we have given a list, 
 Fechner is far from being guarded in this respect and the 
 boldness of his theories sometimes resembles pure fancy. 
 We find in him a mixture of Berkeley and Leibnitz, to- 
 gether with adventurous hypotheses on the nature of atoms, 
 the soul of the stars and of the universe. All this is outside 
 our subject, and whatever conception of the world Fechner 
 has elsewhere presented, nothing of it appears in his Psy- 
 chophysios. " Our investigations," he says, " pertain only to 
 the phenomenal side of the physical world and the psychical 
 world, that is, to what is immediately given in internal and 
 external perception, and as much as can be concluded from 
 phenomena — in short, we study the physical as physics and 
 chemistry present it ; we study the psychical as experimental 
 psychology (Erfahrungsseelenlehre)^ gives it, without in- 
 vestigating, behind the phenomena, the essence of soul and 
 body, as metaphysic exhibits it." 
 
 In the preliminary portions of his book, the only general 
 idea that Fechner has thrown out on the relation of the 
 physical and mental is that the opposition between body 
 and mind arises from a difference in point of view only ; 
 what, in fact, is one, appears double. "What from an 
 internal point of view seems to be your spirit, the spirit 
 that is yourself, seems, from an external point of view to 
 be the bodily substratum of that spirit. That is, all the 
 
 ^ Better translated, empirical psychology. — Tr. 
 
FECHNER AND PSYCHOPHYSTCS. 137 
 
 difference consists in thinking with the brain or considering 
 it the brain of a thinking being." In nature, nothing 
 more frequently occurs than that opposition which seems at 
 first sight real, disappears when we consider it under an- 
 other aspect. If we stand at the centre of a circle, the 
 convex is hidden from us by the concave side ; if we place 
 ourselves without, the concave is hidden by the convex 
 side. These two sides of the circle are as inseparable as 
 the two sides of man (spiritual and physical), and it is 
 equally impossible, in the two cases, to perceive the two 
 at once as long as we remain in the same position. Simi- 
 larly, our planetary system, seen from the sun, then from 
 the earth, presents an entirely different aspect. On the 
 one hand, the Copernican system ; on the other, the Ptole- 
 maic. It is impossible for any observer to see these two 
 aspects at once, although they are necessarily connected with 
 each other. There are in nature many other cases of this 
 kind, and to Fechner the difference between the physical and 
 psychical is one of them.^ 
 
 It is hardly necessary to remark that this position is not 
 at all paradoxical ; that it has been held by eminent scien- 
 tists, and that it can have no direct influence on psycho-phys- 
 ical research. Moreover, adds Fechner, the object of my 
 work is not to treat of this fundamental question ; let each 
 solve the enigma as he please ; it is of no consequence to 
 the work that follows. 
 
 A single point, whose importance we will appreciate 
 further on, in the metaphysic of Fechner, breaks in upon 
 his investigations, i. e. his hypothesis of psycho-physical 
 movement. It would be useless to speak here of a theory 
 which will be made intelligible in the course of our exposi- 
 tion. We will only say that, while, if we hold to the 
 simple data of experiment, the fact of transmission only 
 
 * Elemente der Psychophysik, Introduction. 
 
188 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 by the nerves and nerve centres between the excitation pro- 
 duced by an external object and the sensation which results 
 from it, is given, Fechner intercalates between these two 
 terms a psycho-physical movement in order to explain the 
 disproportion between the cause (excitation) and the effect 
 (sensation) ; and that this hypothesis has given rise to the 
 most serious criticism. 
 
 We must also bear in mind that, although Fechner 
 pretends to give a general theory of the relations of the 
 physical and mental, his experimental research bears defi- 
 nitely upon a single point alone : the relation of excita- 
 tion and sensation. It is true that under the name of 
 " internal psychophysics," he includes a series of studies oil 
 the seat of the soul, wakefulness and sleep, attention, rem- 
 iniscence, &c., &c. ; but these studies are far from having 
 the exact character that psychophysics requires. So we 
 may say that Fechner has concentrated all his efforts, as his 
 opponents all their criticisms, upon a single question. The 
 question of sensation is, after all, capital, since from it all 
 else comes, and this would be sufficient reason to Fechner 
 for digging to the foundation. Let us see, then, wherein his 
 work and its value consist. 
 
 II. 
 
 PSYCHO-PHYSICAL EESEARCH. 
 
 Fechner's principal object is to measure sensation. To 
 accomplish this he has given long years to experiment and 
 calculation. He has found, besides, in different memoirs 
 on mathematics, physics, astronomy, physiology, by Euler, 
 Bernoulli, Laplace, Bouvier, Arago, Masson, Poisson, Stein- 
 heil, &c., scattered observations, made with a different end 
 in view or left before without psychological interpretation. 
 He has met these results with his own. 
 
FECHNER AND PSYCHOPHYSICS. 139 
 
 The way was opened for him, however, by E. H. We- 
 ber. Weber (in his Programm. collect, and his celebrated 
 articles in Wagner's Handworfr'b. der Physiol.) deduced a 
 law from certain experiments on the perception of weight, 
 length, &c. He had remarked that, if we compare two 
 lines almost equal, the smallest perceptible difference is 
 equal always to about A of the shorter, whatever be the 
 length of the lines compared, whether a centimeter, deci- 
 meter, or meter. In the same manner, in order that a 
 weight be judged greater than another, it must exceed it 
 by a fraction varying from wu to ts, according to the indi- 
 vidual, whatever be the initial weight (gram, ounce, pound, 
 kilogram). Weber added to these results an analogous 
 fact in acoustics : between two tones of different pitch, the 
 smallest perceptible difference is always the same, whatever 
 be the pitch of the tones, and this smallest difference is 
 always the same fraction of the lower tone. These experi- 
 ments, resting in three distinct orders of sensation, led 
 Weber to formulate this law : sensation grows with equal 
 increments when the excitation grows with relatively equal 
 increments.^ This law has been stated by M. Delbœuf in 
 another form : " The smallest perceptible difference between 
 two excitations of the same nature is always due to a real 
 difference which grows proportionally to the excitations 
 themselves." 
 
 Such was the state of the question before Fechner. In 
 order to understand well the course of the investigations 
 into which we are about to enter, it is well to remark that 
 
 * This law may be made clear by an example : a sensation of weight 
 grows with equal increments, if to the original excitation, say 3 grams, 
 we add i of 3 grams = 1 gr., if to this second excitation, 4 gr. we add 
 J of 4 gr. ^ f gr. and so on. The excitation, as we see, grows with incre- 
 ments relatively but not absolutely equal. On the difference between 
 the law of Weber and that of Fechner, given later, see the paragraph 
 devoted to criticisms. 
 
140 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 physiology distinguishes in our sensations taken in general, 
 two things : their quality, and their intensity or quantity. 
 Although it may well be possible in their last analysis to 
 reduce these two to one, they are still, in fact, at least, 
 given to us distinct. Thus, in the category of visual sen- 
 sation, red, blue, green, are given as qualities. But 
 these sensations, remaining the same in quality, may vary 
 in intensity : they increase or diminish. Every sensation 
 has, then, a quantitative value. Moreover, the simplest 
 reflection teaches us the same ; there is no one Avho has not 
 compared two sensations, and ascertained that they are 
 equal or unequal, that one is greater or less than the 
 other. We assert without hesitation that it is brighter at 
 midday than by moonlight, that the firing of a cannon 
 makes more noise than the firing of a pistol. There is, 
 then, a quantitative comparison of sensations; but we can 
 only say there is equality or inequality ; never how many 
 times one sensation is greater or less than another. Has 
 the sun a hundred or a thousand times more brilliancy 
 than the moon? Does a cannon make a hundred or a 
 thousand times more noise than a pistol ? It is impossible 
 to answer this question. The natural measure of sensation 
 that each man possesses reveals to him the more, the less, 
 the equal, never the quantum. Our determinations are 
 always vague and approximate. 
 
 Even so, although we may say in a general way that 
 the intensity of a sensation increases or decreases with the 
 intensity of the excitation that causes it, yet we cannot de- 
 termine this relation exactly, or know whether the sensation 
 increases directly as the excitation, more slowly, or faster : 
 in a word, we know nothing of the law that rules the rela- 
 tion of cause to eifect here. We do not know whether an 
 excitation of an intensity 1 causes a sensation of an inten- 
 sity 1 ; whether an excitation of an intensity 2 causes a 
 sensation of an intensity 2, or 3, or 4, etc. 
 
FECHNER A^D PSYCHOPHYSICS. 141 
 
 At first view, every attempt to measure the degree of 
 sensation exactly may appear very hazardous, for sensation 
 has no exact measiye in itself. But upon reflection we see 
 that, while in every measure a standard is necessary, this 
 standard can never be the object measured ; that we measure 
 things only by an artifice. Now this artifice is afforded us 
 in this case by the nature of the phenomena. In fact, we 
 know very well that every sensation is a neural phenome- 
 non, and we know also that neural phenomena depend 
 upon an external movement which we call excitation. To 
 vary the excitation is, through the nerve medium, to 
 vary the sensation ; the nerve force being the jproximate 
 cause of the sensation, and the external excitation the 
 remote cause. But since we hold this external cause — the 
 excitation — under our control, and since it is open to the 
 most exact measuremeiit, it seems that through it we can 
 measure the sensation itself. 
 
 As far as we compare sensations under the relation of 
 intensity, we treat them as magnitudes : and if, from the 
 point of view of the internal sense, we are led to say that 
 a sensation is equal, inferior, or superior to another, it does 
 not follow that we meet here an obstacle to all exact meas- 
 urement. The time element at first consists in vague 
 notions only of before, after, together; and this does not 
 interfere with very exact measurement. And just as this 
 exact measure must be found not in time itself, but en- 
 tirely in movements in space, so the exact measure of 
 sensation must be sought not in the sensation itself, but 
 in external events which occur in space. Now what better 
 measure for sensation can be found than the external move- 
 ment from which the sensation arises ? The excitation is 
 not only the most direct, but indeed the only possible meas- 
 ure of sensation. Between the sensation and its measure, 
 there exists a necessary relation. The sensation would not 
 exist if the excitation did not precede it. Thus we take 
 
142 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 the cause as measure of the effect. The essential point of 
 difference between the measurement of psychic and extended 
 magnitudes, is that in the former, the cause serves as measure 
 of the effect ; in the latter, the effect serves as measure of the 
 cause. 
 
 The property of sensations, whereby they increase and 
 diminish, affords us a basis for their measurement. As we 
 have seen, it is generally admitted that every sensation 
 increases or diminishes as the excitation which causes it : 
 when the sensation of light increases in the eye, we believe 
 that there is more light without ; and when sound in the 
 ear is augmented, we believe that the noise without is also 
 augmented. Further, common sense is disposed to assert 
 that the sensation increases or decreases directly as the ex- 
 citation. Herbart, who, as we have seen, attempted first 
 to introduce measurement into psychology, finds it very 
 natural to say " that two lights shine tv/ice as brightly to 
 us as one." ' Yet this supposition is fiilse. Certain facts 
 of obsérv^ation alone, without the aid of experiment, are 
 sufficient to prove the law in accordance with which sensa- 
 tion and excitation vary, and to explain this law, at least in 
 a general way. 
 
 Every one knows, says M. Delbœuf,^ that in the silence 
 of the night noises are heard that pass uuperceived during 
 the day : the tic-tac of the pendulum, the light wind cur- 
 rents that blow through the chimney, and other noises 
 of this kind. In the din of the street, or in a train in 
 motion, we do not hear our neighbor and sometimes not 
 even our own voice. The stars, so brilliant during the 
 night, do not appear by day, and the moon pales before the 
 sun. To a weight of 10 grams in your hand, add another 
 
 1 Herbart, Werhe, vol. VII, p. 358. 
 
 * Delbœuf, Recherches théoriques et expérimentales sur la mesure des sensa- 
 tions. Brussels, 1873. Extract from the memoirs of the Acad, of Bel- 
 glum. 
 
FECHNEIl AND PSYCHOPHYSICS. 143 
 
 weight of 10 grams, and you will perceive the difference 
 distinctly ; but if you add 10 grams to a quintal, the dif- 
 ference is not perceivt^d. 
 
 These are every-day facts : it is generally believed that 
 they are simple enough, and yet it is not so. For it is 
 indisputable that the pendulum continues its tic-tac during 
 the day ; that we speak high on the railway train ; that the 
 moon and stars shine by day as by night, and that 10 grams 
 always weigh 10 grams. 
 
 Other examples : " We know by experience to-day," says 
 M. Deîbœuf, again, "that in the great vocal and instru- 
 mental concerts in which the performers are counted by 
 hundreds, the effect produced is not as great as we expect ; 
 that is, to double the number of singers is not to double the 
 intensity of the sensation. We know also that in eclipses 
 of the sun, a considerable portion of the disc may be dark- 
 ened with no perceptible decline in the brightness of the 
 day." 
 
 What do these phenomena signify ? They signify that 
 one and the same excitation may, according to the conditions 
 in which it acts, produce a sensation more or less intense, or 
 none at all. 
 
 And how is this change produced ? The facts show that 
 the conditions of the change are always the same, and that 
 they may be formulated thus : In order that an excitation 
 be felt, it must be feebler as the excitation to which it is added 
 is feeble, stronger as the excitation to which it is added is 
 stronger. We see that this is only a vague expression of 
 the law formulated above by Weber : but it is still 
 important to remark that ordinary facts show us before all 
 experimental investigation, that the relation between excit- 
 ation and sensation is not as simple as we supposed. For if 
 the relation were the simplest possible, the sensation would 
 increase directly as the excitation : to an excitation 1 would 
 correspond a sensation 1 ; to an excitation 2, a sensation 2, 
 
144 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 and so on. But it is not so ; otherwise an excitation would 
 be always equally felt, whether it be added to a strong exci- 
 tation or a feeble one : the light of the stars, for example, 
 would be perceived equally by day and by night. The 
 conclusion then from all this is : thai the intensity of the 
 sensation grows, not proportionally to the intensity of the exci- 
 tation that occasions it, but more slowly. 
 
 Consequently this question arises : by how much is the 
 increase in the sensation less than the increase in the excita- 
 tion ? Every-day experience can not reply to this : here 
 the exact measurement of intensities is necessary. 
 
 It is impossible to measure directly the force of a sensa- 
 tion ; we can measure differences of sensation only. To do 
 this three methods of experiment have been hitherto em- 
 ployed, which Fechner, who brought them into use, desig- 
 nated by the names Method of smallest perceptible différencies; 
 Method of true and false cases; Method of mean errors} 
 
 The first method (der eben merhlichen Unterschiede) is 
 this. We are to compare two weights A and B. If the 
 difference of these two weights is very small, perhaps it is 
 not possible to perceive it, and we judge them equal. On 
 the contrary, if the diiference is considerable, it will not 
 escape our notice. If, then, the diiference d of the weights 
 A and B be made to grow, an instant will arrive when it 
 passes from the imperceptible to the perceptible. In general, 
 when we employ this method, we proceed in two opposite 
 ways ; first we cause the difference d to grow until it be- 
 come perceptible; then we cause it to decrease until it 
 cease to be. Naturally, the sensibility of the subject in 
 judging differences is by so much greater as the quantity d 
 is smaller. 
 
 The second method (der richtigen und falschen Falle) 
 
 ^ Fechner, Eleimnte der Psychophysik, vol. I, pp. 71-76. We follow in 
 general the exposition of Delbœuf, as it is much clearer than Fechner's. 
 
FECHNER AND PSYCHOPHYSICS. 145 
 
 consists in using weights whose diâèrence is very small. 
 Error is possible in the comparative judgment passed upon 
 them. The heavier ^ weight is sometimes designated as 
 heavier and sometimes as lighter. In a word, in com- 
 paring eacili pair of weights on which judgment is given, 
 there will be a certain number respectively of true and 
 false judgments. As the difference in the weights in- 
 creases, the number of true judgments increases at the 
 expense of the number of false judgments. Let us repre- 
 sent the total number of cases as 100, and the number 
 of true cases, 70 : we have the relation tW, obtained from 
 the comparison of the two weights A and B. Now, given 
 a weight a we may seek to determine the weight b which, 
 compared with a, will give the same relation tVo. It must 
 be noted that the uncertain cases are to be divided propor- 
 tionally between the true and false cases. 
 
 The third method {der mittleren Feliler) consists in taking 
 first a mormal weight A, determined in the balance, then in 
 seeking to determine, by the judgment which accompanies 
 the sensation alone, another weight B to be equal to A. 
 In general, the second weight differs from the first by a 
 quantity d which is smaller as the sensibility is greater. 
 We repeat this attempt a great number of times, add the 
 positive errors and the negative errors, disregarding signs^ 
 divide the total by the number of cases, and thus obtain 
 the mean error. 
 
 "These three methods," says Fechner, "supplement one 
 another, and lead by different routes to the same result. The 
 first serves to determine the smallest perceptible difference. 
 The second gives differences which exceed the smallest percep- 
 tible difference (they fall sometimes in the true cases, some- 
 times in the false) ; the third gives differences which are 
 below." In practice, the first method is the simplest, most 
 direct, leads proportionally soonest to the end, and requires 
 least calculation. But, as is justly remarked by M. Del- 
 is 
 
146 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 bœuf, lack of precision is its great defect. " Where and 
 when does a difference in external excitation cease to be 
 perceptible? We see how vast a field remains open to 
 doubt." 
 
 III. 
 
 We are now done with the preliminaries on method. 
 It remains to see the work itself and to say what results 
 it has reached in the sphere of pressure, muscular, temper- 
 ature, light, and sound sensation. 
 
 Sensations of p7-essure. — Let a man place his hand well 
 extended on a table ; then place on the hand any weiglit 
 whatever. To this weight add a very small one, and ask 
 the subject of the experiment (whose attention should be 
 directed from his hand throughout) whether he feel the 
 différence. If he reply in the negative, try a heavier weight, 
 and so on until the additional weight cause a perceptible 
 difference. After having done this with the first weight, 
 repeat it with a second and third, until the necessary mag- 
 nitude of the additional weight is determined in a sufficient 
 number of cases. 
 
 Investigations conducted in this way lead to a result of 
 striking simplicity. We find that the additional weight 
 bears a constant relation to the original, whatever be the 
 magnitude of the latter. For example, let us suppose it is 
 found that for one gram. the additional weight is one-quar- 
 ter gram ; for one ounce, one-quarter ounce ; for one pound, 
 one-quarter pound. In other words, to ten grams we must 
 add two and one-half grams ; to one hundred, twenty-five ; 
 to one thousand, two hundred and fifty. 
 
 These numbers show the nature of the law according to 
 which sensations of pressure or weight change with changes 
 in the external cause. This law is expressed by a number, 
 and this number expresses the relation of the additional 
 weight to the original. Now the mean of a great number 
 
FECHNEE AND PSYCHOPHYSICS. 147 
 
 of experiments gives as the expression of this relation one- 
 third ; that is to say, given any 'pressu7'e on the skin, an in- 
 crease or decrease of pressure will not be felt unless the iceight 
 added or withdravm be in the rekUion one-third at least to the 
 original weight} 
 
 Sensations of muscular effort. — Experiments analogous iu 
 nature and of great number liave been made on the sensa- 
 tion of effort (to raise a Aveight). But here the conditions 
 are not as simple. When we raise a weight we have not a 
 sensation of pressure in the hand alone ; but also a sensa- 
 tion in the muscles of the arm which raises the hand and 
 weight. In this case the sensation is much more delicate 
 than in the case of simple pressure. Consequently, iu 
 the effort made to raise the weight, we perceive much 
 smaller differences. And, in fact, exact investigations show 
 that in the case of muscular effort we feel an additional 
 weight only tïïïï of the original. The sensibility, then, is 
 in this case about five times greater than in the preceding. 
 
 The number t^ô, therefore, expresses the law according 
 to which the sensation of muscular effort depends upon the 
 excitation. This number applies to all weights, great or 
 small, be they grams, pounds, or kilograms : that is, to one 
 hundred grams we must add six ; in short, to any weight 
 I Too of that weight must be added in order that the differ- 
 ence may be felt.^ 
 
 I Setisations of temperature. — The skin is an organ of 
 double sense. . By it we feel not only the pressure, but the 
 I temperature of bodies which come in contact with us. To 
 determine whether sensations of heat and cold depend on 
 the intensity of the external excitation, we take two vases 
 of water of different temperatures and plunge into each a 
 
 ^Fechner, Elem. d. Psychol., vol. I, p. 182, etc. Experiments of 
 Weber and Fechner. 
 
 ^ Wundt, Varies ub. Menseh. u. Thiersede, lect. 7, vol. I, p. 92. Experi- 
 ments of Weber. 
 
148 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 finger of the same hand ; then, by repeated trials, we find the 
 smallest difference of temperature in the two vases to which a 
 difference in the sensation of temperature responds. Calling 
 the normal temperature of the hand zero, we find that, set- 
 ting out from this point, in order that the sensation of dif- 
 ference may be preserved, the relative difference in tempera- 
 ture must be constant. Any temperature must be raised one- 
 third in order that the increase be perceived in sensation. 
 
 The law for sensations of temperature, then, is expressed 
 by one-third, the same number as for sensations of pressure.* 
 
 Sensations of light. — We determine a weight objectively 
 by means of a balance : we determine light objectively by 
 means of the photometer. In a dark chamber a white 
 screen is lighted by two candles A and B. Before the 
 screen a rule is placed which throws two shadows, one A' 
 from the light A, the other B' from B. When B is re- 
 moved, the shadow A' becomes darker. It is then easy 
 to calculate the distances of A and B at which the shadow 
 begins to grow perceptibly deeper. According to the laws 
 of optias, the luminous intensities being in inverse ratio to 
 the squares of the distances of the lights from the screen, 
 we can deduce directly the smallest perceptible difference 
 in luminous intensity. 
 
 The same method is applied to the subject in hand — to 
 measure the relation between the sensation of li^ht and its 
 intensity. The portions of the screen brightly and feebly 
 lighted (the latter where the shadow falls) respectively pro- 
 duce two sensations of light which differ more in inten- 
 sity as the shadow is darker. If we place at first before the 
 rule, two lights of equal intensity at the same distance, for 
 example, two similar candles, the two shadows will have the 
 same intensity, that is, will differ equally from the bright 
 
 ^Fechner, vol. I, p. 201. Experiments of Weber, Feehner, Volk- 
 mann, etc. 
 
PECHNEE AND PSYCHOPHYSICS. 149 
 
 ground on which they are projected. If now we move one 
 of the candles backward, the shadow which it projects will 
 'become more and ijiore feeble ; it will differ less and less 
 from the bright ground of the screen ; finally, it will dis- 
 appear. The distance from the fixed candle to the screen 
 is then measured, as also the distance of the second candle, 
 whose shadow has been reduced to the disappearing point ; 
 thus we obtain data sufficient to show the relation of the 
 growth of the sensation to that of the light. We may remark 
 in effect ; if the fixed candle be alone of course all the light 
 of the screen comes from it. But let us now place the other 
 candle at a very great distance. It adds to the original 
 brilliancy, but this increase is not perceptible. And how 
 do we know the moment that it becomes so ? By the appear- . 
 ance of a second shadow projected from the rule : its position 
 is illuminated by the fixed candle, but not by the moving 
 candle. Consequently at the point where a perceptible in- 
 crease is produced, the shadow must appear. The shadow, 
 then, is only a sign to us of the increase of light. We have 
 now only to apply the optical law for the relation of inten- 
 sity to distance. Suppose that the first candle is one meter 
 from the screen, and the second ten meters when a shadow 
 barely perceptible is produced ; the luminous intensities are 
 in the relation 100 to 1, and consequently the luminous in- 
 tensity of the first light must be increased t^ in order that 
 the increase may be perceptible in sensation. 
 
 The experiment is conducted here just as with the 
 weights. There, we added a lighter weight to a heavier; 
 here, we add a feebler light to a stronger. It remains only 
 to extend our observations to excitations of different inten- 
 sities, as has been done for weight. In this experiment we 
 see that the two lights employed are always distant from 
 each other by a constant relation. If the second candle 
 must be removed ten meters when the first is one meter 
 distant, it will have to be six feet when the first is one foot, 
 
150 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 twenty meters when the first is two meters. — It follows that 
 the luminous intensities which produce the smallest percep- 
 tible difiPerence have always the same relation, i.e.: 100 : 1, 
 200 : 2, etc. We have found, then, a law here and this 
 law is also set forth by a number expressing the relation of 
 the barely perceptible increase of light to the original light. 
 This number is tot; that is, every luminous excitation must 
 be increased by a hundredth in order that the increase may 
 be perceptible.^ 
 
 We may verify this law by another experiment. Let a 
 white disc be provided that may turn very rapidly, and on 
 the surface of this disc let a small black segment be marked 
 out. We then inquire how large this segment must be 
 made in order that, the disc turning rapidly, the eye may 
 perceive a gray circle. The relation of the area of the seg- 
 ment to that of the circle is immediately the appreciable 
 difference, and the constancy of this relation tott, for variable 
 luminous intensities, confirms the law.^ 
 
 Sensations of sound. — In the domain of auditory sensa- 
 tion, similar investigations have been made and the follow- 
 ing principle established : the intensity of the sound pro- 
 duced by a body in striking another, is proportional to the 
 weight of the body that falls and the height from which 
 it falls. If, then, we take a given body and vary the 
 height of its fall, we may vary the sound also at pleasure. 
 This principle can be applied as follows to the measurement 
 of small differences in the intensity of sounds. Let us take 
 two balls of the same size, a and 6, made of the same ma- 
 
 ^ Fechner gives the fraction j^-^ ; according to others, this constant 
 value would vary between -^-^ and j^-^. 
 
 * Experiments of Bouguer, Masson, Arago, Steinheil, Volkmann, 
 Fechner, etc. Elemente d. Psychophysik, vol. I, pp. 139-175. We will 
 speak later of the important experiments of M. Del bœuf. See also 
 Wundt, Menschen u. Thierseele, vol. I, p. 96. — Helmholtz, Physiol. Optik, 
 p. 310, French trans., p. 411. 
 
FECHXER AND PSYCHOPHYSICS. 151 
 
 terial and suspended by threads of the same length. Place 
 between these two balls a small screen. Draw back one 
 of the balls, a, to a given distance (a graduated circle fixed 
 to the screen serves to determine this distance exactly) ; in 
 falling it produces a sound on the screen. Do the same with 
 the ball b. The sounds being proportional to the height of 
 the fall, if the two balls are drawn back equal distances, equal 
 sounds will result ; if unequal distances, the sounds will be 
 unequal. If, now setting out from the moment at which 
 the equality is perfect, we increase the differences in height 
 gradually, when the two balls are allowed to fall in as quick 
 succession as possible, in order better to compare them, it 
 is ascertained that no difference in the sounds is remarked 
 at first, although there is a difference in the heights. It is 
 only when this difference has attained a certain degree that 
 it is perceived. At this instant, we measure the height of 
 the two balls; and see how much the height must be 
 increased to produce a perceptible difference. Supposing 
 the height of the first ball is three inches and of the second 
 four, it results that the intensity of the sound must increase 
 one-third in order that the difference be perceived. If we 
 extend the trial to a great number of cases and very differ- 
 ent heights, we find in all, as in this case, that the relation 
 remains constant and consequently that the intensity of 
 sound must be increased one-third to produce an increase in 
 sensation.^ 
 
 The experiments which we now siun up show that when- 
 ever sensations of pressure, light, temperature, sound, and 
 even of muscular exertion, increase continuously by the 
 
 ^ Experiments of Eenz and Wolf, Fechner, Volkmann, Schaffhautl, 
 etc. Elem. d. Psychophysik, vol. I, page 195, etc. — According to Eenz and 
 Wolf {Vierordt's Arehiv., 1856), in order to distinguish two sounds 
 clearly, their relation must be 100 : 72. The limit at which true pass 
 into false judgments is 100 : 92. Vplkmann's relation is 4 : 3, nearly 
 equivalent to 100 : 75. 
 
152 GEEMAN PSYCHOLOGY OP TO-DAY. 
 
 addition of the smallest differences perceptible in conscious- 
 ness, there is in the corresponding excitation an increase 
 which is always the same aliquot part of the entire 
 excitation. 
 
 Sensations of taste and smell remain. The former were 
 studied by Keppler in 1869, by the method of true and false 
 cases ; but his experiments do not confirm the theories of 
 Fechner.^ We can now sum up what precedes in the table 
 below and say: In order that sensation may increase by 
 the smallest perceptible difference, the excitation must 
 increase : 
 
 For touch 
 
 For muscular effort t^. 
 
 For temperature 
 
 For sound 1 
 
 tV 
 
 Î 
 
 For light T*(7 
 
 lY. 
 
 These figures led Fechner, as we shall see later, to the 
 discovery of a very general law to express the relation of 
 all excitation to all sensation.^ But before arriving at this 
 law, he makes a preliminary investigation ; this is to dis- 
 cover the smallest perceptible sensation. 
 
 To construct a graduated scale upon which to measure 
 the relation between excitation and sensation, it is not suffi- 
 cient to have found an unit of division for the parts of the 
 scale; we must also know from what point the graduation 
 is to begin. Where shall we place the zero? Evidently, 
 in dealing with sensation, the zero of the graduated scale 
 
 ^ On this point and on Fechner's critics, see In Sachen d. Psych&physik, 
 p. 161, etc. 
 
 * Fechner distinguishes between intensive and extensive sensation. 
 The latter might more exactly be called perception of the different 
 manifestations of extension. It may be remarked that his law applies 
 especially to the former. 
 
FECHNER AND PSYCHOPHYSICS. 153 
 
 must be put where the smallest perceptible sensation is 
 produced, the smallest sensation in consciousness.^ This 
 point is designated ^by Fechner by a word borrowed from 
 Herbart, the threshold of excitation (Reizschwellc), and he 
 applies it "as well to the sensation as to the excitation at 
 that point." ^ 
 
 It is necessary, therefore, to determine by a series of 
 observations and experiments the exact value of the 
 threshold for each kind of sensation. We will take them 
 up in order, setting aside various details that would com- 
 plicate the exposition to little profit. 
 
 Weight. — The investigation in sensations of weight is 
 easily made. We place on the point of the skin whose 
 sensibility we wish to test a small weight of cork or elder- 
 pith, and by repealed trials, ascertain the magnitude of the 
 weight which is barely felt, that is, which produces the per- 
 ceptible minimum. A great number of experiments conducted 
 in this way have proved that the sensibility of the skin 
 varies greatly in the different regions explored. The most 
 sensible regions are the forehead, temples, eyelids, and the 
 back of the hand : at these points we feel shis of a gram. The 
 palm of the hand, the belly, the legs, &c., are less sensitive 
 regions, their perceptible minimum being as low as 2V of a 
 gram. Finally, on the nails and heels, it is lowered to 1 
 gram. To sum up, the limit of the excitation, as estab- 
 lished by a great number of experiments, is given according 
 to Aubert, by a pressure of 0.002 to 0.05 gr.^ 
 
 For the muscular sense, the perceptible minimum is 
 
 ^ The question is more complicated than we have for the present indi- 
 cated; as the sensation is measured by means of the excitation, an 
 agreement must be established between the two graduated scales ; diffi- 
 culties arise which will be examined later, in the critical part of the work. 
 
 ' See Elemente d. Psychophysih, vol. I, p. 238 and fol. 
 
 ^ Experiments of Weber, Kammler, Aubert, &c. Elemente d. Psycho- 
 physik, vol. I, p. 163, &c., in particular, p. 264. 
 
154 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 represented, according to Wundt, by a contraction of 0.004 
 mm. of the right inner muscle of the eye} 
 
 Sound. — To determine the limit of excitation for the 
 auditory apparatus, we must take account of several things ; 
 the weight . and material of the body which produces the 
 sound, the material of the body against which it strikes, 
 the velocity of sound, and the distance between the ear 
 and the locus of the sound. 
 
 To measure the perceptible minimum of sound, two 
 methods may be pursued : we may remain throughout at 
 a fixed distance from the sonorous body and cause the 
 intensity of the sound to diminish by degrees to the limit 
 of perception ; or we may withdraw gradually from a 
 sonorous body, of any intensity, until the sound is no 
 longer heard. Since the sound diminishes as the square of 
 the distance, we find by measurement at any point exactly 
 how much the sound has diminished. 
 
 If a small ball of cork be allowed to fall on a plate of 
 glass, the intensity of the sound so produced will vary 
 according to the weight of the ball and the height from 
 which it falls. Now we find that the sound produced by a 
 ball of cork one milligram in weight, falling one milli- 
 meter, the ear being distant ninety-one millimeters, pro- 
 duces the smallest perceptible sound. 
 
 This determination made, it is necessary to make the 
 sound thus produced an unit, to which all other sonorous 
 intensities may be referred. To accomplish this, we proceed 
 as follows. We take any sound whatever, whose intensity 
 is to be measured, and withdraw from it until it is barely 
 perceptible. This is exactly the perceptible minimum, as 
 we have determined it above ; and by measuring the dis- 
 tance we find how many times this sound, at the point at 
 which it is produced, is more intense than the sound of the 
 
 * "Wundt, Phydologie d. Menschen, French Trans., p. 439. 
 
FECHNER AND TSYCHOPHYSICS. 155 
 
 ball of cork. Take, for example, the noise of a musket 
 charged so as to be heard at seveu thousand meters. This 
 distance is about sevçu hundred thousand timts greater than 
 ninety-one millimeters. It results, then, that the intensity 
 of the sound of the musket will be about four thousand 
 nine hundred million times as great as the chosen unit. 
 
 We may proceed, similarly, with all other sonorous 
 intensities. But these measurements must be made in the 
 silence of the night, when the ear is not disturbed by other 
 sounds, and when the atmosphere is more uniform in con- 
 sequence of the absence of solar heat.^ 
 
 Light. — Great difficulties arise in determining the per- 
 ceptible mimmîtm in the range of sensations of light. It 
 seems, at first, that the external conditions of the phenomena 
 are precisely the same as in the other cases ; but it is soon 
 evident that the internal conditions are so diiferent that the 
 investigation becomes singularly complex. 
 
 The determination of the perceptible minimum can 
 naturally be arrived at only when the organ of sense is in 
 a state of repose, i. e. perceiving nothing. Such is the 
 case with the ear : silence is distinguished from noise by the 
 absolute lack of sensation. It seems that in the case of the 
 eye, darkness is to be distinguished similarly from light. 
 But it is not so : darkness differs from light only in degree. 
 If we shut our eyes, darkness results abruptly, but never 
 the entire absence of sensation. External light always 
 penetrates a little. Besides, the natural pressure of the 
 sphere of the eye excites the retina ; so much so that, when 
 the pressure is increased, this internal light increases also. 
 
 But admitting that this mechanical excitation does not 
 exist, and that as far as it is concerned we are in the darkest 
 night, there is none the less light in the eye. It is what is 
 
 ^ Experiments of Schaffhautl, Delezenne, &c. Elemente d. Psycho- 
 physik, p. 257, &c. 
 
156 GEKMAN PSYCHOLOGY OF TO-DAY. 
 
 called its peculiar light. " The field of vision of the normal 
 man/' says Helmholtz/ " is never completely free from those 
 apparitions which have been called luminous chaos, the lum- 
 inous dust of the obscure field of vision." This phenomenon 
 was first studied by Goethe, J. Miiller, and Purkinje. The 
 last mentioned relates that after some physical exertion " he 
 saw a light of feeble intensity, comparable with the last glim- 
 merings of burning alcohol, waving and flaming in his dark- 
 ened visual field." This luminous chaos is certainly indepen- 
 dent of external light, since it is present when the latter is com- 
 j)letely wanting, follows us in our movements and does not 
 respond to any external object. Finally, the most profound 
 darkness itself is a sensation of light. " The obscurest 
 black is not the absolute lack of sensation, but the feeblest 
 sensation of light. The dark has degrees of darkness ; 
 there are differences in black : the deepest black becomes in 
 succession, clearer black, then gray, then white." 
 
 This internal excitation of the eye, having its cause, per- 
 haps, in the chemical processes of nutrition that take place 
 in the tissues, perhaps, rather, in the motor muscles of the 
 eye, which are always more or less in a state of contraction, 
 presents, as it appears, a very serious difficulty to the mea- 
 surement of the perceptible minimum. The eye is in a state 
 of continual permanent sensation, and all the excitation we 
 produce only adds to this unending sensation. We are 
 incapable of determining here the excitation that corres- 
 ponds to the zero of sensation. Yet, if we decide that the 
 sensation experienced by the eye in the deepest darkness 
 shall be zero, then this sensation will be the perceptible mini- 
 mum, and the excitation which causes it, the unit of excita- 
 tion. This manner of procedure will conduct us to some- 
 thing definite. In truth, we commit error ; but the error is so 
 small that it may be neglected, especially as, in the majority 
 
 * Physwhgische Opiik, p. 202, Frencli trans., p. 274. 
 
FECHNER AND PSYCHOPHYSICS. 157 
 
 of cases, we deal with luminous intensities which are 
 very great, and as, consequently, the final result is not 
 involved in the inv^tigation of the unit. We can not 
 proceed here as in the preceding cases, for there we had 
 to determine the excitation which produced the smallest 
 sensation possible. Here a sensation a little above the 
 minimum, but accepted for it, is given. It is the cor- 
 responding excitation that is unknown ; and we must 
 measure it. 
 
