The Danger From Experimental Psychology
A SHORT time ago there appeared a new book which will find its way everywhere into the hands of teachers, and which will be welcomed heartily. I think that its attitude is dangerous, and that the ready acceptance of it arises from illusions and confusions ; nevertheless, I am glad, too, that such a book has appeared, as I have always believed that, after the very best books, the worst books are those which can be most useful. They show the logical mistakes in a form so exaggerated and unmasked that nobody can help profiting from such a climax of blunders. If we cannot learn from a book, we may be warned by it, and in the present case it is high time to give the danger signal. A warning ought to be sounded to the teachers against their rush toward experimental psychology, — a rush stirred up by the hope that psychical facts will be measured by the new method, and that such an exact mathematical knowledge of mental life will become the long-desired vehicle for a real modern pedagogical scheme. This movement began as a scientific fashion. It grew into an educational sport, and it is now near the point of becoming a public danger. At such a point the discussion should no longer be confined to narrow educational quarters, as the whole country has to suffer for every educational sin.
The book I have in mind is called The New Psychology. Its birthplace is Yale. The name of the author has nothing to do with our arguments. The consistent idea he presents is this : The old psychology, of which the chief method was self - observation, gave only descriptions of mental facts and processes ; the new psychology, of which the chief method is experimentation, gives at last measurements of such facts. The old psychology was qualitative ; the new is quantitative. All other recent books on psychology are mere compromises between the old and the new psychology. Here, the author thinks, is finally a book which is up to date, — a book which gets rid of all the old - fashioned scholastic headings, like Memory, Attention, Feeling, Emotion, Perception, Volition. All the new books have given qualitative descriptions, and have added to them the modern quantitative details, but from cover to cover this book consists of measurements, and its sections are therefore brought under the headings of those conceptions upon which every measurement in the universe depends, Space,Time, and Energy. Consequently, the teacher has here the safe ground of a real, exact psychology on which he can build up his system of pedagogics.
I am not a man whose heart belongs to an old-fashioned forgotten past, and who dislikes, as many do, the modern ways of experimental work. I speak, on the contrary, as the director of the Harvard Psychological Laboratory, — as a man who devotes his life to the most modern methods of psychology ; nevertheless, I must say I have never measured a psychical fact, I have never heard that anybody has measured a psychical fact, I do not believe that in centuries to come a psychical fact will ever be measured. Let us consider what kind of measurements the book in question offers us.
As I have said, the author divides his psychology into three large parts, Space, Time, and Energy, after the analogy with physics. If we knew all about the space, the time, and the energy of physical things, natural science would have reached its ideal. How is it with the space, the time, and the energy of mental facts ? Our book gives a nicely illustrated section on space. Has it found out the dimensions in feet and inches of our feelings and emotions ? Has it found whether our will is a square or a circle in space ? No. The author does not speak about the space extension of mental facts at all, but partly about the dependence of mental facts on the space of the physical world, — that is, of the optical and tactual stimuli, — and partly about the constitution of our idea of space. We learn, for instance, how we come to see the flat pictures in the stereoscope as solid objects; that is, we have a qualitative analysis of our thought about the quantitative measurable physical space, but we have nowhere a spatial measurement of a psychical fact. We are promised the space of thought, and we get the thought of space. That is a juggling with words, and not a new science.
Exactly the same is true for that part of the book which deals with energy. Not the energy of the psychical facts is there in question, but those psychical facts are analyzed by which we are conscious of physical action and energy. The energy of our feelings is not measured, but our feelings of energy and effort are described, — certainly an important thing, but not the thing which is promised to us. To speak of a measurable energy of our psychical elements is absurd, as every energy can be measured only by its effect, and as the psychical products of mental action are inner states which cannot be added and multiplied, and which have no constant unities like the unities of weight and space and time, so that here again the effect can be determined only qualitatively, not quantitatively. But this absurdity, of course, disappears at once, if the analysis of the feeling of energy is substituted for the measurement of the energy of feelings : just this the author does, and he gives us, therefore, something which is possible, but which has no bearing on the promised treatment. Considered as a qualitative mental state, this feeling of effort is no more nearly related to the problem of measurable energy than is the feeling of joy and grief, or the sensation of heat and cold.
