3srrrntTT M i MnH>M *in iii^»>M i i hihui i linn 111 rniMM Hiii f ii - ,— » .-,~, — , , , ■ «. , -i THE RELATION OF PSYCHOLOGY JO PHILOSOPHY, ViTTrr?iiP IB fnrrnTmrr timm/P- m 1, 1 1- OS! t M£f Class_„6i4i Book JYU5L GopyrightN - COPYRIGHT DEPOSIT. THE RELATION OF Experimental Psychology TO PHILOSOPHY. LECTURE DELIVERED BEFORE THE ROYAL BELGIAN ACADEMY BY Mgr. desire merger, Professor of Philosophy at Louvain, and Director of the Institut Sufdrieur de Philosophic TRANSLATED FROM THE FRENCH BY Rev. EDMUND J. WIRTH, Ph.D., D.D., Professor at St. Bernard' 's Seminary, . Rochester, N. Y. New York, Cincinnati, ChicAg6: ' ' BENZIGER BROTHERS, Printers to the Holy Apostolic See, 1902. Btbfl ©bstat OWEN McGUIRE, Ph.D., D.D., Censor Deputatus. Umprfmatur, ^JNO. M. FARLEY, Administrator of New York, New York, July i, 1902. ■■"library of] cowgress, •: :J902 - <£?OCa No, copy g. Copyright, 1902, by Benzig # er Brothers. TRANSLATOR'S PREFACE. Experimental Psychology, the youngest of the natural sciences, is a product of our own days. In a few years it has grown to such an extent as to leave no doubt that it has come to stay, and is not merely a fad of the passing hour that can be ridiculed out of existence. This remarkable growth is especially apparent in our own country. Since the establishment of the first psychological laboratory by Stanley Hall at the Johns Hopkins University in 1881 these laboratories have multiplied so rapidly that there is now no university or academy of higher studies in the country that does 3 4 Translators Preface. not boast of a psychological laboratory, and consequently we number more such laboratories in America than there are in the rest of the world put together. In view of this fact the question presents itself to Catholic philosophers, and for that matter to all students of philoso- phy, What are we to think of this new science? Is it necessarily material- istic in its methods and tendencies ? Can it be brought into harmony with a spiritualistic philosophy ? This ques- tion is imperative ; it can no longer be ignored. To furnish the student of philosophy with an answer to this pressing question was the purpose of the author of the discourse before us. The position taken needs no defence. The words of the author are clear, and contain their own justification. As the author is known in America Translator's Preface. 5 only through his French works, it may not be amiss to say a few words con- cerning him and his method in philos- ophy. Soon after our Holy Father Leo XIII. had exhorted the Catholic world by his memorable encyclical " (Eterni Patris" of August 4, 1879, to return to the sound principles of St. Thomas in philosophy, he turned his eyes to the old university of Lou- vain and desired that a chair of Tho- mistic philosophy be erected there.* This chair was accordingly founded and entrusted to Mgr. Desire Mercier, and classes were opened in October, 1882. The success with which Mgr. Mercier expounded the doctrine of St. Thomas induced the Holy Father to en- large his scheme. He asked the bishops * Letter of Pope Leo XIII. to Cardinal Dechamps, Dec. 25, 1880. 6 Translator's Preface. of Belgium to erect an institute after the model of the Roman schools for the more thorough teaching of Thomistic philosophy.* The bishops carrying out the wish of His Holiness founded such an institute and placed it in charge of Mgr. Mercier. At the same time they founded the Seminaire Leon XIII., where the ecclesiastical students that follow the course of the institute might receive an ecclesiastical training under the guidance of Mgr. Mercier. It was now that the ardent lover of philosophy saw himself enabled to carry out a work which had been the subject of his thoughts and meditations for years. He recognized the great harm done by a false philosophy, and believed firmly that the cure was to be * Letter of Pope Leo XIII. to Cardinal Goossens^ July 15, 1888. Translator's Preface. 7 sought in a return to St. Thomas, the great doctor of the Middle Age. He saw too that the return which was be- ing made had for some reason or other very little influence upon the world; men not belonging to the school treated it as non-existing. The principal reason for this he recognized to be the preju- dice that every Catholic philosopher was in every case nothing but an apolo- gist for his Credo. To remedy this he decided that it was necessary to create a Thomism that would be more than a mere "ancilla S. Theologise" ; a philos- ophy for philosophy's sake ; one that could go out and meet philosophers on their own ground ; one that was able to live in the atmosphere of our age, and did not need to be galvanized into life continually by authority. This was his first thesis. 