 The method to be followed in determining the luminous 
 intensity of a darkened eye is that wliich we have already 
 employed to measure the intensity of any external light. 
 It will be recalled that the process consisted in the projec- 
 tion of two shadows on a screen, by means of two lights 
 placed in front of a vertical rule. In the case before us, the 
 eye itself is the luminous source, whose intensity we wish 
 to measure. In the experiment, conceived by Volkmann, 
 and of which we will giv^e an outline, the light peculiar 
 to the eye is compared with a light whose intensity is 
 known. We place the vertica,l rule in a dark recess, and, 
 at some distance, both the light which serves as measure and 
 the light to be measured, i. e., the eye. Let us conceive the 
 shadow projected by the rule upon the screen ; and at the 
 same time let the light be removed further and further. 
 In consequence, the shadow grows dimmer and dimmer, 
 and finally ceases to be visible. At this instant, the part 
 of the screen which is lighted only by the peculiar light 
 of the eye is no longer distinguished from the other portion 
 — from that which receives the external light, plus the light 
 of tlie eye. Here is, then, the exact point at which the 
 external light is so feeble that it gives no longer a percep- 
 tible increase upon the light of the eye. Since we know 
 from earlier investigation that the proportional constant is 
 T7ÏÏ for light, and since we can determine the distances, we 
 have sufficient data to calculate the peculiar light of the 
 14 
 
158 GESMAN PSYCHOLOGY OF TO-DAY. 
 
 eye.^ Volkmann used for his experiments a screen of 
 black velvet and an ordinary caudle, and found that 
 this caudle at a distance of about nine feet (eight feet, 
 seven) produced a light equal to the peculiar light of the 
 eye. It remains to make of the quantity of light thus 
 determined a unit to be used in practice. To do this, 
 this unit must be compared with the other different 
 luminous intensities employed as excitants. This task 
 presents no difficulty since the subjective light has already 
 been successfully referred to a luminous intensity which is 
 objective, and, consequently, measurable. 
 
 Temperature. — Here difficulties present themselves of 
 another nature entirely than those of vision. The skin, 
 we cannot doubt, experiences sensations of heat constantly. 
 We must then determine how much this temperature of 
 the skin, at the point where neither heat nor cold is felt, 
 is to be raised or lowered, to produce the perceptible minî- 
 mum of heat or cold. Now, two difficulties arise that have 
 not as yet been completely overcome : 1st, The nerves of 
 the skin at that temperature at which there is no sensation 
 of heat are so sensitive that we feel any elevation or de- 
 pression of temperature even before the thermometric in- 
 struments can register it with precision. 2d, The tem- 
 perature at which no sensation is felt, and which answers, 
 consequently, to the excitation zero, is not the same for 
 different parts of the body, and varies, probably, for the 
 same part. This is easily seen by putting different parts 
 in contact. Beforehand, no sensation of temperature is 
 
 * Let us call, says Fechner, the intensity of the peculiar light Hj,. 
 "When an eye capable of perceiving a difference of y J-^ regards a surface, 
 a part of which receives no external light, and a part of which has the 
 intensity h, we have Hq and Ho+^ as the apparent intensities of the 
 two parts, in dealing with the peculiar light of the eye. If A be the 
 feeblest intensity perceivable, we have h=jlô Hq ; thus the intensity Hq 
 of the peculiar light is measured by the objective light. 
 
FECHNER AND PSYCHOPHYSICS. 159 
 
 felt ; but, upon contact, one part is felt to be warm and 
 the other cold. Thus, if the hand is placed on the fore- 
 head or cheeks, it seeijps clearly cold and the cheeks or fore- 
 head warm. The portion of the skin which covers the 
 trunk is warmer than that of the extremities. The fin- 
 gers are warmer than the rest of the hand, and, of the 
 hand, the back is warmer than the palm. 
 
 As far as the hand is concerned, it is admitted that 19° 
 centigrade represents the state of no perceptible excitation, 
 and that an elevation or depression of ^° centigrade pro- 
 duces the perceptible minimum of heat and cold. Until 
 the degree of temperature which answers to the excitation 
 zero is determined for all parts of the body, the general 
 law can be applied to sensations of temperature only 
 in an incomplete way. Yet we may consider the human 
 skin as having the mean temperature of 18.4° centi- 
 grade : if we place the zero of excitation at this point, 
 the error will not be great. At present, the perceptible 
 minimum, in the case of elevation or depression of temper- 
 ature, has not been fixed exactly. However, it is set gen- 
 erally at ^° centigrade. 
 
 We gather up, in the following table, the results of the 
 experiment :^ 
 
 For touch Pressure of 0.002 to 0.05 gr. 
 
 Muscular eflfort . . Contraction of 0.004 mm. of the right ^ 
 internal muscle of the eye. 
 
 Temperature . . . (The heat of the skin being 18. 4°) ^° 
 centigrade. 
 
 Sound Ball of cork of 1.001 gr. falling 0.001 m. 
 
 on a plate of glass, the ear being dis- 
 tant 91 mm. 
 
 Light Cast on black velvet by a candle situ- 
 ated 8 ft. 7 in. distant. 
 
 For the perceptible minimum in the sphere of vision, 
 * Elemente d. Psychophysik, vol. I, p. 267. 
 
160 GEKMAN PSYCHOLOGY OF TO-DAY. 
 
 Aubert gives as unit the intensity of a light about three 
 hundred times feebler than the full moon. 
 
 V. 
 
 THE PSYCHO-PHYSICAL LAW. 
 
 These facts will now serve to give a connected view 
 of our subject, that is, to allow the deduction of a law to 
 express the general relation of excitation to sensation. By- 
 how much must a given excitation be increased to produce 
 a determined increase in the corresponding sensation ? If 
 I increase an excitation by a determined quantity, in what 
 proportion does the corresponding sensation increase ? We 
 are in a state to reply to these and other questions of the 
 same kind. 
 
 Excitation and sensation are magnitudes dependent upon 
 each other. Both are expressed in numbers. The expres- 
 sion for the sensation increases when the expression for the 
 excitation increases. But in what relation ? The simplest 
 relation would evidently be this : that successive excitations 
 be represented by the numbers 1, 2, 3, 4, etc., and the sen- 
 sations by the corresponding numbers 1, 2, 3, 4, etc. We 
 would say, in this case, that the sensation grows proportion- 
 ally to the excitation ; that when the excitation is doubled, 
 tripled, quadrupled, the sensation is likewise doubled, 
 tripled, quadrupled. 
 
 But this is not the case. It is not so simple ; the exci- 
 tation grows much faster than the sensation. 
 
 But there are many ways in which a series of quantities 
 may grow faster than a corresponding series. For example, 
 the excitation might grow as the square, the cube, etc., of 
 the sensation. But this still is not the case ; the numer- 
 ical ratio which expresses the relation of sensation to exci- 
 tation is more complex. 
 
FECHNER AND PSYCHOPHYSICS. 161 
 
 We may indicate it in a simple manner as follows : 
 
 Let us draw a straight line X of a given length ; and at 
 some point of this line place a zero. This point indicates 
 the perceptible minimum, for example, A gram if we are 
 dealing with sensations of pressure. Setting out from the 
 point 0, we divide the line X into equal parts indicated by 
 the figures 1, 2, 3, 4, etc., on the right. From the point 
 0, we draw a vertical line 06 of any length to represent 
 the perceptible minimum. Now since the proportional con- 
 stant, that is, the smallest perceptible difference, is one-third 
 in the case of pressure, we must draw from the point 1 a line 
 =: 06 + ^ ; from the point 2, a line equal to the line at 1 
 plus one-third of that line ; from the point 3, a line equal 
 to the line at 2 plus one-third of that line, and so on. We 
 understand that the increase must always be by one-third, 
 and, as these vertical lines have always the same relation 
 to each other as the weights they represent, it is clear that the 
 differences of length between the line and the lines 4, 5, 6, 
 etc., indicate the weights which must be employed to quad- 
 ruple, quintuple, sextuple, etc., the perceptible difference. 
 
162 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 If we join the extremities of the vertical lines which repre- 
 sent the magnitudes of the different excitations, there results 
 a curve which exhibits to the eye the way in which the sen- 
 sations depend upon the excitations, not only for the points 
 1, 2, 3, 4, &c., but for all the points lying between them, 
 for example, 1^, 1^, etc., etc. For it is evident that the 
 equal lengths 1, 2, 3, etc., can be divided into parts as small 
 as we please, and, if it is desired to find the intensity of the 
 excitation that corresponds to any point situated between 
 two units, we have only to join this point, by a vertical line 
 to the curve : the length of this line will give the magni- 
 tude of the excitation sought. The difference of sensation 
 that answers to the point between two units is perhaps not 
 perceptible to us ; but we cannot conclude that it does not 
 exist. The perceptible difference can be obtained only by 
 accumulating a great number of imperceptible differences. 
 
 Our measure, then, is continuous, and the curve that rep- 
 resents the increase in sensation, proportional to the increase 
 in the excitation, passes from the imperceptible to the per- 
 ceptible, precisely as the sensation itself. This curve is, 
 in its nature, infinite in two directions and never cuts the line 
 
 This prepares us to understand better the law formulated 
 by Fechner. He tells us ÇElemente d. Psychophysik, vol. II, 
 pp. 553 and 554) that after much reflection and many fruit- 
 less efforts, he discovered finally, " one morning the 22d. 
 October, 1850, while lying in his bed," a method that seemed 
 sufficient to measure sensation by means of excitation. 
 
 To be better understood, we will first indicate in a gen- 
 eral way, and without mathematical details, the course pur- 
 sued by Fechner. 
 
 We have two series before us : that of excitations and that 
 of sensations. The problem is to measure the second by 
 
 ^ Wundt, Menschen u. ITiiersede, vol. I, lect. 8. 
 
FECHNER AND PSYCHOPHYSICS. 163 
 
 means of the first. The quautitative value of the excitation 
 and its increase can be determined. In dealing with weight, 
 light, or sound, we aie able, by experimental processes more 
 or less complex, to affirm that the initial excitation is in- 
 creased a third, a fourth, is doubled or tripled, etc. But it 
 is not so with the sensation. Consciousness cannot inform us 
 whether the initial sensation has increased a third, a fourth, 
 has doubled or tripled. We must then have recourse to an 
 indirect method, and this method consists in determining 
 the smallest perceptible diiferences of sensation ; then in 
 determining the relation existing between the differences of 
 excitation which grow progressively and the differences of 
 sensation which grow uniformly, and in expressing, thus, 
 the sensation in terms of the excitation. 
 
 We will now enter into some details. The method of 
 Fechner is based from the beginning upon the following 
 mathematical principle : 
 
 The increments of two continuous magnitudes which are 
 functions of each other continue proportional as long as they 
 are very small. "But," says Fechner (vol. II, p. 7), "this 
 term ' very small ' is entirely relative. Speaking absolutely, 
 the proportion will hold only for infinitely small increments : 
 the approximation will be greater as they approach nearer 
 the infinitely small. With this reservation, we may say 
 * that the increments of sensation are proportional to the 
 increments of excitation, while the increments of each are 
 very small.' " 
 
 Assuming two principles, i. e. 1st. That differences of 
 sensation are equal among themselves, when the correspond- 
 ing differences of excitation are relatively equal among them- 
 selves (principle of Weber) ; 2d. That small increments of 
 sensation are proportional to the increments of excitation 
 (mathematical principle stated above), Fechner reasons 
 thus : 
 
 " Let the increment of the excitation be, agreeably to 
 
164 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 the investigations of Weber, very small in proportion to 
 the excitation itself. Let us call the excitation /3 and the 
 increment d^ (the letter d signifying no particular mag- 
 nitude, but only the smallest increment of i? which can 
 be considered its difierential). The relative increment of 
 excitation is then -j. On the other hand, let us call y the 
 sensation which depends upon the excitation /S, and dy the 
 increment of sensation produced during the growth of the 
 increment c?/S {d having the same meaning as above). . . . 
 " According to the experimental investigations of Weber, 
 dy remains constant, while j remains constant, whatever 
 absolute value ^ and d^ may have. And, according to 
 the a priori mathematical principle already given, the in- 
 crements dy and d[i are proportional to each other, while 
 they are very small. These two relations are expressed in 
 the following equation : 
 
 dy = ^> 
 
 k being a constant." 
 
 Whence, by integration : 2/=k loq. i?. 
 
 Which gives the value of the sensation.^ 
 
 This is the result of the investigation, and Fechner has 
 stated it concisely in the famous formula called the psycho- 
 physical law : 
 
 The sensation grows as the logarithm of the excitation. 
 
 ^ Fechner, Elem. d. Psychophys., vol. IT, pp. 9 and 10. — The following is 
 an exposition of Fechner under another form in greater detail, which I 
 owe to the kindness of M. Delbœuf. 
 
 " Fechner proceeds by the method of perceptible minima of sensation, 
 and assumes that : 
 
 " 1st. All these minima are equal, i. e., the sensation of an increase of 
 weight, light, etc., is always the same, whatever be the weight or light 
 to which the increase is added. 
 
 " 2d. Experiment shows that this sensation of increase is produced 
 whenever the increase in excitation is an aliquot part, always the same, 
 of the total excitation. 
 
FECHNER AND PSYCHOPHYSICS. 165 
 
 This law has been put in other forms, simpler and less 
 transcendent in a mathematical sense (by Weber, Delbœuf, 
 Budge, &c.), for exajiiple : In order that the sensation grow 
 by quantities always equal, it is necessary that the external 
 excitation grow by quantities always proportional to the exci- 
 tation itself, — or again : the excitation must grow in geomet- 
 rical progression (such as 1, 2, 4, 8, — or 1, 3, 9, &c.) in order 
 that the sensation may grow in arithmetical progression 
 (such as 1, 2, 3, 4, &c.). In fact, the logarithms of num- 
 bers which form a geometrical progression are in arithmet- 
 ical progression.^ 
 
 " 3d. If we express this under the form of a differential equation, the 
 only exact form for this sort of phenomena, we have : 
 
 Ac (increment of sensation) :^k (indicating proportion, not equality) 
 X — (the relation of the increment of excitation to the total exci- 
 tation), i. e, : 
 
 Af = k ^- 
 
 e 
 
 " Fechner, hy a process which is legitimate in certain circumstances, 
 transforms this equation of finite differences into an equation of infin- 
 itely small differences (criticism of this process could only result in 
 showing that the resulting equation is only approximate). It is then 
 ■written : 
 
 dç = kdf . 
 
 e 
 
 " In this way we obtain an equation which may be integrated, that is, 
 one which gives a relation not between dç and de, which are now infin- 
 itely small, inestimable, but between ç and e, the end desired. This 
 
 relation is 
 
 f ^ k loq. e, 
 
 in consequence of some transformations indicated in my Etude psycho- 
 physique, and in Fechner himself, In Sachen d. Psychophys., p. 10." 
 
 ^ On this point, see Wundt Menschen u. Thierseele, lect. 8, p. 11 6. We 
 borrow some examples from him. In our tables, 10 being the base, 
 this is the most convenient way to proceed. Put the sensation 1 under 
 the excitation which is equal to ten times the perceptible minimum. This 
 done and any excitation expressed by a number being given, we have 
 only to look for this number in the table: the logarithm at the side 
 gives us at once the value of the corresponding sensation. We know 
 
166 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 VI. 
 
 rECHNER's CEITICS. 
 
 We have now exhibited the great characteristics of the 
 psycho-physical law and the experiments upon which it is 
 based. As far as possible we have followed Fechner him- 
 self, borrowing from others only some details which were 
 necessary to make his thought clear and complete. It 
 remains to speak now of the critics, whose existence we 
 have seemed hitherto to ignore. Yet, if the importance of 
 a theory may be measured by the number of attacks made 
 upon it, psychophysics must be considered of great value. 
 Objections come from all sides, under all forms, and it is 
 by no means a slight difficulty to present them in order. 
 
 It is well to remark from the very first that the law is 
 true only within certain limits. 
 
 Just as there is a lower limit below which the excitation 
 is too feeble to produce the nervous movement which is the 
 condition of sensation ; so there is also an upper limit above 
 which sensation increases more slowly than the logarithm 
 of the excitation, and a point is finally attained above which 
 any increase in the excitation does not increase the sensa- 
 tion. As touching luminous intensities, common experience 
 teaches that if the light diminish much, we can no longer 
 
 that for pressure the perceptible minimum is -^-^ gr. Let us then call the 
 excitation of -^q gr. = 1 ; an excitation ten times as great will be | gr. 
 Under this excitation let us place the sensation 1. Suppose now that I 
 wish to make the sensation two and one-half times stronger. I take the 
 table and opposite the logarithm 2.5, I find the number 316, that is 316 
 units of excitation, or ^--^ gr., or, more simply, 6.3 gr. Let us now reverse 
 the operation. Let there be an excitation of 5000 units (or 100 gr.) ; 
 the question is to find the magnitude of the sensation it produces. I 
 find in the table the logarithm of 5000 to be 3.698, that is, that a pres- 
 sure of 100 gr. produces a sensation 3.698 times greater than the sensa- 
 tion produced by -^t^ gr. Wundt has given a complete exposition of the 
 law of Weber in the 2d edition of his Physiol. Psychol. I, sec. 2, chap. 8. 
 
FECHNER AKD PSYCHOPHYSICS. 167 
 
 distinguish anything ; and if the h'ght be very bright there 
 results a general daze. But scientific experiment warrants 
 more positive statements. Fechner had already pointed out 
 the anomalies which the psycho-physical law presents in 
 cases in which the luminous sensations are very strong orvery 
 feeble. Aube'rt and Helmholtz show, further, that these 
 anomalies are even slightly greater than was at first believed. 
 Aubert's researches demonstrate that, when the luminous 
 intensity is very feeble, the differential constant may fall as 
 low as xV- 
 
 Upon these partial restrictions, which bear only on the 
 limits of the law and on but one order of sensations, more 
 general criticisms follow. 
 
 Bernstein,^ while admitting Fechner's law and the loga- 
 rithmic form of it, gives it an altogether different meaning. 
 The fact he insists more particularly upon is the propaga- 
 tion of the excitation in the central organs, that is, in the 
 cerebral cells. According to him, the intensity of the sen- 
 sation is proportional to this "propagation in space," i.e. 
 to the number of vibrating cells ; but this " propagation " 
 represents in intensity the logarithm of the external excita- 
 tion. The law would have thus a purely physiological 
 character. 
 
 Brentano, in a passage in his Psychologie aus empirischen 
 Standpunkte, 1874 (p. 87, &c.), and in a correspondence 
 with Fechner, which the latter has told us exists,^ criticising 
 the psycho-physical law, maintains that the relative incre- 
 ments of sensation must be equal when the relative incre- 
 ments of the excitation are. Fechner placed this criticism 
 with those which Plateau and Ueberhorst addressed to him. 
 
 In 1876, Sanger, in his book on the Foundation of Psy- 
 
 ^ Zur Théorie des Fechnerschen Gesetzes der Empfindung, in the Archiv 
 of Keichert and Dubois-Eeymond, 1868. 
 * In Sachen d. Psychophysik, p. 24. 
 
168 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 chophysics,^ emphasized especially the mathematical side of 
 the law of Fechner and proposed another formula to 
 express the relation between sensation and excitation. 
 
 But the most complete criticism which has been made of 
 the work of Fechner in all its details is due to Hering and 
 Delbœuf. 
 
 M. Hering, professor in the University of Prague, as the 
 preceding chapter has already informed us, in a series of 
 articles or memoirs published 1872 to 1875,^ attacked psy- 
 chophysics at every point, or nearly so, denying or contesting 
 nearly all the positions of Fechner. He rejects the latter's 
 experiments or admits them only with extensive limitations; 
 he denies that the logarithmic law is a legitimate deduction 
 from the law of Weber ; he deprives the law of all gener- 
 ality, and maintains that it is verified so far only for light and 
 sound, and that in a certain measure. To the physical and 
 mathematical objections, he adds others which he denominates 
 teleological : in short, it is the severest assault that the doc- 
 trine of Fechner has had to meet. 
 
 The position of M. Delbœuf is more complex. More a 
 partisan than an adversary of psych ophysics, known him- 
 self from important experiments and works on this subject, 
 he still does not admit the mathematical formulas of Fech- 
 ner ; and as to the doctrine as a whole, he rejects part and 
 modifies what he does not reject. In his eyes, the Elemente 
 d. Psychophydh is a work worthy of admiration, but, in 
 coming time, it will be valued rather for what it suggests 
 than for what it accomplishes. He has given his views in 
 his Etude psychophysique,^ in his Théorie geney^ale de la sen- 
 
 * Grundlage d&r Psychophysik : eine krUische Untersuchung, Jena, 1876. 
 
 ^ Six memoirs relating to visual sensation, hut especially the articles 
 JJeber Fechner's psychophysiches Oesetz. Wien. Bericht, vol. 72, 1875. 
 
 * Etude psychophysique. Theoretical and experimental investigations 
 on the measurement of sensations, and especially sensations of light and 
 fatigue. Acad, des sciences de Bruxelles, 1873. 
 
PECHNER AND PSYCHOPHYSICS. 169 
 
 sibHite, and in three important articles in the Revue philoso- 
 phique} In these last he defends Fechner against Hering 
 and discusses the ne\^ book in which Fechner replies to his 
 critics. 
 
 We see that in its short life of twenty years psycho- 
 physics has not been left undisturbed. And there are otlier 
 critics to be mentioned : Mack, Classen, and an anonymous 
 mathematician in the Revue philosophique of March 13 and 
 April 24, 1875. 
 
 Fechner believed that all the objections brought against 
 him could be stated under the following five heads :^ 
 
 1st. The laws and formulas of psychophysics do not accord 
 with the facts : they are mistakenly deduced : experimental 
 research shows more exceptions to these laws than confirm- 
 ations of them. 
 
 2d. Admitting that these laws and formulas are valid for 
 external psychophysics, they cannot be carried into internal 
 psychophysics. In other words, they have only a physio- 
 logical value. 
 
 3d. They are open to mathematical objections and are 
 unsound. 
 
 4th. They are irreconcilable teleologically with a rational 
 conception of the external world. 
 
 5th. The psycho-physical formulas, consequently, must 
 be abandoned or modified : or if they are formally estab- 
 lished, must be interpreted in an entirely different way. 
 
 We will not enter equally upon all these points. We 
 will, examine especially the objections relating to the value 
 of the experiments, to the mathematical interpretations, and 
 finally to the nature of the law itself. 
 
 I. Hering, as we have said, contests nearly all the experi- 
 ments of Fechner. As to sensations of weight, he devoted 
 
 1 March, 1877, Jan. and Feb., 1878. 
 ^ In Sachen der Psychophysik, pp, 13, 14. 
 15 
 
I 
 
 170 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 himself with two of his pupils to repeated experiments during 
 many months. He starts with 250 grams, and by successive 
 additions reaches 2700 gr. According to the law of Weber, 
 the additional weight giving the smallest perceptible differ- 
 ence in sensation must be a fraction always constant of the 
 original weight ; now experiment shows that this fraction 
 becomes smaller and smaller to a certain point, and then 
 begins to grow again. The following figures prove it : 
 2Tj /ï» ts) eV; Tïït TSf vij jhot TTï> gV. In truth, Hering 
 knows that if the weight of the arm be taken into account 
 these figures will be modified^ favorably to the psycho- 
 physical law. But, oj)erating with weights much smaller 
 (from 10 to 500 grams) and modifying the experiment in 
 such a way as to rule out the weight of the arm, he 
 finds that the fractions still fail to confirm the law of 
 Fcchner.^ 
 
 For luminous sensations, Hering seems disposed to ad- 
 mit the law. M. Delbœuf does the same ; but insists upon 
 the limitations of Aubert and Helmholtz, relying upon his 
 own experiments. " Let us imagine," says he, " three con- 
 centric contiguous rings colored in such a way, for a given 
 illumination, say that of a candle 25 centimeters distant, 
 that the middle intermediate shade shall appear in bright- 
 ness equally removed from the brighter on one side and the 
 darker on the other. If the candle be removed, this shade 
 ceases to be intermediate between the two others, but 
 approaches the darker. The law is not applicable at the 
 extreme limits." On the other hand, he asks how Hering's 
 principle of proportion can accord with this fact : that a 
 gray, mean between a white whose brightness is 32, and 
 
 ^ Fechner, in his turn criticising the experiments of Hering, shows 
 that if the weight of the arna is allowed for, i. e., 2,273 gr., the fractions 
 are: ^, aVs) tt-sj A» 2V 2 > À- 2; 2V 4> 2V 6> A-ïj i-s* {^"i^ Sachen u. 
 s. w., p. 193.) 
 
FECHNEE AND PSYCHOPHYSICS. 171 
 
 a black whose brightness is 2, has a brightness not of 17, 
 but of 8, the exact number required by the law of Fechuer. 
 
 As to sensations of sound, Hering distinguishes intensity 
 and pitch (tonalité), and maintains that the psycho-phys- 
 ical law holds for neither. If the intensities of sounds, 
 says he, follow a logarithmic law ; if, as they increase, the 
 corresponding sensations increase more and more slowly, 
 the titiibre of an instrument would vary to us according to 
 its remoteness or nearness to us, in forte and piano ; the 
 timbre in effect, as Helmholtz has shown, is due to the com- 
 bination with the fundamental note, of consonant notes, 
 vibrating with definite relative intensities. In reference to 
 pitch, Hering gives an objection not at all conclusive. He 
 acknowledges, as has been known from all antiquity, that 
 two musical intervals seem equal when the relation of tlie 
 numbers of vibrations of the two constituent tones remains 
 the same for the two intervals ; but the tones not being per- 
 ceived as a determined number of vibrations, it matters little, 
 according to him, that the numerical relation of the inter- 
 vals remains the same. Delbœuf has replied to these criti- 
 cisms,^ and shown, notably for sound, that the sensation 
 is a subjective phenomenon, having a nature peculiar to 
 itself, and that it perceives numerical relations in its own 
 way, without perceiving them as numbers. 
 
 Besides smell, which no experiment has touched, and taste, 
 which, as we have seen, defies the law, temperature remains. 
 Now Fechner, in his latest work, acknowledges that for 
 sensations of this kind, the question is still open.^ 
 
 Ï0 sum up, the merciless critic, Hering, comes to this 
 conclusion : that the psycho-physical law cannot be applied 
 to smell, taste, heat, weight or sound, that it is only in a 
 
 ^ For the details of this reply, see the Revue philosophique, vol. Ill, p. 
 236 and fol., March, 1877. 
 
 ^ Ich halte die Frage der Beziehung des Geseizes zu diesen Empfindungen 
 noch nicht fur erledigt (p. 165). 
 
172 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 measure verified for sensations of light ; that, consequently, 
 it has not the general character of a law of the sensibility. 
 M. Delbceuf, on the contrary, though criticising many de- 
 tails, believes that we can give it a provisional acceptance 
 as far as the experimental question is concerned. 
 
 II. The mathematical validity of the law has given rise 
 to difficulties of another nature. 
 
 The gravest is this : Do we admit, with Fechner, thatj 
 when a sensation grows by the smallest perceptible differ- 
 ences these differences ds, ds', ds", remain always equal? 
 On this hypothesis, as we have seen, all his mathematical 
 deductions rest. 
 
 Wundt, who defends the position of Fechner on this 
 point, maintains that " we are conscious, in certain given 
 cases, that one sensation has decreased or increased as 
 much as another, notably in the case where the increase 
 (or decrease) is of a perceptible minimum of magnitude. 
 These changes of a perceptible minimum in sensation are 
 necessarily equal to each other in magnitude. If the 
 change of either of the two sensations compared were 
 greater or less than the other, it would be therein less than 
 the perceptible minimum, which is contrary to the hypoth- 
 esis. The sensation then has entirely the character of a 
 measurable magnitude — measurable always in certain con- 
 ditions, i. e., in conditions of very small changes of value." 
 
 M. Delbœuf, who has many times declared the law in- 
 capable of being sustained from a mathematical point of 
 view, accepts neither the hypothesis of Fechner nor the 
 justification of Wundt, and subscribes to the criticism 
 of the anonymous mathematician, who was spoken of 
 above. The latter says that if the psycho-physical law 
 be true, it is necessary that sensations be represented by 
 numbers ; that it would be well to say of what measure 
 they are the expression, by means of what unit they are 
 arrived at ; that, this is the method of procedure in phys- 
 
 AbM 
 
FECHNER AND PSYCHOPHYSICS. 173 
 
 ics, where the units are defined with great care, and the 
 process of measure described : here nothing of the kind 
 appears. In fact, J^echner measures sensation by excita- 
 tion. All that precedes has shown abundantly that his 
 process of measure rests on the relation of dependence ex- 
 isting between the excitation and the sensation that results 
 from it, and that thus, according to his expression, " the 
 internal sensation is measured by an external measure." 
 Now here, says M. Delbœuf, is a pure illusion. Sensa- 
 tion must be measured by its natural unit, which can only 
 be sensation. The excitation in its turn must be meas- 
 ured by a unit of excitation. In this way sensation and 
 excitation are reduced to numbers which can be compared 
 for reduction to a common law. It is only after the law 
 has been discovered that we can take the measure of the 
 sensation, and deduce by calculation that of the excita- 
 tion.^ 
 
 In addition to this general criticism, there is another on 
 the method pursued by Fechner to establish his scale of 
 comparison between sensation and excitation. In the con- 
 struction of this scale of measure, it is important to fix 
 the position of the zero as the point from which the 
 graduation proceeds. For sensation, it seems natural 
 to place the zero at the vanishing point; so Fechner 
 proceeds. But, objects M. Delbœuf, it results in a grave 
 difficulty. The external excitation, to be felt, to be- 
 come a state of consciousness, must have acquired a cer- 
 tain intensity, must have passed its zero point. At the 
 precise moment when the excitation attains its "thresh- 
 old," that is, a degree of intensity just sufficient to be felt, 
 Fechner takes this "threshold" as the wm^ of excitation. 
 At this threshold, he places the zero of sensation. To 
 
 ^ In his Etude psychophysique, M. Delbœuf attempts to determine for 
 sensations of light a unit of sensation to be used as measure, and has 
 given mathematical formulas to be substituted for those of Fechner. 
 
! 
 
 174 GEEMAN PSYCHOLOGY OF TO-DAY, 
 
 the excitations that are below the threshold, that, conse- 
 quently, are not felt, correspond negative sensations.^ It 
 follows that opposite the excitation 0, the sensation nega- 
 tive indefinite is written ; opposite the sensation 0, the exci- 
 tation 1 is written. It is not so that we proceed in experi- 
 ments involving exact measurement. If, for example, says 
 M. Delbœuf, we wish to measure the space passed over by a 
 falling ball by the time elapsed since the beginning of the 
 fall, and thus compare portions of space with portions of 
 time, we take care that there be a perfect agreement between 
 the starting points of the two series, that the time be 
 opposite the space 0.^ 
 
 III. The teleological criticism of the doctrine of Fech- 
 ner would not detain us here, if it were concerned simply 
 with metaphysical hypotheses, or a question of final causes ; 
 but it enters into the life of our subject, since its object is 
 to determine the true character of the psycho-physical law. 
 
 According to Hering, the most natural hypothesis, that 
 which arises at once in thought, is that the effect is propor- 
 tional to the cause, and that consequently, in the present 
 case, the sensation must be proportional to the excitation. 
 This hypothesis is so simple, clear, and satisfactory, that 
 very good reasons must be given for rejecting it. 
 
 This reasoning seems correct, and, in its abstract form, 
 only expresses a very general law of the phenomenal world, 
 i. e., the transformation of forces. The principle of the 
 direct proportion of cause and effect is but the metaphys- 
 
 ^ This expression Las been greatly criticised, especially by Delbœuf 
 and Langer. It would seem that negative sensations are unconscious ; 
 Fechner says that this interpretation is nonsense. M. Delbœuf also 
 considers the notion of threshold unimportant; but we cannot em- 
 brace all the details of the question here. 
 
 * For a general criticism of mathematical psychophysics, see an article 
 by M. P. Tannery, in the B^im& philosophique for Jan. 1st, 1884: " (M- 
 tique de la loi de Weber" 
 
 . fclit ii«:i 
 
FECHNER AND PSYCHOPHYSICS. 175 
 
 ical translation of this generalization, which is based upon 
 numberless and uniform experiences : nothing is created, 
 nothing is annihilated, all is transformed. But in the case 
 we are dealing with, there is nothing to prove that the sensa- 
 tion is the entire effect produced by the excitation. Even 
 to those who do not admit the law of Fechner in its rigorous 
 form, it is beyond doubt that the sensation does not grow 
 directly as the excitation. Many facts prove it. There must 
 be, then, some causes of waste. The excitation does not pro- 
 duce a psychic effect alone — sensation ; it produces other 
 effects of a physical and physiological order that must 
 occasion a certain expenditure of its original intensity. It 
 acts upon an elastic and compressible medium in such a 
 way that the psychic phenomenon is connected with a 
 phenomenon of compression or expansion. So there is 
 nothing here to contradict the proportion of cause to effect. 
 
 M. Delbœuf, who shows, in reply to the objections of 
 Hering, that in different cases in nature, the relations be- 
 tween cause and effect are far from simple, has thrown 
 great light, by his experiments on fatigue, upon the true 
 character of the psycho-physical law, and the bearing of 
 the natural causes which limit it. 
 
 There is in Fechner a very marked tendency to neglect 
 the biological conditions of excitation and sensation. He 
 reasons altogether as a physicist. Yet a sense organ in 
 activity is very different from an instrument in use. When 
 it receives a series of constantly increasing excitations, it is 
 not exactly the same to the second as to the first, to the 
 third as to the second. Among Fechner's critics no one 
 has brought this out better than Delbœuf, The intensity 
 of the sensation, says he, does not depend alone upon the 
 intensity of the exciting cause, but also on the quantity 
 of sensibility or force that the organs in exercise possess 
 at the moment. This quantity or store of sensibility is 
 continually drawn upon and diminished by the excitation. 
 
176 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 M I 
 
 Consequently _, at the time of a subsequent excitation, equal 
 or unequal, the feeling subject is in new conditions. The 
 excitation acts, so to speak, upon another individual. 
 According to the formula of Fechner the sensation grows 
 indefinitely, while the excitation also grows indefinitely ; 
 this takes no account of the alteration which the organ 
 undergoes in consequence of the excitation.^ 
 
 " To sum up, every excitation produces a double eifect : 
 it is the cause of sensation and the cause of exhaustion, 
 and the exhaustion diminishes the sensation. The sensa- 
 tion is at its maximum purity when it exceeds the fatigue 
 most (the author has determined the value of d that gives 
 this maximum). On one or the other side of this value, 
 the judgment begins to grow uncertain." 
 
 IV. Wundt, takes up the study of the psycho-physical 
 law again and again. In a recent profound criticism he 
 compares the formulas of Weber and Fechner, notes their 
 points of difference, and inquires to what extent the second 
 is contained in the first. (^Philosophische Studien, II, bro- 
 chure I.) 
 
 T. H. Weber summed up the results of his experiments 
 in these words : " By the comparison of external impres- 
 sions, we can discover their relations, but not their absolute 
 values." Wundt considers the law of Weber, with the form- 
 ula below, applicable to intensive sensations only : " The 
 difference between two excitations, must, in order that the 
 differences in sensation be equally appreciable, grow propor- 
 tionally to the magnitude of the excitations." The form 
 
 ^ Etude psychophysique, p. 29, etc. M. Delbœuf seeks to determine 
 the formula of fatigue or exhaustion : if tlie excitation be represented 
 by d and the quantity (masse) of free sensibility by m, he has : 
 
 /=K 
 
 '' m-d 
 
 His research has tended, ever since, to modify the formula of Fechner. 
 
FECHNER AND PSYCHOPHYSICS. 177 
 
 in which the law of Fechner approaches nearest that of 
 Weber is this : " The diâèrence between two excitations 
 must, in order that the differences in sensation be equal 
 (equal, instead of equally appreciable), grow proportionally 
 to the magnitude of the excitations." In its mathematical 
 form, if E> represent any excitation, AR its smallest per- 
 ceptible increase, the law of Weber is : 
 
 AE _ 
 
 E 
 And the law of Fechner 
 
 Constant. 
 
 AE representing the constant difference of sensation, 
 and K being a constant whose value depends on the rate 
 of increase of the sensation. 
 
 The transformation of the law of Weber into that of 
 Fechner rests, primarily, on the supposition that sensation 
 in general is measurable : and objections are brought espe- 
 cially against this position. Kries, in a special study, 
 published in the Vierteljahrsschrift fur wlss. Philosophie, 
 VI, 257, does not share the popular prejudgment that psy- 
 chic magnitudes are not measurable ; yet he maintains that 
 no rule of measure can be applied to them. For our situa- 
 tion is this : while we have standards of measure, the 
 units that make them up differ from each other, and we have 
 no means of reducing them to a single type. All physical 
 measures are of space, time, and mass, and it is a necessary 
 condition that these three be clearly distinguished. One of 
 these must always be employed, and its units are always 
 the same. But it is not so for the measurement of intensive 
 psychic magnitudes. In a series of sensations e, Ci, eg, 
 etc., we can not say that the change from e^ to Cj equals the 
 change from 6^ to e^ , for there is no equality here. We 
 can not infer that the change from an impression of 2 
 pounds to 3 is equal to the change from 10 pounds to 15. 
 