To bring its principle fully ad absurdum, our book gives finally, under the heading Energy, two chapters more on sound and color, introducing them with a short but significant sentence : “ One of the forms of energy which we perceive is that of color.” Does it still need a word to show that the writer is speaking, not of the psychical energy of the perception, but of the perception of physical energy? Nobody ever doubted that space and energy of the physical world are measurable. The author offers, not measurement of psychical facts, but qualitative analysis of mental states which are related to measurable physical facts. With the same right with which he brings his report of experimental psychology under the titles Space, Time, and Energy, he might have brought it under the titles Iron, Wood, and Hard Rubber, after the different physical instruments we need for the study of psychical facts, and pretending that therefore the mental facts themselves are of hard rubber, wood, or iron.
Thus far we have not spoken about the time. The case is here a little more complicated. Of course, in dealing with this question the book rushes into the same mistake. It discusses chiefly the mental states by which we think about time periods. The time of the objects of our thought is not the time of our thought; we can think about a century in one second. Just as illogically included here is another problem, the time relations of our physical stimuli. How long must the physical process last to give us a sensation ? It is clear that this is not time measurement of psychical facts. But can we deny that a real time measurement of mental life is possible ? Some one may agree with me that mental elements have no space and energy, but he will say they fill time, they last through seconds and days and years ; and modern psychology can measure this time by thousandths of a second ; can I deny even this measurement ? Well, I confess it is true that our psychological laboratories are filled and overfilled with time-measuring machines,— with electric chronoscopes and chronographs and kymographs and sphygmographs and pneumographs and myographs and ergographs ; and nevertheless I think that the time we measure is not the time of the primary mental experience, but the time of physical processes into which we project our mental states. Our real inner experience has time value in a double way. We have past, present, and future, as forms of subjective attitude : past is the reality on which we cannot act any more ; present is the object of our real action ; future is the reality for which we have still the possibility of planning our actions. These are three attitudes which as acts of our attention are in themselves not divisible.
But we find in our consciousness time in still another way. We feel the time qualities of our ideas. The rhythm, the duration, the interval, the succession of the psychical elements, are characteristics of our inner experience, but characteristics which are fully coördinated to the qualities of color and pitch and smell. They are a unique, indescribable, qualitative experience, which cannot be divided, and which is never identical with the sum of its elements. The tone lasting through a second, and the click filling a hundredth of a second, each gives an impression of time shape, but the one time feeling does not contain a hundred times the other. They are two different qualities, not quantities. The time shape of the inner experience is an absolutely indivisible quality, which therefore never can be measured, — not from lack of means, but from lack of meaning. To say that the time quality of one psychical fact contains five times the time quality of another is not less absurd than to pretend that one emotion or one virtue is five times heavier or has five times more angles than another.
This changes at once, if we leave the standpoint of inner experience, and look on our mental life from the outside ; that is, if we consider it as an accompaniment of our physical processes, as an experience of our physical organism. My organism belongs, of course, like every other physical body in the universe, to the physical objective time which can be divided into years and days and seconds ; and as soon as I project my inner states into this empirical personality, my thoughts and feelings must take part in this objective scheme of time. Now, my thoughts and feelings, as they coincide with this or that physical experience of the organism, have duration in hours and minutes, are to-day or were yesterday, and may grow through years ; if they last a minute they contain sixty times a second, and they can be measured in thousandths of a second.