8 Translator's Preface. Just as philosophy without being in- different to theology was to be studied for its own sake, so also science. The atmosphere of our age is preeminently a scientific one, and we must either ac- cept the conditions of life or refuse to live. Speculation can have no value if not based on facts, and these are fur- nished by scientific investigation. The data of science, then, cannot be neg- lected in philosophy, if it proposes to live and influence the world. His sec- ond thesis, therefore, was to study the sciences and to harmonize their results with the principles of sound philosophy. How well Mgr. Mercier has carried out his programme will be apparent to any one who will take the trouble to ac- quaint himself with the work of the in- stitute. He will find there a complete course of the sciences, with laboratories Translator's Preface. 9 and apparatus such, as no other Catholic college can show in connection with a philosophical course.* He will find that no question of philosophy is treated without an ample explanation of its relation to questions of science. The results of scientific research are used continually to furnish a basis for speculation and to confirm the conclu- sions of reason. It is principally on this account that Mgr. Mercier has been one of the few Catholic philos- ophers that have been able to break the conspiracy of silence on the part of non-Catholic philosophers against Thomism. We need only allude to the * M. Binet in the Annee Psychologique says : "For the course of M. Thiery (professor of Experimental Psychology at the Institute) there is a laboratory and complete equipment for physiological psychol- ogy such as does not exist at present in all France." Since this was written in 1896 one has been founded at the Sorbonne after the model of that at Louvain. 10 Translator's Preface. articles on !N~eo-Thomism that have ap- peared in the Revue PMlosophique, the Annee Psychologique, the Kant- studien, the Zeitschrift fur PsycTio- logie und Physiologie der Sinnesor- gane, the Revista Critica of Morselli, the Revista Filosoftca. As additional evidence of this we may also mention the invitation which has been extended to him by the Brit- ish Government to appear before the 4 ' Royal Commission on University Edu- cation in Ireland 55 to offer suggestions relative to the philosophical course in the proposed University of Ireland. This then is the purpose Mgr. Mer- cier has set to himself in his life's work, and this some of the success already attained. May the good work prosper. Edmund J. Wirth. THE RELATION OF EXPERIMENTAL PSY- CHOLOGY TO PHILOSOPHY. Ladies and Gentlemen: The subject of the lecture which I have the honor to deliver before you is "The Relation of Experimental Psy- chology to Philosophy." If a philosopher had pronounced the word Experimental Psychology in 1820 or 1850, he would have astonished, not to say scandalized, every one. ' ' What, ' ' they would have exclaimed, "experi- ment on the soul ! Is not the soul by its very definition invisible and inaccessible to our senses, and hence to experiment ? 11 12 The Relation of Do not the operations of the soul ema- nate from a principle that is spiritual in its nature, and therefore independent ? Are not its acts for this reason above material laws and measurements ? But if this be the case, how can there be an experimental science of the soul ; since without laws it would not be a science, and without processes of measurement not experimental ? " The spiritualistic philosophers of the first half of the nineteenth century — Cousin, Jouffroy, Gamier — in conform- ity with Des Cartes, taught that the soul had but one means of knowing itself, and that this was to contemplate itself by means of the eye of inner conscious- ness. The task of the psychologist ac- cording to them was limited to the ana- lyzing, describing, and arranging of one's inner acts in distinct categories Experimental Psychology to Philosophy. 13 under the various faculties that elicited these acts. This comprised all the psychologist was supposed to do. Inner consciousness, made by these philosophers the sole means of the soul's information, seems at first sight a very unsafe one. Has it not been abused continually? Does not the very fact that you submit a mental state to the scrutiny of consciousness modify more or less profoundly the nature of the state which is to be examined ; so that consciousness itself will falsify the re- sults of its analysis ? Auguste Comte has gone so far as to declare interior observation physically impossible. " It is obvious," he writes, " that by an in- vincible necessity the human spirit can observe directly all phenomena except its own. We understand that a man 14 The Relation of can observe himself as a moral agent, because in that case lie can watch him- self under the action of the passions which animate him, precisely because the organs that are the seat of these passions are distinct from those that are destined for the functions of obser- vation. . . . But there is a manifest im- possibility to observe the intellectual phenomena whilst they are being pro- duced. The individual thinking cannot divide himself in two, so that one-half should think and the other watch the process. Since the organ observing and the one to be observed are identical, there can be no self-observation. This so-called psychological method, there- fore, is radically wrong in principle."