178 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 On the other hand, Boas {Pjivger's Archiv, XXVIIT, 
 p. 566) maintains that different luminous intensities are no 
 more comparable than different sense qualities, from which 
 he infers that intensive differences are only a form of quali- 
 tative differences. In short, notwithstanding points of dis- 
 agreement, Kries and Boas rest upon the pretended impos- 
 sibility of comparing changes in sensations which are of 
 different degrees of intensity. 
 
 Let us examine the conditions of physical measurement 
 more closely, replies Wundt. We remark ordinarily that all 
 time measurements suppose invariableness of duration in the 
 regular natural phenomena that we measure (rotation of the 
 earth on its axis, &c.) : but this invariableness does not exist 
 in an absolute sense in any physical movement. We sup- 
 pose in natural law, also, an invariableness that never 
 exists. We can not compare two quantities of time, like 
 two quantities of space, by superposing them one upon 
 another ; while the measure of space rests upon direct intui- 
 tion, we must have for time, and, consequently, for mass, 
 velocity, force, &c., besides intuition, the foregoing hypothesis 
 of invariableness. Wundt then examines the case of inten- 
 sive magnitudes that are transformed into extensive mag- 
 nitudes of space and time, as is the case in the measurement 
 of sonorous and luminous intensities. The process rests 
 upon the hypothesis that a determined law of nature, which 
 presents a phenomenon of objective movement as a function 
 of determined special conditions, is valid ; for example, the 
 active force of light vibrations as a function of the distance 
 from the source of light. Besides this hy[)othesis, tliere is 
 anotlier, of a psychological nature, that is implicitly admit- 
 ted: that the conditions of consciousness are sufficiently 
 constant to admit a valid determination of the equality or 
 inequality of sensations at different times. 
 
 Psychic measurements are most frequently measurements 
 of intensity : their first characteristic is this essential point, 
 
FECHNER AND PSYCHOPHYSICS. 179 
 
 that thej are not concerned as much with the equality as with 
 the inequality of sensations. This is the capital point — ^the 
 source of all the difficulties raised; for the measurement 
 of unequal sensations seems, at once, to contradict the fun- 
 damental condition of all measure. But it only appears so. 
 What we compare is really not two sensations, but their 
 différence, and the judgment is, after all, one of equality. 
 In truth, this judgment bears, not directly on differences of 
 sensation, but on the degree of perceptibleness of this differ- 
 ence. Yet the judgment " two differences in given sensa- 
 tions are equally perceptible" is undoubtedly a judgment of 
 equality, as the judgment, "two spaces, two durations, two 
 luminous or sonorous intensities are equal," is such. If it 
 be objected that we measure, not the sensations themselves, 
 but simply their degree of perceptibleness, we reply that 
 here, in fact, the ultimate psychic elements are reached, 
 which alone are measurable in this case. To put the ques- 
 tion under any other form, is to put it wrongly, and it is 
 not astonishing that it can not be solved. 
 
 This principle of psycho-physical measurement, moreover, 
 can not be restricted to the law of Weber. It finds legiti- 
 mate application in researches on the sense of place, time, 
 the area of consciousness, &c. 
 
 On what condition, then, can Weber's principle of meas- 
 urement be applied to the law of Fechner ? This reduc- 
 tion is possible " only when the differences of sensation 
 compared belong to changes taking place in constant 
 conditions of space and time, and in a series belonging to 
 one and the same sense." This induction supposes, more- 
 over, that "the state of attention being constant, equal 
 changes in perception respond to equal changes in its 
 cause." 
 
 These considerations afford an answer to this question : 
 what relation does the law of Weber sustain to that of 
 Fechner? The law of Weber does not relate to sensation 
 
180 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ^I!t 
 
 
 itself, but to the manner in which we experience it ; it is 
 not a law of sensation, but of perception. The law of 
 Fechner, on the contrary, is characteristically a law of sen- 
 sation. Strictly speaking, therefore, we cannot say that 
 the law of Weber is the same as that of Fechner : for this 
 is to ignore absolutely the process of sensation, considered 
 independently of apperception.^ 
 
 We have given only a very summary view of the 
 criticisms which have been addressed to Fechner, neglecting 
 objections to details, and giving only the essential points. 
 A complete exposition would fill a large volume.^ 
 
 In replying to them, the founder of psychophysics yields 
 only in points of detail, and, trusting in the durability 
 of his work, closes with a Nachwort like this ; it is very 
 good : 
 
 " The tower of Babel was not finished because the 
 workmen could not agree as to the method of constructing 
 it ; my psycho-physical monument will remain, because the 
 workmen cannot agree as to the method of destroying it."^ 
 
 Yet Fechner has this confidence all to himself, for, ac- 
 cording to the remark of M. Delbœuf, "though he has 
 many admirers, there are few adepts — and he has against 
 him both his declared adversaries and his more or less 
 faithful disciples." 
 
 If we attempt, from all these criticisms, general and par- 
 tial, to gather some conclusions, the first that arises is that the 
 law of Fechner seems rather to be a physical law. Accord- 
 
 ' In regard to apperception, we can only refer to what the author 
 says in his Physiolog. Psychologie, 2d edition, p. 351, etc., and to chapter 
 VI. below. 
 
 '■' The most recent and complete is by G. E. Miiller, Zur Grundlegung 
 der Psychophysik: kritische Beitrdge, Berlin, 1878, 440 pp. in 8vo. See 
 also the critical study of F. A. Miiller : Das Axiom der Psychophysik, 
 Marburg, 1882. 
 
 ^ In Sachen der Psychophysik, p. 215. 
 
FECHNER AND PSYCHOPHYSICS. 181 
 
 ing to an hypothesis of which we have hitherto said 
 nothing, but to which our author attaches the utmost im- 
 portance, between ^he excitation, a fact entirely external, 
 and the sensation, a fact entirely internal, "an internal 
 physical activity " must be intercalated, to which the 
 name psycho-physical movement is given. Fechner affirms 
 very clearly {Elemente der Psychophysik, vol. II, p. 377, 
 etc.), that it is impossible to know the nature of this psy- 
 cho-physical movement. But that matters little ; in physics, 
 we do not know the nature of electricity, but this does not 
 hinder the progress of the science of electrical phenomena. 
 In truth, this hypothesis of Fechner has only one object : 
 to explain the fact that the sensation is not proportional to 
 the excitation. In its relation to the external, psycho-phys- 
 ical force would conform to the universal principle of the 
 proportion of cause and effect. In its relation to the inter- 
 nal, it would be subjected to a certain law of progression. 
 Like all the metaphysical solutions of nature in its two- 
 foldness, this explains none of the difficulties; so it has 
 been universally condemned. 
 
 This psycho-physical tertium quid rejected, the effect is 
 placed beside its cause, the sensation beside the excitation, 
 and as, in most cases, there is a manifest disproportion be- 
 tween the growing intensity of the one and the other, it 
 must be attributed to the physical expenditure of which 
 we have spoken above. The law thus takes on a physical 
 character. The experiments of Dev/ar and Mackendrick, 
 published in the Transactions of the Royal Society of Edin- 
 burgh (1873),^ relative to the physiological action of light, 
 afford, moreover, strong presumption in favor of this mode 
 of interpretation. According to these researches, the in- 
 tensity of the nerve current transmitted by the optic nerve 
 
 ^ See also Fechner, In Sachen, etc., p. 275, etc., and Mind, No. IV, p. 
 463. 
 
 16 
 
182 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 to the brain is proportional to the logarithm of the exci- 
 tation of the retina. Here is " a concordance, as the ex- 
 perimenters point out, with the law of Fechner which 
 cannot be regarded as accidental." 
 
 But if this law has a physical character, has it no inter- 
 est for psychology ? This conclusion seems inadmissible. 
 The study of perception is of capital importance; it is 
 perhaps the key to all the rest. If we are to be limited, 
 as the "internal" psychologists say, to the study of the 
 fact of consciousness alone, then the psycliology of percep- 
 tion would be very brief, and would contain about as many 
 errors as truths ; for the consciousness of the adult mis- 
 takes fatally mediate knowledge for immediate, and ac- 
 quired for innate. Objective experiment is indispensable 
 here. Only the study of the physical conditions of percep- 
 tion can give its precise nature. The fact of conscious- 
 ness reduced to itself, disengaged from its setting of material 
 conditions, would remain so abstract, so vague, that it 
 could be no longer distinguished from some of the states 
 of consciousness, for example, from memory. It is only by 
 an illegitimate process that a separation can be established 
 between elements that reciprocally imply and suppose each 
 other. All the results of the experimental sciences have 
 not indeed equal importance for the psychological theory 
 of perception, although there is perhaps not one that is 
 entirely without value ; but the facts brought to light by 
 psychophysics can be numbered among those that con- 
 tribute most. 
 
 Wundt, who has recently declared for the psychic nature 
 of the law, sees in it " the mathematical expression of a 
 logical phenomenon." According to a theory of his own 
 to be explained elsewhere, all the activity of thought (con- 
 scious or unconscious) can be reduced to a logical pro- 
 cess, — to inference. In this case, the logical process takes 
 a more definite mathematical form. A more certain inter- 
 
 ! 
 
FECHNER AND PSYCHOPHYSÎCS, 183 
 
 pretation than this is that the psycho-physical law is a new 
 proof of the relative character of our knowledge. It 
 shows that in sensation we have no measure of absolute 
 magnitudes, that to perceive two sensations is in reality to 
 perceive a difference between two sensations. 
 
 This law, whatever its nature be, conducts also to another 
 result that is worth attention. During the last century, the 
 great eifort of the analytical psychology has been to show 
 that, contrary to the prejudgments of common sense, per- 
 ception does not give a copy of the external world. Be- 
 tween qualities in the object and states of consciousness in 
 the subject, there is only a correspondence ; these qualities 
 are signs that the mind interprets and groups after its own 
 nature. The psycho-physical law shows that this is true 
 also in the order of quantity. It teaches that there is no 
 equality or equivalence between variations of objective in- 
 tensity (excitation), and variations of -subjective intensity 
 (sensation) ; that our knowledge consists still in an inter- 
 pretation only, made by the mind in accordance with its 
 nature. So Fechner appears to have inaugurated in the 
 quantitative study of perceptions, a line of work analogous 
 to that which, after Locke, Hume and Berkeley pursued 
 in their qualitative study, and to have arrived at results 
 analogous to theirs. 
 
 We have little to add to this general exposition of Fech- 
 ner's law and its nature. The preceding criticisms, when 
 brought together, are : 
 
 1st. That under its mathematical form it cannot be 
 accepted ; 
 
 2d. Observation and experiment show that, generally 
 speaking, sensation grows more slowly than excitation ; 
 
 3d. Though it be verified, within certain limits, for 
 visual and auditory sensations, it is contested for pressure, 
 and does not hold for the other sensations. 
 
 To every question as to the value of the law of Fechner, 
 
::l! 
 
 184 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 it may be replied roughly : it is the result of work so far 
 done, and for the present, no definite judgment is possible. 
 ;| Whatever become of the work of Fechner, his will remain 
 
 the glory of having put in new form the old question of the 
 relation of the physical and the mental, and of having 
 brought out, like every original spirit, among his adver- 
 saries and admirers, works of verification and investigation, 
 efforts, attempts in all directions, which will not have been 
 made in vain. 
 
 ADDITIONAL NOTE. 
 
 The possibility of measuring psychic facts (not their dura- 
 tion; this will be spoken of later in the volume) having 
 raised many objections, as we have seen, it will not be with- 
 out profit to look at a recent article of Wundt's, written in 
 reply to the criticisms of Zeller on this subject (Philosoph- 
 ische Studien ; Heft. 2, p. 251 and fol.). 
 
 Under this title, psychic measurements, E. Zeller read 
 March 3d, 1881, before the Academy of Sciences at Berlin, 
 an article in which he discussed the question whether psych- 
 ical facts are capable of measurement, and, if so, under what 
 conditions. He reaches, on the whole, a negative result, 
 although in the end he recognizes the psychological import- 
 ance of Weber's law, which rests, nevertheless, upon such 
 measurement. 
 
 Zeller is disposed to relate the law of Weber to the gen- 
 eral principle of the relativity of psychic states, realized 
 particularly in the domain of sensibility (including the feel- 
 ings). 
 
 The objections of Zeller, says Wundt, to the idea of the 
 measurement of psychic phenomena, can be reduced to two 
 points, one of which is, as it were, speculative, and the other 
 empirical. They are these : Psychic facts are not measur- 
 able : 1st. Because every attempt to measure them contradicts 
 the conditions that all measurement must fulfill ; 2d. Be- 
 
FECHNER AND PSYCHOPHYSICS. 185 
 
 cause, in fact, all attempts to do this have failed. Let us 
 examine these two points. 
 
 Psycliic facts, sgys Zeller, are known to us only through 
 consciousness ; they can then be compared only with and 
 measured only by other facts of consciousness. But what 
 unit of measure is to be employed ? When we compare two 
 states of consciousness, the first is the standard to which we 
 refer the second. Every attempt at measurement gives only 
 a determination of a relation that is always variable and in- 
 capable of numerical expression. When we say, for exam- 
 ple, that we have been well amused, we express ourselves 
 through the memory of the way in which we are ordinarily 
 amused. But there is no possible reply to the question : 
 How much does one amusement surpass another ? Further, 
 all changes in nature are movements, simpk or in groups, 
 and are, as such, reducible to space magnitudes, that is, to 
 irreducible elements ; but since the facts of consciousness 
 are not reducible to movement they are not reducible to 
 measurement. 
 
 With similar reasoning, says Wundt, we might maintain 
 from a philosophic point of view that all external natural 
 phenomena are not measurable : and yet it is upon such 
 measurement that physics and mechanics rest. We might 
 say with reasoning similar to Zeller's : Every phenomenon 
 is measurable only by a similar phenomenon. Sensation is 
 our only means of knowing the external world. Sensation 
 is a state of consciousness differing wholly from mechanical 
 movement. Therefore every attempt at measurement is an 
 illusion. 
 
 These two arguments rest in the same sophism. They 
 are a part of the fiction that there is a world within us and 
 a world without us, and that these two worlds meet at their 
 limits, but have nothing in common. Purely fiction, since 
 the external world is made up of representations to which 
 we attribute an external value ; and the internal world is 
 
186 
 
 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 made up of the same representations with their subjective, 
 changing conditions, of feeling, and accompanying volition. 
 The physicist can then reply in all security : Physics seeks 
 to measure objective representations by objective represen- 
 tations; it measures like by like. The psychologist 
 can reply in like manner : Psychology seeks to measure 
 representations by representations, and, if it measures purely 
 subjective representations by objective representations, the 
 latter do not cease for all that to be representations, and 
 consequently there is still a sufficient sameness between the 
 objects measured. 
 
 We now reach the second position of Zeller. It can be 
 stated in two points : 1st. No absolute measurement can 
 be reached in the domain of psychic facts ; ""only relative 
 measurements can be determined ; 2d. These latter cannot 
 be formulated in numbers, and consequently they also are 
 impossible. 
 
 No psychologist flatters himself that he can establish 
 absolute constants in his science, like the constants of weight, 
 electro-static and electro-dynamic units, etc. Psychological 
 facts are too complicated for this. But even admitting that 
 the absolute measurement of a psychic fact can never be pos- 
 sible, still the possibility of a numerical measurement will not 
 be excluded. Zeller himself acknowledges this in a certain 
 sphere, sensation, when he remarks that the law of Weber 
 exhibits a measurement of psychic states which is entirely 
 relative. But the law of Weber was not discovered by 
 philosophical speculation or internal observation, but by 
 experimental measurement, and is itself expressed in num- 
 ber. How can Zeller be reconciled with himself, when he 
 not only accepts this law, but extends it throughout the 
 whole domain of sensibility ? 
 
 Moreover, he adds, all measurement of this kind pertains 
 only to the intensity of sensation. The quality has hitherto 
 remained inaccessible, and always will remain so. The only 
 
FECHNER AND PSYCHOPHYSICS. 187 
 
 exception is the calculation of musical intervals, which 
 are based upon qualitative marks. This reasoning, replies 
 Y/undt, is not cle^r : We must understand, by the " meas- 
 urement of psychic facts" either an immediate tendency of 
 consciousness to compare its states in view of measurement, 
 and then the case cited is an example, in whatever the differ- 
 ence of musical intervals consists ; or an experimental pro- 
 cess, and in this case the theories of which Zeller speaks are 
 based upon results arrived at by processes of measurement. 
 So it is entirely erroneous to maintain that these processes are 
 not applicable to other sensible qualities, for example, sen- 
 sations of color. 
 
 Zeller has not seen fit to speak of the investigations 
 relating to the complex processes of perception. Yet here 
 also, as in the case of elementary psychic facts, the question 
 of measurement is agitated. In the theory of vision, for ex- 
 ample, investigations of the relation of the smallest move- 
 ments of the eye to the acuteness of vision, of errors in the 
 estimation of distance and direction, of the quantitative 
 conditions of visual illusion, are important. Yet all these 
 are psychic facts : and the investigation of the quantitative 
 changes that these phenomena undergo through the varia- 
 tion of these objective conditions requires, as Weber's law 
 requires, the employment of measurement in the domain 
 of psychic fact. 
 
CHAPTER VI. 
 
 WUNDT. 
 
 Physiological Psychology. 
 
 I. 
 
 WuNDT is considered, at the present time, the principal 
 representative of experimental psychology in Germany. 
 He alone has treated it in all its area. Fechner, though 
 his work was so original, was confined to a single question ; 
 Lotze was essentially a metaphysician and often seemed to 
 enter the domain of experience by necessity and mth regret ; 
 Helmholtz, despite the great value of his analysis of 
 elementary sensation, is a psychologist only on occasion ; 
 and others, who are following in Wundt's footsteps, are 
 still far behind and can not overtake him. He alone has 
 made a complete and systematic study of the problems of 
 psychology from this standpoint. 
 
 In 1862, in his Beitrage zur Théorie der Sinneswahrneh- 
 mung (contributions to a theory of sense perception), he 
 studied, in the form of monographs, many questions relat- 
 ing to the physiology of the senses, of sight in particular. 
 Since then his publications have treated either of pure 
 physiology, as the Medicalische Physik, the Lehrhuch d. 
 Physiologie d. Menschen, and the Untersuchungen zur Me- 
 chanik der Nerven u. Nervencentren (1871—1876), or of phys- 
 iological psychology, as Vorlesungen uber die Menschen u, 
 188 
 
WUNDT. 189 
 
 Thiei^seele (1863), and especially the Grundzilge der physio- 
 logischen Psychologie (2d éd., 1880)/ 
 
 The unity of his work arises from his method. It is 
 based on the data of physiology : directly it deals with sen- 
 sation considered distinctly as the basis of all psychology 
 and the food of the mental life, and, further, with involuntary 
 movement, language, the lower forms of feeling and their 
 natural expression ; indirectly, it deals with the will, atten- 
 tion, complex notions of space and time, the sesthetic 
 feelings. Where physiology fails, anthropology, ethno- 
 graphy, history, statistics, afford a foundation. In short it 
 differs in toto from both the speculative method and its near 
 relative, the method of internal observation. 
 
 Psychology must be treated, then, as a natural science : 
 for this it must be exact. " More than once in late years," 
 says Wundt, " has psychology been treated from the point of 
 view peculiar to the natural sciences, but we must admit 
 that these attempts have made no real progress on earlier 
 speculative systems. For psychology, even when considered 
 as a natural science, has looked to internal observation as its 
 only help. Now nothing has been added since man first 
 began to think and reflect, to the facts of consciousness 
 found by observation in the bosom of every one ; the science 
 has added little to the familiar experience of the whole 
 world. Thanks to this method, psychology has remained 
 for centuries the same ; what is scientific in it can scarcely 
 be separated from ordinary experience." ^ 
 
 The first object to be desired is the transformation of 
 psychology into an explicative science. If we examine the 
 earlier or even the actual state of the sciences of the 
 phenomena of nature, we find that some simply describe, 
 
 ^ Wundt has also published a Logik, a large work in two volumes, and 
 many memoirs on psychological questions, of which we will speak inci- 
 dentally. (None of these have been translated into English. — ^Tr.) 
 
 * Menschen u. Thierseele, I, Vorrede, p. 5. 
 
190 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 while others explain. The more a science is advanced, the 
 less it describes : or, at least, the less it confuses description 
 and explanation. " Thus most of the works of empirical 
 psychology belong to the natural history of the soul. The 
 recent profound studies in the psychological interpretation 
 of history and ethnography belong in the same category, 
 though in a larger sense. For the psychology of peoples 
 'II Ij deals with phenomena so complex, that they can be ex- 
 
 plained only by the facts and laws of the individual con- 
 sciousness. Here, above all, is a work of classification of a 
 peculiarly descriptive kind." ^ 
 
 Wundt, on the contrary, proposes a work of explication. 
 To do this, it is necessary to add experiment to the internal 
 observation which, alone, gives description only ; and with 
 this measurement must also be employed. This is the object 
 of physiological psychology. It starts with physiological 
 facts and seeks to discover the elementary psychological 
 facts which are connected with them. Our point of view, 
 says Wundt, is not that of internal experience. We begin, 
 on the contrary, without and seek to penetrate within : and 
 to do this we employ means altogether peculiar to natural 
 science, i. e., the experimental method. In truth, this 
 method can be employed only in the domain of psycho- 
 physics ; or more exactly, it employs experiments that are 
 psycho-physical and not purely psychological. Yet, as this 
 method consists in varying the external conditions that are 
 necessary to the production of internal phenomena, it 
 follows that we have in this a doorway to internal phenom- 
 ena. In this sense, every psycho-physical experiment is at 
 the same time a psychological experiment, and within these 
 limits experimental psychology is possible. Thus the end 
 is to construct psychology ; physiology is but the means. 
 This is the meaning of the term physiological psychology. 
 
 ^ Physiolog. Psychol., Introd., p. 5. All quotations are made from the 
 second German edition. 
 
WUKDT. 191 
 
 Further, we will allow the author to explain the course 
 which he intends to pursue : 
 
 " When we ent^r a little further into the question, we 
 see that the traditional opinion that consciousness is the 
 entire field of the internal life can not be accepted. Every- 
 where in nature, the object of all immediate observation is 
 phenomenal and complex : the laws by whose action the 
 phenomenon is realized, remain hidden from our sight. Is 
 psychology the one exception ? Must we admit that psy- 
 chic laws are within the reach of immediate perception ? 
 What, then, are the reciprocal relations of these laws ? In 
 consciousness, psychic acts are very distinct from one 
 another : desire, feeling, sensation, idea, are given us as 
 distinct modes of activity. Must we give to each of these 
 activities a separate sphere ? This is the current doctrine 
 of fundamental faculties of the soul. But a science is still 
 in its infancy, whose task is simply to show differences 
 among the objects of its analysis. The full-grown science 
 tends to unity. And observation itself necessarily con- 
 ducts to unity in psychology. But the agent of this unity is 
 outside of consciousness, which knows only the results of 
 the work done in the unknown laboratory beneath it. Sud- 
 denly a new thought springs into being : we know not 
 whence it comes, for the conditions which produced it have 
 already disappeared. Ultimate analysis of psychical pro- 
 cesses shows that the unconscious is the theatre of the most 
 important mental phenomena. The conscious is always 
 conditioned upon the unconscious. 
 
 " How can we descend into this secret laboratory where 
 thought has its hidden spring ? How separate the thousand 
 threads that make its tissue ? The investigations that follow 
 are intended to show that experiment is, in psychology, the 
 necessary guide to the hidden foundation where the con- 
 scious life has its rise. Internal observation, as observation 
 in general, gives only complex phenomena. By experiment, 
 
192 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 on the contrary, we strip the phenomenon of all its acces- 
 sory conditions. The phenomenon is produced artificially, 
 in given conditions, which we can change at will, and 
 measure. Everywhere and ahvays, experiment conducts to 
 natural law, because it exhibits cause and effect simulta- 
 neously. 
 
 The naturalist begins with the observation of phenomena 
 given immediately in nature : the psychologist begins, in 
 the same way, with the facts of consciousness. When, by 
 this means, he has resolved psychological phenomena into 
 simple elements, he casts a sly glance also upon the mech.an- 
 ism that elaborates, in the unconscious depths of the soul, 
 the impulses derived from external impressions. The nat- 
 uralist pursues the same path. When from the entangled 
 phenomena which observation gives he rises to the laws 
 that rule them, he reaches evidently the hitherto unknown 
 foundation of these facts. The process below consciousness 
 whence the conscious act proceeds, bears the same relation 
 to this act as the concealed law bears to the phenomenon 
 given in sensation. 
 
 " Experiment is accompanied by measuremeyd, step by step. 
 Weight and measure are the great instruments of experi- 
 mental research, and are always employed in the search for 
 exact laws. With experiment, weight and measure enter 
 into the science : for they give it a definite character. Meas- 
 urement reveals the constants of nature, the laws that reg- 
 ulate phenomena. The results of ail measurement are 
 expressed in number. Numbers are not the object of 
 measure ; but they are the indispensable means of arriving 
 at its true object, for only numbers can reveal law. 
 
 "But, it will be asked, how is it possible to apply experi- 
 ment to the psychic principle which is entirely distinct from 
 sensation? The principal cause of the phenomenon es- 
 capes sense ; so experiment reaches the phenomenon only. 
 Although the effects and conditions of the psychic life alone 
 
WUNDT — SENSATION. 193 
 
 are accessible to our investigation, yet these effects and con- 
 ditions, if they are sufficiently analyzed, bring us to the ulti- 
 mate essence of the faftts which constitute the psychic life. By 
 the senses and by movement of the body the soul sustains a 
 continual relation to the external world. We can apply ex- 
 ternal agents to the senses and produce movement at will, 
 observe the effects, and from these effects draw conclusions as 
 to the nature of the psychic processes. Our measurements 
 never apply directly either to the efficient causes of the 
 phenomena, or to the efficient causes of the movements : 
 we can measure iliem only by their ejects." ^ 
 
 II. 
 
 SENSATION. 
 
 The author has treated of the anatomy and physiology 
 of the nerve system at length, and collected in some 
 detail^ the most recent views on this subject. He falls 
 back upon the work of Meynert, and shows that the anat- 
 omy of the spinal cord, medulla oblongata, protuberance, 
 peduncles, cerebrum and cerebellum, reveals the psycho- 
 logical functions of these different organs, and indicates the 
 difficulties to be met at every turn of this subject. 
 
 With the study of sensation, he enters into the subject 
 proper : " If we begin with tlie study of the simplest psy- 
 chological phenomena, we must confess that their ultimate 
 elements always escape our observation, or are found con- 
 nected with other phenomena. Yet of them all, pure 
 sensation certainly presents the greatest simplicity. By this 
 we mean the primitive states which man finds in himself, 
 isolated from all the relations and connections that the 
 adult consciousness gathers round them." Sensation must 
 be distinguished thus from perception, a phenomenon which 
 is much more complex, and which must be studied apart. 
 
 * Menschen u. Thierseele. Preface. ' Grundziige, I, pp. 19-264. 
 
 17 
 
194 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 Placed in this degree of isolation, sensation presents two 
 immediate determinations only : 
 
 1st. It is strong or feeble ; it has a certain intensity. 
 
 2d. It has a characteristic mark, which differences it from 
 everything else ; it has a certain quality. 
 
 3d. Finally, it has a third characteristic, less clear than 
 the two others. In a real sensation, there is something 
 which belongs to the thinking subject : a secondary state ac- 
 companying the primitive sensation, which may be called a 
 feeling. Especially in sight and hearing do we notice these 
 concomitant feelings. They are the elementary factors of 
 the aesthetic effect. They exist also in touch, taste and 
 smell. Tbis is the tone of the sensation.^ 
 
 The two first mentioned are primitive elements : if we 
 suppress them, the third disappears. 
 
 Intensity. — We will not take this question up again, 
 as it has been already discussed at length under the psycho- 
 physical law. 
 
 Quality. — By quality, we understand the element of 
 sensation that remains if we suppose the intensity sup- 
 pressed. Under relations of quality, sensations may be 
 divided into two great classes : 
 
 1st. Sensations qualitatively uniform, presenting owe de- 
 termined quality, but having all possible degrees of inten- 
 sity. Such are the organic sensations, the cutaneous sensa- 
 tions (pressure, heat and cold), and the muscular sensations. 
 The last are further divided into two classes : sensations 
 of innervation, *. e., of the expenditure of muscular force 
 in movement ; muscular sensations proper, caused by the 
 state of nutrition, fatigue or lesion of the muscles. 
 
 2d. Sensations qualitatively different ; those of the four 
 special senses : hearing, sight, taste, smell. Each species is 
 made up of a combination of different qualities, of which 
 each may have different degrees of intensity. 
 ^ German, Gefiililston — Tr. 
 
WUXDT — SENSATION. 195 
 
 We may suppose that qualitative differences depend im- 
 mediately upon dilfereuces of structure. In this connec- 
 tion, Wuudt enterg into the histological study of the 
 terminal sense organs : for smell, the olfactory cells be- 
 tween the epithelial cells that line the mucous membrane 
 of the nose ; for taste, the calicular, fungiform, and fili- 
 form cells ; for sight, the different coatings of the retina ; 
 for hearing, the fibres of Corti ; for touch, the corpuscles 
 of Pacini, Meissner, and Krause. 
 
 The excitation, acting upon these terminal organs, gives 
 rise to a movement which ls transmitted to the nerve centres. 
 But this is done in two distinct ways. In the mechanical 
 senses (touch and hearing), the external excitation is trans- 
 mitted in the nerve substance iu a way very probably 
 peculiar to itself, and by a process that corresponds, in 
 general, to that of the exciting movement. In the chemical 
 senses (sight, taste, smell, temperature), the external exci- 
 tation gives rise to a nerve phenomenon entirely different 
 from itself, both in its form and its process ; although, 
 within certain limits, it changes according to the variations 
 of the excitant. In the first case, there is a direct trans- 
 mission of the external movement. In the second, the 
 excitation produces a fact of a different nature, probably a 
 chemical molecular movement. Thus it may be said that 
 the excitation is felt more immediately in the first than 
 in the second case ; in the latter, the form of the excitation 
 depending, in the highest degree, upon the molecular con- 
 stitution of the nerves, which is unknown. The mechani- 
 cal senses are evidently the simpler ; and the most general 
 of all, touch, serves probably as basis for the development 
 of the four special senses. 
 
 Wundt places sight among the chemical senses, though 
 recoo-nizing the difficulties which this classification involves : 
 he explains iu detail the reasons which lead him to put this 
 sense with taste and smell. From the first, the excitation 
 
 ^ 
 
196 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 is changed in the retina to another form of movement. 
 " We can not at once define the transformation that takes 
 place here, but it seems proper to call it a chemical action. 
 On this supposition, we can account for the easy chemical 
 decomposition of the nerve substance and the chemical 
 action of light in general. In the lower forms of the 
 organ of vision, the photo-chemical action seems to be fol- 
 lowed by the absorption of the most refrangible luminous 
 rays. These lower forms consist of nerve fibres in con- 
 nection with epithelial cells containing a red pigment. 
 The same process of absorption takes place in the retina 
 of birds, since we find inside the cones touches of red and 
 green pigment." It is to be remarked also that the diver- 
 sity in sensations of light cannot be explained by the 
 simple differences of degree in the action of different 
 luminous rays upon the retina : instead of different colors, 
 we would see different degrees of light intensity only. 
 There must be then other differences in the chemical effects 
 of luminous excitations, differences whose nature we can 
 not determine. Further, sight presents this remarkable 
 property, that all diflfei-ences in the form of the excitation 
 disappear when it is very strong or very feeble ; luminous 
 excitations of all kinds are perceived as black if they are very 
 feeble, as white, if very strong. Only medium intensities 
 produce clear photo-chemical action. And differences of 
 photo-chemical action answer to differences of sensation, as 
 each species of ray acts in a different way upon the chemical 
 combinations of the nerve substance. 
 
 Another question, of very general import and much 
 discussed, is that of specific nerve energy. It offers a special 
 philosophic interest, since it has been brought forward by 
 many writers as the physiological expression of Kant's 
 doctrine of the subjectivity of knowledge. If we admit 
 the theory of specific nerve energv, the quality of the 
 sensation becomes a function of the substance of the 
 
WUNDT — SENSATION. 197 
 
 given sensor nerve. When we have sensations of light, 
 sound, heat, &c., it is not the external impression that is 
 reported to consciousness, but the reaction of the sensor 
 nerve upon this impression. This doctrine rests upon 
 the fact that each nerve is sensitive to certain determined 
 excitations only (the optic nerve to light, the acoustic to 
 sound, &c.) ; and that if we employ an excitant of a general 
 character (electricity, <fec.) each nerve reacts in its own 
 specific form. 
 
 There are several difficulties in the way of this solution, 
 and one of them is capital. This is the functional indiffer- 
 ence of the nerves. To avoid it, specific energy is attributed 
 exclusively to the terminal organs and brain. The nerve 
 fibres, to cite a comparison mucli used, are like telegraph 
 wires, which produce very different effects (ring a bell, move 
 a magnet, &c.) according to the point with which they 
 connect. Yet since the terminal organs have simply a 
 power of transmission through the nerves, and this does 
 not give rise to sensation, it is the brain distinctly to which 
 the specific energies are to be attributed. Moreover, if 
 indeed we allow the terminal organs a part in the phenom- 
 enon, still the internal differences that arise as signs answer- 
 ing to peripheral differences must be located in the nerve 
 centres, since the specific sensations come into being even 
 after the ablation of the sense organs. There are reasons 
 for extending to the central terminations of the nerves the 
 principle of functional indifference. The differences they 
 present are certainly not as great as those of nerves of 
 different kinds, and yet these, as experiment shows, can be 
 indifferently motor or sensor. It is then a subterfuge 
 merely to make the nerve centres the seat of specific func- 
 tions ; for these centres are not well known and one can say 
 of them what he please. 
 
 The difficulties that this doctrine encounters are greater 
 still, if we attempt to explain by it the qualitative differ- 
 
198 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ences of sensation in one and the same sense. Let us take 
 sight. According to the hypothesis of Young, adopted 
 and modified by Hehuholtz, there are three kinds of nerves, 
 sensitive to red, green, and violet light. But since a lumi- 
 nous impression is confined to an extremely small point, and 
 never has a definite color in perception, it must be main- 
 tained that there is an intermingling of these three kinds 
 of nerves on very small portions of the retina : an hypo- 
 thesis difficult to believe considering the diameter of the 
 rods. Each seems to have only a single fibre. With sen- 
 sations of sound, the difficulties are still greater. 
 
 The two ways in which excitations undergo change in the 
 nerves may be represented in a general manner. In the one 
 case the nature of the molecular phenomena does not 
 change, while the periodic vibrations increase and decrease 
 in amplitude (sound). In the other case, the nature of the 
 molecular phenomena does change, according to the kind 
 of excitation (chemical senses). In the two cases it is 
 admitted that the molecular phenomenon is transmitted just 
 as it enters, throughout the entire nerve, to the brain ; that 
 the processes in the central cells are different, and through 
 them different sensations are reported to consciousness. 
 This is the only way to accord the fact of functional differ- 
 ence in the organs with the principle of functional indiffer- 
 ence in the elements. On this hypothesis the nerve elements 
 have no longer specific functions, for every change in the 
 nature of the molecular phenomenon arises from the manner 
 in which the elements come in contact among themselves, 
 and in the organs of sense, with the external excitation. 
 
 " The point that essentially distinguishes the hypothesis 
 of specific energy from the foregoing is this, that the former 
 supposes the sensation to be determined exclusively by the 
 parts over which the excitation runs, while to us the 
 form of the phenomenon is the immediate ground of the 
 form of the sensation. It is hardly necessary to show 
 
WUNDT PERCEPTION. 199 
 
 that this opinion, even from a psychological point of view, 
 is more reasonable. It can indeed be maintained that 
 consciousness is determined qualitatively by the nature of 
 our organic processes ; but that these qualitative differences 
 are connected with local differences of process alone, is very 
 difl&cult to conceive." 
 
 The theory of specific energies, as Wundt remarks, is a 
 physiological echo of the philosophy of Kant, of his 
 attempt to determine the subjective conditions of knowl- 
 edge : this is very clearly shown also by J. Miiller, one of 
 the principal representatives of this theory, in his Elements 
 of Physiology. But there is no bond of logical necessity 
 between the two doctrines ; and the purely subjective view 
 of the nature of sensation leaves the field free as to its 
 physiological foundation. It is evident also that the discusr- 
 sion of this theoretical point does not involve the estab- 
 lished relation of sensation to external excitation.^ 
 
 It still remains to speak of the feeling that accompanies 
 sensation ; but this question will be postponed until we 
 treat of feeling in general. 
 
 III. 
 
 PERCEPTION. 
 
 Sensation is the content of representation. Compared 
 with sensation, representation is a complex fact ; sensations 
 are its constituent elements and it results from their com- 
 bination. A representation that relates to a real object is 
 called a perception. If it relates simply to an object in 
 thought it is a concept of tlie imagination. Only the first 
 engages our attention. 
 