If I make such a substitution of the psycho - physical organism for the original psychical experience, my mental states get space just as they get time. I can say, then, with the same right, that my ideas are now in this country, while three months ago they were in Germany ; that they are in this room, that they are in this brain ; and just as I measure them in fractions of a second, an ideal science which knows all about the functions of the ganglion cells in the brain could measure the distance of my thoughts in the brain by millionths of an inch. The time we really measure is the time of physical processes of our physiological body, but the psychological facts as such have as little measurable time as energy or space. In all three cases we measure physical facts which are in special relations to the psychical life, but we cannot measure the psychical facts themselves, and it remains an illusion to believe that a kind of mathematical psychology is the outcome of our laboratories.
To be sure, these most modern illusions of which the book under consideration is such a striking illustration are not without predecessors. Two of the greatest and most influential psychological systems of this century have tried already to introduce numerical measurements and mathematical methods, — the systems of Herbart and Fechner. Both attempts were of the highest importance for the progress of psychology. Herbart gave an impulse toward a careful analysis of the mental states, and Fechner started experimental work; both have even today plenty of followers, but the mathematical part of both systems is recognized everywhere as mistaken. Their psychical measurement was an illusion.
The logical error of Herbart and Fechner was not exactly the same as that of the tendencies of to-day. They did not substitute physical objects for psychical facts, but they gave to the psychical facts some features which belong in reality to physical objects only. Herbart treated the ideas like solid billiardballs which are pushed into consciousness and out of consciousness. Certainly Herbart’s mathematical presuppositions about the moving forces of ideas are the simplest possible ; but the simplest are just as misleading as any others, if the objects are not measurable at all. Only by a thoroughgoing comparison of the mutual effects of ideas with bodily movements did his conjectures become possible. But a metaphor which is useful for the explanation cannot transform changes of mind into real mechanical statics and dynamics of psychical elements. The movements of ideas, if you call them movements, are not measurable. Of course, if you make any numerical presuppositions about the amount of these movements, you can build up a full mathematical system.
Still more natural appears the presupposition with which stands and falls the famous psycho-physical system of Fechner. Every part of it depends upon his belief that a strong sensation is a multiple of a weak one ; a weak sensation, a fraction of a stronger one. But have we a right to accept this assumption ? Does a strong sound sensation contain so and so many weak sound sensations, just as a strong physical sound contains the weak sounds ? Does our more intense light sensation contain two or ten or a million faint light sensations, in the way in which a physical light of tencandle power contains five times the light of two - candle power ? In other words, is white a multiple of light gray, light gray a multiple of dark gray, dark gray a multiple of black ? Is hot sensation a multiple of lukewarm sensations ? Is lukewarm sensation equal to so and so many cold sensations ? Does a strong sensation of pressure contain x times the weak sensation of touch ? By no means. All our inner experience revolts.
It is the old confusion between the sensation and the knowledge about the causes of the sensation. The white sunlight contains the red and green and violet sun - rays, but it is absurd if the psychologist pretends that therefore the white sensation contains the sensation red and the sensation green. Nothing of that kind is in our consciousness. White and red are psychologically two different qualities, and just so are white and gray, hot and cold, pressure and touch, strong sound and faint sound, psychologically only different qualities of which one never contains the other, notwithstanding that the physical stimuli contain one another. A sensation never consists of smaller sensations, as a foot consists of inches, or a minute of seconds, or a pound of ounces ; and Fechner’s fundamental mistake was to give to sensations this characteristic which belongs to the world of physics only. If we think a strong sensation made up of weak sensations, as a foot is made up of inches, the way is open to a brilliant mathematical construction.
We can say, then, that wherever psychical facts have been measured, either physical facts were substituted, as in our most modern tendencies, or psychical facts themselves were falsely thought after the analogy with physical objects. Well, some one may say, granted that all the endeavors to measure psychical facts have been so far unsuccessful: is that a sufficient reason for giving up all attempts to measure them ? Must we not be grateful for every new effort to reach mathematical exactitude in psychology ? The north pole of our earth has not as yet been reached : is that a reason for saying that it cannot be reached ? Certainly not. Send new ships and balloons to the north pole, but do not send ships to the fairyland of Utopia, as we know beforehand that it does not exist, and that it is therefore impossible to reach it. The land of measurable psychical facts is a Utopia which will never be reached because it cannot exist at all, and it cannot exist because it contradicts the antecedents with which psychology starts.