* Des Cartes had divided the objects of human knowledge into two vast classes: *Cours de philosophie positive, liere le9on. Experimental Psychology to Philosophy. 15 the one comprising matter, extended, divisible, subject to mechanical laws, and consequently knowable by ex- ternal observation; the other, simple beings, spiritual, endowed with thought, and knowable by internal observation only. This division of human knowl- edge was accepted more or less for- mally by the majority of thinkers down to the middle of the nineteenth cen- tury. Under the influence of Gilbert (1540- 1603), Galileo (1564-1642), Pascal (1623- 1662), Huyghens (1629-1695), Newton (1642-1727), Fresnel (1788-1827), Am- pere (1775-1836), Faraday (1791-1867), and many other illustrious men the natural sciences had made marvellous progress. This was principally due to the development of the experimental method, at the same time inductive 16 The Relation of and mathematical. In 1842 Mayer dis- covered the mechanical equivalent of heat. It was found that a law of cor- relation ruled the forces of nature. No force is produced without the loss of another ; none disappears without giving place to another. The idea of consider- ing all natural forces merely as different forms of mechanical energy and of ap- plying to them the law of the conserva- tion of energy thus gradually prevailed. Kepler had long before prepared the mechanical theory of the heavens; Newton wrote the first chapter; La- grange, Laplace, LeVerrier continued the work. Chemistry began to be con- sidered as made up of a relation of weights. The efforts of a great many chemists were directed towards tracing chemistry and mechanics to a common parentage. The discovery of the Abbe Experimental Psychology to Philosophy. 17 Hauy gave Crystallography geometrical laws and promised to reform the science of Mineralogy. On the other hand, the relations of human Physiology to Chemistry and Physics became closer from day to day, so that the attempt made by Des Cartes in his Traite de Vhomme to give a mechanical explanation of the functions of organisms seemed no longer impossi- sible. At the same time Darwin pushed the biological sciences into new meth- ods. Henceforth organisms were no longer to be merely observed under the microscope, described according to their specific type, arranged in their order, class, and family; the laws of their origin was to be the important ques- tion. Schwann' s discoveries created the sciences of cellular biology and histol- ogy. Embryology was being studied 18 The Relation of and gave hopes of results. In a word, all the natural sciences had received a new impetus. Everywhere, then, scientific discover- ies, and at times even superficial hypoth- eses which seemed to be favored by discoveries, tended to develop the ex- perimental method in the study of the natural sciences. They made men sim- plify by analysis, give precision to their results by measurements, generalize by calculation. The relation between or- ganic kingdoms was substituted for simple description. The question arose naturally enough whether in this new movement psychology alone was to re- main stationary or whether it, too, was to adopt the new method. This was a critical moment for psy- chology. If it remained refractory to the general conditions of progress, Experimental Psychology to Philosophy. 19 would it not virtually abdicate its claims of being a science ? On tlie other hand, could it in any way attach itself to physics and mechanics and submit, by any title whatever or in any degree, to the experimental method without becoming materialistic ? This dilemma has only too often been considered com- plete in circles not acquainted with the work of Experimental Psychology and the history of philosophy. We believe that this is not the case. Neither the work nor the method of Experimental Psychology are opposed to the princi- ples of spiritualistic philosophy. We believe that they are not only in har- mony with each other, but that philos- ophy will even receive valuable assist- ance from the new science. 20 The Relation of I. In the first transports of joy at the birth of the new science those that had taken it upon themselves to popularize it misrepresented its purpose and im- portance. They took delight in styling it the New Psychology, in order to oppose it to the old or metaphysical psychology. The latter, they claimed, had exhausted itself in foolish discus- sions on the soul and its faculties, and that the time had come to create a psychology that would be scientific. These sentiments were expressed es- pecially by M. Bibot in his two well- known works, LapsycJiologie anglaise contemporaine and La psychologie allemande contemporaine. The conse- quence of this was that works on Ex- perimental Psychology were often re- Experimental Psychology to Philosophy. 