 ^ Wundt explains at length the facts and physiological problems that 
 belong to hearing, considered as type of the mechanical senses and to 
 sight as type of the chemical. He also has a very interesting criticism 
 of Young's hypothesis of three primitive colors, vol. I, p. 640, &c. 
 
200 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 It would be impossible for us to follow Wundt iu his 
 long study of tactile, auditory, and visual perception, 
 conducted as it is on his method and involving many 
 physiological results. We will only attempt to expound a 
 single point, that in which he is most original ; the answer 
 to this question : How are our tactile and visual percep- 
 tions localized in space ? 
 
 We have seen that there are two theories on this point 
 in Germany : those of innateness and experience. Wundt 
 adopts neither the one nor the other. 
 
 Neither of these theories, says he, is sufficient. The 
 theory of innateness maintains with reason that anatomical 
 dispositions are of the first importance, that experience 
 exerts only a very narrow influence, that variableness, 
 indeed, finds its cause in the physical organism. But it is 
 too hasty in drawing the conclusion that since the condi- 
 tions are innate, the perception of place is innate also. 
 Nor can we refuse to accord, with the empiricist, a very 
 large function to experience ; but there is no proof that the 
 perception of place arises from it alone. If we attempt, 
 by a sort of eclecticism, to unite the two theories, we com- 
 mit at least a new error, since, if we maintain that the per- 
 ception of space is given to a fixed degree, we must still 
 maintain that experience determines it. If we intrench 
 ourselves in the hypothesis of an entirely indeterminate local- 
 ization, related to real space only in experience, we place our- 
 selves in manifest contradiction with the very idea of local- 
 ization, since this implies relation to definite points in space. 
 
 The theory of Wundt, as we have already indicated it^ 
 and are now about to expound it in detail, can be summed 
 up at the outset thus : Each point of the skin (in touch), 
 each point of the retina (in sight), has a local sign, a pecu- 
 liar and especial kind of sensitiveness to impressions : this 
 is the beginning of localization. Further, these different 
 impressions are accompanied by movements, and con- 
 
WUNDT PERCEPTION. 201 
 
 sequently by a certain feeling of innervation, varying accord- 
 ing to the member and place affected. Neither local impres- 
 sions alone, nor movements alone, can give localization in 
 space ; but these two elements, united by a sort of mental 
 chemistry, by a psychological synthesis, form a combination 
 which is nothing other than the notion of space. 
 
 Let us first examine touch on this hypothesis. 
 
 Sensations of touch, pressure, and even of temperature, 
 are referred to points of the skin. But this localization is 
 not always made with the same degree of precision. 
 
 Weber first brought exact and minute research to bear 
 upon this point. It has been continued since. By employ- 
 ing the two methods, of smallest perceptible differences and 
 true and false cases, the relative delicacy of the sense of 
 place in different parts of the body has been determined. 
 
 Moreover, it is easy to show that the skin is not equally 
 sensitive in all its parts. If we touch the cheeks and then 
 the palm of the hand with one finger, exerting each time 
 the same pressure, the sensation seems, notwithstanding, 
 different in the two cases. It is the same if we compare 
 the palm and the back of the hand, the chest and the back, — 
 in a word, any two parts of the skin distant from each other. 
 
 And we find, on close observation, that two points nearer 
 together on the epidermis, still differ as to the nature 
 of the sensation produced. If we pass from one point of 
 the skin to another, we find that there is a successive and 
 continued change in the sensation, although the external 
 pressure remains constant. Sensations produced at cor- 
 responding points of the two halves of the body, although 
 analogous, are no nearer alike. And we can not believe that 
 these differences come simply from our representing the 
 sensations compared as produced at different points. ISTo : 
 proceeding with great attention and considering the nature 
 of the sensation only, independently of all consideration of 
 place, we find the difference as great as before. It is admit- 
 
202 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ted, theu, that each part of the skin has a determinetl local 
 characteristic, which gives to the seusation a quality due to 
 the place at Avhich the impression is jwoduced. The quality 
 of this local characteristic varies from one point of the skin 
 to another, in a continuous manner, and in such a way that 
 Ave perceive these differences only when the distances are 
 sufficiently great. If the external impression is intense 
 (yet within the limits of the painful), the local characteristic 
 is very clear. It is admitted also, as has been indicated, 
 that symmetrical parts of the body have local characteristics 
 that are very analogous, but not identical. This hypothesis 
 rests on evident analogies in anatomical structure and on 
 other physiological facts. 
 
 The local cause of these differences of sensation must 
 reside in the peculiar nature of the sense organ, that is, in 
 small constitutional differences ; or in the disposition of the 
 nerve endings. The result is that we recognize the place 
 of an impression, provided we have already had experiences 
 at this point. 
 
 It remains to examine the second element in perception, 
 concomitant movement. Its influence is very great in the 
 direction of exactness of localization. The easier the move- 
 ment of the part of the body, whatever sense be affected, 
 the more precise is the localization. According to the in- 
 vestigations of Kottenkamp and Ullrich, the sense of place 
 decreases in delicacy continuously from the end of the fingers 
 to the hand, forearm, arm, shoulder. In the leg the 
 decrease is analogous. This has led Vierordt to formulate 
 the following principle, which he calls a law : When any 
 portion of the body moves as a whole, the delicacy of the 
 sense of place is always proportional to the distance from 
 the skin to the axis of movement.^ 
 
 ^For more details, see Vierordt, Die Abhangigkeit der Aushildung des 
 Raumsinnes der Haut von der Beweglichkeit der KorperiheUe, in the Zeii- 
 schrift fiir Biologie, VI, p. 53. 
 
WUNDT — PERCEPTION. 203 
 
 Finally, habit has yet a further influence on the exact- 
 ness of localization, as is seen in the case of those who are 
 born blind. Fatigue or a lowering of temperature makes 
 the sense less delicate. Diseases of the brain and spinal 
 cord modify or destroy it. A patient suiferiug from sesthesis 
 of the lower extremities felt in the upper part of the thigh 
 impressions made low down upon his leg or upon his foot. 
 
 The theory of tactile perception ought to explain the pro- 
 duction, in a given organization, according to psychological 
 laws, of an order of tactile sensations in space. All obser- 
 vations show that movement is a factor of the greatest 
 importance in this order of perception. Language itself, 
 for example the word " touch," implies movement of the 
 feeling parts. Such an influence of movement upon tactile 
 perception can arise only by means of the sensation of 
 motor innervation. 
 
 The feeling of innervation combines in all possible ways 
 with tactile sensations. Tactile sensations arising from 
 pressure upon the tissues of any part of the body are in- 
 variably associated with the movement of that part, and 
 there is a constant relation in degree of intensity between 
 the motor and tactile sensations. It is probable that the first 
 notion of place arises from this combination : it is the differ- 
 entiation of the parte of the body according to their situation 
 in space. The more easily these parts can be brought into 
 contact one ^vith another, the more clearly can they be dis- 
 tinguished one from another. 
 
 It is clear that when we distinguish the movement of 
 the arm from that of the head, it is by means of a qualita- 
 tive diflerence in the accompanying sensations. Further, 
 experiment shows that if the sensibility of the skin be 
 destroyed, the notion of the position of our limbs in space 
 is strangely altered, a fact that is explained by the close 
 connection of tactile sensation with the feeling of inner- 
 vation. 
 
204 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 According to a well-known psychological law, différent 
 sensations which are constantly associated form a whole so 
 complete, that if part of this whole be excited, the rest is 
 excited also. This law applies to the case before us. In 
 fact, tactile sensations and feelings of innervation form an 
 indissoluble whole. It may be said that we never experi- 
 ence tactile sensations alone, nor feelings of innervation 
 alone ; it is impossible to isolate either of them completely. 
 
 The process, then, in this case, is a psychic synthesis. " We 
 may understand by this expression, the especial combina- 
 tion of peripheral sensations, with feelings of central 
 innervation, whence results an order of first data in space.^ 
 For the idea of synthesis ordinarily has reference to new 
 properties in the product which were not present in the 
 constituent parts. Just as in the synthetic judgment a 
 new predicate is attached to the subject, and as a chemical 
 synthesis is a combination with new properties, so the psy- 
 chic synthesis gives, as a new product, an order of sensa- 
 tions in space." But psychological analysis can give only 
 the elements of this combination ; the order in space, as a 
 synthesis, is as foreign to our analysis as the properties of 
 water are to its analysis into oxygen and hydrogen. 
 
 "The local signs of the sense of touch present a con- 
 tinuity of two dimensions, from which it is possible to 
 arrive at the idea surface. But this continuity does not, 
 in itself, involve the notion of space. This latter, we 
 maintain, arises first from a relation of reaction upon the 
 simple continuity of the feelings of innervation. These 
 feelings, by their purely intensive variatfons, constitute a 
 uniform measure for the two dimensions of the local sigus. 
 The form of the surface in which these signs are arranged 
 is at first entirely indeterminate. It varies with the form 
 of the surface that is felt. But the laws of the movement 
 
 ' Hawrdiche Ordnung der ersteren ; Grundeiige, II, p. 28. 
 
 -Tr. 
 
WTJNDT — PERCEPTION. 205 
 
 of the members are sucli that, in most of the changes in 
 position, the organ of touch moves in a 7'ight line toward 
 or from its object. 6ince, then, the right line becomes a 
 determining element, tactile space has the form of plane 
 space, in which the surfaces which we perceive, and which 
 change as to their curvature, must be referred to three 
 right-line dimensions." ^ 
 
 The same question arises as to visual space, and Wundt 
 answers it in the same way. 
 
 Do we admit that the sensation itself has from the first 
 the form of space? No. In fact, although the sensitive 
 elements form a mosaic in the retina, and a part of this 
 organ, called the blind spot, is insensible to light excita- 
 tions, yet the field of vision is seen as a continuous whole. 
 Now, if this perception of space were immediate, this in- 
 sensible portion of the retina would appear as a hole or 
 break in the visual field. In experience, however, it is 
 not so. 
 
 We meet the same two elements again here : 1st, local 
 signs ; 2d, movement, and the feeling that accompanies it. 
 
 First the local signs : " If we hold in the hand before 
 the eye a piece of red paper, and then carry it slowly to 
 
 ^ Wundt puts the same theory in another form in liis Physiologie d. 
 Menschen. The perception of space is the result of a psychic synthesis 
 whose elements are, an order of peripheral sensations, and the corres- 
 ponding order of sensations of innervation. In other words : If we 
 suppose a series of local impressions, a, b, c, . . . to be passed through, 
 the passage from a to b, from b to c, etc., will answer to the elementary 
 sensations of movement, a, ,5, 7 . . ., which, during the passage of the 
 series of local impressions to the term x, may be summed in a sensation 
 A. Neither the series a, b, c, . . . alone, nor the series a, (i^y . . . alone, 
 can give the perception of co-ordination in space, or the notion of 
 place. But the perception of «pace is due to the reciprocal relation of 
 the two series. For more details, see Wundt, Beitràge zur Théorie der 
 Sinneswahrnehmung, part 3. Physiologie d. Menschen, Fr. trans., p. 518. 
 Menschen. u. Thierseele, I, p. 233, etc. GrundzUge d. Physiol. Psych., II, 
 
 p. 27. 
 
 18 
 
206 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 one side, the eye remaining still, the image of the red 
 object is projected first upon the centre of the retina, and 
 then more and more upon the sides. We notice that while 
 this sideways movement continues, the sensation of red 
 undergoes successive changes ; the color becomes first 
 deeper, then a little blue ; at last the red object appeals 
 entirely black. Analogous changes can be produced with 
 any color, simple or composite. Evidently the explanation 
 of this phenomenon is that the different parts of the retina 
 are differently sensitive." 
 
 As to movement and the part it plays, Wundt first 
 introduced it as one of the primitive elements of the visual 
 field. 
 
 The following are the arguments he brings forward on 
 this point :^ 
 
 1st. Vertical distances appear greater than the same hori- 
 zontal distances ; the relation between them is about 4.8 to 
 4. This is also the relation which holds between the forces 
 which move the eye horizontally and vertically ; a relation 
 that is determined by tlie arrangement of the muscles. 
 
 2d. We can distinguish a difference in the length of two 
 lines when they differ by tV. The difference in the move- 
 ment of the eye in this case is also ts of its entire linear 
 movement. 
 
 3d. The smallest absolute distance perceptible and the 
 feeblest movement of the eye, to be appreciable, are in exact 
 agreement ; they answer to an angle of one minute. 
 
 4th. In cases of paralysis of the abductor muscle of the 
 ball, as we have already said, objects seem to be situated 
 farther away. The distance seems longer because the mus- 
 cular contraction must be greater to execute the same 
 movement. The patient sees anobject farther off than it 
 really is, and when he wishes to grasp it, grasps the space 
 
 ^ Physiologie der Menschen, Ft. trans., p. 517 ; Maischen u. Thierseele. 
 
WUNDT — PERCEPTION. 207 
 
 beyond. After very great effort, he can accustom himself 
 to it and regulate his movements.^ 
 
 So, then, we have in the sensation that accompanies 
 movement, a real measure of the intensity and extent of 
 that movement. 
 
 In truth, the process here is the same as in the rise 
 of the order of tactile sensations in space. The local 
 signs of retinal sensation form an indissoluble combination 
 with feelings of innervation whose intensity is variable. 
 The point which distinguishes visual sensations is that this 
 combination is referred to a single point, the centre of 
 the retina. This reference, facilitating the exact measure- 
 ment of the field of vision and making the functional union 
 of the two eyes, in binocular vision, possible, has its ground 
 in the laws of movement. Inasmuch as these laws belong 
 to an innate central mechanism, we can say that the indi- 
 vidual is born with a completely developed tendency to 
 give his visual sensations an immediate order in space. 
 However short be the time that elapses between the first 
 action of the retinal impressions and perception, we must 
 nevertheless interpose a psychologically determined fact, by 
 means of which this perception is realized. 
 
 For tactile perception, this fact can be considered a 
 synthesis, since the resulting product presents new proper- 
 ties, différent from those of its sensible components. 
 This synthesis consists in measuring the quantitative 
 variations of peripheral sensation by the intensive varia- 
 tions of feelings of innervation. The eye can move in 
 two principal directions (above and below, to the right 
 and left) and between these, in all possible directions, each 
 position corresponding to a given combination of the sensi- 
 tive elements. When the eye moves, the image of each 
 point perceived moves also upon the retina ; the local signs 
 
 ^ For more details, see above, chap. IV. 
 
208 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 are modified in a determined way, and thus is formed the 
 notion of a continuity of two dimensions. " But these dimen- 
 sions are not homogeneous, since the local signs are changed 
 in an especial way for each change in direction. The feel- 
 ings of innervation that form a continuity of one dimension, 
 serve to measure, in all possible directions, the continuity 
 in two heterogeneous dimensions, and to refer it to a homor 
 geneous continuity in two dimensions, i. e., a surface. Thua 
 the monocular field of vision is formed." 
 
 In the case of binocular vision, the combination of the 
 local signs with feelings of innervation is variable. Sup- 
 pose a sign a of the right eye combines with a sign a' of 
 the left, both answering to a point 10° left of the point 
 of vision. To this combination a a' there will correspond 
 a feeling of innervation of 10°. JS^ow if a combine with 
 another sign a' only 5° to the left, the combination a a' 
 corresponds to another feeling of innervation made up of 
 convergence and conversion to the left. The synthesis here 
 is more complicated, and the fact of perception may be 
 decomposed into two acts : first, that by which the position 
 of a given point a is fixed in relation to the visual point, 
 due to the local signs and feelings of innervation of the 
 first eye ; second, that by which the position of the visual 
 point and the point a is fixed in relation to the seeing 
 subject, due to the added influence of the second eye. If 
 we consider the monocular field of vision as a plane, certain 
 parts of this field may stand out from this plane in conse- 
 quence of the addition of the second eye. This plane 
 changes into a surface of another form, varying according 
 to the special conditions of the case. To illustrate this by 
 a comparison, suppose — as is the case in monocular vision — 
 a fixed point and a right line proceeding from it, capable 
 of moving in all directions ; by means of this twofold 
 apparatus we may construct only one simple surface, a 
 plane, provided the line is infinite. Suppose now — as is 
 
WUNDT — THE GENERAL JSTOTION. 209 
 
 the case in binocular vision — two fixed points and two right 
 lines, in constantly varying direction, whose points of inter- 
 section can give a «irface ; by this fourfold apparatus we 
 may obtain a surface of any form whatever. 
 
 Remembering; that Wundt calls each sensation a conclu- 
 sion, we may say with him : The synthesis of two series of 
 conclusions (impressions of sense and sensations of move- 
 ment) in a single conclusion gives space. This synthesis 
 he likens to chemical combination. " Just as in chemical 
 synthesis, new properties arise from the combination of 
 certain elements, so the psychic synthesis gives a new 
 product which is the order of elementary sensations in 
 space. And, while the elementary sensations are given us 
 by psychological analysis, the notion of space can not be, 
 because it is the result of their synthesis." 
 
 IV. 
 
 THE GENERAL NOTION. 
 
 Composite psychic forms arise from simple perceptions. 
 They may be divided into three classes : complex notions ; 
 general notions ; forms of intuition, i. e., time and space. 
 
 Notions or complex perceptions are formed by the union 
 of simple perceptions of diiferent kinds. The greater part 
 of our representations belong to this class, since they cor- 
 respond to real, concrete, complex objects. 
 
 General notions are formed from a certain number of 
 simple perceptions which are analogous to one another and 
 agree largely in their elements (example : man, tree). As 
 every psychic state is the more easily reproduced as it has 
 already been the oftener in consciousness, it results that 
 these analogous elements must possess great reproductive 
 force. A sense impression will awake elements that have 
 been already often reproduced. " The laws of reproduction 
 suffice to explain the genesis of the general notion, and 
 
210 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 there is no reason to attribute it, with the old psychology, 
 to a special faculty of abstraction." 
 
 The author distinguishes the general notion from the 
 concept {Begrif)} The concept has no place, as sensa- 
 tion and perception, as a determined psychological form. 
 It has in consciousness a single substitute : a word, 
 spoken or written. This explains the fact that the abstract 
 concept is not found with the animal or young child, while 
 the general notion is. The general notion is, properly 
 speaking, only a schema of the particular notions that it 
 includes. The concept is something more : it constitutes 
 scientific knowledge and gives law to phenomena. It 
 is, says Wundt, a postulat. " When we resolve a general 
 notion into its final elements, we see that the more extended 
 this notion is, the more insufficient is its comprehension of 
 the objects entering into the schema. We remark at the 
 same time that however indeterminate in its compass the 
 general notion be before it is resolved into particular facts, 
 still each of the elements it contains may be changed with- 
 out destroying the general notion. Thus the postulate of a 
 general notion is produced which ; 1st, contains the elements 
 common to all the particular subordinate conceptions, and 
 2d, can be extended, if completely resolved by analysis, to 
 all these particular conceptions. It is a postulate of this 
 kind that we call a concept." 
 
 Wundt distinguishes empirical and abstract concepts. 
 The first includes a sum of general notions, just as the 
 general notion includes a sum of particular notions. 
 Common experience alone is sufficient to form it (for 
 example, the concept man) ; but it is vague, without pre- 
 cision or scientific rigor. An ultimate process of mind 
 forms the abstract concept (cause and effect, means and end, 
 quantity, number, necessity, &c.), so called because they go 
 
 * Qrwndzuge, II, p. 310, and Menschen u. Thiersede, lect. 25-26. 
 
WUNDT — THE GENERAL NOTION. 211 
 
 beyond experience, and are not immediately applicable to 
 the objects of observation, internal or external. The differ- 
 ence in these two orders of concepts is one of degree. " We 
 call a concept empirical which includes a limited group of 
 phenomena ; abstract, when it includes several groups." 
 
 The forms of intuition, time and space, are related to the 
 general notion as well as to the concept. On the one hand, 
 they set out from particular perceptions, since they corres- 
 pond to the entire impression of the internal (time) or the 
 external (space) order of representation. On the other hand, 
 this order is itself wanting in the representation : time and 
 space are then postulates, as concepts are postulates. They 
 differ, however, in this, that a simple sign can not represent 
 them : they are transformed in consciousness into a particular 
 lapse of time and a particular length of space, which become 
 sensible substitutes for time and space in general ; and it is 
 because they are thus connected with particular representa- 
 tions that common sense and the old philosophy, with this in 
 view, considered them independent existences, embracing 
 all things. 
 
 Time. — The intuition of time arises from a succession of 
 varied representations, each of which remains disposable in 
 consciousness, when a new representation enters. It con- 
 sists less in the real reproduction of representations than in 
 the representation of their possible reproduction. Psycho- 
 logically, this takes place when each representation, dis- 
 appearing from consciousness, leaves a tra<;e, a certain effect, 
 which persists with the new representations that enter. 
 
 Let us take the most simple case. Originally the idea 
 of time finds a condition indispensable to its genesis in the 
 succession of sense impressions. Let us suppose a conscious- 
 ness free from all other representations ; and receiving only 
 regular acoustic impressions, for example, the swinging of 
 a pendulum at regular intervals. The first beat has its 
 place in consciousness ; its image persists until the second 
 
212 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 follows. This reproduces the first immediately. By vir- 
 tue of a general law of association, identical or analogous 
 states of consciousness excite each other. But at the same 
 time the second beat encounters the image that has persisted 
 during the interval. The new beat and the image are re- 
 ferred to the first perception, and to it the repeated impres- 
 sion gives its original intensity, while the image remains in 
 a state of memory. Consequently, the present perception 
 is immediately distinguished from its image. We have in 
 this simple fact all the elements of the idea of time : the 
 first sound is the beginning ; the second, the end ; the 
 image, the interval of time. At the instant of the third 
 impression, the notion of time exists entire, all at once, since 
 the three elements are given simultaneously : the second 
 impression and the image immediately, the first impression 
 by reproduction. But we are conscious at the same time, 
 of a state in which the first impression existed alone, and of 
 another in which the image existed alone. This state of con- 
 sciousness constitutes the notion of time. 
 
 The question has been put under its simplest form. But 
 more complicated cases suppose the same fundamental psy- 
 chological process. Thus the last point may be different 
 from the initial point; there may be, between the two 
 points, not a pause but a series of other impressions, etc. 
 In these cases one of two things happens, at the moment 
 that the final impression is made : either it is analogous 
 to the initial impression, when the process is as above, 
 and we have a determinate idea of the lapse of time ; or 
 there is no occasion for a reproduction, when we have an 
 indeterminate idea of the lapse of time. 
 
 Space. — We have already spoken of the genesis of the 
 concept of space. We have seen that its characteristics are, 
 plurality, continuity, and homogeneity of dimensions ; that 
 the idea of space arises from a synthesis by which the 
 heterogeneous continuity of two dimensions formed by local 
 
WUNDT — ^THE GENERAL NOTION. 213 
 
 signs, is referred to a homogeneous continuity by means of 
 sensations of innervation, which are continuous, but of one 
 intensive dimensioiiK)nly. We have seen also, that, by vir- 
 tue of the laws of movement, the right line serves as elemen- 
 tary measure of space, and that, from these diverse conditions, 
 the concept of plane space of three dimensions is formed. 
 
 The pure intuition of space is a concept which always 
 assumes the form of particular representation, i. e., of an 
 object in space ; and as the existence of an object in space 
 su])poses other extended objects besides itself, it results that 
 space as a concept, like time, is unlimited. 
 
 Wundt's considerations on the concept of space, afford, 
 according to the hypothesis of imaginary geometry, ground 
 for considering ordinary geometry a particular case of a 
 much more general science. "Investigations in imagi- 
 nary geometry, from the side of mathematics, conduct to 
 results analogous to those reached by our physiological 
 analysis. These investigations show that space, considered 
 as a continuous diversity of homogeneous dimensions, is a 
 general concept of which our intuition of space is a par- 
 ticular form. On the other hand, physiological analysis 
 shows that the particular form of plane space of three 
 dimensions has its ground in the determiued conditions of 
 our organism. But mathematical considerations can not 
 lead us farther. We cannot conjecture, as Zœllner has in 
 his book On the Nature of Comets, that the ultimate world- 
 space is of varying curvature. For, whatever view we 
 hold as to the relation of our representations to the real 
 world, we can never justify the assertion that real things 
 should be represented in a form in which we are not able, in 
 a general way, to represent them. Scientific theories of the 
 nature of matter may put very various constructions upon 
 the appearances given us in immediate perception ; but they 
 can never establish hypotheses which do not conform to our 
 general intuition of space and time. The representable can 
 
214 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 never be derived from the irrepresentable. The imaginary- 
 forms of space have a real value in a certain sense, in as 
 far as space is the form in which we represent diverse con- 
 tinuities ; but we have seen that there are continuities (for 
 example, color) which can not be construed in ordinary 
 space." 
 
 As to whether space is merely a subjective form of 
 thought, or has also an objective reality, this question does 
 not belong to psychology. As an empirical science, psy- 
 chology asks how we can perceive things under this form, 
 but nothing farther. 
 
 V. 
 
 UNITY OF COMPOSITION : APPERCEPTION. 
 
 In his early works, and even in the first edition of his 
 Physiologische Psychologie (p. 714), Wundt took a position 
 that is worth recalling. It may be stated thus : at the base 
 of all psychic phenomena, there is unity of composition ; all 
 are reducible ultimately to conclusions. 
 
 Thought — understanding by this word a state of con- 
 sciousness in general — can be considered as to its form and 
 as to its nature. 
 
 In form, thought sustains the condition of time. Every act 
 of thought has measurable duration : we are not able, more- 
 over, to have two states of consciousness at once. Internal 
 observation presents a false appearance of simultaneousness, 
 the error arising from rapid succession. It is one of the 
 numberless cases in which observation alone deceives us, 
 and ordinary facts readily explain the illusion. When the 
 smith strikes red hot iron with his hammer, we see the 
 spark fly before we hear the blow. When the physician 
 bleeds a patient, he often sees the blood flow before the 
 lancet has penetrated the skin. These facts, as well as 
 scientific inquiry into the duration of psychic acts, show 
 
WUNDT — UNITY OF COMPOSITION. 215 
 
 that we can not think two things at once. They show fur- 
 ther that in this rapid succession which we take for sim- 
 ultaneousness, the second phenomenon may be perceived 
 before the first, for it is evident that the stroke of the 
 hammer precedes the spark, and the slip of the lancet, the 
 drawing of blood. These facts, and others like them, 
 have, says Wundt, a psychological significance ; they are 
 the expression of an internal fact, the oneness of thought. 
 
 In its ultimate nature, fundamentally, thought may be 
 reduced to a single fact : reasoning, inference {Schliessen). 
 
 There is, in all mental phenomena, however varied and 
 diverse they may be, oneness of composition. Sensa- 
 tions of every kind, judgments, ideas, feelings, etc., are 
 reached by reasoning, are the results of inference. All 
 differences arise from diiferent degrees of complexity only 
 in the original act, and from the diversity of the materials 
 that enter into it ; so that the mind, thus interpreted, may 
 be defined as a thing that reasons. 
 
 This is Wundt's fundamental position. However ob- 
 scure and unexpected it may be, we beg the reader to accept 
 so much on trust ; only after he has read the author, can 
 he accept or reject it, with proper knowledge of the case. 
 Yet, to simplify his task, we will try to indicate in some 
 detail the course that Wundt pursues. 
 
 All psychological data are referable ultimately to a 
 single fact : sensation. The most simple sensation is to 
 Wundt a conclusion. What does a conclusion suppose? 
 Premises. What are the premises here ? Facts absolutely 
 unconscious, of physiology and the nerve processes. There 
 is, then, this difference between ordinary reasoning and 
 simple sensation : in the former, both premises and con- 
 clusion are conscious acts ; in the latter, the premises are 
 physiological states, and the conclusion alone a state of 
 consciousness. It is generally said, to think is to judge. 
 Wundt maintains, on the contrary, that the act of judging 
 
216 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 is not original ; that as a conscious state, it presupposes a 
 series of unconscious states ; it is a term of the operation, 
 not the whole ; this latter, the reasoning process, is a syn- 
 thesis of premises. 
 
 Wundt applies the same method to all the forms of 
 psychic activity,, Each higher form is a conclusion for 
 which lower forms are premises. So that, complex phe- 
 nomena being referred by analysis to phenomena more and 
 more simple, these to sensation, and sensation to the nerv^e 
 processes, we are led to seek the hidden law of all psycho- 
 logical phenomena in the unconscious, that is, in the do- 
 main of physiology. 
 
 This throws light upon the analyses that follow. 
 
 " In order to understand well the connection of the 
 internal laws of thought with their external manifesta- 
 tions, we must have their essential elements well before us. 
 Now the elements of thought are ideas, judgments, con- 
 clusions. Ideas and judgments form a stable domain, 
 embracing science and all knowledge. Conclusions are 
 the means by which we give value to this domain, and 
 without which all our ideas and judgments would remain 
 unproductive capital. We will see that conclusions are 
 essential to thought, considering the manner in which judg- 
 ments and ideas are formed." 
 
 It is indisputable that the formation of any judgment 
 whatever — the lion is an animal — presupposes a great 
 number of antecedent mental acts. Not to enter into an 
 analysis that would be very long, and which the reader, 
 upon reflection, will supply, we will offer only a few re- 
 marks. I can know that this object is an animal only 
 after I have compared it with a great number of other 
 objects, similar or different (plants, stones, liquids). Each 
 object is characterized by a certain number of marks or 
 qualities peculiar to itself; and the comparison of two or 
 more objects can take place only Avhen the maries of the 
 
WUNDT — UNITY OF COMPOSITION. 217 
 
 objects compared are in part similar, in part different. A 
 judgment is the result of such a comparison of different 
 things by means of tkeir characteristic marks. 
 
 Every judgment of this kind, founded upon a consid- 
 erable sum of experiences, arises, then, from a great number 
 of antecedent judgments, of which some are affirmative, 
 others negative : for we determine a thing by saying at 
 once what it is and what it is not. And each of the ex- 
 periences that serve as basis for the entire judgment, is 
 itself a judgment, since, when I wish to express an experi- 
 ence, I must give expression to a judgment. But these 
 judgments passed on given objects, have no bond of 
 connection among themselves. In order that they may 
 conduct me to a final judgment which shall comprehend my 
 entire intuition of the object, it is necessary that some bond 
 unite these scattered marks. How is this connection made ? 
 Do my experiences remain a scattered aggregate ? Or is 
 there something which unites them profoundly ? We know 
 only a single form in which judgments can be bound to- 
 gether ; it is the reasoning process.^ The conclusion unites 
 a certain number of given judgments in a new judgment. 
 
 What is the nature of this reasoning process ? It is an 
 induction, for it proceeds from the particular to the general. 
 Wundt is here in full accord with Stuart Mill. He remarks 
 that all deduction supposes a previous induction, since the 
 principle that serves as basis for the deduction must be the 
 result and condensation of a mass of antecedent experiences.^ 
 
 ^ Raisonnement — translated sometimes also condusion : the two ideas 
 are included in the corresponding German word Schliessen. — Tr. 
 
 ^ Menschen u. Thierseele, I, lect. 4. Wundt remarks that inductive 
 as deductive reasoning rests upon three points : 1st, judgments or 
 affirmative facts (such and such a man is dead) ; 2d, judgments or 
 negative facts (there is no example of a man who dies not) : with- 
 out these latter, the affirmative facts, however great their number, are 
 valueless ; 3d, the general conclusion, serving, in its turn, as basis for 
 deduction. 
 19 
 
218 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 These judgments of experience, — which are, at the same 
 time, particular, and from which we draw the laws of nature 
 and of thought — seem to be the original elements of our 
 knowledge. Yet it is possible to pursue the analysis further 
 and show that they are composed of yet simpler elements. 
 In fact, there is no judgment, however simple it be, which 
 does not suppose some previous act of thought. But if 
 I resolve a judgment into simpler forms and these into 
 yet simpler, what result do I finally reach? Primitive 
 sensation. Every object is given me as having such a 
 color, form, as undergoing such changes, &c., &c. In 
 short, the ultimate marks, those at which we are obliged to 
 stop, are everywhere and always perceptions of sense. 
 
 " But every perception of sense is itself a judgment of 
 experience, the simplest of all such judgments. What I 
 see is white, red, brilliant, corporeal ; these are judgments 
 of experience, data of sensible intuition. Are these 
 primitive acts of thought or do they suppose others? 
 
 " When I am conscious that what I see is red, I thereby 
 distinguish it from yellow, green, blue, &c. I distinguish 
 likewise a sensation of light from a sensation of sound or 
 touch. How do I make this distinction ? Evidently by 
 means of definite marks that the object possesses in my 
 sensation. These marks agree in part, difièr in part. Thus 
 objects that are red, yellow, green, &c., agree in certain 
 marks and difier in others, as sound, smell, &c. But we 
 have seen that each of these marks is nothing more or less 
 than a judgment. Every perception of sense, then, results 
 from a mass of judgments, partly affirmative, partly nega- 
 tive, and the perception itself is nothing else than a con- 
 clusion drawn from these judgments. 
 
 " This leads us farther. The original act of thought is 
 not the judgment that exists in the immediate intuition of 
 sense, but the judgment that expresses the especial mark of 
 the sensation. How is this really primitive judgment 
 
WUNDT — UNITY OP COMPOSITION. 219 
 
 formed ? It has a property absolutely peculiar to itself and 
 it can not be expressed. Neither words nor thought can 
 grasp it. AVe know»nothing of it, except that it exists. I 
 know, indeed, that the sensation red is distinguished by 
 marks from that of blue, green, &c. What are these 
 marks ? This is absolutely unknown. AVe can not discover 
 these marks either by the most profound reflection, or by 
 the most minute research into the conditions under which 
 the sensation is produced. We know, indeed, that ether undu- 
 lations of a given amplitude, falling upon the eye, produce 
 the sensation of red. But these undulations are not the 
 marks by which we distinguish red from other colors, since 
 we made this distinction long before we knew that light 
 rasulted from undulations of ether." 
 
 These primitive judgments present, therefore^ such a char- 
 acter, that their existence can not be doubted, and yet that 
 their content, their fundamental constitution, remains entirely 
 unconscious. " Conclusion, not judgment, is the beginning 
 of thought." A j udgment, as a state of consciousness, exists 
 only in consequence of a process of reasoning. So that we 
 may say "the conclusion is knowledge that becomes (qui se 
 /aif), the judgment is knowledge that is reached" [qui est 
 faite). 
 
 It remains to account for the third form of thought : the 
 idea. It results also from the reasoning process. If I take, 
 for example, the idea man, I observe that it presupposes a 
 number of experimental data, each of which is character- 
 ized by a mark : he is of such a form, he moves, he thinks, 
 &c., &c. These are the judgments that make up my idea 
 man. But the idea does not result from the simple juxta- 
 position of these judgments; for if this were the case, the 
 idea would be simply a sum of marks, and a sum of marks 
 no more constitute an idea than head and limbs upon a trunk 
 constitute a man. The idea arises from the fusion of all the 
 marks into unity. And whence comes this fusion? Evi- 
 
220 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 dently from the one form of mental activity by which we 
 have power to bind, to unify, i. e., the reasoning process. 
 
 It has been remarked that, in this reduction of all the 
 forms of mental activity to one, Wundt is not in accord 
 Avith the common doctrine ; and he has himself observed it. 
 " We have shown that the true series of psychic acts is 
 altogether diiferent from that generally supposed. We do 
 not admit first ideas and from these judgments and then 
 conclusions ; but thought commences with conclusions, and 
 they conduct to judgments, which in turn give ideas." The 
 activity of thought consists in the reasoning process alone ; 
 all the rest is a result, a product. So he establishes the 
 iinity of composition of thought. All mental activities and 
 faculties are finally reduced to a single form, and this form 
 is essentially a succession. All mental phenomena are referred 
 to a logical operation (the reasoning process). 
 
 These are the general characteristics of the fundamental 
 position of the author. In the second edition of his Psy- 
 chologie he places the unity elsewhere, in a psychological 
 state called by a term borrowed from the philosophy of 
 Leibnitz : apperception} 
 
 In the come and go of internal states, we are more or 
 less clearly conscious of an activity which we call attention. 
 Internal observation teaches us that this activity does not 
 attach equally and at once to all states of consciousness, but 
 that it is sometimes exerted in a high degree. Consciousness 
 
 » Grundzuge : I, p. 218 ; II, p. 205, &c., 384, 392, &c. M. Wundt writes 
 to us on this subject that he does not now consider the hypothesis of 
 unconscious reasoning as more than a general expression, for which, in 
 actual states of knowledge, the processes of association and apperception 
 must be substituted. Every psychical process may take a logical form ; 
 but this form is not the process itself; it is a popular way of expressing 
 clearly that it is psychic processes which are emphasized in this case.. 
 For a complete study of apperception, see an article by M. H, 
 Lachelier, " Psychological Laws in the School of Wundt." {Revue philr 
 osophign£ : Feb., 1885.) 
 
WUNDT — APPERCEPTION. 
 
 221 
 
 has been called internal vision. Adopting this figure, we 
 may say that all the representations of consciousness at a 
 given moment are in» the visual jidd of consciousness, and 
 those to which the attention is directed are at the visual 
 'point. " The entrance of a representation in the visual 
 field, is perception ; its appearance at the visual point, is 
 apperception." 
 