What should we think of an astronomer who had found with his telescope a place in the physical universe where no space exists, or of a geologist who had found a pre-glacial period in which no time existed, or of a physicist who had found a physical metal which does not underlie causality? We should say, with full right, that the assertion is absurd : space, time, and causality are the presuppositions for the existence of the physical world, and the naturalist has to take them for granted. He has not to investigate whether they exist or not. He has to think the world within these forms, and if he gives up these presuppositions he does not speak any more about the physical world. To examine the right and wrong of these conceptions, and therefore the right and wrong of the fundamentals of natural science, is not the business of the naturalist, but the task of the philosopher. Every special science has to start with assumptions which it accepts. Philosophy has to examine them, and so to determine the field in which the special sciences can have free movement, but which they never are allowed to transcend.
The unmeasurable character of psychical facts belongs to those fundamental presuppositions with which the special science of psychology starts, and which therefore cannot be destroyed by any psychological discoveries. The psychologist who discovers a measurable sensation or feeling stands on the same level with the physicist who discovers that metal which is not in space and time and causality. This is not the place to give even in the most superficial outlines the arguments for this philosophical decision. I indicate briefly only the direction in which these arguments move forward.
The world in which we really live is primarily neither physical nor psychical. We do not know those atomistic objects of which mechanics tells us ; those objects which have no colors and sounds and smells and temperatures, but are only moving ether atoms and molecules. And just so we do not know primarily the external objects as our perceptions in our own consciousness, those ideas about which psychology tells us. The book I am reading is to me in real life neither physical molecules only nor my own optical idea. It represents a kind of object which has objective and subjective characteristics at the same time. It is an object which is not differentiated into a physical thing and a psychical idea. In this world of undifferentiated objects we find ourselves as willing subjects, and the chain of our subjective attitudes and actions means our life. In this world we are free subjects, whose single acts are related to ends, and not determined by causes. In this world we are ourselves not physical and not psychical ; we are subjects of will. And that is not a constructed metaphysical reality, but the only reality to which our daily life and all history belong, and to which logic and ethics refer. It is a world of will, of action, of appreciation, of values.
But we willing subjects create by our will still another world, — a world of less reality, a world which is a logical construction only. We have an interest in thinking the objects of our will as independent of our will, and the real objects cut loose from the subjects cease to be in the world of values. They become existing objects. Out of the world of values we create the world of existence, — a world which is real only in our abstraction, and which is true only as it has a value for us to think the objects so, and not otherwise. But in creating such existing objects the subjects can think them in a double way. We separate on the one side the objects in so far as they are possible objects for every subject; on the other side, the same objects in so far as they are objects for one subjective act only. The first group contains the physical, the second group the psychical objects. Both represent, as we have seen, not realities, but complicated transformations of reality produced by abstractions made for a special purpose of the willing subjects. And if there were not a multitude of such subjects, the separation of physical facts and psychical facts would have no meaning. The physical world is a world for many ; the psychical world is a world for one only, — not for one subject, but for one subjective attitude, one act only.
If that is so, we understand, first, that in psychology we must forever do without that necessary basis of every measuring science, the constant unity. We can measure the physical world and describe it in mathematical terms because we can agree there about units. My minute and hour, my inch and foot, my ounce and pound, are also yours. The physical world is made up of the objects in so far as they are given to all subjects. My mental objects are not accessible to any other subject. No psychical fact can be shared by one subject with another. That is the presupposition with which psychology starts.