21 ceived by some with satisfaction and by others with mistrust, for no other reason than that it was considered incompat- ible with spiritualistic philosophy. The object of Experimental Psychol- ogy is mental states, their relation to one another, and the laws of their devel- opment.* * The research of Experimental Psychology has to- day taken considerable proportions. Since Wundt founded his first laboratory of Psychophysics in 1878, a number of learned men, trained for the most part in his school, have established similar centres of study in Germany, Denmark, Italy, Switz- erland, Belgium, France, Russia, Japan, and partic- ularly in the United States. It is in the United States that the greatest interest in the new science is taken. Wundt, Ziehen, Kuelpe, Ebbinghaus in Germany, Hoeffding in Copenhagen, Sergi in Italy, Sully in England, Ladd, James, Baldwin, Dewey, Titchener, and Scripture in America, have published the results of psychophysical experiments. Several reviews and a number of special works have been published and are still publishing, notably Philo- 8ophische Studicn (Leipzig), Beitraege zur experiment tellen Psychologic (Freiburg i. B.), Zeitschrift fur Psychologic und Physiologic der Sinnesorgane (Leip» 22 The Relation of Since, then, psychology treats of mental states in themselves, it must describe their quality, quantity, tonal- ity, and dynamogeny. The study of the quantity of mental states places them immediately in rela- tion to the physical activities that pre- cede and accompany the sensation. It is here that materialistic prejudices find their principal field. Materialists have zig), The Psychological Review (New York), L'Annee psychologique (Paris). Finally four congresses have been held, the fourth taking place at Paris in 1900. The purpose of these researches is vast, and we cannot undertake to point out their numerous appli- cations. However, in a general way we may say that it is twofold : first, the description of conscious states, simple or complex, in the order of cognition or emotion ; secondly, the conditions and the laws of their combination and dissociation. The interpreta- tion given to the results of the first order will de- termine that of the second. If the first class does not favor the materialistic hypothesis, then the sec- ond, which is founded on the first, can never sup- port it. Eocperimental Psychology to Philosophy. 23 tried to turn the result of the experi- ments made by Weber on the quantity of sensation, as interpreted and erected into a law by Fechner, against spirit- ualistic philosophy. In like manner they treated the known fact that psychic acts take time. Let us examine these facts a little more closely. The general result of Weber's exper- iments was to confirm the fact ordina- rily perceived, that to every difference in the intensity of two given excitants or stimuli producing a sensation there does not always correspond a similar difference in the sensation itself. To this fact of every-day observation Weber gave scientific precision. He found that the quantity that must be added to an excitant in order to cause a perceptible difference in the sensation 24 The Relation of is not an absolute one, but a relative one. Thus if the initial weight causing a sensation of pressure be 1, we must add ^ to make the difference percepti- ble ; if it be 2, we must add J of 2, or f ; if it be 3, we must add £ of 3, or 1, to cause a perceptible difference in the sensation of pressure. Hence the for- mula of Weber's law : The increase of the excitant necessary to produce a perceptible modification of the sensi- bility is in a constant relation to the quantity of the excitant to which it is added. Although the law of Weber, as psychologists themselves confess, has obtained only an approximate confirma- tion, we are still inclined to look upon it with confidence. As the methods of measurement are being perfected and the instruments are becoming more pre- cise, and hence the internal and exter- Experimental Psychology to Philosophy, 25 nal causes of error are being more and more eliminated, the deviations from the law diminish ; so that we may now re- gard the exceptions as proving the rule. Fechner and others after him have ex- pressed the law in a mathematical for- mula. Considering the smallest per- ceptible difference as equal to 1, the ordered series expressing the intensity of the sensations will be 1, 2, 3, 4, 5. . . . They therefore form an arithmetical progression, since the numbers differ, each from the preceding one, by the same quantity, i.e., by 1. On the other hand, the additional excitants capable of producing such a series of sensations form among themselves, according to the experiments of Weber, a geometri- cal progression. Hence the formula of Fechner : That a sensation may in- crease in arithmetical progression the 26 The Relation of corresponding excitant must increase in geometrical progression. This mathematical interpretation of Weber' s law seems defective. It would make ns believe that the psychologist compares the gradual increase in the intensity of the sensation to a continu- ous quantity, divisible into equal parts commensurate with one another. To have an arithmetical progression all the terms of the series must increase by the same quantity, which is called the ratio of the progression. To arrange the minimal differences in arithmetical progression supposes that we know them to be equal. The mathematical formula of Fechner implies therefore that we perceive an equal minimal dif- ference between visual and auditive sensations. That this is impossible is clear. In Experimental Psychology to Philosophy. 