 Apperception is passive or active. Passive precedes active 
 apperception. Apperception whit;h by necessity attaches 
 to a strong representation is passive. Active apperception 
 arises when several impressions enter into conflict. It is, 
 then, in general, an activity opposing certain states of con- 
 sciousness, sometimes passively determined by a controlling 
 excitation, sometimes appearing as active choice among 
 different impressions. Its function in both cases is to rein- 
 force the central excitation. The boundary between the 
 two cases is indeterminate. The preponderance of a single 
 excitation suffices to give passive form to the apperception ;j 
 the presence of another excitation of the same intensity 
 gives it active form. 
 
 "VVe must believe, moreover, still denominating appercep- 
 tion the visual point of consciousness, that we here arrive 
 at a principle of unity in the order of knowledge, as also 
 in the order of action. Apperception is the primitive form 
 of will. We will study it later (§ X) under this new aspect. 
 
 Wundt applies this theory of apperception to an 
 anatomo-physiological hypothesis, indicated briefly as fol- 
 lows. He thinks that the frontal regions of the brain are 
 concerned in the physiological phenomena which accompany 
 the apperception of sense representations. As long as the 
 central excitations remain limited to the sense centres, 
 properly so called, we have simple perception ; but their 
 apperception is always connected with a simultaneous exci- 
 tation of the elements of the central region. Each act of 
 apperception is accompanied by a determined physiological 
 
222 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 process : one of the clearest examples is the sensation of 
 effort that accompanies intense apperception. With this sen- 
 sation^ probably central, muscular tension is often combined, 
 to be referred necessarily to a simultaneous motor excitation. 
 Let us suppose the organ of apperception to be joined to a 
 double system of conducting ways : one centripetal, transmit- 
 ting centrally sensor excitations from all the organs of the 
 body ; and the other centrifugal, transmitting impulses issu- 
 ing from' the frontal region to the sensor and motor centres. 
 According as impulses are transmitted to the sensor or to 
 the muscular centres, the result is the apperception of sensa- 
 tion or the execution of voluntary movement. Very often 
 the two operations take place together : we perceive a repre- 
 sentation and execute, at the same time, an external act that 
 corresponds to it. The conducting ways which proceed 
 from the organ of apperception are connected in each of 
 two principal directions — centrifugal sensor and centrifugal 
 motor— directly with the sensor and motor centres, and indi- 
 rectly also, by means of intermediate centres, that repre- 
 sent,^ in certain complex functions (articulation in speech, 
 writing, &c.), nodal points of transmission. 
 
 It remains to speak of the role of apperception in the 
 association of simple and composite states of consciousness. 
 This point will be treated in the next chapter, in connection 
 with the discussion of the duration of psychic acts. 
 
 VI. 
 
 FEELING. 
 
 To consider the feelings, we must revert for a moment 
 to sensation, and examine its third characteristic, spoken 
 of above, and postponed until now. As we have seen, 
 it is only in abstraction that a sensation has two charac- 
 
 * Grundzuge, I, 218. 
 
WUNDT — FEELING. 223 
 
 teristics — intensity and quality ; in reality, every sensation 
 is conscious to a living being and has consequently a tone. 
 
 The feeling or tope of sensation is either agreeable or 
 disagreeable. Pleasure and pain are contrary states, either 
 of which is transformed into the other when a point of 
 indifference is traversed. There are sensations at this 
 point which have no tone, are accompanied by no feeling. 
 Since the relation of sensation to consciousness is continu- 
 ally varying, this point of indifference answers in general 
 to an easy state of transition to pleasure or pain. Yet 
 there are many sensations whose accompanying feeling is so 
 feeble that they seem to play always about the point of 
 indifference. With others, the feeling is so strong that 
 it hides the sensation. The former are sensations properly 
 so called. 
 
 Since feeling is a relation to consciousness, that is, a con- 
 tinual change of state, it is open to exact analysis in a much 
 less degree than the other elements of sensation. In a good 
 historical resume "VYundt reduces the hypotheses hitherto 
 advanced on the nature of feeling to three. 
 
 According to the first, held by the most noted thinkers, 
 from Aristotle to Kant, feeling is an immediate affection of 
 " the soul," caused by sensation. All the doctrines of this 
 group find, more or less, in feeling an element of knowledge. 
 But experience tells us nothing of pleasure or pain of " the 
 soul ; " it gives us knowledge of states of consciousness 
 only ; we perceive our feelings as immediate affections of 
 consciousness, and there is no reason for substituting the 
 metaphysical concept soul for the empirical concept con- 
 sciousness. 
 
 According to the second, represented by Herbart and his 
 school, feeling results from a reciprocal relation between 
 sensations or ideas : it is not a primitive state. Reciprocal 
 antagonism of sensations gives rise to the feeling of pain ; 
 their reciprocal union to the feeling of pleasure. This 
 
224 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 theory involves a great diiïiculty : it does not explain tlie 
 simplest form of feeling, that which accompanies sensation ; 
 for, in this case, there can be no question of reciprocal relation 
 between ideas. It is applicable only to the more complex 
 feelings, notably those of the aesthetic order. 
 
 According to the third, held by the author, feeling is the 
 subjective complement of sensation and the result of an 
 internal activity : apperception. We will approach nearer 
 the truth if we conceive the relation in this way : in the 
 indissoluble whole which we call a sensation involving 
 quality, energy, and some shade of feeling, the shade of feel- 
 ing is the element that sustains no direct correspondence 
 with the objective conditions of the excitation. 
 
 If we give this last expression to the relation sustained 
 by the tone of feeling to the other elements of sensation, 
 the thought is suggested that we ought to find in the tone 
 an intimation of a process onoi^e central than that which 
 pertains to the quality and energy of the sense excitation. 
 In fact, sensation, however simple a process it may seem, is 
 complex both from the physical and from the psychical 
 side. And since we are absolutely incapable of saying any- 
 thing touching sensations that are not perceived, the act of 
 apperception constitutes an element inseparably connected 
 with all the sensations offered for psychological examination. 
 Thus feelings of sense become immediately intelligible, 
 under all the influences to which they may be subjected, if 
 we consider them as modes of reaction, exerted through the 
 activity of apperception, against sense excitation. 
 
 This supposition explains at once, in the most simple 
 way, the multiplied psychological conditions of the tone of 
 sensation. Apperception depends, on one side, upon excita- 
 tion experienced, on the other, upon the state of conscious- 
 ness as a whole, in such a way that it is determined by the 
 combined action of present impressions and past memories. 
 Apperception is an internal activity, and thus the subjective 
 
WUNDT — FEELING. 225 
 
 value we attach to the tone of each feeling is explained. 
 Finally, this internal activity must be absolutely the same as 
 the efficiency of the will ; and this explains the fact that the 
 direct perception of feeling inclines us to attribute to it 
 some relation to the will. In order to write and explain 
 more clearly what we feel within, in pain or pleasure, it is 
 better to call pleasure an aspiration or tendency toward an 
 object and pain a disinclination or repulsion from it. In 
 our descriptions we continually confuse feeling, instinct, 
 determination of the will, because all these states are really 
 connected, and are separate only in our psychological abstrac- 
 tion, and because apperception exhibits in the play of exter- 
 nal impressions, sometimes a passive and sometimes a spon- 
 taneous activity: in the first case we speak especially of 
 feeling, in the second, of instinct, desire, and will. 
 
 At the same time, the property, common to the feelings 
 and all analogous states, of moving between contraries, 
 indicates immediately their relation to the will. When 
 the will is full-grown, developed, this opposition finds 
 expression in the fact that some sensations are voluntary 
 and others involuntary. Now the excitations called plea- 
 sure and pain which oppose the activity of apperception, are 
 necessarily anterior to this opposition between the volun- 
 tary and the involuntary. 
 
 The psychological relation of the feeling in sensation to 
 the process of appercepticm must determine our conception 
 of the fundamental physical basis of this process. The 
 intensity and quality of sensation depend directly upon the 
 processes of excitation produced in the sense centres, and, 
 further, since they are measured in terms of their reciprocal 
 influence, upon the activity of apperception, which finds 
 expression in the law of relation. But the tone of feeling 
 is present only in as far as the sensation is perceived. It 
 must be considered then directly as the subjective or psychic 
 side of the more central process which is connected with the 
 
226 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 central sensorial excitation, when the activity of conscious- 
 ness is turned toward this point. The variable energy of 
 this reaction of feeling is to be referred, from a physiolog- 
 ical point of view, to the mobile states of the organ of 
 apperception, states that are analogous, in some measure, to 
 the changing states of reflex excitability in the inferior 
 central organs. 
 
 These comparisons show the psychologist as well as the 
 pliysiologist that the general law of relation which governs 
 the perception of the intensity and quality of sensations 
 is equally valid for the reaction of feeling. This law 
 was formulated for feeling before it was applied to the 
 other elements of sensation. Daniel Bernoulli, to whom we 
 owe its application to the complex feelings, called it the 
 " mensura sortis,'^ and Laplace, interpreting it in the same 
 sense, gave it the form of a law of relation between the 
 "fortune phydque" and the "fortune morale." In its 
 general significance the law is formulated thus : The inten- 
 sity of the reaction of feeling increases proportionally to 
 relative increments of excitation} 
 
 ^ In Wundt's early studies on sensibility, there was a marked tendency 
 to refer it in large measure to the intelligence. "In every feeling, 
 every affection, and every inclination, there is, says he, an instinctive 
 cognition. The feeling, indeed, is identical with the cognition and dis- 
 appears when the latter becomes conscious. When we say that feel- 
 ing is an instinctive cognition, we mean that it rests unconsciously 
 upon the processes that constitute cognition in consciousness. So it 
 enters in consciousness only as a result. We can never resolve it into 
 elements as we can known truth. And the cognition may be mistaken 
 only in so far as there is not a clear consciousness of the logical oper- 
 ations from which it flows : but feeling is always uncertain, since we can 
 never know clearly the method of its production. Feeling can never 
 attain truth ; it can only point it out ; it shows the way and is the 
 pioneer to'knowledge." Menschen u. Thierseele, II, pp. 41-44, also p. 31. 
 All knowledge is originally instinctive. Wundt gives examples: the 
 penetrating glance of the naturalist and physician ; the experimental 
 method instinctively used by the alchemists before Galileo, &c. (lect. 43). 
 
WTJNDT — FEELING. 227 
 
 YII. 
 
 After having treated of the feelings whose basis is purely 
 physical — those which depend upon the state of organ 
 and tissue (sinnllches Gefliht) — the author studies three 
 important groups ; the aesthetic, the moral, and the religious 
 feelings. 
 
 We have seen that, in the order of intellect, the entire 
 process of thought consists in the transition from j^erception 
 to ideas or abstract notions, which constitute the limit of 
 knowledge. In the order of feeling, the process is analo- 
 gous. It is a transition from purely physical aifections to 
 an ideal, which sets limits to the play of the three groups 
 of feelings of which we speak. The relation of perception 
 to the idea is analogous to the relation of feeling to the 
 ideal, except that the former is conscious, the latter, uncon- 
 scious. " Ideal, then, is a word which defines the limit of 
 the unconscious process of knowledge, as idea that of the 
 conscious process." As the idea results from a sum of 
 marks and from logical operations which are entirely con- 
 scious, we can always refer it by analysis to the concrete 
 elements that produced it. The ideal, on the contrary, 
 does not result from clear operations, and can not be re- 
 solved into a given sum of predicates : hence it has an 
 indeterminate character, and we denominate it " infinite." 
 The task of the sciences, adds Wundt, is to transform all 
 ideals into ideas. 
 
 His theory of the ideal, as we see, is not at all mystical, 
 and the same may be said of his aesthetic as a whole. It 
 rests upon geometry and physics. Evidently only a rough 
 sketch of aesthetic is possible in the present state of the 
 science. Yet, when we read the Optics and Acoustics 
 of Helmholtz, the memoirs of Fechner on experimental 
 œsthetics, the works of 2ieising and Briicke, we see the 
 possibility of replacing vague discussion and uncertain 
 
228 
 
 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 generalization by a theory resting upon the positive sciences, 
 the possibihty of an aesthetic which will diifer widely from 
 our present science of the beautiful. We will attempt, fol- 
 lowing Wundt, to indicate some of its features.^ 
 
 In aesthetics two methods are generally pursued : one, 
 the speculative, sets out with the idea of the beautiful and 
 deduces its laws ; the other, the empirical, sets out with the 
 analysis of beautiful objects and works of art, and reaches 
 aesthetic laws by induction. Hegel represents the former, 
 Lessing the latter. The advantages of both are united in 
 the experimental method, which seeks, says Wundt, to de- 
 termine the factors and thus the simple elements in any 
 aesthetic effect. 
 
 Let us take impressions of sight. Here there are two 
 factors, the form and color of objects seen. The analyses of 
 physicists, Helmholtz in particular, have shown that optics 
 afford a solid basis for an aesthetic of color. We will con- 
 sider the former of these elements. Of two very simple 
 figures, a square and trapezium, one of which is regular, the 
 other irregular, the former pleases, while the latter does not. 
 Why? Because the former offers greater symmetry. If 
 we compare a great number of forms, in architecture, sculp- 
 ture, painting, and even in living organisms, we see that 
 the law of symmetry is a fundamental aesthetic fact. Not 
 that naked and bodiless symmetry is pleasing ; on the con- 
 trary, the effect results from the proper ordering of a plu- 
 rality of elements. 
 
 Geometricians discovered, long since, a linear division 
 which is valuable in aesthetics. To put the question under 
 its simplest form, we are led to ask : if two straight lines 
 cut each other at right angles, what is the most pleasing 
 relation between the vertical and horizontal sections. If 
 this relation is 1 : 1, there is perfect symmetry. But there 
 
 ^ Menschen u. Thiersede, II, lects. 33-36, and Grundzuge, part 3, ch. 14. 
 
WUNDT — FEELING. 229 
 
 are other proportions which please : the relation 1 : 1.6. 
 What is the mysterious law that these numbers express ? 
 On an examination of the figure, we discover it imme- 
 diately. Our two lines form a cross, whose vertical section 
 = 1, and horizontal section = 1.6. By addition, 1 + 1-6 
 = 2.6, the entire line, and we then have the proportion 
 1 : 1.6 :: 1.6 : 2.6 (or, to be exact, 2.56). In other words, 
 we have this law : The finest effect in vertical proportion is 
 produced when the smaller section is to the greater as the greater 
 to the whole} Zeising, in his New Theory of the Propor- 
 tions of the Human Body^ was the first to verify this law in 
 its application to the masterpieces of ancient architecture, 
 the Parthenon, Erechtheum, Propylaea, and even, in a 
 measure, to Gothic art ; to the most beautiful models of 
 Greek sculpture ; to the human body as it exists ; and fur- 
 ther, throughout the entire animal and vegetable kingdoms. 
 This suffices to indicate Wundt's conception of aesthetics. 
 In the order of auditory sensation, he studies similarly the 
 three factors, rhythm, melody, and harmony ; and deduces 
 their mathematical conditions. Thus two sounds are har- 
 monious if their vibrations sustain a simple numerical rela- 
 tion, as the octave 1 : 2, the fifth 2 : 3, the fourth 3 : 4, etc. 
 
 ^ All aesthetic proportions in form range between perfect symmetry 1 : 1 
 and the relation 1 : -, where x is so great that - becomes very small in 
 relation to 1. A proportion which scarcely departs from symmetry is less 
 pleasing than one further removed, because it appears as an unfinished 
 symmetry, lacking completeness. On the other hand, when the smaller 
 dimension cannot be measured in perception relatively to the larger, the 
 effect is very disagreeable. Between these limits the aesthetic propor- 
 tions are found, according to the law given above (x + 1 : x : : x : 1). 
 Grundziige, II, p. 183. We have spoken particularly of the work of 
 Zeising, because he is less known than Fechner and Helmholtz : Wundt 
 has shown at length the importance of Helmholtz's work in the sesthe- 
 tic of music. 
 
 '^ Neue Lehre von der Proportionen des menschlichen Kôrpers, Leipzig, 
 1854.— Tr. 
 
 20 
 
230 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 It is impossible to pursue the details here. Tlie import- 
 ant point is the method ; it is briefly this. We make a 
 physiological and physical analysis of sensations which pro- 
 duce an aesthetic effect, fix this analysis with numbers, and 
 thus derive a law. Wuudt remarks that " the analysis of 
 aesthetic feeling conducts everywhere and always to the same 
 process : a process that begins with the comparison and meas- 
 urement of impressions. The aesthetic feeling is satisfied when 
 this comparison shows harmony among impressions ; and in 
 the highest degree when this harmony arises from a diver- 
 sity of elements." 
 
 Since it is the function of science to transform every ideal 
 into an abstract idea, to what idea does the beautiful corres- 
 pond ? To that of order. Every aesthetic phenomenon ex- 
 presses this idea, that the world is not a confused mass of 
 units with no bond of union, but a cosmos. And herein 
 the beautiful approaches religious and moral ideals. The 
 eternal order of nature seems to us incomprehensible and 
 infinite, and it is in this idea that religion has its root. 
 External order indicates an internal order that is bound to 
 the order and development of the universe as a whole : this 
 gives rise to moral sentiment. 
 
 Existing at once in nature and in mind, in external forms 
 and in thought, " the beautiful speaks to us of the profound 
 agreement of the laws of the external with the laws of the 
 internal : the two are one in nature, and our intuition alone 
 makes and keeps them separate." 
 
 YIII. 
 
 All the feelings, and not those we call moral alone, may 
 determine us to action : the practical importance of the 
 moral feelings, however, is very great. Yet the moral is 
 as indeterminate as the aesthetic. The good and bad serve 
 as basis for an ideal only, the result of an instinctive cog- 
 
WUNDT — ^FEELING. 231 
 
 nition. The moral ideal, like the aesthetic, is a vague and 
 imperfect notion which scientific analysis must reduce to 
 clear ideas. Morality as a science, has as great a task 
 as aesthetics. Unhappily, the good, as an idea, has not 
 been resolved as yet : and as an ideal, its origin rests en- 
 shrouded in the shadows of the unconscious. Kant, it is 
 well known, placed the origin of this feeling outside the 
 range of psychological research : the moral law was for him 
 altogether special in its nature, having nothing in common 
 with the general laws of knowledge, indeed, opposing and 
 hindering them. But to show that this position can not be 
 maintained, it is only necessary to remark that the moral 
 condition of man is most intimately connected with the 
 development of knowledge. Although this relation can not 
 be questioned, we know the moral ideal only as a vague 
 form of feeling. What is necessary to make it clear ? 
 
 If the individual appeal to consciousness only, he makes 
 but little progress, for this is a question of origin. The 
 real concern is to know by what unconscious induction this 
 full-grown consciousness was formed within him, from 
 which in each case he deduces the motives of his action. 
 
 If we study the history of ethical theories from the 
 dawn of philosophy until to-day, our failure is as signal ; 
 for we find in all these theories different forms of indi- 
 vidual reflection only. Here the results are clearer, however, 
 inasmuch as they are expressed by loftier minds ; but the 
 question of origin remains untouched. 
 
 In order to study the feeling of harmony, we must know 
 objectively what harmony is. In like manner, in order 
 to understand moral sentiment, we must know objectively 
 what the moral is. We can learn this from history, especi- 
 ally from the natural history of man, which carries us 
 back to ages that are prehistoric, to the origin, in primitive 
 custom and rude organization, of the moral sentiments which 
 we find ready at hand in consciousness. Anthropology, 
 
232 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 therefore, ethnology, history prehistoric — these must serve 
 as guides. 
 
 Wundt devotes several chapters of great interest to 
 noting and interpreting ethnological facts of all kinds.^ 
 We will indicate the principal points. 
 
 The moral life of a people is expressed in their customs ; 
 from the state of their customs we can infer the state of 
 their morals. Now, as the lowest society has its manner 
 of life, i. e., its customs, to study these is to study indi- 
 rectly the feelings which produce them. It may be said fur- 
 ther that, at the most primitive state, a people has only 
 custom. It is only as its historic life begins that it attains 
 unto law, — law that generally embraces, rules, and provides 
 for all things. Then the circle of law is contracted, legisla- 
 tive and statute morality is reduced to a minimum, and 
 individual life is ruled by custom. England is a striking 
 example. 
 
 Custom, then, is the whole of primitive morality. But 
 in custom there is no contract either explicit or implicit. 
 It is an instinctive feeling which the individual blindly 
 obeys. Among peoples in a state of nature, it is deter- 
 mined in large part by climate and surroundings. la 
 general we may say that extremes of temperature are not 
 favorable to moral culture. Yet here there are excep- 
 tions. In the arctic zone, while the Kamtchatkans and 
 the inhabitants of the Aleutians are lawless, the Green- 
 landers have a certain moral tone. And in the tropics, we 
 find, in the same latitude, the Bushmen, Hottentots, and 
 Australians on the one hand ; and on the other the ancient 
 civilizations of Mexico and Peru. 
 
 Among primitive peoples, one of the most embarrassing 
 customs to the moralist is cannibalism, a phenomenon 
 probably universal to the human race in a state of nature; 
 
 ^ Menschen u. Thierseels, II, lects. 37 and 41. 
 
WUNDT — ^FEELING. 233 
 
 for the accounts of Marco Polo lead us to think that it 
 existed as late as the thirteenth century in China and 
 Japan. Wundt su^ests its probable causes — the entire 
 destruction of an enemy, scarcity of food, the delicacy of 
 human flesh, considered so great by the inhabitants of the 
 South Sea islands, that the privilege is reserved for the 
 gre^t. He shows, however, that even among primitive 
 peoples, cannibalism was indulged under protest. In the 
 Fiji Islands, before the arrival of Europeans, factions com- 
 batted as "immoral" the "good old custom" of eating men. 
 
 The author next studies, with the customs that charac- 
 terize them, the three forms of social organization which 
 precede civilization, properly so called: 1st, the life of 
 chase, with its mixture of barbarities and virtues : the 
 heroism of the prisoner of war among the North American 
 Indians, regard for promises, hospitality, etc. ; 2d, the 
 nomadic life, of which the Mongols offer a type : united 
 once by the genius of Tchengis-Khan, they wander on the 
 plateaux of upj)er Asia, with no memory of their ancient 
 splendor ; 3d, the agricultural life, which, in its sedentary 
 character, lays the first steps toward civilization. The 
 Foullahs and Mandingos, negro tribes of the interior of 
 Africa, offer examples of the transition from the primitive 
 to civilized forms of life. 
 
 Does the family exist in a state of nature? We can not 
 reply to this question categorically. Inasmuch as it is gen- 
 erally maintained that the social bond becomes stronger and 
 more constituent as culture advances, we are led to conclude 
 that there was a primitive state in which the individual was 
 absolutely isolated. But this is a conclusion a priori. 
 Since the true state of nature is nowhere to be found, we 
 are compelled, if we would reason from facts, to resort to 
 the study of animals. Now we find that many of the 
 higher species have a sort of marriage, and live in a state 
 of polygamy or even of monogamy. Analogy would lead 
 
234 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 US to believe that, with primitive man, the case was the 
 same. The oceanic races, negroes, the peoples of the icy 
 zones, and the primitive tribes of America, offer different 
 and curious types of domestic life. 
 
 The author then shows how the state arises from the 
 family ; whether it be the patriarchal form, of which China 
 still offers a curious model ; or the despotic, which often 
 arises, as with the negroes, from the necessity of resisting an 
 enemy. To these primitive forms succeeds the rule of 
 caste (India, Egypt, Per'sia), vestiges of which are still 
 found in Greece and Rome. Finally historic life appears, 
 with democracy, centralization, etc., etc. 
 
 " The varied changes which ethical notions have under- 
 gone in the course of history, however incompatible with 
 each other they may seem upon objective observation, have 
 nevertheless a subjective bond of union. The moral end 
 that nations strive to attain remains always fundamentally 
 the same ; it is the means alone which change. There is an 
 identity of character that reappears in all the variations in 
 morals. The conscience of nations, asicell as of indi- 
 viduals, designates as moral every act that is useful to the 
 agent himself or to others, to the end that all may live 
 conformably to their own nature and in the exercise of their 
 powers. Thus, at first, one factor is supreme, physical 
 force ; it is only a question of physical needs. Then little 
 by little knowledge opens up a new way. Society appears 
 as a whole whose members are united together, and the 
 notion is developed of duty to others and to the state." 
 
 Such is the result of the study of the ethnological facts 
 which we have briefly indicated. Its concern is to interro- 
 gate the national consciousness with a view to the transfor- 
 mation into clear ideas of the vague feelings within us. 
 The historical development of moral notions reveals espe- 
 cially a process of knowledge, from an unconscious original ; 
 for it is only by knowledge, by a reasoning process based 
 
WUNDT — FEELING. 235 
 
 upon experience, that the individual sees the necessity of 
 submitting, in common with others, for the development of 
 his faculties, to the rule of custom and law. This uncon- 
 scious reasoning, the basis of moral feeling, is enriched 
 with conscious elements, and approaches constantly nearer 
 its ideal end. Hence it conies that every epoch, while 
 believing its moral law perfect, expects a law still more 
 perfect, and this expectation has never been disappointed. 
 
 IX. 
 
 The religious feeling affords a study of great interest : 
 and it has a character of novelty, for Wuudt is one of a 
 very small number of psychologists who have attempted it. 
 Whether it be from mistaken respect, or prudence, or dis- 
 dain, it is generally entirely overlooked. The problem of 
 the origin and nature of religious sentiment, in whatever 
 way we interpret it, still arises for recognition ; and the 
 role that this sentiment plays is too important to be ne- 
 glected. The method to be pursued here has been indi- 
 cated elsewhere ; we must begin with the facts of ethnology 
 and history. Not that we are concerned with the history 
 of religions ; that is quite another thing. But it is needful 
 by the study of facts, that is, the facts of all forms of 
 religion, rude and refined, to build up our psychological 
 interpretation, and so discover the different processes from 
 which these varied forms have arisen. 
 
 The task is fraught with insurmountable difficulties, and 
 if we consider merely the hot strife of opinions in the do- 
 main of religion, it becomes evident that this feeling can not 
 be transformed into clear ideas. Further, the creative 
 imagination plays so great a part in religious conceptions, 
 that it may well be asked if they are not as much the work 
 of fancy as of feeling. 
 
 Yet these facts seem to prove that all religion is, origin- 
 
236 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ally, the worship of the forces of nature. This is their 
 common point of departure, and their salient point of dif- 
 ference. Differences arise from the character of peoples, 
 the influence of external nature, the creative work of poets, 
 the reflective work of philosophers, and these influences often 
 unite in hopeless confusion. 
 
 All the forms of worship of Asia, China perhaps ex- 
 cepted, are addressed to the changeless phenomena of the 
 starry heavens. Chaldea gives us sun-worship in its purity. 
 Peru is an analogous case in the New World. But it is 
 worthy of remark, as showing the influence of nature upon 
 religious conceptions, that the Chaldee religion, while 
 passing from the open skies and uniform country of the 
 Euphrates into Phœnicia and the fertile region of Syria, 
 shut in by rivers and irregularities of territory, takes on a 
 terrestrial character. Babylonish Mylitta becomes the god- 
 dess of fertility for man and beast. Astarte, the opposing 
 divinity, presides in war. Thus birth and death are no 
 longer ascribed to the influence of the sun. The marked con- 
 trast in the seasons in Syria and Phœnicia gives rise, in the 
 same way, to a multiplication of many gods from the original 
 few. Egypt, as far as we can conjecture, had at first a wor- 
 ship like that of Chaldea, but the influence of nature is seen 
 also here. The refreshing overflow of the Nile is followed 
 by seventy-two days of devouring heat ; this natural event 
 becomes a myth — Osiris beaten to death by Typhon and 
 his seventy-two companions. In India and Persia there 
 are myths of the same kind. The Vedas tell of the com- 
 bat of Indra the sun-god with gloomy Mist ; and in the 
 old hymns of the Zend-Avesta, the Spirit of Light strives 
 with Demons of darkness. 
 
 In this worship of the forms of nature, a tendency is 
 developed more and more to personify the gods. This 
 tendency, very perceptible in Eastern religions, attained its 
 highest state in Hellenism. 
 
WUNDT — ÏFEELING. 237 
 
 From the results reached, we may generalize this conclu- 
 sion : the worship of the forces of nature takes on one of 
 two forms. It is adc^'essed sometimes to regular and calm 
 phenomena (Chaldees, Egyptians), sometimes to changing, 
 violent, destructive phenomena (Jews and Indo-Europeans). 
 It tends in almost all cases to the personification of these 
 forces. 
 
 Let us now attempt to interpret the psychic process from 
 which religion and cultus spring. Here, as everywhere in 
 the domain of feeling, we have a case of instinctive cogni- 
 tion. The mind receives from experience certain data and 
 elaborates them unconsciously by laws peculiar to itself; and 
 the result merges into consciousness. How does the mind 
 arrive at this result ? In other words, what is the intel- 
 lectual process at the basis of religious sentiment ? It is a 
 process of reasoning in analogy. Science tends to refer all 
 its matter to the category of clear ideas : it is gaining ground 
 constantly. But there is always a residuum called by Wundt 
 and others the unknowable. Science can penetrate it neither 
 by induction nor by deduction. What, then, is our recourse? 
 Analogies may be found in all things and everywhere ; and 
 so analogy, although the most vague and imperfect of all 
 the logical processes, remains when no other mode of reason- 
 ing is possible. Man in a state of nature sees everywhere 
 wills analogous to his own, in the thunder, in the stars, &c., 
 and thus he forms the conception of gods like to himself, 
 and differing from him only in the possession of superior 
 power. 
 
 But this is not all. When the gods have thus taken on 
 living form, they detach themselves from the phenomena in 
 which they were first perceived. They become living be- 
 ings with a high hand upon human destiny. This leads to 
 another form of the religious idea : the nature-god becomes 
 the fate-god. * 
 
 One of the grossest forms of this religious conception is 
 
238 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 fetichism. It has two distinguishing characteristics : 1st, 
 the idol is itself god — a stone, a tree, a broken urn, a 
 piece of pottery, as among the Bambarras, according to 
 Mungo-Park ; 2d, each individual has his god to adore, 
 maltreat, or burn as the circumstances may require. The 
 fetich is for the individual at first, although it may extend 
 its power over a family or tribe. Thus among the African 
 tribes, when some disaster befalls, the warriors go forth in 
 war to conquer the hostile fetich, bring it back in triumph, 
 and worship it. The fetich is a fate-god ; herein is the pro- 
 foundly egoistic character of this form of worship. 
 
 It is generally understood that fetichism is peculiar to the 
 lower races. But there are incontrovertible facts which go 
 to show that it is psychologically possible among cultivated 
 peoples. Not to speak of faith in talismans and amulets, 
 " we find that among the Greeks, the Zeus of Olympus was 
 not the Zeus of Crete, &c. With Christians, the saints have 
 special miraculous powers in different chapels. The Virgin 
 Mary has hundreds of names according as the pilgrim bows 
 at one shrine or another : and further, each cross, each holy 
 image, upon his way, has its own peculiar worship." ^ 
 
 Next to fetichism there is the worship of animals as it 
 existed in ancient Egypt, and is still found among the ne- 
 groes of Africa, who worship the serpent, the hyena, the 
 crocodile, the tiger, the elephant. What is the genesis of 
 this religious form? 
 
 Wundt answers the question as follows. To man in his 
 natural state everything astonishing is divine and every- 
 thing that exists is astonishing. Not the lightning and 
 thunder alone, but the river that overflows, the leaves that 
 tremble, the brook that murmurs, all are supernatural to 
 him. The negro in particular is inclined to attribute 
 to animals intelligence superior to man's. The negroes 
 
 ^ Menschen u. Thierseele, II, lect. 46, p. 262. 
 
WUNDT — FEELING. 239 
 
 of Borneo speak of a time when " man understood the lan- 
 guage of the beasts." And the instinct of animals, so 
 mysterious to us, is still more mysterious to the savage, 
 who can interpret it only as a revelation of the divine 
 nature within. Thus to man in a state of nature, all is 
 inspirited, divine ; everything speaks. The roaring of the 
 wind, the cry of the animal, are voices of terror to him. 
 He takes a pebble with him by chance and succeeds in his 
 enterprise : the stone becomes the good spirit of his life. 
 
 Fetichism rests then upon a post hoe ergo propter hoc. 
 One event follows another ; the second is caused by the first. 
 It rests upon a perpetual fear of fate — fate which to the 
 ignorant is the will of harsh and jealous gods and is 
 transformed by worship into an artless egoism. The idea 
 that man creates his own destiny belongs to modern civili- 
 zation, and is one of its noblest products. 
 
 In fetichism, the supernatural power is embodied in 
 phenomena; the god is not yet become a distinct entity. 
 An advance upon this is seen in the worship of spirits and 
 phantoms. Throughout the vast country that stretches from 
 the Ural to the sea of Japan, and from the Himalayas on the 
 south to the Arctic Ocean on the north, we find this belief 
 dominant — among the Tartars, Mongols, the nomadic tribes 
 of Siberia, and the dwellers on the banks of the Obi and 
 Yenesei. Shamanism, as it exists among the Ostiaks, the 
 Samoyeds, the Jakuts, &c., is another form of the same. This 
 belief, as Wundt says, has been properly called the Religion 
 of the Steppes. In the sandy plains of upper Asia, arid 
 and waterless, everything conspires to hallucination. The 
 plaintive groanings of the storm are mingled with the cries 
 of wolves and tigers ; the eye wanders continually over 
 immense wastes, while unknown noises strike upon the ear. 
 Man, wasted with hunger and thirst, prey to burning fever, 
 peoples these deserts with fantastic forms, born of a diseased 
 imagination. 
 
240 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 Thus worship cousists always in the production of ecstasy 
 within through artificial means. The Shaman priests, 
 and the sorcerers of Finland and Lapland, dance before 
 the fire, beating drums with savage cries. And the priest 
 throws himself upon the ground when his ecstasy is at its 
 height. Two men tie a cord around his neck and draw it 
 to the strangling point, when he awakes and relates what 
 the spirit has said to him. 
 
 This need of communication with the so-called super- 
 natural world by means of hallucination and ecstasy, has 
 existed everywhere : it explains a great number of facts 
 often badly understood in the history of religions. In 
 Greece the mysteries of Samothrace and Eleusis, the Diony- 
 sia with their dances and orgies, their seas of wine, and 
 furious cries, were originally only a violent means to ecstasy. 
 Wine had the same part as opium in the south of Asia, 
 hashish in the north of Africa, and the taboo in the islands 
 of the Pacific. In India and later among Christians, 
 fasting and asceticism served the same end and produced a 
 morbid excitation of the nervous system that passed for a 
 revelation from the other world. The Christian can not 
 understand the ecstasy of the drunken Bacchant ; but the 
 macerations of the hermit are part of his solitary orgy; 
 and monks and nuns, on their part, ardently clasp in their 
 arms fantastic images of the Virgin and Saviour.^ 
 
 To what conclusions points this rapid review of facts in 
 the domain of religion ? It shows first, that religious sen- 
 timent, which ought to have some necessary basis of knowl- 
 edge, rests sometimes in the imagination, sometimes in the 
 reason. Thence it comes, says Wundt, that all polytheism 
 is monotheism and all monotheism polytheism. The simplest 
 religions, as that of the natives of America, speak of "a great 
 Spirit;'' that of the negroes of the "great Friend;" that 
 
 ^ Menschen u. Thiersede, II, p. 285. 
 
WUNDT — THE WILL. 241 
 
 of Polynesia, of a Creator of the world, &c. On the other 
 hand, India has its Trinity ; Christianity, its deified saints. 
 Among the Jews, Jehovah is the national god, but his ex- 
 istence does not exclude strange gods ; later, moreover, 
 the rabbins imagined angels with different theistic func- 
 tions. Religions differ then in this, that sometimes a god 
 disappears before the gods, sometimes the gods disappear 
 before a god : a fact that is explained by the pre-eminence 
 sometimes of poetic imagination, sometimes of philosophic 
 reflection. 
 
 In short, religious sentiment arises from two sources : 
 observation of nature and consideration of destiny. Obser- 
 vation of nature leads to the worship of natural force, calm 
 or violent. The uncertainty of destiny leads us to attribute 
 marvelous virtue to objects around us. Imagination gives 
 form to the gods of nature and destiny. But while it 
 peoples its domain with more numerous forms, reflection 
 works the contrary. It simplifies, unifies. It refers all 
 the gods of nature to one alone, all the gods of destiny to 
 a single Fate, and then unites the two conceptions in one, 
 a first cause. 
 
 We have called feeling the forerunner of knowledge. 
 Religious feeling points out the road to knowledge, to the 
 highest knowledge that man can make his own : the cause 
 and the destiny of the individual and the universe, as far 
 as they are realized in the world. But it attains strength 
 only as it is based upon science. Alone it is weak, for it is 
 only conscious knowledge that can givx authority to feeling 
 and set limits to the imagination. 
 
 X. 
 
 WUNDT — THE WILL. 
 
 The will, like consciousness, is incapable of exact defini- 
 tion. To say that a conscious activity rules our internal states 
 21 
 
242 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 and external movements helps us little, since the very idea 
 of activity is furnished altogether by our voluntary acts. 
 The will to Wundt (leaving out for the moment the ques- 
 tion of liberty) is a primitive state, fundamental to the 
 essence of the individual. Instead of considering feelings 
 and impulses (Triebe) as the first stages in voluntary devel- 
 opment, we must place the will as primal fact and birth- 
 place of feeling and impulse.^ 
 
 Voluntary activity is internal and external. 
 