But there is not only an impossibility of an objective measurement through lack of units. It is, secondly, just as impossible that a single subject should think one of his mental states as a multiple of another state. We have seen that we call a fact psychical if it is the object for one subjective act only. The consequence must be that physical matter lasts, and never disappears, — it is a possible object for every subject; while psychical facts cannot last, — they disappear with the single act, and can never be renewed. The one mental object can therefore never be repeated in another object. New objects must appear in consciousness which may be more or less similar, but the one can never be in the other ; each must stand for itself; and the criterion of physical measurement, that every part having the dimensions of the given unit could be replaced by it, is a priori excluded.
The act by which we as willing subjects transform the real objects into physical and psychical objects, — that very act forbids for all time the measurement of psychical facts, and we must ignore our deepest presuppositions if we believe that we can measure them. Malicious persons have pretended that women often do not know the difference between a good conscience and a bad memory. The assertion is certainly more true as to some sciences. The experimental psychology which believes that it can have a good conscience in measuring mental states has really only a bad memory. It has forgotten all that it has promised in its presuppositions. Measure mental life, and it flows back to the logical primary state which did not know the differentiation of objects into physical and psychical facts. The real psychical facts cannot be anything else than a world of qualities.
All that may be granted, but nevertheless the energy may be censured with which I fight against these most modern tendencies. It will be said, perhaps : “ Look on Herbart and Fechner. Their mathematical systems are blunders, and yet they were immensely productive, and gave everlasting impulses to modern thinking. Error is the most important source of knowledge. What is astronomy without foregoing astrology ? What is chemistry without alchemy ? Why fight against this new scheme ? It may be erroneous, but it may also suggest new ways and new insights, and above all one great result is perceivable already : it has turned the attention of teachers toward experimental psychology. Is not that in itself something which excuses many defects?” Well, I do not deny in the least that the effects of a system may transcend the intentions of an author, that error may be productive, that Herbart and Fechner have helped us immensely, and that this new scheme attracts teachers toward experimental psychology ; but I come to quite other conclusions. I acknowledge the pedagogical effect of the new scheme fully, but I do not excuse the theoretical wrong on account of the practical service. No ; on the contrary, I fight against these pseudomeasurements in first line just on account of this practical outcome, as the effect upon teachers seems to me a confusion and a pedagogical blunder which is even worse than the psychological mistake. This brings me finally to the point toward which I started.
The teachers of this country instinctively feel that the educational system is still far from having reached its ideal shape. Much needs to be improved, and as the teachers are serious and conscientious, they stand on the lookout for new schemes and new ideas. There came a new science into the field, — experimental psychology. This experimental psychology said, in Sunday newspapers and elsewhere, with loud voice : Teachers, the thing you lack is a scientific knowledge of the child’s mind. How can you hope for a solid pedagogical system if it is not built up on the basis of a solid psychology ? The old psychology was of no help to you. The old psychology was a dreamy thing for philosophers and ministers, filled with lazy self - observation. There was no exact measuring in it. The end of the century, our time of technics and inventions, needs an exact measurement. We have captured it by our new laboratory methods. Come and measure the psychical facts, and the new era of exact treatment of the child’s mind, on the basis of an exact knowledge of mind by accurate measurements, will begin.
Is it surprising that there set in a great rush for the benefactions of experimental psychology, that the laboratories have become for teachers the ideal goals, that experimenting with children has become the teacher’s sport, and that contempt for the poor old psychology which did not measure has become the symbol of the rising generation ? No, it is not surprising, but it is deplorable. And if this movement deserves to be stopped, some little advantage may be gained, perhaps, if teachers come to understand that those hopes are on a wrong track, that no laboratory and no experiment can ever measure a psychical fact, and that all hope for pedagogics on the basis of a mathematically exact psychology is and will be a perfect illusion.
I do not wish to discuss here the great question of child study, where the dangers are not less threatening. It has always been my conviction that love and tact and patience and sympathy and interest are more important for the teacher than any psychological observations he can make on children, and that these observations are natural enemies of his instinctive emotional attitudes because they dissolve the personality into elements, while love and tact have nothing to do with a bundle of elements. They turn to the personality as one unit. They mean the child, and not its ganglion cells and its psychical atoms of sensation.