27 fact the experiments of Weber have no such results to show. The experi- menter asks the subject whether he has perceived a sensation differing from the one perceived before, but he does not and could not ask seriously how much it differed from the first. To be able to answer such a question the subject would have to have the consciousness that the first sensation A increased until it became the second sensation B. In that case he would perceive the same sensation A increasing, and not first the sensation A and afterwards the sen- sation B distinct from the sensation A. In this way we would no longer com- pare a series of sensations with one an- other, but a sensation with itself, and thus the object of the law itself would disappear. Weber's experiments warrant only 28 The Relation of one conclusion, namely: The series of mental states perceived by conscious- ness is subordinate to physical excit- ants, which stand in a constant and definite relation to one another. Inter- preted in this manner his experiments show nothing that is not in perfect har- mony with the most rigorous spiritual- ism. Sensation is an act of the nervous organ ; it is therefore bound in its functions to the chemical and physical conditions of nervous activity. " The acts of sensitive life," says St. Thomas — and this conclusion of the great doctor is confirmed by the youngest science — " the acts of sensitive life do not belong to the soul alone nor to the body alone, but their subject is the combination of both." Sensations from their qualitative as well as from their quantitative point of Experimental Psychology to Philosophy. 29 view, their association, the emotions that result in consequence of them, all are so many mental states whose sub- stratum is the nervous substance. If it is true that there are in man acts that do not result from nervous functions and are not reducible to them, it is equally true that there are none that are not pre- ceded and accompanied by functions of nerve-centres. So far as the applications of "Weber's law are verified, there is not and can never be an opposition between it and the spiritual philosophy of St. Thomas. * * * The same answer may be given to the objection which Schiff of Florence and Herzen of Lausanne have drawn from the duration of psychic acts. A super- ficial observation would lead us to be- lieve that the sensation of a flash of 30 The Relation of lightning, of the pricking of the hand or foot, is perceived instantaneously. Still psychologists measure in hundredths of a second the exact time it takes from the moment the light strikes the retina until the sensation is perceived ; the time it takes from the irritation of the nerve-end until the pain is felt; the time required to judge between the excitation of the foot and the excita- tion of the hand. " Since all processes," says Herzen,* "that take time are motion, psychical activity is nothing but a form of mo- tion." Again, "Since the production of a psychical act takes time that is rel- atively very long and apparently inert between the cause at the point of de- parture and the realization of the act itself, we must conclude that the act * Le cerveau et Vactivite cerebrate, pp. 86, 94. Experimental Psychology to Philosophy. 31 takes place in a substratum which is extended, resisting, and complex, just as other phenomena of nature do. Further, as every interval is employed in transmitting and eventually in modi- fying the external impulse in the in- ternal substratum, and since all trans- mission and modification is finally reduced to some form of motion, it follows that every psychical act con- sists in a transmission and modifica- tion of some external impulse, i.e., in some particular form of motion. Such is the generalization or inductive con- clusion which the numerous well-estab- lished facts relating to the duration of psychic acts warrant us to draw." The objection is always based on the same equivocation. Psychical acts, such as having a sensation, noticing it, local- izing it, distinguishing it from others, 32 The Relation of are not operations of an immaterial soul, but of a living body. They imply func- tions of the nervous substance. These functions bring with them changes of various kinds, molecular motion, varia- tions of temperature, chemical combina- tions, and decompositions. These phe- nomena succeed one another, and this succession takes time. There is nothing in all this that cannot be brought into harmony with the most orthodox spir- itualism* To assert with Schiff and Herzen that these processes are nothing but motion is, to say the least, inexact. Such a proposition is unintelligible. If you assert that acts of seeing, hearing, judg- ing, willing, enjoying, are accompanied by motion the meaning is clear ; but if you affirm that such acts are motion the proposition becomes utterly unintelli- Experimental Psychology to Philosophy. 