 As an internal activity it is confused with apperception, 
 and is in fact only a form of the same. " In the will, the 
 subject knows his own act immediately." " What we per- 
 ceive in us in simple passive apperception is in part repre- 
 sentation, in part the feeling of an internal activity that 
 grows with the intensity of the representation. Active 
 apperception is distinguished from this simple phenomenon 
 only in that it is accompanied by the consciousness of a 
 plurality of disposible representations, whence result qual- 
 itative changes in the feeling of internal activity, according 
 as the intensity of one or another representation is increased." 
 
 As to the external activity (manifested in movement) the 
 author maintains that it does not result from education, 
 groping, and happy accidents, by whicli the will discovers 
 that the body is obedient to its commands, but from the 
 direct apperception of representations of movement. "Inter- 
 nal activity of the will is given from the first in conscious- 
 ness, for we have no consciousness without apperception : 
 the external act appears as the realization of the will. Consid- 
 ered as a simple phenomenon c^f consciousness, the external 
 activity of the will is from the first only t^e apperception of a 
 representation of movement. The real movement which fol- 
 lows, and the subsequent efifect that it produces in con- 
 sciousness and apperception, is a secondary consequence, not 
 
 ^ Grundzuge : II, lect. 5. 
 
WUNDT — ^THE WILL. 233 
 
 depending exclusively upon the will. The apperception of 
 a representation of movement may take place without the 
 real movement, when»the organs are diseased or hindered." 
 
 As to choice — it is a state of the mature consciousness in 
 which the number of voluntary impulses is greatly increased, 
 and there is either such equilibrium as to prevent the exter- 
 nal action or, while one prevails, the external activity that 
 manifests it is accompanied by the idea that instead of the 
 prevailing impulse another might have determined the will. 
 " In this idea is the consciousness of liberty." 
 
 This is a subject of endless debate.^ But the advocates 
 of liberty and their adversaries might fight eternally, seeing 
 that each party occupies its own peculiar ground and never 
 leaves it. It is said on the affirmative : I have an internal 
 feeling of liberty, therefore I am free. On the negative : 
 Everything is subject to law, therefore liberty is an 
 illusion. 
 
 Consciousness, says Wundt, tells us one thing : that we 
 are able to act without internal or external compulsion ; it 
 does not tell us that we can act without cause. Determin- 
 ists are wrong in saying that the will is subject to cause, 
 therefore to compulsion. Their adversaries are wrong in 
 saying that the will is not compelled, therefore is without 
 cause. Cause and compulsion are different ideas. Com- 
 pulsion exists only where there is resistance. We can not 
 say that the earth is compelled to move, but we can say that 
 a man is compelled to die. Yet both are subject to natural 
 law. Where is the différence? The difference is, that 
 man, as a conscious being, fears death and strives against it. 
 
 An important point we know — that every voluntary act 
 has its cause. Although we are ignorant of the cause, it is 
 unreasonable to deny it and conclude, as is sometimes done, 
 that the will is a first cause, a primum movens. Conscious- 
 
 * 3fenschen u. Thiersede, I, II, lects. 55 and 56. 
 
244 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ness reveals facts to us of which this takes no account. But 
 are the utterances of consciousness sufficient ? 
 
 Let us look at these facts and see what they reply. No one 
 will deny that social phenomena — marriage, divorce, suicide, 
 murder, theft — emanate from the individual will. They 
 are but the total of the actions of individual men. Statistic 
 records these facts, classifies and interprets them. And 
 what does it teach ? Open the Physique sociale of Quetelet, 
 and you see that social phenomena recur with astonishing 
 regularity : the number of thefts, crimes, misdemeanors of 
 all kinds, marriages, etc., is approximately the same for suc- 
 cessive years in the same country. Thus in Belgium, during 
 a period of five years (1841-45), the mean of marriages was 
 2642 ; the extreme deviations being -f 46 and — 136. In 
 France, during the long period from 1826-1844, the number 
 of criminals each year varied from 8237 to 6299. In London 
 during the period 1846-1850, suicides varied from 266 to 
 213. Further, the very variations, if we examine them, 
 can be referred to exact causes. It is proved that famine 
 increases the number of crimes, diminishes the number of 
 marriages. A great epidemic, like cholera, diminishes the 
 number of marriages, but when the scourge is passed, we 
 note a proportional reaction and increase. 
 
 Evidently, then, social phenomena and consequently indi- 
 vidual actions are subject to determinate causes. But it must 
 be remembered that in dealing with great masses the statis- 
 tician eliminates causes which act upon the individual. He 
 proceeds, like the physicist, to collect a great number of 
 cases in order to eliminate accidental influences. The 
 physicist neglects these accidental influences because they 
 are of no importance to him. Even the statistician proper 
 may forget them. But the psychologist can not. When he 
 asks whether there is in voluntary action beside natural and 
 social causes, some individual cause, how can he neglect the 
 small deviations, peculiar to individuals, which furnish ex- 
 
WUNDT — ^THE WILL. 245 
 
 clusively the data for his study ? Besides, statistic itself 
 shows that crimes, misdemeanors, suicides, vary with age, 
 sex, fortune, rank, etc.* In proportion as we go into details, 
 we discover more important individual causes. Yet we 
 discover them only as œnstanis. The individual fact in 
 its totality can only be explained on the assumption of the 
 existence of a personal factor. If we connect these two ele- 
 ments, we will have from the statistician the external causes 
 and from the personal factor the iniemal cause of voluntary 
 action. 
 
 This is the reply to the question put above. But what 
 is this " personal factor " that is to be so strangely inserted 
 in the series of natural cause and effect ? It is a cause of an 
 essentially complex nature which we may call by another 
 name : charade)'. " Character is the only immediate cause 
 of voluntary action. Motives are mediate causes only. 
 Between motives and character as causes there is this great 
 difference, that the former are conscious or liable readily to 
 become so, while the latter is absolutely unconscious." This 
 personal factor is then " a dark point," as it were, in the 
 brilliant light of causes, effects, and motives, which are all 
 know^able and explainable by the general law of causation. 
 Experience can not tell us immediately whether this personal 
 factor is subject to universal causality or not. " When we 
 say that the character of a man is a product of air and light, 
 of education and circumstances, of food and climate, that it 
 is necessarily determined, as every natural phenomenon, by 
 these influences, we draw an entirely undemonstrable con- 
 clusion. Education and destiny imply an earlier charac- 
 ter, to be determined : we take for effect that which enters 
 earlier as part of the cause." 
 
 Pushing the question to its limits, Wundt remarks that 
 there are two possible hj^otheses on the nature of this per- 
 sonal factor : either character is a new creation in each in- 
 dividual ; or it is the product of conditions inherent in 
 
246 GEKMAN PSYCHOLOGY OF TO-DAY. 
 
 earlier generations. The first accords with the doctrine of 
 fixity of species ; the second with the theory of evolution. 
 On the second theory, the germ of character would not be 
 the product of a free unintelligible Will, blindly distributing 
 its gifts ; but it would result of necessity from the constitu- 
 tion of the parents and the conditions of generation.^ 
 
 The problem of the origin of character is thus referred to 
 the question of psychic heredity, that is, definitely to a fact 
 of necessity. But this question is beyond the limits of 
 experimental psychology, and we return to our earlier posi- 
 tion that the will is a particular aspect of apperception. 
 
 XL 
 
 CONSCIOUSNESS. 
 
 All the states of which we have now spoken, perception, 
 representation, idea, feeling, volition, form the continuity 
 called consciousness, of which only tautological definitions 
 can be formulated. Its fundamental characteristic, given 
 in experience, is unity : its condition, that mental facts be 
 united and co-ordinated according to law. 
 
 The physiological basis of the unity of consciousness is 
 the continuity of the nerve system, and this excludes the 
 possibility of diverse kinds of consciousness. We can not 
 admit a determined organ of consciousness, in the ordinary 
 sense of that word, for each region of the nerve system 
 has its influence upon representation and feeling. Yet in- 
 vestigations on the nerve systems of the higher animals 
 show that the gray matter of the brain is more intimately 
 connected with consciousness than other parts. For there, 
 not only the difiêrent sensor and motor peripheral regions, 
 but the connections of the second order in the cerebral 
 ganglia, cerebellum, &c., are represented by special nerve 
 
 ^ Grundzuge, II, p. 396, 
 
WUNDT CONSCIOUSNESS. 247 
 
 cords. It is, therefore, the peculiar function of the cortical 
 layers to connect immediately or mediately, all the states of 
 the body whose function it is to awake conscious representa- 
 tion. In this sense only can we say that in the case of man 
 and probably of all the vertebrates, the cortical layers of the 
 brain are the organ of consciousness, yet without forgetting 
 that the function of this organ presupposes the subordinate 
 central parts (corpora quadrigemina, optic thalami, &c.), 
 which give, in all probability, the synthesis of sensation.^ 
 
 Considered in its psychological aspect, consciousness is 
 a unification, an activity that essentially unites, combines. 
 Two principal phenomena show it forth : the formation 
 of representations from impressions ; the succession of rep- 
 resentations. 
 
 Each representation appears to us as the combination of 
 a plurality of sensations. For example, we assign to each 
 color its place in space, we co-ordinate it with a certain 
 number of accompanying visual sensations. Pure sensa- 
 tion is an abstraction which never enters into consciousness. 
 Yet psychological and physiological analysis constrains us, 
 none the less, to maintain that it is by a synthesis of sen- 
 sations that our representations are formed. We must, 
 therefore, consider this fusion of elementary sensations in 
 every act of representation as the characteristic mark of 
 consciousness. 
 
 Further, the succession of representations is given imme- 
 diately as cohesion, resting upon the internal and external 
 conditions of representation. Their reproduction and asso- 
 ciation are necessary manifestations of consciousness. A con- 
 nection of representations disposed according to law — this, 
 from the psychic side, is the form under which we know con- 
 sciousness. 
 
 We have seen that Wundt maintains, by analogy with 
 
 ' Grundzuge, lect. 4, ch. 15. 
 

 248 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 the distinction established by physiologists between the 
 visual field, which is large but vague, and the visual point, 
 which is small but exact, that there is a distinction in con- 
 sciousness between perception and apperception. That 
 which enters consciousness in a general way is perceived, 
 that to which the attention is directed is apperceived. At- 
 tention marks then the most exalted moment of the mental 
 life. Subject to external or internal, physiological or psy- 
 chological influences, it is always accompanied by a feeling 
 of tension. So that, taken as a whole, the act which physio- 
 logical psychology seeks to interpret, embraces the follow- 
 ing moments : impression, transmission to a nerve centre, 
 entrance into the field of consciousness, passage to the par- 
 ticular point of apperception, voluntary reaction, trans- 
 mission by the motor nerves. 
 
 It is impossible, without extending beyond bounds this 
 study already so long, to follow Wundt in what he says on 
 movement, language, morbid states of consciousness, and 
 animal psychology. It must suffice to have indicated his 
 method and shown the variety of questions treated. It 
 remains to speak of his experimental work : to this the 
 next chapter is devoted. 
 
 We can not conclude this exposition, however, without 
 saying some words upon the theories recently put forth by 
 Wundt in his Logih, and showing in what measure they 
 modify or supplement his earlier work. Their influence is 
 seen most strongly in the important part assigned to the 
 activity of apperception, of which we have already said so 
 much. 
 
 States of consciousness may be considered as depending 
 immediately upon the organism, and their study, therefore, 
 belongs to psychophysics and physiological psychology. 
 Their ultimate law is that of association, analogous to the 
 laws of physics. 
 
 But apperception, as indicated above, is identical with the 
 
WUNDT — CONSCIOUSNESS. 249 
 
 will, in a sense autonomous, and gives unity to representa- 
 tions or states of consciousness : it is a synthetic principle. 
 To it the concept of the soul is ultimately reduced. There 
 are only two ways of conceiving the soul, says Wundt; 
 as a substance and as an act. To the first conception be- 
 long all the theories according to which psychic facts are 
 manifestations of a hypothetical substratum, a substance 
 material or immaterial. According to the second, the 
 psychic is pure actuality, immediately given in the mani- 
 festations of the mental life. Hume, Kant, Fichte and 
 Hegel are representatives of the theory of actuality. Psy- 
 chology cannot, like the physical sciences, attach to itself a 
 metaphysical concept outside the fact of internal perception, 
 or allow itself to be embarrassed with the useless hypothe- 
 sis of a substance, to hinder all progress in the explanation 
 of phenomena. Internal activity can not be compared with 
 external activity, as experience reveals it to us, although 
 we use the same word for both. It is not a simple hap- 
 pening ; it is an apperception ; our acts of logical thought 
 are always connected with an immediate feeling of spon- 
 taneity. And this spontaneity is not something external to 
 the activity or distinct from it ; they can be logically sep- 
 arated, but not in fact. 
 
 We indicate this theory very summarily, for it leaves 
 the sphere of purely empirical, and leads to general psy- 
 chology.^ 
 
 ^See a detailed exposition in the article of M. Lachelier, already 
 cited. 
 
CHAPTER YII. 
 
 DUEATION OF PSYCHIC ACTS. 
 
 I. 
 
 Although not exclusively their work, the researches we 
 are about to consider in this chapter are largely due to 
 German physiologists. Commenced by Donders less than 
 twenty years ago, a series of memoirs has since been pub- 
 lished, of which the latest dates 1877. 
 
 The problem of the duration of psychic acts seems to 
 indicate most clearly the course that psychology must 
 pursue to become an exact science. Considered in its 
 essential points, the method of procedure consists in : 
 choosing a well-determined question, gathering the imme- 
 diate data of consciousness upon it, interpreting these by 
 means of reflection, on the part of self and others, and, 
 finally, attaining, if possible by actual experiment and 
 measure, a truly scientific, objective, and verifiable statement 
 of the time period. 
 
 The common fact which serves as point of departure is 
 this : we think sometimes faster, sometimes more slowly. 
 It is a matter of universal consciousness. In times of ex- 
 citement, anger or dread, our ideas are precipitated like a 
 torrent, rushing together as in a storm, and the triteness 
 of the figure indicates our familiarity with the fact. 
 
 But reflection goes further. If accustomed to analysis, 
 we are able to submit to delicate examination these violent 
 states and their contraries, ennui, tœdium vîtœ, weariness in 
 250 
 
DUEATION OF PSYCHIC ACTS. 251 
 
 the mental life. We can study especially facts which are 
 less subjective in character and more open to analysis. Thus 
 it has been ascertained that the rapidity of thought is pro- 
 digious in dreams/ delirium, some forms of madness, as 
 acute mania. On the other hand, thought is sluggish with 
 the idiot, the half-witted, and in certain kinds of paralysis. 
 The ideas of such patients are so disjointed that any one can 
 perceive it at once. These and kindred facts are of great 
 scientific interest, and throw light on many questions. They 
 show, for example, that our subjective appreciation of time 
 depends entirely on the rapidity or slowness of our thought. 
 When Thomas de Quincey, the celebrated opium eater, 
 increased his usual dose, he believed " that in one night he 
 had lived a thousand years, or, indeed, a length of time 
 that exceeded the limits of all human experience." 
 
 We may go still farther. Instead of these estimates of 
 the internal sense, which are always vague and are applicable 
 only to a series of states, we propose to measure the indi- 
 vidual state of consciousness in its duration and with its 
 variations, by means of exact apparatus. 
 
 This work is recent, and, as may well be believed, very far 
 from complete. Not to speak of the great difficulties which 
 the experiments present, there have been many prejudices 
 to overcome. Miiller himself considered every attempt of 
 this kind chimerical : and the first suggestions came not 
 from physiology, but from a science that seemed com- 
 pletely foreign to studies of this kind, astronomy. For a 
 long time, too, these suggestions were not taken up. 
 
 In 1795, Maskelyne, astronomer in the observatory at 
 Greenwich, noticed that his assistant Kinnebrook always 
 noted the passage of stars across the meridian from 0.5'' to 
 0.8" too late, and thinking such negligence inexcusable, 
 
 ^ For the facts on this subject, see Maury, Le Sommeil et les Rêves, 
 chap. V, pp. 138, 139, and Brierre de Boismont, Des hallucinations, obser- 
 vation 77, 
 
252 
 
 GEBMAN PSYCHOLOGY OF TO-DAY. 
 
 discharged liim. Later, about 1820, Bessel, while com- 
 paring his own observations with those of otiier astrono- 
 mers, especially Struve and Argelander, found that they 
 were always in advance of himself, and in his search for the 
 cause of this difference, discovered the personal equation. 
 According to the method of Bradley, then used in the obser- 
 vatories, a telescope was employed in which was stretched 
 a thread so fine that the exact instant of the transit of the 
 star in question could be noted. A pendulum beating sec- 
 onds was used for the observation. The observer had then 
 to unite two sensations of distinct orders, one visual, the 
 passage of the star, the other auditory, the beat of the 
 pendulum. Yet this would be simple enough if the sensa- 
 tions were simultaneous; but this occurs rarely and by 
 chance, the beat of the pendulum very seldom coinciding 
 with the passage of the star. In fact this is what occurs : 
 
 Suppose the thread is at M ; the first beat of the pendu- 
 lum is heard when the star is at e ; at the second beat the 
 star has crossed the meridian and is at e' . To give the exact 
 instant of its passage the astronomer must estimate the dis- 
 tance e M, as, for example, two-thirds of e e', the distance 
 passed over in one second. It is in this subjective estimate 
 that observers differ. 
 
 Differences due to the personal equation sometimes 
 amount to more than 1 second, but oftener fall below 
 0.3".^ They vary with hours of the day, the momentary 
 feelings of the observer (circulation of the blood, nervous 
 
 * The difference between Bessel and Argelander was considerable, and 
 the regularity of the variation is interesting. This difference for 
 instantaneous phenomena was 0.22'''' : with a pendulum beating half 
 seconds, 0.72^'', that is, 0.5'''' + 0.22''^ : with a pendulum beating seconds, 
 1.22^^ that is, 0.5^' + 0.5'^ + 0.22'^. For details, see Wolf, l'Equation 
 personnelle, ses lois, et son origine, 1871, and Eadau, Moniteur scientifique, 
 Nov. 15, 1865, et. fol. 
 
DURATION OF PSYCHIC ACTS. 253 
 
 fatigue, (fee), and may be reduced, says Wolf, by attention 
 and habit, to 0.1''. Bessel explains these differences by 
 saying that a visual and an auditory impression can not be 
 simultaneously compared, and that two observers require 
 different lengths of time to superpose the two impressions. 
 He adds with reason that the difference is greater still if 
 one observer passes from sight to hearing and the other 
 from hearing to sight. Yet he does not seem to assign a 
 great enough part to memory. The comparison is really 
 made not between sensations of different orders merely, but 
 between present facts and past facts (for example, the posi- 
 tion of e). " It is certain," says Wolf, " that at the moment 
 of the passage, the observer does not hear the stroke of the 
 pendulum, but an internal stroke which his thought substi- 
 tutes for it, just as the musician does not wait for the stroke 
 of the director's baton, but catches himself the rhythmic 
 advance of the measure. This is no more the superposition 
 of two sensations from without." The fact that memory 
 intervenes here is very important for the psychologist. It 
 indicates the possibility of a comparison in duration of a 
 present state with a past state. Thus we see, from this 
 case, that a longer time is needed for the reproduction of a 
 state of consciousness than for its production. 
 
 After astronomy, physiological experiment opened the 
 way for new research. In 1850, Helmholtz, carrying out 
 a program of experiments suggested by Dubois-Reymond 
 some years previously, measured in an exact way the time 
 of the transmission of nerve action through a given nerve 
 length. He excited the nerve near the muscle with which 
 it acts and noted the time between the excitation and the 
 contraction. Then repeating the experiment at a point 
 more distant from the muscle, he found the time longer. 
 This retardation gives data for calculating the velocity of 
 nerve transmission. 
 
 The experiments of Helmholtz have been taken up by 
 
 22 
 
254 
 
 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 different scientists, Dubois-Reymond, Marey, Hirsch, 
 Schelske, Jaager, Baxt, &c., &c., who have studied nerve 
 transmission with simpler apparatus, and in the most varied 
 conditions, and have experimented upon sensor as well as 
 motor nerves,^ 
 
 These experiments are only an introduction to the 
 problem before us : the measurement of the duration of 
 psychic acts. Yet they do more than indicate the route : 
 they furnish the elements essential to the calculation. Let 
 us mark well the conditions of the experiment. The sub- 
 ject feels a sensation and exhibits it in a reaction, a move- 
 ment. Sensation, the initial moment, and movement, the 
 final moment, are alone accessible to our methods of measure- 
 ment. A period of time elapses between the two, of which 
 part is occupied with centripetal and part with centrifugal 
 nerve transmission. These two periods being known, the 
 duration of perception, the psychic act proper, becomes more 
 easily accessible. 
 
 The direct measurement of this duration was attempted 
 about 1861 by different experimenters, particularly Donders. 
 He remarked first that the physiological time, that is, the 
 interval between the excitation and the sign of reaction, 
 varied according to the excitation employed. If it be a tactile 
 impression — pricking the hand with an induction coil — the 
 reaction takes place after \ second. If it be an auditory 
 impression, \ second. For a visual impression, the time is 
 further lengthened to i second. To determine exactly the 
 duration of the psychic act alone (perception and consequent 
 volition), deduction must be made of the time necessary for 
 
 ^ A résumé of results is to be found in the last edition of Hermann : 
 Grundriss d. Physiologie des Menschen, 5th éd., Berlin, 1874, pp. 304-305. 
 Hermann gives as the true mean of transmission in the sensor nerves of 
 man 33. 9 m. a second. For work sinc'e done in France, see Ch. Kichat. 
 Recherches expérimentales et cliniques sur la sensibiliiê. Paris, 1877, p. 52, 
 &c. Bloch, Archives de Physiologie, 1875, p. 588, &c. 
 
DURATION OF PSYCHIC ACTS. 255 
 
 nerve transmission. Donders and Jaager contrived various 
 experiments with this in view. 
 
 The method employed is briefly this : the subject is told 
 that he is to receive an electric shock in the right foot, and 
 that he must react with the right hand ; the physiological 
 time, as we have seen, is | second. 
 
 The experiment is repeated under new conditions. The 
 subject does not know which foot will receive the shock ; 
 but he is to react with the hand on the same side. A cer- 
 tain indecision results. In this case, the physiological time 
 is longer than before. 
 
 We have here an extremely simple psychic act, since it 
 is reduced to a comparison of two perceptions, one real, 
 the other possible, and an action in consequence. This 
 experiment shows that the most elementary state of con- 
 sciousness has a measurable duration. Donders applied 
 the same process of experiment to visual and auditory im- 
 pressions, and reached analogous results. 
 
 These curious investigations were continued by Helm- 
 holtz, Mach, Vierordt, Baxt, and more recently by Ex- 
 ner (of Vienna), in an important paper bearing the title : 
 Experimental Investigations on the simplest psychie Pro- 
 cesses} This physiologist makes use of sudden electric 
 impressions on the skin, retina, etc. On a cylinder 
 wrapped with charcoal paper, the excitation is first recorded, 
 and then the reaction of the subject, by sudden pressure 
 upon a lever. An interval separates the two records on 
 
 * ExperimenteUe Untersiiehungen der einfaehsten psychischen Processe in 
 Pfluger's Archiv, 1873, vol. VII, pp. 601-669. The instruments used to 
 measure the duration of psychic acts vary with different experimenters. 
 One may use the chronoscopes of Pouillet and Hipp, or the registering 
 apparatus of Krille, Hankel, etc. For descriptions of them, see tlie works 
 cited, and particularly Marey, Du mouvement dans les fonctions de la vie. 
 For the other authors cited, see Mach, Sitzunsberichte der Wiener Akad., 
 vol. 51, p. 142. Vierordt, Der Zeitsinn nach Versuchen, 1868. Baxt, 
 Pfi.ilger's Archiv, vol. IV. 
 
256 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 the charcoal, and as the circular velocity of the cylinder is 
 known, the time of the reaction can be calculated nearly to 
 the ten-thousandth of a second. 
 
 Exner, whose results we give later, has studied with care 
 the accidental conditions of the physiological time. Above 
 all, the degree of attention has a very marked influence. The 
 greater the attention, the shorter the time ; when attention 
 is at its maximum, the time is at its minimum. 
 
 The time varies also according to the organ affected, and 
 the point of the body to which the excitant is applied. 
 
 Age has an influence. Exner found the minimum of 
 time = 0.1295" for a young man of twenty-two years; 
 and the maximum = 0.9952'' for an old man of seventy- 
 six years. 
 
 The experiments of Wundt must be added to those of 
 Exner. In his Physiological Psychology, he has gathered 
 together the work of his predecessors and added his own. 
 Vie will take him as guide in the following exposition. In 
 fact, we find in him, as is rarely the case in such study, at once 
 the physiological data and their psychological interpretation. 
 
 We may mention finally the recent investigations (1877) 
 of J. von Kries and F. Auerbach, which, as we will see 
 later, deal with a special point : the time of " discernment," 
 that is, of the intellectual act alone. 
 
 II. 
 
 We must notice, from the first, that the time v/hich 
 elapses between the excitation and the reaction involves 
 several phenomena of different kinds. Exner, who has 
 analyzed it very minutely, finds in the whole time the fol- 
 lowing moments : 
 
 1st. Time occupied by the transformation of the force 
 of excitation into nerve force (zero when the nerve is 
 directly excited). 
 
DUEATION OF PSYCHIC ACTS. 257 
 
 2d. Time occupied with the transmission of the excita- 
 tion through the nerve to a nerve centre. 
 
 3d. Time occupied in transmitting the excitation through 
 the spinal cord (zero for the cranial nerves). 
 
 4th. Time necessary for the transformation at the cen- 
 tres of the impression into motor excitation. 
 
 5th. Time of transmission of motor excitation through 
 the spinal cord. 
 
 6th. Time of transmission through the motor nerve. 
 
 7th. Time necessary to muscular contraction. 
 
 Of these different elements, it is the fourth which concerns 
 us. The others are known, determined — except the first, 
 which has been studied for the retina only, and without con- 
 clusive results. 
 
 Wundt, who has also made an analysis of physiological 
 time, shows that for psychological purposes, these different 
 elements may be reduced to two principal moments.^ The 
 physiological time, as a whole, comprises : 1st, transmission 
 by the nerves to the centres ; 2d, entrance into the visual 
 field of consciousness or perception; 3d, entrance to the 
 visual point of consciousness or apperception; 4th, time 
 necessary to volition ; 5th, transmission by the nerves to the 
 muscles. 
 
 The first and last of these elements may be consid- 
 ered purely physiological. The others are psycho-phys- 
 ical in their nature. We have reason to believe, says 
 Wundt, that the impression which acts with sufficient 
 force upon the central parts, enters thereby into the 
 visual field of consciousness. A special effort, felt within, 
 is necessary to give attention to this impression, and it 
 is by this effort that apperception is distinguished from 
 perception pure and simple. The duration of perception is 
 thus contained in the duration of the sensor transmission : 
 
 ^ Griindzuge, cliap. XVII. 
 
258 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 it is at once the last act of the physiological fact, and the 
 first act of the psychological fact. By duration of per- 
 ception we must therefore understand both the time of the 
 excitation of the sensor nerve centres, and the time of the 
 entrance of the impression in the field of consciousness. 
 
 On the other hand, the time of volition is connected in 
 the same way with the time of the motor or centrifugal 
 excitation. It is a contradiction of facts to maintain that an 
 act of volition may be completely accomplished before the 
 motor excitation of the nerve centres begins. The internal 
 sense, at least, gives us the two facts as simultaneous. 
 
 Thus the excitation of the sensor centres and perception, 
 the excitation of the motor centres and volition, are given 
 each as a psycho-physical fact. There remains another 
 element: apperception, which seems at first to be purely 
 psychological. But it is not so. Without stopping to 
 examine the different hypotheses that may be urged upon 
 the nature of this state, it is certain that it is always ac- 
 companied by a feeling of tension or effort ; and this feel- 
 ing has necessarily, as physiological basis, a fact of central 
 innervation. In many cases it is impossible to distinguish 
 certainly apperception from volition, as to duration. We 
 may, therefore, comprehend them under the common term 
 duration of reaction, since each consists in a central reac- 
 tion against the perceptions which enter consciousness. 
 
 To sum up, then, the physiological time is finally re- 
 solved into two physiological facts — sensor transmission and 
 motor transmission — and two psychological facts, duration 
 of perception and duration of reaction. The time of trans- 
 mission is known. It is more difficult to determine the 
 relative duration of the two internal acts. Yet it is done by 
 experiments designed to complicate or facilitate the acts of 
 perception and reaction, and indicate in what cases the 
 variations in duration are to be attributed respectively to 
 either of these psychological acts. There is a last desidev' 
 
DURATION OF PSYCHIC ACTS. 259 
 
 atujfiy involving new and often impossible research : to 
 decompose the duration of reaction into two parts, apper- 
 ception and volition*. 
 
 Th« status of the problem having been well indicated, let 
 us enter now into the detail of experiment and its results. 
 We may group the different cases studied under the follow- 
 ing heads : 
 
 1st. Impression known but not determined as to the 
 time of its appearance. 
 
 2d. Impression known and determined as to its time. 
 
 3d. Impression neither known nor determined as to its 
 time. 
 
 4th. Impression accompanied or followed by another 
 impression sometimes like, sometimes unlike. 
 
 5th. Regular series of perceptions in which a new per- 
 ception is intercalated. 
 
 6th. Mixture of internal states and perceptions, allowing 
 the measurement of the duration of these psychic acts 
 during reproduction. 
 
 7th. Duration of discernment, that is, of the most simple 
 intellectual act taken alone. 
 
 I. We will examine' the first case. The subject of the 
 experiment knows that he is to experience a tactile, visual, 
 or auditory sensation : all his attention is concentrated on a 
 single undetermined point, the instant of its appearance. 
 In this case the physiological time is about \ second. It 
 is a little shorter for impressions of touch and sound than 
 for sight. The experiments of Wundt give the following 
 numbers : 
 
 Sound . 0.167 or about ^. 
 
 Touch 0.213 " " \. 
 
 Sight 0.222. " " \. 
 
 The mean figures given by other observers, Hirsch, Han- 
 kel, Exner, Auerbach, and Kries, are : 
 

 260 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 Sound 0.149, 0.1505, 0.1360, 0.122, 0.120. 
 
 Touch 0.182, 0.1546, 0.1337, 0.146, 0.117. 
 
 Sight 0.200, 0.2246, 0.1506, 0.191, 0.193. 
 
 But, as Wundt remarks, the excitants employed to pro- 
 duce the three orders of sensation are far from being of the 
 same intensity. We have no means of comparing things 
 as dissimilar as a noise and an electric spark. Yet difîèr- 
 ences in duration may be due to differences in the intensity 
 of the objective cause. To solve the problem, the sensa- 
 tions compared must be referred to the point at which they 
 reach the " threshold of excitation/' the perceptible mini- 
 mum ; ^ for there they are equal in consciousness. Setting 
 out from the perceptible minimum, Wundt obtains the fol- 
 lowing figures, as mean result of twenty-four observations : 
 
 Sound 0.337 . . mean variation, 0.0501. 
 
 Sight 0.331 . . " " 0.0577. 
 
 Touch 0.327 . . " " 0.0324. 
 
 He concludes that the conditions of nerve transmission 
 remaining the same, " the duration of perception and reac- 
 tion is constant when the excitation is at its minimum." 
 Experiment shows further that the physiological time 
 diminishes in proportion as the intensity of the excitation 
 increases. He has two pieces of apparatus, one a ball 
 weighing fifteen grams let fall upon a surface, the other an 
 electro-magnetic hammer, with which, when the height of 
 the ball and hammer and, consequently, the intensity of the 
 sound that their fall produces are changed, he obtains the 
 following results : 
 
 Height of ball. Time. Height of hammer. Time. 
 
 0.02 m 0.161. 1mm 0.217. 
 
 0.05 0.176. 4 0.146. 
 
 0.25 0.159. 8 0.132. 
 
 0.55 0.094. 16 0.135. 
 
 ^ This expression threshold of excitation {Beizsehwelle), used so much 
 in contemporary German psychology, has already been explained. 
 
DURATION OF PSYCHIC ACTS. 261 
 
 These two series of experiments show clearly the icverse 
 ratio, already enunciated, between the intensity of the exci- 
 tation and the physiological time. Without doubt the time 
 of nerve transmission enters here. It increases with the 
 intensity of the excitation ; but the quantity by which it 
 increases is so small compared with the total physiological 
 time, that it is necessary to carry the difference to the 
 reckoning of the perception and reaction. 
 
 How is the physiological time to be divided between 
 perception and reaction ? It is difficult to say. Yet the 
 conditions of the experiment throw light upon the ques- 
 tion. In cases of minimum perception one finds himself, 
 at least in many cases, in a state of doubt which lasts a 
 certain time ; he asks, v/ith indecision, whether an impres- 
 sion has really been made, and feels clearly that this inde- 
 cision takes a given amount of time. I^ow it must be 
 remarked that a state of this kind arises not only in cases 
 in which the judgment is suspended, but also in cases in 
 which the impression is clearly above the perceptible mini- 
 mum. 
 
 In what relation, then, as to duration, are the two 
 elements (apperception, volition) which are included under 
 the term duration of reaction ? In some cases they exist 
 in consciousness as two successive acts, but they are nearly 
 always given simultaneously in one and the same indivisible 
 moment. Yet it can not be denied that the conditions of 
 the experiment render very probable this conclusion, i. e., 
 that the duration of volition is very small and the larger 
 part of the reaction must be attributed to apperception. 
 The conditions of the experiment are in fact such that the 
 register is made with mechanical exactness, and, while the 
 attention is concentrated upon it, the voluntary impulse is 
 almost instantaneous. 
 
 Another fact in favor of this conclusion is this ; it some- 
 times happens, that, when an impression is eagerly expected. 
 
2G2 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 Î ■ ' i i? 
 
 an entirely diiferent impression is registered (light instead 
 of sound) ; and it is known at the very moment the move- 
 ment is made, that the mistake has been committed. 
 
 II. The foregoing experiments may be simplified by 
 placing the subject in conditions such that his effort in 
 attention is ruled out. To do this, it is only necessary that 
 the character of the impression he is to experience be en- 
 tirely understood, and all cause for indecision removed. 
 He knows beforehand the nature of the sensation (sound, 
 light, etc.) ; further, its appearance is announced to him by 
 a signal. Thus a luminous or auditory impression is pre- 
 ceded by the beat of a pendulum that indicates to the 
 subject the exact moment at which the impression is to 
 be made. 
 
 The physiological time is then considerably diminished. 
 With the use of the ball spoken of above, which, by a 
 simple arrangement, can be made to strike a ring before 
 or after its fall, and thus produce a sound, \Yundt estab- 
 lishes the following differences : 
 
 
 131 
 
 17 j Number 
 
 of 
 14 \ experiments. 
 
 17/ 
 
 The experiment shows that when the constant interval 
 between the signal and impression increases, the physio- 
 logical time diminishes. Further, repetition and habit 
 have a very great influence upon this diminution. In a 
 long series of experiments, the external conditions remain- 
 ing the same, the physiological time grows very small (some 
 thousands second), perhaps zero. 
 
 The diminution of the physiological time is explained 
 by the extreme state of attention : it prevents all delay in 
 the perception and reaction. But how can this time become 
 
DUEATION OF PSYCHIC ACTS. 263 
 
 zero ? In actual experiment, all cause for indecision being 
 removed, the subject tends to make his movement of reac- 
 tion coincide exactly with the impression perceived, and 
 this is accomplished after repeated attempts. In certain 
 cases, the attention is so active that the impression is per- 
 ceived before it actually takes place, and as the state of 
 motor innervation is at its maximum, the reaction follows 
 the perception immediately. 
 
 Exner remarks that in such rapid experiments, the 
 practiced subject knows very well whether his register is 
 good or bad, although the diiference felt in such a case be 
 not more than some hundredths second ; and he knows it 
 by the diflFerence of interval which he perceives between the 
 impression and the movement. This shows what extra- 
 ordinary precision the internal sense may attain in investi- 
 gations of this kind. 
 
 III. Instead of simplifying the experiment, as in the 
 preceding case, we may complicate it. 
 
 The case of least complication is this : the nature of the 
 impression is known, but the moment of its appearance and 
 its intensity are unknown. Suppose there is a single auditory 
 impression, and intense and feeble sounds follow without 
 rule. In this case, the physiological time is always increased. 
 Wundt made two series of experiments, one with uniform 
 changes, the other with changes without rule : 
 
 I. Uniform change. II. Change without rule. 
 
 Intense sound .... 0.116 0.189 
 
 Feeble sound .... 0.127 0.298 
 
 The physiological time is further increased when a feeble 
 sound is suddenly intercalated in a series of strong sounds, 
 and vice versa. The duration may reach 0.4 to 0.5 second. 
 In such cases, the difierences can be attributed neither to 
 the duration of the perception, nor of the transmission, but 
 
264 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 to the duration of the reaction. This duration increases be- 
 cause the conditions of the experiment are such that the 
 attention is taken oif guard ; the earlier effort to simplify 
 the work of apperception is wanting. In fact, the conditions 
 of innervation are the same here as in the other experi- 
 ments ; so that the difference must be looked for else- 
 where. 
 