But I now leave child study aside. I look on psychology as a whole, and say with the fullest assurance to all teachers : This rush toward experimental psychology is an absurdity. Our laboratory work cannot teach you anything which is of direct use to you in your work as teachers ; and if you are not good teachers it may even do you harm, as it may confuse you and inhibit your normal teacher’s instincts. If you are interested in the subtle studies of modern laboratory psychology, devote your free time to it. Certainly, there are few sciences so attractive. Study it as you would study geology or astronomy or Greek history or German literature, but do not expect that it will help you in your work as teachers more than astronomy or geology would help you. You may collect thousands of experimental results with the chronoscope and the kymograph, but you will not find anything in our laboratories which you could translate directly into a pedagogical prescription. The figures deceive you. There is no measurement of psychical facts, and therefore no psychology which is antagonistic or in any contrast with the psychology of introspection. The methods are more developed, but the general aim is the same, — a purely qualitative analysis of the inner life ; no quantitative calculation.
If teachers connected no hopes with the old self-observing psychology, there would be no reason to change the attitude. But that old distrust of psychology was unfair. Teachers ought always to have had confidence in a sound qualitative psychology. A serious understanding of the mental functions certainly will help them in their educational work. Only that kind of study which is added by the new experimental methods has no direct value for them. In the hands of the professional psychologists, experimental results are important suggestions for a more subtle and more refined qualitative analysis than the pure observation allowed. In the hands of the outsider, in the hands of the teacher, those results are odd bits and ends which never form a whole and which have no meaning for real life. Far from being an exact science of measurable psychical facts, they would be to him a mass of disconnected, queer details, of which no one could be generalized for a practical purpose.
I know that if the flood of intellectual fashion is rising, one man’s voice cannot do much. We must wait until the ebb tide comes. I am confident that this new educational sport must have and will have its reaction. The time must come when teachers will feel that it was a misled curiosity which made them expect pedagogical help from their own psychological experiments, and that it was a logical mistake to think that a quantitative psychology would be a better basis for education than a qualitative one. I believe this time will come soon as a result of the necessary disappointments which are already expressed in all educational quarters ; but even if this reaction is near, it remains the duty of the psychologist to repeat and repeat his warning; he can at least aid in rendering the reaction less painful and less overwhelming. Above all, his warning may prevent the reaction from bringing us to the other extreme, which is wrong too, — the extreme view that because experimental psychology is not quantitative, therefore psychology in general is useless for the modern teacher. This view is mistaken. Let us keep in mind from the start that if the rush to the illusory measuring psychology is over, the teacher ought to go back to the solid, sober, qualitative analysis of the human mind; he will find there plenty of help for his sacred educational work.
To be sure, the future will transform the situation, and will connect the interests of both sides. As the anatomist, with his microscopical study of the stomach, may finally suggest the ways for cooking more digestible food, so the experimental psychologist will combine and connect the detailed results more and more, till he is able to transform his knowledge into practical educational suggestions. But such suggestions are possible only for those who are able to consider the full totality of the facts. Single disconnected details are of no value for such a practical transformation ; and even after all is done, this more highly developed knowledge will be but a more refined understanding of qualitative relations, — never the quantitative measurement which so many teachers now hopefully expect. Above all, that connection is a matter of the future. To-day there is almost no sign of it, and I for one believe that that future will be a rather distant one, as experimental psychology is yet quite in the beginning, like physics in the sixteenth century.
I do hope for a high and great and brilliant progress of experimental psychology, and I do hope still more for a wonderful growth of the educational systems in this country; but I feel sure that the development of both will be the stronger and sounder and greater, the longer both education and experimental psychology go sharply separated ways, with sympathy, but without blind adoration for each other.