33 gible. Sensation, differentiation of psy- chical acts, emotion, have no sense if they are only physical and not also psychical acts, modifications of my inner consciousness, subordinate if you will to external excitants, but not identical with them. An American psychophysicist, pro- fessor at Yale, openly takes the side of men like Lewes, Comte, Maudsley, and even Spencer, and pretends to express conscious states in terms of physics and physiology, identifying a physical excitation or a nervous shock with an act of consciousness, confounding phys- iology with psychology, and subordi- nating the latter to the former. " There can be nothing more absurd than that sort of language in the mouth of a psy- chologist," says Ladd,* " for the foun- * Ladd, Outlines of Descriptive Psychology, p. 60. 34 The Relation of elation of all psychology is conscious- ness. The physical conditions of conscious life are the constant object of research. The moment the psycholo- gist studies psychical states scientifi- cally he does not know or care to know that there is such a thing as nervous substance or cerebral hemi- spheres." We might adopt the figura- tive language of Taine or of Fouillee and say that the conscious phenomena are the within and the nervous func- tions the without of the same act ; but it is evident that it is not indifferent for a phenomenon to have only a with- out as the falling of a stone, or to have also a within for the introspection of consciousness. We have thus far examined the re- lation between elementary mental states and their physical antecedents. This Experimental Psychology to Philosophy. 35 may be summed up in the statement of the law of Weber. We have indicated the results of measurements applied to the duration of psychic acts in themselves. In all these experiments there is nothing that contradicts true philosophy. Psychical activity may further be considered in its relation to the effect produced on the muscles, the circu- lation of the blood, the temperature of the organism. These effects are measured by the dynamometer, the sphygmograph, the plethysmography and the thermometer. It is easy to show that from this point of view the data of consciousness and of experiment are in perfect harmony. There is not a single thought, were it even the con- ception of the law of universal gravita- tion, that is not accompanied by a cerebral image. This image is produced 36 The Relation of by some sensitive nerve-centre, and consequently has some influence on motor-centers and on the muscles. Hence it varies the dilatation of the arteries, the volume of the bodily mem- bers, and in general the physical con- dition of the whole organism. Mental states are considered in the three relations of which we have spoken. What we have seen certainly does not justify the mistrust of spiritualistic philosophers, and their suspicions must be reduced to misinformation ; no more does it justify the pretensions of ma- terialistic popularizers of psychology. We shall, however, not be content with a negative defence. We assert that Experimental Psychology widens the road of progress for true philosophy and furnishes it with valuable infor- mation. Experimental Psychology to Philosophy. 37 II. The first merit of Experimental Psy- chology is to have turned empirical psychology into a natural science, and to have multiplied, and treated with greater precision, the materials which will prepare a more comprehensive synthesis at some future time. Profes- sional psychologists have the laudable ambition of creating a new science, and are not — or at least are no longer — think- ing of substituting it for metaphysics. " Let us well understand this important point," writes Binet* " Experimental Psychology is independent of meta- physics, but it does not exclude meta- physics." Hoeffding f and others that * Binet, Introduction a la psychologie, p. 146. f Hoeffding, Outlines of Psychology , p. 14. London, MacMillan; 1891. 