 A more complicated case than the preceding arises when 
 the impression is entirely unexpected. Its result is a 
 lengthening of the physiological time. This case arises 
 sometimes accidentally, when the subject, instead of giving 
 attention to the expected impression allows it to be diverted. 
 It may be produced artificially by breaking in upon a series 
 of long intervals with a very short interval. The physio- 
 logical time is then lengthened to ^ or |^ second.^ The 
 lengthening is least, although still noticeable, when the 
 subject does not know the nature of the impression he is 
 about to receive, whether sound, sight, or touch. 
 
 It is possible, finally, to occasion complication not in 
 the impression felt, but in the movement of reaction. 
 Such are the experiments suggested by Donders and 
 Jaager, of which we have spoken above. An electric 
 shock is given sometimes to one foot, sometimes to the 
 other, and the hand on the side affected is to react. Or the 
 impression is produced by a light, sometimes red, some- 
 times white, and the right hand is to react for the former, 
 the left for the latter. Finally, a third method : a vowel 
 is spoken and the subject repeats it, the two move- 
 ments being registered by means of a point moving upon 
 a drum. Sometimes the vowel is known beforehand by the 
 subject, sometimes not. The instrument shows the follow- 
 ing differences of duration : 
 
 ^ When an impression is sudden enough to occasion fear, the physio- 
 logical time is increased, according to Wundt, diminished according to 
 Exner. 
 
DURATION OF PSYCHIC ACTS. 265 
 
 Impression kuown. 
 
 Impression unknown. 
 
 Difference. 
 
 Touch . . . 0.205 
 
 0.272 
 
 0.087 
 
 Light . . . 0.184 
 
 , 0.356 
 
 0.172 
 
 Sound . . . 0.180 
 
 0.250 
 
 0.070 
 
 Yet it must be noticed that in these three series of ex- 
 periments, the conditions of reaction are not the same. 
 There is, in fact, a close association between an impression 
 upon the foot and a reaction of the hand upon the same side, 
 favored by anatomical conformation, exercise, habit, etc. 
 It is the same between an auditory sensation and a vocal 
 reaction. But this natural organic association does not 
 exist between a sensation of red and a movement of the 
 right hand. 
 
 It can, therefore, be concluded " that the duration of 
 volition depends principally upon the physiological connec- 
 tions between the sensor nerve centres and the motor organs 
 of reaction." When the reaction is favored by the mechanism 
 of the nerve system and by habit, the time is due largely to 
 apperception. In the contrary case, the time of volition 
 plays the principal role. 
 
 IV. So far we have dealt with single impressions only. 
 Let us see the result when, beside the principal impression 
 which is registered and whose nature and intensity are known, 
 another is produced in order to fatigue the attention. 
 
 We will take, first, two impressions of the same kind. 
 Wundt employs a bell struck by a small hammer. He 
 registers the impressions in the ordinary way. Then by 
 means of an instrument arranged for this experiment, con- 
 sisting of a toothed wheel in contact with a metallic thread, he 
 produces a continuous sound ; the differences are these : 
 
 T ,r J ^ J f without simultaneous sound, 0.189. 
 
 I. Moderate sound: I ^.^^ , „ '^3^3^ 
 
 -^ ^ . . f without simultaneous sound, 0.158. 
 
 n. Loud sound: | ^.^^ „ „ ^^203. 
 
 23 
 
266 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 The increase in the physiological time is evident. It is 
 the same when the two impressions are of different kinds : 
 
 _„ . . , f witliout simultaneous sound, 0.222. 
 
 Electric spark: | ^.^^ , „ ^3^^^ 
 
 "When the sensations are unlike, the difficulty of atten- 
 tion is greater. We feel it harder to react correctly and 
 experience a feeling of pain akin to embarrassment. 
 
 If the experiment be performed in another way, a 
 curious result is reached. With the principal impression, 
 let another be produced either simultaneously, before, or 
 after.^ Observation shows that the internal succession of 
 perceptions can not correspond with the external succession 
 of excitations : in other words, an excitation which is really 
 later than another may be perceived before it. Internal 
 observation leaves no doubt as to the cause of this illusion ; 
 it is due to the changing state of the effort of attention. 
 When the effort is feeble, this never takes place ; but when 
 it is intense, a true anticipation in time may be occasioned. 
 
 We may remark, also, that in this kind of experiment 
 the secondary impression, when it is later, has no influence 
 upon the principal impression ; all takes place as in simple 
 conditions. It is the same in cases of simultaneousness^ 
 Bat if the disturbing impression is earlier, the physiological 
 time is always increased, as the following experiments 
 show: 
 
 Disturbing impressioïi. Sound. Light. 
 
 Simultaneous or posterior .... 0.176 0.218. 
 
 Anterior 0.228 0.250. 
 
 When the experiment is conducted as before, with the dif- 
 ference that the accessory follows the principal impression by 
 a very short interval, the method of observation changes. It 
 
 ^ The experiment may be made with two impressions of the same or 
 of different kinds. 
 
 
 I 
 
DURATION OF PSYCHIC ACTS. 267 
 
 is no longer necessary to register the perception of the princi- 
 pal impression by movement ; the second impression, provided 
 it belong to the same sense, serves to establish the duration 
 of apperception for the first. For this, it is sufficient to 
 vary the interval between the two impressions, and thus 
 determine, by the experiment, the time taken by the second 
 to efiace the first. The portion of the duration of the 
 reaction that belongs to the voluntary impulse disappears 
 of itself 
 
 We can not call too much attention to the new process 
 employed here. The period of physiological time is short- 
 ened since it includes but two principal elements, centripetal 
 transmission and apperception ; and the determination of 
 the duration offers the simplest conditions. To understand 
 clearly the mode of this determination, it must be remarked : 
 that if two excitations are separated by an interval of time 
 n (which is indicated by the registering apparatus), and 
 if they are perceived as a single excitation, we can con- 
 clude that the first sensation has a duration equal at least 
 to n. If the interval be increased by n' (giving, in con- 
 sequence, n -f n'), and if the subject now perceive two 
 sensations, we can conclude that the first sensation has a 
 duration less than n -(- n'. By causing n' to vary, we can 
 .determine, with sufficient exactness, the physiological time 
 iof the first sensation.' 
 
 ■ Yet this method of experiment offers difficulties. Each 
 impression leaves after it, in the organ, a certain residuum, 
 a persistence of purely physiological action, which remains 
 when the second impression is received ; in short, this 
 
 ^ Experiments designed to determine the velocity of sensor nerve 
 action are based upon a similar principle. They eliminate, in the same 
 way, the time of the reaction and rest upon the longer or shorter per- 
 sistence of the sensation. See Archives de physiologie, 1875, p. 588, &c. 
 These experiments, performed by Bloch, have given rise to various crit- 
 icisms upon the method. 
 
268 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 residuum lasts throughout the interval that separates the 
 two simple impressions.^ 
 
 According to Baxt, the difficulty disappears when the 
 principal impression is composite rather than simple. He 
 uses letters and geometrical figures for the experiments. 
 By causing the interval of time that separates the principal 
 impression from the second which effaces it to vary several 
 times, we find on repeated attempts the maximum interval 
 between two excitations that will result in a single percep- 
 tion. Since, if acting alone, a momentary impression pro- 
 duces a sensation, we may assume that the interval answers 
 to the duration of apperception. 
 
 But the time thus measured varies greatly and grows with 
 the intensity of the second excitation. Working with differ- 
 ent degrees of intensity, Baxt found that the time neces- 
 sary to perceive three letters varied from ?V to xV second. 
 When he used, in turn, simple and complex curves the rela- 
 tion of their respective times was 1 to 5. 
 
 In these experiments, the excitations are produced in 
 such a way that there is no objective interval between them ; 
 the first persists, when the second is produced : and yet, sub- 
 jectively, we feel a small interval very clearly, during which 
 neither of the excitations is clearly perceived. So that 
 
 ^ According to Mach, the interval of time necessary for the separation 
 of the two impressions is.: 
 
 For the eye 0.0470 second. 
 
 For touch (finger) 0.0277 
 
 For the ear 0.0100 
 
 To be complete, we will add that according to the researches of 
 Vintschgau and Honigschmied, published in Pfluger's Archiv (vols. 10 
 and 14), the duration of taste excitations is from 0.15 to 0.23 second. It 
 varies with the point of the tongue excited and the nature of the sapid 
 substance : salt, sweet, acid, bitter, representing a series of lengthening 
 duration. 
 
DURATION OF PSYCHIC ACTS. 269 
 
 while there is continuity iii the causes of our perceptions, 
 there is discontinuity in the effects. This character of dis- 
 continuity presented T)y the order of our internal states arises, 
 as Wundt remarks, from the nature of apperception. It 
 takes time to transfer the attention from one impression to 
 another. As long as the first endures, our effort is directed 
 toward it ; even at the moment that the second appears, the 
 attention is not predisposed to observe it. There is, there- 
 fore, a certain period during which the attention diminishes 
 for the first and increases for the second : this period seems 
 vacant and indeterminate to us. There are tliree possible 
 forms of perception in the case of two given impressions 
 which are really simultaneous or nearly so : simultaneous- 
 ness, continuity, discontinuity. If we perceive them as 
 simultaneous, they are for us integral parts of one whole : 
 they constitute one object. If not, we always perceive them 
 as discontinuous, under the discrete form of time : and this 
 form, as we see, has its source in the very nature of the act 
 of apperception. Continuity arises only from variations of 
 intensity in one and the same representation, never from 
 the juxtaposition of two. 
 
 V. If we suppose a series of perceptions of the same 
 kind proceeding in regular order and their interruption by 
 the intercalation of another impression, to which term 
 of the series will apperception attach this new term ? Will 
 the two impressions which are simultaneous without be 
 simultaneous within ? 
 
 The terms of the series and the new term interposed 
 are either homogeneous or heterogeneous. 
 
 In the former case, as, for example, when a luminous ex- 
 citation enters in a series of visual representations, a sound 
 in a series of sounds, a derangement in the apperception of 
 the series may result, but it will be very light, and restricted 
 to extremely narrow limits. AH takes place as though there 
 
270 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 were but two isolated impressions : the difiPerence between 
 the union of representations and the real union of impres- 
 sions is nothing or very small. 
 
 In the second case, all is different. To show this, Wundt 
 intercalates a sound in a series of visual impressions, in the 
 following manner. On a graduated scale, an indicator is 
 moving uniformly ; and it is placed in such a position that 
 the place of the needle can be seen very clearly at each mo- 
 ment. The action of the clock which moves the needle gives 
 forth a sound at any desired time ; in such a way that the 
 subject never knows beforehand when he is to hear it. In 
 this experiment, one of three things must happen : 
 
 1st. The auditory impression is perceived at the exact 
 moment when the indicator is at the point answering to the 
 sound : in this case there is no derangement or lengthening 
 of time. 
 
 2d. The sound may be heard when the needle is farther 
 advanced : the time of representation then undergoes a 
 lengthening, to be called positive when the sound is heard 
 later than its real time.^ 
 
 3d. The sound may be connected with an indication of 
 the needle earlier than its real position : this is called a 
 negative lengthening. 
 
 In other words the sound may be heard exactly as it is 
 emitted, too late, or too soon. It would seem at first sight 
 that the positive lengthening would be more frequent, since 
 apperception always requires time. Experiment, however, 
 shows the opposite. By far the most frequent case is that 
 of negative lengthening, *. e., we believe we hear the sound 
 before it is really emitted. It rarely happens that there is 
 no lengthening, either positive or negative. 
 
 For many years, Wundt has experimented on this 
 
 ^ In these experiments, it is, of course, necessary to takg account of 
 the difference in the velocity of sound and light. 
 
DUEâTION OP PSYCHIC ACTS. 271 
 
 point, varyLog the conditions, method, and apparatus. We 
 can not explain his work in detail. The principal result, 
 however, that he has reached, is this : when impressions 
 which form a series are varied considerably, in respect to 
 rapidity, the lengthening is positive, within certain limits. 
 
 The explanation of these facts is suggested by the ex- 
 periments already examined. We have seen that the apper- 
 ception of any impression takes a period of time ; but that 
 this period is shortened if the nature of the impression is 
 known, and that it is further shortened if the instant of 
 its appearance is known. We have shown that in such a 
 case one of the results of extreme attention is that apper- 
 ception may precede the real impression. Now the very 
 conditions of the experiment before us must produce this 
 negative lengthening with regular certainty. In fact, when 
 the series of uniform impressions develops slowly, the 
 attention, which is directed entirely toward the secondary 
 impression (the sound), attains its maximum before this 
 impression arises, and consequently is combined with a 
 visual impression earlier than the real sound : so the sound 
 is heard too early. On the contrary, the more rapidly the 
 series of uniform impressions develops, the more difficult 
 it becomes to realize full attention before the sound is pro- 
 duced; consequently the lengthening becomes less and 
 less negative, then zero, then positive. 
 
 From all these experiments as a whole, Wundt concludes 
 that apperception and voluntary reaction constitute a con- 
 nected fact, whose physiological point of departure is found 
 in the motor centres. He recalls to mind : 
 
 1st. That when apperception is not followed by a vol- 
 untary impulse (that is, when its duration is determined 
 by means of an immediately succeeding impression), its 
 duration is least. 
 
 2d. That when there is a natural or habitual relation 
 between the impression and movement, apperception and 
 
272 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 volition coincide ; and when a choice is to be made, the 
 phenomenon is made up of two independent acts. 
 
 But, in any case, he maintains, the whole fact is to be 
 referred to a voluntary excitation which is sometimes di- 
 rected toward the sensor centres (apperception), sometimes 
 toward the motor centres (volition proper). "Appercep- 
 tion and motor impulse are, therefore, only different forms 
 of voluntary excitation. Hence it is that they are so inti- 
 mately connected, and that they coincide in certain cases. 
 A physiological fact that has hitherto been an enigma by 
 reason of the common separation of sensation from vol- 
 untary reaction is greatly cleared up. It is probable 
 that the anterior parts of the brain are centres of vol- 
 untary movement, while the sensor centres are located 
 principally in the posterior regions of the cortical layers. 
 On the other hand, we can doubt as little that the highest 
 functions of mind are always involved in the development 
 of the frontal portions. This becomes clear when it is 
 remarked that this seat of voluntary innervation, is in 
 itself the grand centre for all the peripheral centres, deter- 
 mining movement and the apperception of impressions. 
 
 VI. We now come to a different class of investigations. 
 We have to deal not with the duration of actual sensations 
 in consciousness ; but with the time necessary for the repro- 
 duction in memory of past perceptions. 
 
 In fact, however, an absolute line of demarcation between 
 present and reproduced perceptions is impossible ; for traces 
 of earlier impressions mingle with states awakened in con- 
 sciousness by sense impressions, sometimes completing 
 them, sometimes remaining distinct. Moreover, we have 
 seen already in our study of the perception of impressions 
 which are expected or foreseen, that reproduction plays a 
 role there, and enters largely into the phenomenon of 
 present perception. 
 
DURATION OF PSYCHIC ACTS. 273 
 
 Experiment shows that in general the time of the repro- 
 duction of a state of consciousness is longer than the time of 
 its production. Ytt this general statement, to be exact, 
 must be modified in several ways. 
 
 Memory may represent the interval between two percep- 
 tions as longer or shorter than it is : longer when the in- 
 terval is small ; shorter, when it is large. Every one who 
 is accustomed to reflection has noticed it. When we pass 
 over in recollection certain periods of our lives, a short 
 section always seems relatively longer than a long one. A 
 month and a year are both shortened in memory, but the 
 year is shortened more relatively. 
 
 This law may be established, also, by direct experiment. 
 If we seek to represent to ourselves fractions of a second, 
 such representations are always too great : and the con- 
 trary is the case when we represent minutes or hours. To 
 study the duration of these small intervals, Vierordt 
 causes the subject to attend for some time to the beating of 
 a metronome ; then he is to reproduce the beats as fast as 
 he heard them. Now, the repeated intervals are too 
 short when the real intervals are long, and too long when 
 the real intervals are short. The individual variations 
 on both sides of the exact point are large. 
 
 Vierordt concludes from his own experiments upon him- 
 self that the estimation and excitation exactly coincide, 
 when the internal is : 
 
 For the ear between 3 and 3.5 seconds. 
 
 For touch " 2.2 and 2.5 " 
 
 He allows only a small interval between the sensation 
 and its repetition. 
 
 The feeling of duration, as Wundt remarks, differs 
 according as it is retrospective or prospective. In the former 
 case, it rests on a reproduction of former states, in the 
 latter on an effort of attention. This explains the fact that 
 
274 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 time spent in waiting for some one seems so long, and that 
 when the expected person comes, the time of waiting, now 
 thrown into the past, seems very short. Time occupied 
 with uniform work seems much shorter than the same time 
 devoted to a number of tasks which have no connection. 
 Tlie influence of attention enters also here. 
 
 We arrive, therefore, at this general result, that the 
 reproduction of states of consciousness depends, as their 
 immediate perception depends, upon the degree of effort in 
 attention. Each representation to be perceived, must accom- 
 modate itself to the attention, must enter what we have 
 called the visual point. And just as each impression can 
 be perceived too soon or too late, because too much or too 
 little time is allowed for attention ; so a representation, a 
 purely internal state, can be reproduced too soon or too 
 late, according as its reproduction ought to be slow or fast. 
 
 To sum up, differences in the duration of perception 
 and reproduction may be referred to the two following 
 principles : 
 
 1st. In reproduction, the time necessary for the complete 
 passage of the attention from one state to another is consid- 
 erably increased. In cases of real impressions, we have 
 seen that this time is hardly a second since, for two sounds 
 separated by an interval of one second, the lengthening is 
 zero. The passage then of the attention from one state to 
 another takes less than a second. On the other hand, if a 
 short interval be left between the impression and its repro- 
 duction, the time may reach several seconds. 
 
 2d. The difference between immediate perception and 
 reproduction increases with the interval of time between 
 internal states and with the interval between the impression 
 and the moment of reproduction.^ 
 
 ^ When we compare two intervals of time, and the second differs from 
 the first (is longer or shorter), it necessarily happens that at the moment 
 of comparison the first interval is given only under the form of mem- 
 
DURATION OF PSYCHIC ACTS. 275 
 
 VII. It remains to examine the last case. In all the 
 preceding we have been concerned with the determination 
 of the variations of physiological time (that is the interval 
 which elapses between the excitation and the sign of reaction) 
 in the different conditions described. Here we arrive at a 
 determination still more exact. 
 
 "We have seen that Bonders proposed to measure the time 
 necessary for a very simple intellectual operation, and called 
 it the solution of a dilemma. It is the same problem that 
 Kries and Auerbach have just taken up.^ 
 
 To understand their method we must provide ourselves 
 with two lights, one blue and the other red, to be brought 
 forward one at a time indiscriminately. The subject is to 
 react only when he sees the light agreed upon beforehand. 
 Under this condition, the reaction is delayed. This delay 
 must be attributed to an intellectual operation, an act of dis- 
 cernment ^ between two simple perceptions, terminating in 
 a conclusion. The duration of this act of discernment is 
 to be determined. To do this, experimenters have been 
 obliged : Ist^ to determine the personal equation, that is, 
 the entire duration of the reaction, the excitation remaining 
 constant : 2d, to determine the duration of the reaction, the 
 excitation changing. The difference between these two 
 
 ory ; consequently, it is subject to the error that belongs to reproduced 
 states. Different experimenters, Mach, Vierordt, Hering, have shown 
 that the apperception of this difference of duration varies between a 
 maximum and minimum ; but their experiments do not agree. More 
 recently (1882), Wundt, Kollert and Buccola have made new experiments 
 to ascertain with what approximate exactitude we reproduce in memory 
 the succession of external events. From 1790 experiments, Buccola 
 concludes that the errors are proportional to the duration ; the time esti- 
 mate becomes less exact in proportion as the lengths of time are greater. 
 For details of experiments and results, see La legge dd tempo : p. 321 
 and fol. 
 
 ^ Archiv.filr Anatomie u. Physiologie, 1877, p. 296. 
 
 ^ What Bain calls diserimiv/xtion. 
 
276 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 quantities gives the duration of the act of discernment. 
 
 Their experiments, using different orders of perception, 
 give the following results : 
 
 Auerbach Kries 
 seconds. seconds. 
 Localization of tactile perceptions (i. e., distinc- 
 tion of different parts of the tactile organ) 0.021 0.036 
 Distinction between two tactile excitations, 
 
 When feebler. . . . 0.053 0.105 
 
 When stronger . . . 0.022 0.061 
 
 Discernment of a high note 0.019 0.049 
 
 « " low note 0.034 0.054 
 
 " between a tone and a noise . . . 0.023 0.046 
 
 Localization of sound 0.015 0.032 
 
 Discernment between two colors 0.012 0.034 
 
 " of the direction of light 0.011 0.017 
 
 " of distance of objects seen . . . . 0.022 0,030 
 
 From this table, Auerbach's mean duration of the act of 
 discernment is 0.026, and that of Kries, 0.049, that is, the 
 latter is almost double the former : consequently the dura- 
 tion of psychic operations may vary greatly with the 
 subject.^ 
 
 III. 
 
 The foregoing reproduces, without important modifica- 
 tion, the exposition of our first edition. We have changed it 
 little, because during the last six years psychometric study 
 has been very active, and it is well to point out the road 
 which it has traversed. Wundt has established a psycho- 
 physical laboratory at Leipzig, where, with the help of his 
 students, he has arranged the new experiments which we are 
 now about to consider. They are recorded in various 
 articles published in a special organ, the Philosophische 
 Studien. To the present, six^ brochures have appeared. 
 
 ^ For a criticism of these results, see Eichet, Revue philosophique, VI, 
 p. 395. The author thinks that a duration so small (about 3 hun- 
 dredths second) is altogether below the limit of the experimental error. 
 
 2 Now ten, January, 1886.— Tr. 
 
DUEATION OF PSYCHIC ACTS. 277 
 
 Besides the German work, experiments have been conducted 
 in Italy, especially by Buccola, which will be spoken of in- 
 cidentally. 
 
 In the first period of psychometric study, investigation 
 was confined to the simplest states of consciousness (dura- 
 tion of sensation, reaction, discernment).^ At present re- 
 search is being made in the most complex forms of mental 
 activity : duration of associations of different kinds, volition 
 or choice, pathological variations, &c. 
 
 We will commence with the question as to the time of 
 the perception of representations which are composite, but 
 whose elements are so homogeneous that the product still 
 remains relatively simple. In order to see the increase of 
 the duration of the perception as the complexity of the rep- 
 resentation increases, we must cause the latter to grow 
 regularly. Wundt employs visual representations, printed 
 numbers varying from 1 to 6 figures. Of the results reached 
 by many observers, I transcribe the most important. The 
 unit is always a second : 
 
 1 figure. 
 
 2 fig. 
 
 3 fig. 
 
 4 fig. 
 
 5 fig. 
 
 6 fig. 
 
 0.324 
 
 0.339 
 
 0.314 
 
 0.474 
 
 0.687 
 
 1.082 
 
 0.308 
 
 0.358 
 
 0.385 
 
 0.491 
 
 0.627 
 
 1.079 
 
 These numbers are taken from one hundred and twenty 
 experiments made at different times : the first series during 
 one month, and the second, the next month. With most 
 observers, the differences are small, while the numbers are 
 of one, two or three figures ; but when they reach four to 
 six figures, we find them important. 
 
 I will mention, also, the researches relating to the area or 
 circle of consciousness ( Umfang des Bewusstseim). How 
 
 ^ Quite lately (1883) the duration of olfactory perception has been 
 measured for the first time almost simultaneously by Beaunis, in France, 
 Buccola in Italy, and Moldenhauer in the laboratory of Wundt. The 
 three experimenters have reached results that agree in the main. They 
 are to be found in the Eevue philosophique for May, 1883, pp. 566 and 577. 
 24 
 
278 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 can it have simultaneous states ? It is a question that has 
 been much discussed, especially by Herbart and his disciples, 
 Waitz and Lange. But it is clear that internal observation 
 can not answer this difficult question : we must rely upon 
 the experimental method to reach it. Wundt takes a series 
 of simple impressions : the beats of a pendulum interrupted 
 regularly by the ring of a bell. We find that there is a 
 certain rapidity which gives the maximum of perception. 
 If it increase or diminish, the conditions become less 
 favorable for the experiment. "We find that the most 
 favorable rapidity is that which gives an interval of 0.3'' to 
 0.5" between the impressions. The maximum number of 
 impressions that can form a series in consciousness is as high 
 as 12. We may say, therefore, that twelve simple represen- 
 tations give the maximum area of consciousness for succes- 
 sive and relatively simple states." We reach the same 
 result for tactile sensations, but we cannot retain as great a 
 number of impressions unless they present rhythmic form.^ 
 
 We now reach more complicated researches. Their object 
 is to determine the duration of association, that is, the time 
 of the reproduction of a remembrance (Erinnerungsbild) 
 called up by any perception. The four experimenters are 
 Wundt, Stanley Hall, Besser and Trautscholdt, the author 
 of the article.^ The four initials W. H. B. T, will designate 
 these persons in the tables which follow. 
 
 As a preliminary to the question of quantity, a very 
 minute classification of associations is made as to quality, 
 since the experiments must be performed separately for each 
 distinct group of associations. Trautscholdt, as also Dro- 
 bisch, Herbart, and Taine, makes two great classes : associa- 
 tion external or indirect, and internal or direct. 
 
 ^ Orwndzuge, II, p. 213. These researches were reported by Dietze 
 in an article in the Philosophische Siudien (II, 3), recently published 
 (January, 1885). 
 
 ^ Philosophische Studien, I, p. 213 and fol. 
 
duratiojSt of psychic acts. 279 
 
 We will give briefly the leading features of his classifica- 
 tion, which contains, in the original, no less than 42 divisions 
 and subdivisions : * 
 
 I. — Internal Association. 
 
 A. — ^Association of simultaneous representations. 
 
 1st. Association of the parts of a single representation 
 (example : association of whole and parts, and of parts with 
 one another). 
 
 2d. Association of representations co-existing in an in- 
 dependent way. 
 
 B. — ^Association of successive representations. 
 
 1st. Association of successive auditory impressions (in 
 particular, association of words). 
 
 2d. Association of successive impressions of sight and 
 the other senses. 
 
 II. Internal Assodation. 
 
 1st. Association by eminence (TJeherordnung) and subor- 
 dination (association with a more and less general repre- 
 sentation). 
 
 2d. Association by co-ordination (resemblance and con- 
 trast). 
 
 3d. Association by relation of dependence (causality, 
 finality). 
 
 In the following table may be seen the distribution of 
 cases to the four experimenters in these different forms of 
 association : 
 
 From a total of 100 cases: W. B. H. T. 
 
 I. Internal Association 48 64 31 73 
 
 A. Simultaneous " 20 23 16 33 
 
 1st. Whole and parts 9 8 2 7 
 
 2d. Independently co-existing representations 11 15 14 26 
 
 B. Successive association (words) 23 41 15 40 
 
 1st. Completion of a word 19 20.5 12 21 
 
 2d. " " phrase 9 20.5 3 19 
 
280 GERMAN PSYCHOLOGY OP TO-DAY. 
 
 II. External Association 52 36 69 27 
 
 1st. Subordination 14 10 26 15 
 
 2d. Co-ordination 38 24 37 8 
 
 3d. Dependence 2 6 2 
 
 We will remark, to help the reader, that taking the 
 column W. of the table (experiments of Wundt), we see 
 that in 100 cases there are 48 internal associations, 52 ex- 
 ternal. The 48 internal associations are made up of 20 
 simultaneous, 28 successive, and the 20 simultaneous are 
 made up, as the table shows, of 9, 11, and so on. 
 
 We must remark, also, that the small number of associa- 
 tions of words by Stanley Hall is due to his want of fam- 
 iliarity with the German language. 
 
 Trautscholdt examines, then, the " part that subjective 
 moments play in association." Experiment shows that 
 the two most important are habit and vividness. He re- 
 calls on this subject the researches of Galton (published in 
 Brain, 1879), which show that the associations of youth 
 are most firmly fixed, and that about half of our associa- 
 tions date back to that period. Wundt reaches similar 
 results. He divides his life into three periods : childhood, to 
 sixteen or seventeen years ; from seventeen to twenty-five ; 
 the later period. Of forty-four associations, he finds that 
 twenty -five belong to the first, fourteen to the second, five to 
 the third period : that is, 57, 32, and 11 per cent, respectively. 
 
 The second part of the article is devoted, not to the 
 number, but to the duration of associations, the time re- 
 quired for their formation. The author classes his experi- 
 ments and results under the following heads : 
 
 1st. Time of simple reaction : time from the action of a 
 simple auditory impression to the reaction by voluntary 
 movement. 
 
 2d. Time of reaction of a word ( Wortreaction) : time 
 from a verbal impression to the voluntary reaction which 
 follows the apperception of the word. 
 
dueatiojst of psychic acts. 281 
 
 3d. Time of the discernment of a word (Wortunter- 
 soheidungszeit). The two preceding experiments being in 
 the same conditioife as far as possible, subtraction gives 
 the time necessary to distinguish a word ; we take quantity 
 (1) from quantity (2). The time necessary to the trans- 
 mission of the impression to the brain, and for the reac- 
 tion from the brain to the muscles, being the same in the 
 two cases, the third result may be readily deduced from 
 the two. 
 
 4th. Time of reaction in association : time that elapses 
 from the impression of a word to the reaction that follows 
 the apperception of an idea awakened by association. This 
 time is obtained by subtracting the time of the reaction of 
 a word (2) from the total time of t*he experiment. Exam- 
 ples of associations in point are : zero — infinity ; market 
 — market-place ; letter — portfolio {Brief — Biiefiasche). 
 
 I. Time of the réaction. — The initials, as before, indicate 
 
 the four experimenters : 
 
 W. 0.196 B. 0.108 H. 0.143 T. 0.116 
 
 Mean variation 0.009 0.012 0.017 0.010 
 
 Number of experiments . . 40 104 32 88 
 
 The average of the four is 0.141'', agreeing with the 
 average of other experimenters : Hankel, 0.150 ; Hirsch, 
 0.149 ; Exner, 0.136. 
 
 II. Time of the reaction of a word : 
 
 W. 0.303 B. 0.285 H. 0.280 T. 0.173 
 Mean variation . . 0.026 0.036 0.029 0.023 
 
 III. Time of the discernment of a word: Obtained, as 
 was said above, by subtraction. 
 
 W. 0.107 B. 0.177 H. 0.137 T. 0.057 
 
 IV. Time of an association: It will be remembered 
 that we must obtain the total reaction, and subtract the 
 numbers of (2). 
 
B. 
 
 H. 
 
 T. 
 
 1.037 
 
 1.154 
 
 0.896 
 
 0.099 
 
 0.175 
 
 0.168 
 
 282 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 W. 
 
 Total duration 1.009 
 
 Mean variation 0.128 
 
 The time necessary to the association is then : 
 
 W. 0.706 B. 0.752 H. 0.874 T. 0.723 
 
 Throwing out the results of Stanley Hall for the reason 
 given above, we have as the average 0.727''. 
 
 The third part of the monograph is devoted to " Re- 
 searches on the duration of the judgment of subordina- 
 tion." They deal, it seems, with a psychic process rather 
 more complicated than simple association. A word is 
 spoken and the observer reacts when he conceives an idea 
 in logical subordination to the word concept. 
 
 Duration of the total reaction . W. 1.148 B. 1.014 T. 0.898. 
 Mean variation 0.148 0.197 0.120. 
 
 To reach the real time of the subordinate judgment, we 
 must subtract, for each observer, the time of the reaction of 
 a word. We have : 
 
 W. 0.845 B. 0.729 T. 0.725 
 
 The average is 0.766'', greater than the association time 
 by 0.04". 
 
 The author remarks that the time necessary for the for- 
 mation of judgments differs according to their nature. He 
 makes three classes : 
 
 1st. A shorter time, when the judgment relates a con- 
 crete term to its genus. Examples : salamander — animal, 
 0.523 ; lime— oxide, 0.488, etc. 
 
 2d. A longer time, when the subject is not concrete. 
 Example : paralysis — physical disease, 1.750. 
 
 3d. Maximum time, when the judgment relates an 
 abstract subject to a general concept. Example : glory— 
 
DURATION OF PSYCHIC ACTS. 283 
 
 a kiud of fame, 2.023 ; art — aesthetic activity of man, 
 1.899.^ 
 
 Taking one of the three observers, B, we see that the 
 time varies with the three classes of judgments : 
 
 1st. = 0.625, 2d. = 0.876, 3d. = 1.250. 
 
 Trautscholdt thinks that the true mean is to be obtained 
 from the last two categories, in which the judgments are 
 more abstract, and finds it : 
 
 W. 0.8G5 B. 0.917 T. 0.839, 
 
 and as general average 0.874'', which is higher than the 
 average above (0.766''), and exceeds by nearly one-tenth 
 the time of association (J). 
 
 Variations in duration have also been studied in path- 
 ological states (intoxication, mental diseases, &c.). As early 
 as 1873, Exner, in PJlilger's Archiv, showed that after 
 drinking at once two bottles of Rhine wine, the time of the 
 reaction went up to 0.1904"-0.2969", although he had 
 the feeling of reaction in the last case much sooner. These 
 experiments were repeated with the same result by Dietl 
 and Vintschgau, and by Kraepelin under the direction of 
 Wundt. The last used nitrite of amyle, ether of ethyl, and 
 chloroform, and published the results of his experiments in 
 two long articles {Philosophische Studien, I, Hefte 3 u. 4). 
 He found that discernment and choice taken together rep- 
 resent, in a certain measure, a psychic act which in its 
 duration, shows no notable individual difference. In the 
 first period of the action of alcohol choice is quicker ; in the 
 second, discernment is quicker ; and the simple reaction, in 
 the act of choice, becomes longer throughout. 
 
 Some words, in closing, on mental diseases. Obersteiner, 
 in 1879, found that a subject whose normal reaction was 
 
 ' It is important to notice that in all these experiments the wox'4 giveq 
 is a German monosyllable : Milch, Kalk, Ruhm, &c. 
 
284 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 0.133, in a state of fatigue and somnolence gave 0.183 ; and 
 with a headache, 0.171 ; in the first stage of general par- 
 alysis 0.166, and at the last stage at which experiments were 
 possible, from 0.281 to 0.755. Finally we must mention 
 also the long investigations made by Buccola in the lunatic 
 asylum at Reggio and the Psychiatric Institute at Turin. 
 He experimented on imbeciles, idiots, demented, deluded 
 and melancholy persons, monomaniacs, and epileptics. Out- 
 side of cases of abnormal excitement, he found the duration 
 of perception always more or less lengthened. With imbe- 
 ciles and idiots the retardation is very great. 
 
 It is not possible to examine here all the recent works on 
 psychometry.^ We have only tried to explain the method and 
 principal results. It shows that the facts of consciousness, 
 like all other phenomena, have exact duration, variable and 
 measurable. No doubt all would have admitted, especially 
 since Kant, that internal phenomena are distinctively time 
 phenomena; but this vague expression left thought in a 
 region so mystical that it has seemed inaccessible to all time 
 measurement. 
 
 Yet at the beginning of the century the illustrious physi- 
 ologist, J. Millier, maintained that the time of the reaction 
 of a sensation in movement is infinitely small and incapable 
 of measurement (unendlich Mein und unmessbar). 
 
 And perhaps it may be asked, when all this work, so 
 tiresome, minute, and destitute of literary attractiveness, is 
 done, is it worth what it costs, whither does it conduct, and 
 does it throw any light upon thought and its nature? 
 We may answer at once that it is worth more to solve 
 small problems than to debate unceasingly great questions 
 whose solution is impossible. But is the question we are 
 
 ^ A complete study of the question is to be found in the important 
 •work of Buecola La legge del tempo nei fenomeni del pensiero : saggio di 
 psicologia sperimentale, 1883. Milan, Dumolard. {Bihlioteca sdentijka 
 internazionale.) 
 
DUEATION OF PSYCHIC ACTS. 285 
 
 occupied with really so small? It is evident that it teaches 
 us nothing of the ultimate nature of thought : observers 
 do not propose to tlfemselves this end, when they treat this 
 problem from the standpoint of experience. Science has 
 nothing to do with such insoluble problems. Its work con- 
 sists in resolving each wdiole called a fact, and submitting to 
 experiment and measure all its constituent elements. It can 
 do nothing more. Scientific knowledge of a fact is the com- 
 plete determination of its relations : what remains is the busi- 
 ness of metaphysic. 
 
 The process here is that pursued in every science. The 
 psychic fact — complex though it be — is studied in one of its 
 constituent elements : variations in duration. It would be 
 more profitable, no doubt, to penetrate other and more 
 essential conditions of thought, such as the physiological 
 variations of nerve structure; but each conquest opens the 
 way for farther progress and offers a new outlook. The de- 
 termination of the velocity of sensor and motor nerve action 
 appears to be of secondary importance only for psychology ; 
 and yet by it the psychic fact is driven nearer its ultimate 
 stronghold and the subterranean approaches, so to speak, 
 are opened up. Instead of the subjective method hitherto 
 exclusively employed in the study of the succession of 
 sensations and ideas, we employ an objective method which, 
 among other results, exposes the error of the supposition 
 that the internal order of representations reproduces imme- 
 diately the external order of phenomena. The experimental 
 method has also shown that consciousness is a discontinuous 
 series of states, separated by short intervals, together with 
 the manner and conditions of their variation. 
 