38 The Relation of might be mentioned hold the same view. Like cellular biology, embryology, anatomy, cerebral physiology, and a host of other sciences which bygone centuries did not know and whose bril- liant future they could not foresee — like these, and more than these, Experimen- tal Psychology helps to give a scientific basis to the philosophy of man. By means of physical and physiological excitants it calls forth determined states of consciousness systematically ; sim- plifies them ; observes their genesis ; compares them from different points of view as regards their quality, intensity, duration, tonality, dynamogeny; it studies how they manifest themselves ; how they externalize themselves. How can any one be blind to the advantages this gives us in the study of mental Experimental Psychology to Philosophy, 39 facts. It gives us a new orientation, and favors as a necessary consequence the development of our metaphysical knowledge of the Ego. Secondly, Experimental Psychology has already contributed much to give precision to spiritualistic doctrine as regards the sciences, and will no doubt dispel many more doubts and equivo- cations. The scientific proof that there exist definite and regular relations of inter- dependence between our mental states and their excitant causes, between them and their effects, will do much to drive from the field of philosophy the sub- jective spiritualism of Des Cartes and Cousin. At the same time the prejudice that spiritualistic philosophy and the sciences are hostile to each other, that materialistic positivism is the sole 40 The Relation of authorized representative of positive science will have to fall. Men of science too much accustomed to look only at the external, physical, or physiological aspect of man's activ- ity have learned in the school of Ex- perimental Psychology to turn their minds also to the internal psychical life. Those that for a long time accepted on faith the identification of conscious states with modes of motion now see that they have only been juggling with words. Psychologists to-day are agreed that internal observation must predominate and that external means, far from re- placing it, can only aid it. What, after all, is a fact of nature if the mind has not seized, examined, and assimilated it ? True, the information of conscious- ness is often precarious. For this rea- Experimental Psychology to Philosophy. 41 son we do well to aid and control it by scientific apparatus. These apparatus can only aid, never supplant, introspec- tion. The telescope does not replace the eye, but extends its vision. Like- wise man whose study is man is aided in this by apparatus that increase his perceptive faculties tenfold. We see, then, that the hope of sub- stituting experiment for self-observa- tion on the plea that it falsified the re- sults is vain. We remember the state- ment of Comte that internal observation of mental acts is impossible. When Zeno by subtle argument denied the possibility of motion he was refuted by the simple process of walking. Just so we answer Comte that we know noth- ing that is not in some way within us. A thing to be known must in some way become present to our minds, as the 42 The Relation of schoolmen said, " The object known is in the subject knowing." Comte said : "We understand that a man can ob- serve his passions for this anatomical reason, that the organs which are their seat are distinct from the organs of ob- servation ; but when we speak of intel- lectual phenomena, the organ observing and the organ observed are identical. How can there be any observation in this case?" In answer we might ask a few ques- tions : Can the passions be observed without becoming the object of our cognition? Is the organ of the inner sense the same as those of the external sense ? Do not all organs finally be- long to the same subject ? Is that sub- ject necessarily material ? Can the French positivist not see that he is beg- ging the question, since the point in Experimental Psychology to Philosophy. 43 question is precisely the nature of the intellectual phenomena ? Say what he will, the court of last appeal is and re- mains consciousness. In addition to the general influence of orientation in psychology, the inves- tigations of Experimental Psychology have, by reason of the exact methods used, given philosophy some confirma- tions worthy of note. The first of these is the distinction between sense and intellect; the other bears on English Associationism. It is commonly observed that after a strong sensation our senses remain for a time incapable of perceiving weaker ones. After a strong odor we do not smell a light perfume ; after a strong detonation our ears are for a time deaf to sound ; a flash of lightning blinds us 41 The Relation of so that we do not perceive the luminous surface of objects round about us. This accounts for the expressions of a deaf- ening sound, a blinding light, a dead- ening pain. By these expressions we simply mean that the sensation has been so strong as to leave our sensibility in- active. This wearing out of the organs by use has not escaped the penetrating minds of Aristotle * and his commentator St. * On 5'oi>x bfJLola ^ dirddeia rov dio-dyTiicov Kal rot vorjTucov (pavepbv iirl t&v aLcrdrjTrjpluv Kal ttjs di68pa porjrbv, ovx tjttop voe? ra virobeivTtpa , d\Xd /cat fxaXkov • rb fxkv yap di(rd7]TiKbv 6vk &vev