 We have given these facts, not as exaggerating their defi- 
 nitive importance, but as seeing in them the corner-stone of 
 a new structure, and in the method employed a sure promise 
 of its successful erection. 
 
 We can not close better than by quoting these reflections 
 
286 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 from Buccola : " It seems that this rigorous branch of 
 piiysiological psychology, psychometry, is destined to solve 
 many of the old problems. Its real and legitimate import- 
 ance in dealing with mental phenomena does not rest, as is 
 generally believed, in a simple search for numbers. Sus- 
 tained rigor of method and experiment must be employed 
 to apply to these numbers the test of analysis and to derive 
 the different moments of the psychic process. To this point 
 the most careful and unprejudiced study must be directed in 
 the future" (work cited, p. 33). 
 
CHAPTER YIII. 
 
 CONCLUSION. 
 I. 
 
 We have grouped under different titles and with the names 
 of men distinguished in this department, the researches from 
 which, it seems, most can be deduced for the positive study 
 of psychological questions. They are, as we have seen, of 
 recent date. After Kant, metaphysic reigned in Germany for 
 half a century, and all science of the phenomena of conscious- 
 ness was forgotten or despised. The reaction which followed 
 was not more favorable to psycliology. Men continued to 
 treat it as an illegitimate child of metaphysic and wrote 
 books which were epitomes of artificial, profitless, and insol- 
 uble questions ; discarded altogether a positive basis of fact, 
 and lost themselves in the interminable mazes of pre-estab- 
 lished harmony, physical flux, occasionalism, materialism, 
 and pantheism, in all their forms. Men seriously discussed 
 the relative merit of " traducianism " and " creationism." In- 
 stead of doctrine, we find history, an enumeration of conflict- 
 ing views, whose only effect is to make the conscientious 
 reader regret that he has lost so much time. 
 
 Yet even then, scientists, as it were by chance and through 
 the study of details, were preparing for the birth of scientific 
 psychology. The first workers stirred up others, who pur- 
 sued the same end by different routes. We have already 
 insisted many times upon the method which they were com- 
 pelled to employ, and it would be superfluous to give here 
 
 287 
 
i I 
 
 288 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 a list of their names and works. Under a guise of history, 
 our object is dogmatic. We have endeavored to bring before 
 the public a definite way of dealing with the phenomena of 
 consciousness and to show the results obtained by the method 
 of the natural sciences. Only what is new has arrested us. 
 So, in conclusion, we will pass rapidly in review some works 
 which are of lesser importance, it is true, but which it would 
 be unjust to leave unmentioned. 
 
 HOEWICZ. 
 
 I. It is not our intention to give a detailed exposition 
 of the theories of Horwicz. We wish only to indicate his 
 place in the contemporary movement and bespeak briefly 
 his part. 
 
 Horwicz is not a professional physiologist. Nor is he 
 an ideologist ; that is, his psychology is not simply an 
 analysis of ideas and words, after the manner of the 
 eighteenth century, and the method of some representatives 
 of the Scottish school, as Stuart Mill. He proposes to borrow 
 contributions from physiology and make them the point of 
 departure in his psychological study. The title of his work,^ 
 Psychological Analyses upon Physiological Bases, is well 
 chosen and expresses his object exactly. 
 
 Setting aside his theory of knowledge — the most ques- 
 tionable portion of his work, in our opinion, and least 
 suited to his turn of mind — ^we find in him the highest 
 qualities for psychological study; delicacy, penetration, 
 sometimes depth, ingenuity in framing hypotheses, and 
 aptitude in construing observations and details. Unfortu- 
 nately, he often lacks order in the general course of his 
 exposition. It is hard to connect clearly the diiFerent sub- 
 
 ^ Psychologisehe Analysen auf physiologischer Grundlage: ein Versuch zur 
 Nevhegriindung der Seelenlehre. 1st part, Halle, 1872, 2d part (2 vols.), 
 Magdeburg and Halle, 1875 and 1878. 
 
CONCLUSION — HOSWICZ. 289 
 
 jects of which he treats, many of them being discussed 
 again and again under différent headings. The misuse, 
 moreover, of divisions and subdivisions tends to embarrass 
 the reader. 
 
 His doctrine can not be reduced to a system or connected 
 whole ; but be it far from us to reproach him for this. 
 Psychology at present demands, above all things, a study 
 of details. Yet in this collection of analyses, we find it 
 possible to disengage two general principles whereby to 
 characterize the psychology of the author : 1st, he employs 
 the physiological method ; and 2d, he assigns to feeling the 
 leading part in the psychic life. 
 
 The data of consciousness, says Horwicz, serve only as 
 preliminaries ; they alford only an ordinary and rough 
 view of the activity of mind. They must be supplemented 
 by physiology. Physiology presents the organic conditions 
 of psychic phenomena, and is thus not a useful acces- 
 sory alone, but " the regular vehicle of research, the thread 
 of Ariadne." The author does not proceed as many others, 
 who make this avowal and then hasten to betake them- 
 selves to the old method, or content themselves with 
 paying a Platonic tribute to the natural sciences by scatter- 
 ing a few facts throughout their pages. He, on the con- 
 trary, makes a persistent effort to realize the spirit of the 
 biological sciences by the ultimate reference of all his ex- 
 planations to them. "A psychology," says he, "which 
 p]'ofesses to make the great discoveries of physiology useful 
 to the science of the soul must employ experiential data 
 tliroughout its entire domain. It must not be content, with 
 the old psychologists both empirical and speculative, with 
 arranging facts or explaining them in the line of a priori 
 construction. To take a particular case, it does not suffice to 
 show that some sensations are to be referred to objects with- 
 out (sense-perception), and others to the organism and its 
 states (organic sense) ; but we must know, if possible, the con- 
 25 
 
290 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 ditions, organic or otherwise, under which the two orders 
 of sensation are produced." ^ 
 
 Psychological questions take form for him strictly from 
 the point of view of observable phenomena, and he finds 
 in the metaphysical psychology only vanity and nonsense 
 (vbllige Eitelkeit und TollheU). " It must not be expected 
 that our method will attain to ultimate questions. What 
 is the soul, substance or accident ; what becomes of it at 
 death ; what relation does it sustain to body ; all these are 
 problems which are in no wise to be considered at the out- 
 set, at least, if they are ever to be brought into our inves- 
 tigation. Our warfare against materialism has no other 
 object than to keep the way open to true scientific research, 
 and in cases in which such research has no issue, to distin- 
 guish it from subjective beliefs and opinions, religious and 
 moral. We employ the word ' soul,' therefore, not in the 
 sense of an immaterial substance whose existence is to be 
 proved, but simply as the collective denomination of the 
 phenomena and processes called psychic." ^ 
 
 This being the general spirit of the method of Horwicz, 
 let us see its application to a particular case : the study of 
 feeling. To him, "feeling is psychic activity in its simplest, 
 most elementary, and most general form, and this activity 
 is point of departure for all the other psychic processes." 
 Feeling, therefore, plays the leading role in his psychology. 
 
 Four different views have had currency among psycholo- 
 gists as to the essential nature of feeling :^ 
 
 1st. What is advantageous to the organism is felt to be 
 agreeable ; that which injures it, disagreeable (Wolff, Kant, 
 Lotze with modifications). 
 
 2d. Feeling arises from contrast (Stiedenroth, Wundt). 
 
 ^ Pyschologische Analysen, I, p. lOO. 
 
 ^ Ibid., pp. 134, 135. 
 
 3 Ibid. II ; 2d part, p. 31, and fol. 
 
CONCLUSION — HORWICZ. 291 
 
 3d. The basis of all desire is lack, privation (Scliopeu- 
 haiier, Hartmann). 
 
 4tli. Feeling results from molecular equilibrium in the 
 nerve substance, and is therefore physiological. 
 
 No one of these theories is exclusive ; each implies the 
 others, partially, at least. The author shows, in a detailed 
 criticism, that no one of them is sufficient to explain the 
 nature of feeling. Yet of them all the last is most nearly 
 his, as he gives the following as one of the principal re- 
 sults of his critique : There is for every sentient organ, 
 and for the organism in general, a state of equilibrium, 
 about which the feelings gravitate, in such a way that ils 
 suspension is felt to be disagreeable, and its continuance 
 agreeable (p. 43). 
 
 But there is no stable equilibrium in the nerve substance : 
 cellular equilibrium is unstable, entirely relative. It can not 
 be considered, therefore, as a normal state, and we are led 
 to admit that what we feel is not a state, but a change in 
 the nerve substance ; in other words, the essence of feeling 
 is change, a becoming.' 
 
 If, conformably to the physiological method, we enter 
 farther into the nature of the nerve phenomenon with a 
 view to a better understanding of the psychic, we ascer- 
 tain that this state of unstable equilibrium, with its con- 
 tinual changes, favorable and unfavorable, — the author 
 [designates them by .the words contrasts — answers to a 
 imore general law of the entire organism : " Objective 
 fmolecular equilibrium has a subjective psychic correlate, 
 habit : to contrast, the new and unaccustomed corresponds " 
 (p. 50). To go still further, we find two molecular processes 
 in the organism : one, the storing up of disposable work 
 by the formation of complex combinations ; the other, the 
 
 ^ Work cited, part 2, vol. Ill, p. 41. The author cites in point Léon 
 Damont. The view of Herbart, given above, also comes to mind. 
 
292 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 disengaging of active force by the dissolution of these com- 
 binations : acquisition and outlay — molecular work negative 
 and positive. These correspond to the subjective processes 
 of self-conservation (Selbsterhaltimg) and change; habit 
 and contrast. This parallelism, questionable perhaps in 
 its rigorous sense, is exa(!t in a general way, habit corres- 
 ponding to the preponderance of the negative process, 
 contrast to that of the positive. ^ 
 
 From all these considerations, the author concludes that 
 " the essence of feeling is self-conservation, that is, the 
 mode of reaction with respect to change, a reaction that is 
 distinguished from purely physical reaction by autonomy 
 or spontaneity" (p. 51). Pleasure arises from strength in 
 the psychic life ; pain from feebleness and inertia (p. 55). 
 
 Feeling is closely connected, therefore, with the most ele- 
 mentary vital processes. 
 
 " My analyses," says Horwicz, " have a very definite end : 
 to refer to a fundamental psycho-physical element the totality 
 of the psychic processes." We have just given an example. 
 And if it be objected that only the feelings of a lower order, 
 the sinnliche Gefuhle, maintain this intimate connection 
 with the laws of life, the author replies that the higher 
 feelings are to be referred to the lower, for they are com- 
 plexes only, and consequently are to be referred by analysis 
 to the nerve processes (p. QQ). 
 
 We will not follow the author into his classification of 
 feelings ; it has nothing new,^ and lias been severely criti- 
 cised : it is better, following the plan we have adopted, to 
 show by an example the ruling part that he assigns to 
 
 ^ To sum up these terms, negative and positive work, acquisition and 
 outlay, habit and change, equilibrium and contrast, represent different 
 aspe-ts of one and the same process considered in the order of life, feel- 
 in?, or intelligence. 
 
 ^ He classes them as feelings of sense, aesthetic, intellectual, and 
 moral. 
 
CONCLUSION — HORWICZ. 293 
 
 feeling in the intellectual life. We will take the fact of 
 reproduction or memory/ 
 
 As a condition of Reproduction it is necessary that a trace 
 or residuum, to be utilized by memory, remain in the nerve 
 elements. Can this residuum be explained, as Volkmann 
 thought, by the law of persistence or conservation of energy ? 
 Horwicz does not believe that the persistence of representa- 
 tions consists in simple mechanical action, because sensation, 
 which is a reaction of the soul, differs in nature from 
 physical reaction in that it implies spontaneity. A sensa- 
 tion conserved is a tendency that persists. 
 
 Feeling (Gefuht), to Horwicz, is the cause of the sus- 
 pensive action whereby representations are held in an 
 unconscious state, and is, at the same time, "the vehicle 
 of the association of ideas, that is, the cause of their return 
 to consciousness." The basis of the fact of the conserva- 
 tion of residues is a persistent tendency to movement, a 
 tendency to respond to an excitation determined by a deter- 
 mined movement. This the essential nature of memory 
 (the persistence of a tendency to movement), although often 
 concealed, is sometimes manifested to us in a striking way. 
 Many of our memories are accompanied by movement. In 
 cases in which there is no movement proper, some analogous 
 phenomenon appears : for example, if I picture a lemon to 
 myself, the idea of eating the fruit produces a secretion of 
 saliva, which can be considered the equivalent to movement. 
 
 The question here is only of the simplest cases, that is, 
 of the forms of feeling which accompany sensation and are 
 followed by movement. The higher forms, like theoretical 
 ideas, escape our analysis. Yet we can suppose that the 
 case is analogous with the more complex forms. 
 
 Our theory, adds Horwicz, accords well with the well- 
 known fact that the feelings themselves have a very feeble 
 
 * Psychol. AnalyseUf II, p. 276 and fol. 
 
294 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 power of reproduction (we have, for example, only a feeble 
 representation of a past tooth-ache), and, indeed, explains 
 it. At first siglit, this seems a contradiction ; for if feeling 
 plays the part we assign to it, how is it that it is not most 
 readily reproduced ? " This exception proves our rule. 
 It is not, in fact, the feeling itself that is the elementary 
 factor of memory ; but it is feeling in its necessary relation 
 to movement and the manifestations which follow. Feeling 
 is the mediator, not the immediate ground of association. 
 This explains the fact that feeling rules and determines the 
 internal combinations, and at the same time is itself with 
 difficulty reproduced." 
 
 This function of feeling explains a point in respect to 
 the laws of association, also, which has been hitherto 
 obscure, and indeed, inexplicable. 
 
 The new psychology reduces these laws to two : 1st, law 
 of contiguity in space and time ; 2d, law of resemblance 
 (identity, analogy, contrast). It is plain, however, that 
 contrast can not enter in the action of the law to which it 
 is assigned, without violence. We are compelled, on this 
 hypothesis, to say that contrast is a kind of resemblance, 
 that is, that there is no association by contrast. For if 
 contrary ideas awake each other only by what they have in 
 common, analogy and not contrast is the ground of the 
 association, A desert ought to make us think of other 
 deserts, and not, as is often the case, of fertile country. But 
 this and analogous cases are really explained by the func- 
 tion of feeling. It is a characteristic of feeling that its two 
 opposing forms, pleasure and pain, have a reciprocal depend- 
 ence. The same feeling is produced sometimes under the 
 form of a tendency to reconciliation, sometimes a tendency 
 to separation. The ideas corresponding to these two con- 
 trary forms must, therefore, be intimately connected. 
 
 In a general way, feeling to Horwicz is the original 
 psychic fact. Every representation has been once a feeling, 
 
CONCLUSION — EEENTAKO. 295 
 
 and ail knowledge is inert and profitless^ unless feeling work 
 it up like leaven. "It is very difficult," says Horwicz, "to 
 act on merely thecft-etical knowledge. All men know very 
 well that time, and health, and money, should be econo- 
 mized ; but many do it not. It is necessary, in most cases, 
 that our knowledge be changed into will as food is changed 
 into chyle and blood. An intermediate factor is needed to 
 change knowledge into desire, as diastase changes starch 
 into sugar. This factor is feeling. The idea, accompanied 
 by a feeling, is changed into a desire corresponding to this 
 feeling ; otherwise, nothing takes place." ^ 
 
 Such are the principal features, to our mind, of the unfin- 
 ished work of Horwicz. We give them to the reader only 
 as suggestions. 
 
 BEENTANO. 
 
 II. In the contemporary movement in psychology, there 
 are two currents which may be characterized as follows : 
 
 The representatives of the old psychology, that is of a 
 heterogeneous mixture of facts, descriptions and metaphys- 
 ical hypotheses ; 
 
 The representatives of the new psychology, that is, those 
 who exclude all metaphysics and confine themselves to 
 actual phenomena. 
 
 But among the latter, two tendencies must be distin- 
 guished, the ideological or logical and the physiological. 
 It is not necessary to mention names. Every reader who 
 has kept up at all with the philosophy of the last fifteen 
 years will recall them himself. 
 
 To the first of these tendencies belongs Franz Brentano, 
 at present professor-ordinary in the University of Vienna. 
 He passes in Germany as a disciple of Stuart Mill, who, 
 like himself, has no physiological leaning. And thereby 
 
 * Psychol, Analysen, I, pp. 152, 153. 
 
296 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 he is distinguished from Horwicz, although he is as clearly 
 empirical. 
 
 " My point of view/' says he, " in psychology, is empirical ; 
 experience is my only master ; but I share with others the 
 conviction that a certain ideal intuition (eine gewisse ideals 
 Auschauung) is perfectly tenable from this point of view." 
 In the place of psychologies, we must seek to establish 
 a psychology. " We find already the beginnings of a 
 scientific psychology, modest as yet ; but there are signs of 
 a possible development that will bear abundant fruit for 
 future generations." ^ 
 
 The first part of Brentano's work is devoted to a de- 
 tailed study of the question of the nature of psychology 
 and its method. 
 
 Psychology may be conceived in two ways : either as the 
 science of the soul — ^this is the old conception — or as the 
 science of psychic phenomena — ^this is the new conception. 
 The first has led to the second in this way. It has been 
 often remarked that alchemists in seeking for the philoso- 
 pher's stone, that is, for the undiscoverable, have found 
 what they did not seek ; positive facts, which have given 
 birth and development to chemistry. Metaphysicians have 
 done the same. To them the great problem has been the 
 immortality of the soul. While their seeking has been 
 unceasing and unsuccessful, they have found that for which 
 they did not seek : facts, observations, by which psychology 
 profits anew. In their pursuit of a transcendent problem, 
 they have discovered the laws of reasoning, the associa- 
 tion of ideas, the formation of concepts ; they have studied 
 the desires and passions. Like the children of the old 
 man in the fable, they sought a pretended treasure buried 
 in the earth, and they found riches of another kind. 
 
 ^ Psychologie vom errvpirischen Standpunkte. 
 1st volume has appeared), Vorwort, p. 1. 
 
 Leipzig, 1874 (only the 
 
CONCLUSION — ^BEENTANO. 297 
 
 The author shows, on exœllent grounds, that the devel- 
 opment of psychology is conditioned upon the previous 
 constitution of the'subordinate sciences. After defining it 
 as " the science of psychic phenomena," he remarks that 
 this new conception of psychology is entirely unacceptable 
 to the disciples of the old school. Whether there be a soul 
 or not, it is certain that there are psychic facts. The dif- 
 ference between the two conceptions is this : the old is 
 encumbered with metaphysical hypotheses, and the new is 
 entirely free from them. The latter is occupied with facts 
 common to all schools, while the former is colored by the 
 claims peculiar to its own. The comparison certainly 
 casts no credit upon the old psychology. 
 
 The practical importance of the scientific psychology is 
 indisputable. The author, who insists properly upon this 
 point, shows such confidence in future results that he does 
 not hesitate to call psychology " the science of the future." 
 
 The object of psychology thus fixed, we turn to the 
 question of method. It is here that Brentano, while main- 
 taining his empirical position, separates from the physio- 
 logical school. The principal source of psychology to him 
 is internal perception (innere Wahrnehmung), which must 
 be carefully distinguished from internal observation {innere 
 Beohachtung). The author attaches the greatest import- 
 ance to this distinction. Observation, says he, applies only 
 to external objects ; internal observation is impossible. It 
 is the confusion of these two distinct states, observation 
 and perception, that has given rise to the objections brought 
 against the subjective psychology by Comte in France, 
 Maudsley in England, and Lange in Germany. 
 
 Brentano admits, indeed, that by memory a retrospective 
 study of the states of consciousness is possible ; but, since 
 memory is subject to illusions and errors, psychology is at a 
 great disadvantage in the race with the other natural sciences. 
 
 Besides the data of internal perception and memory, the 
 
298 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 author, as every one else, indicates as helps to psychology, 
 the study of language, human conduct, history, mental 
 diseases, etc. 
 
 Setting out with these facts, we seek to rise to laws purely 
 empirical. Yet the author does not admit that the higher 
 laws of psychology should or can be deduced from physi- 
 ology, and he criticises Horwicz and Maudsley on this 
 point at length. Maudsley has made a lively attack on 
 the subjective method in the introduction to his Physiology 
 and Pathology of Mind. He miglit have said what fol- 
 lows, written against Stuart Mill, most appropriately of 
 Brentano : " Mill was wrong in neglecting the physiolog- 
 ical method, which would have brought such fruitful results 
 to psychology ; in imagining that, by the old process, 
 based upon internal perception, he could attain that which 
 Plato, Descartes, Locke, Berkeley, and so many others, 
 have failed to attain. We have the sure conviction that 
 thousands of men like Mill can not do what these great 
 men have failed to do ; while if he had employed the ma- 
 terial furnished by the new method, which was not at the 
 disposal of his great predecessors, he would thereby have 
 acquired better results than they all." 
 
 Brentano also criticises the work of Weber, Fechner, 
 and Wundt, in psychophysics ; not that he disowns its 
 value, but because he is opposed to all attempts at quanti- 
 tative determination in the order of psychic phenomena. 
 He reaches this conclusion : that psychology must rest 
 content with empirieal laws. 
 
 The second part of his book treats of psychic phenom- 
 ena in general." Their essential character to Brentano is 
 that they are representative : in other words, psychic state 
 = representation. On this point he approaches Herbart : 
 " All psychic states are representations, or are based upon 
 representations." This leads him to a more and more 
 exact determination of this representative character. 
 
CONCLUSION — BEENTANO. 299 
 
 Wherein does it consist? In the relation between a 
 psychic phenomenon and its object. It is generally main- 
 tained that every*intellectual act supposes an object ; intel- 
 ligence is objective : but to feeling, to sensibility in general, 
 we do not attach an objective character. On this point, 
 Brentano recalls Hamilton, who argued this distinction at 
 length ; he rejects it as erroneous. " Joy, hate, love," says 
 he, " are always related to something." 
 
 If we admit this view in regard to feeling, it follows that 
 the character of " intentional existence " — as the author ex- 
 presses it, borrowing the term from the scholastics — is to be 
 found in all psychic activity ; indeed, is its fundamental 
 characteristic, since the intellectual states and the desires 
 necessarily relate to something. " Every psychic phenome- 
 non is related to an object ; without the object nothing of 
 the kind exists." 
 
 This point established, the author passes to the study of 
 consciousness in general, and opens a campaign against the 
 unconscious. He makes attacks especially upon Hartmann 
 and " his arbitrary a priori speculations." But, in a general 
 way, it would be difficult to reconcile the ideological method 
 of Brentano with the hypothesis of an unconscious activity 
 of the soul, for internal perception knows only its own 
 domain and never leaves it, and if psychology is rigorously 
 confined to the limits of consciousness, we are false to our 
 psychology, when we overstep these limits.* 
 
 The third part has a classification of the phenomena of 
 consciousness. Brentano makes three classes or funda- 
 mental forms of psychic activity : 1st, the representation ; 
 2d, the judgment ; 3d, tendency and desire, or, more simply, 
 
 ^ He explains and discusses four hypotheses, which, according to him, 
 are capable of being advanced in favor of unconscious ps_vchic activity. 
 This discussion does not seem to be above criticism : but it is long and 
 profound, and whatever one's opinion be, he should read it. See work 
 cited, pp. 131-176. 
 
300 
 
 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 love and hate. This division is unexpected enough, but 
 the author himself does not apologize for its novelty. He 
 gives at length (chaps. VII and VIII) his reasons for 
 making an essential distinction between the representation 
 and the judgment, and for making feeling and will origi- 
 nally one. The remainder of the work is to be devoted to 
 a detailed study of these three groups. 
 
 It is impossible to pass just judgment upon a book of 
 which only half has been published. We have only tried 
 to show in what respect Brentano, while holding fast to 
 empirical psychology, is separated from the group of phys- 
 iologists. The impression we gather from the study of his 
 work is, that although the ideological school may show 
 more delicacy and aptitude in analysis than the physiologi- 
 cal school, and, although they confine themselves more 
 closely to what is strictly psychological, yet their method 
 leads them into serious mistakes ; arbitrary classification, 
 too much reasoning, and too little fact. 
 
 III. Besides more extended works, there are some recent 
 monographs that should be mentioned in passing, as show- 
 ing the extending taste for psychological study in Germany. 
 
 The Vienna anatomist Strieker, in short discussions on 
 consciousness, language, the representation of movement, 
 and the association of representations,^ has made important 
 contributions to the study of movement and its integral and 
 necessary part in the psychic life. We may also mention 
 Kussmaul, who, in his book die Storungen der Sprache 
 (recently translated into French), has given us a very inter- 
 esting monograph on the disorders of language. 
 
 A naturalist, G. H. Schneider, devoted to the theory of 
 evolution and familiar with the doctrines of Darwin and 
 
 ^ Studien vher das Bcwusstsein. Studien uher die Sprachvorstellungen. 
 Sludien uher die Bewegungsvorstdhmg. Studien uher die Association der 
 Vorstellun-gen. Vienna, 1879-1883. 
 
CONCLUSION. * 301 
 
 Plœckel, gives to the public a chapter in comparative psy- 
 chology, tracing the development of will from the lower 
 forms of life up t*o man/ Feeling, in its most general 
 sense, is the basis of the psychic life. Feeling has its cause 
 in the organism, that is, in the vital animal processes, and 
 the different kinds of feeling are conditioned upon differ- 
 ences in the corporeal organization. The problem of the 
 origin of feeling, therefore, has its root in the problem of 
 animal life. Just as among the infinitely diverse chemical 
 combinations found in nature, there is one which gives 
 rise to conditions that produce a living substance capable 
 in turn of producing other living substances ; just as, in a 
 word, life is only a special case in an infinity of cases : so 
 feeling is only one case among innumerable possible combina- 
 tions; and it is not more difficult to conceive of feeling com- 
 binations born of combinations not feeling, than of living be- 
 ings born of things not living. Quite recently Schneider 
 has studied pleasure and pain from the same evolution-point 
 of view, and drawn practical moral and social conclusions 
 which are very optimistic. To him both pleasure and pain 
 have positive value. The whole question is to know their 
 function when taken together ; and this question is solved 
 by the ultimate law of biological evolution, which would 
 be impossible without the predominance of processes by 
 which progress is assured. 
 
 "We must mention also the experimental researches in 
 cerebral localization of Meynert, Fritsch and Hitzig, Exner, 
 Munk, &G. The psychological interpretation of these 
 experiments, however, is very incomplete and uncertain. 
 And it is far from being exclusively German work. 
 
 Outside of the Naturforsclier, and among the purely 
 philosophical schools, the Neo-kantians, very numerous just 
 now, have best served the interests of the new psychology. 
 
 ^ Der ihierhche Wille (1880). Der menscklische V/Ule (1882). 
 26 
 
302 GERMAN PSYCHOLOGY OF TO-DAY. ' 
 
 In general, their work has had a slightly different end, the 
 theory of knowledge ; but the Vierte/jahrsschriftfurmsse'n- 
 sehaftliohe Philosophie, founded in October, 1876, has 
 favored psychological research in its scientific tendency and 
 published important articles in this direction. 
 
 II. 
 
 "While contemporary psychology in England, in spite of 
 many individual variations, has been properly called asso- 
 ciationism, for the reason that it makes the law of associa- 
 tion fundamental in the mechanism of mind, there is no 
 general conception to serve us in grouping the foregoing 
 researches in Germany. As concerns the spirit and method, 
 common to the authors of whom we have spoken, there is 
 only one subject that serves to group their work as a con- 
 nected whole : it is the subject of sense perception, under- 
 standing it in its broadest sense : its immediate conditions 
 and its immediate consequences. 
 
 Let us try to sum up under this principle the leading 
 results of the German psychology, neglecting all that does 
 not properly belong to it. 
 
 The first striking point is the study of the elements of 
 simple sensation. The elements of the simple — this seems 
 a contradiction. But it is one of the rewards of the physi- 
 ological psychology that it has shown that the simple in 
 consciousness is really complex, a synthesis. It is true 
 that the experiments of physicists had long before prepared 
 the way for this conclusion ; and it would have been 
 reached sooner if psychology, confined to thé Ego, and 
 exclusively given to internal observation, had not looked 
 upon these researches as foreign and unprofitable, as causes 
 of distraction which it was bound to ignore. Wliile physi- 
 cists were very far from the phenomena of consciousness 
 and psychologists were ignoring the matter, physiologists 
 
CONCLUSION. 303 
 
 were led, by their experiments, to the very point at which 
 the physiological and mental meet; and thus made a study, 
 sometimes all unconsciously, of elementary sensation. It is 
 therefore, just to give physiological psychology — whose prin- 
 cipal representatives are in Germany — the credit of having 
 inaugurated an order of research in which more recently 
 psychologists have borne a good part.^ Helmholtz,^ above 
 all, deserves signal mention. His studies on physiological 
 acoustics, especially the experiments by M^hich he proved 
 that timbre, the quality which seems so indefinable, is due 
 to complementary notes grouped about the fundamental in 
 definite relations, showed that the immediate physical cause 
 of sensation is a complex group of elements, each of which, 
 in its variations, causes corresponding variations in the sen- 
 sation. 
 
 The lowest state of consciousness, the perception of sound 
 and color ; the simplest form of sensation, stripped of all 
 association, all localization, — these are still complex. A 
 sotmd has pitch, intensity, timbre, corresponding with the 
 number, amplitude, and form of its vibrations. A sen- 
 sation of color, in the same way, depends upon the velocity 
 of ether vibrations and their wave lengths. Setting aside 
 all hypothesis as to the transformation of nerve phenomena 
 into psychic phenomena, and restricting ourselves to the 
 question of fact, it is not possible to consider as simple a 
 state of consciousness which varies with its immediate con- 
 ditions. If the impression is different, the nerve processes 
 (probably molecular movement in the nerves and cells) are 
 different, and the sensation is different. Physiological ex- 
 periment, with the aid of subjective analysis, tends to 
 reveal, in the mental world, something analogous to the 
 
 ^Herbert Spencer, Pririciples of Psycholoçjy, part 2, chap. 1. See 
 especially the excellent study of M. Taine on the elements of sensation. 
 The Intelligence, part 1, book III, chaps. 1 and 2. 
 
 * Helmholtz, Physiologisehe Théorie der Musik, part 1, chaps. 5 and 6. 
 
304 GERMAN PSYCHOLOGY OF TO-DAY. 
 
 atoms of the physical world. It can be certainly said, 
 however, that psychology has no more to do with these ele- 
 ments of elements, than physics and chemistry with atoms ; 
 that it is an ultimate question which may be remanded to the 
 sphere of metaphysic ; that psychology has only to build 
 upon the elements as they appear, as the physico-chemical 
 sciences build upon matter in its ordinary simplicity and 
 with its elementary properties. But the researches of physio- 
 logical psychology throw light into the dark laboratory 
 whence consciousness proceeds. For here only two hypo- 
 theses are possible : either we must admit with Leibnitz, 
 that " since a hundred thousand nothings can not make 
 something," the so-called simple sensation is made up of 
 a sum of elementary states which are excluded from con- 
 sciousness by reason of their feeble intensity or short 
 duration ; or we must admit that this simple sensation 
 results from a synthesis of heterogeneous elements, and 
 sustains to them the same relation that a combination in 
 chemistry sustains to the elements of matter. 
 
 Whatever hypothesis we hold, we must admit that the 
 states of consciousness known as simple, and which, for 
 consGÎousness, are simple, are in fact complex. The decis- 
 ions of consciousness appealed to so often by psychologists 
 of a certain school as to an ultimate umpire, have therefore 
 only a relative authority. It is not an infallible oracle. 
 It is a witness like any other, often deceived and deceiving, 
 and never utters the dictum of absolute truth. This is 
 what the physiological psychology teaches us as the result 
 of its investigation of a question which is apparently so 
 modest. 
 
 If we pass from the elements of sensation, to sensation 
 itself, or rather to perception, as an act of real knowledge, 
 we find that the German psychology has been most fruitful 
 in dealing with touch, sight, and hearing. It has treated 
 them, after its own method, always in connection with their 
 
CONCLUSION. ' 305 
 
 physical conditions, considering these conditions not as acces- 
 sories merely, but as essential and necessary data. 
 
 In auditory perception, two principal results are to be 
 noted ; one, important for psychology, the more complete 
 reduction of sensation to its elements ; the other, import- 
 ant for aesthetics, an efiPort to give a scientific basis to the 
 aesthetic of sound. ^ 
 
 In the sphere of touch and sight, the most original in- 
 vestigation has been made upon the Ortsinn, the faculty of 
 localization, that is, the processes by which tactile and 
 visual data are located in space. Two important elements 
 enter in this question : local signs and movement. 
 
 The hypothesis of local signs is peculiarly German. 
 Although, as we have seen, it has many forms, yet it is 
 always fundamentally the same. Somewhat vague, and 
 loaded with metaphysic with Lotze, it takes a more definite 
 form in the later publications of Wundt. It still involves, 
 however, many obscure points. Essentially, the position is 
 this ; each sensible element of the retina and skin gives to 
 sensation " a peculiar coloring," whereby the mind performs 
 its later work of transforming this qualitative modification, 
 by means of movement, into a relation of position. 
 
 The role of effective movement, of simple tendencies to 
 movement, and the accompanying sensations of innerva- 
 tion, has been studied with the care we would expect from 
 a school of physiologists. This subject had never before 
 been treated so extendedly and with so much exactness. 
 
 These researches on the localization of tactile and visual 
 perceptions have led German psychologists to a higher 
 question : what is the origin of the notion of space ? ^ 
 This problem, which belongs properly to the theory of 
 
 ^ See Helmholtz, Physiologîsehe Théorie der Musih, especially the pre- 
 face and last chapter. 
 
 * They are concerned, as we have said many times, only with the 
 empirical genesis of this notion. 
 
I 
 
 306 GEEMAN PSYCHOLOGY OF TO-DAY. 
 
 knowledge, has yet been treated by the method of physio- 
 logical psychology; theories have been constantly tested by 
 experiment. 
 
 There are two solutions yet in the field. 
 
 Nativists maintain that the order of tactile and visual 
 sensation has its ground in the constitution of the organ- 
 ism, that it is given originally with the organism, and is 
 consequently innate. 
 
 Empiricists, basing all upon the influence of association 
 and habit, attribute the fact of tactile and visual localiza- 
 tion to experience, both as to development and origin. 
 
 Heretofore, the latter theory has constantly gained 
 ground upon its rival, but has never resolved all the diffi- 
 culties of the problem. Under one form or another, the 
 same inquiry always arises. Can scientific processes show 
 that the simple and intuitive in consciousness is comjjlex 
 and derived ? The problem of sensation becomes here the 
 problem of the notion of space. By this marked analytical 
 tendency, German psychology has done much to solve the 
 problem that seems upon its face so easy ; to distinguish the 
 fact from its interpretation, the sensation from the inference 
 that accompanies it. 
 
 The study of abstract concepts (time, number, etc.) falls 
 outside the province of physiological psychology, and has 
 been made incidentally only. It bears, in general, how- 
 ever, the mark of Kant. 
 
 One of the newest and most daring attempts of German 
 psychology is its application of quantity and measurement 
 to states of consciousness. Herbart made the first essay, 
 systematic, arbitrary, and ambitious in extent. Since his 
 time the mathematical method has given place to the ex- 
 perimental. 
 
 Two points only have as yet seemed open to investiga- 
 tions of this kind : 
 
 1st. The relation between sensation and excitation — re- 
 
CONCLUSION. 307 
 
 duced to formula by Feclmer in his celebrated logarithmic 
 law, which has been bravely defended, but as bravely con- 
 tested ; « 
 
 2d. The duration of psychic acts — minutely studied in 
 the following cases : 
 
 Impression known, but not determined as to the time of 
 its appearance ; 
 
 Impression known and determined as to time ; 
 
 Impression accompanied by another, like or unlike in- 
 discriminately ; 
 
 Regular series of perceptions in which a new perception 
 is intercalated ; 
 
 Comparison between the real duration and its reproduc- 
 tion in memory ; 
 
 Time necessary for the different kinds of association ; 
 
 Duration of judgment, choice ; 
 
 Influences and pathological variations. 
 
 There is little to say in regard to feeling. It is a ques- 
 tion with which physicists and physiologists have less to do. 
 
 Yet here the influence of Herbart predominates : feeling 
 is held to be, not an elementary state, but the resultant of 
 a reciprocal relation between sensations and ideas. It is not 
 a state, but a change. 
 
 Quite lately, feeling and will have been studied from 
 an evolution point of view, and connected with the funda- 
 mental laws of life. 
 
 In this epitome of results, we have said nothing on the 
 subject of method; that has been sufiicieutly explained. 
 And we have touched upon the essential only, that the 
 ends proposed by the authors themselves might be clearly 
 understood. 
 
 THE END. 
 
T 
 
Elements of Moral Science, 
 
 Theoretical and Practical. 
 BY NOAH PORTER, D.D., LL.D. 
 
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