Harvard Psychological Studies Part 79

5. The ringing of a bell gave results similer to those for a whistle, and the sound of a 500 S.V. tuning fork usually caused a slight increase in the rate of breathing. In these experiments I therefore have evidence, through their effects upon respiration, of the frog's ability to hear sounds ranging from 50 V. to at least 1,000 V.

The croak of the green frog ranges from 100 to 200 V., so far as I have been able to determine. That of the bull frog is lower, from 50 to 75; and in the leopard frog the range is from 80 to 125. The latter is very different from the green frog in its croaking, in that it croaks whenever disturbed, whereas, the green frog rarely responds in that way to a stimulus.

We are now in a position to say that the failure of frogs to give motor reactions to strong auditory stimuli is not due to their inability to be affected by the stimuli, but is a genuine inhibition phenomenon.

XI. THE EFFECTS OF AUDITORY STIMULI ON VISUAL REACTIONS.

Further experimental evidence of hearing was gotten from some work done to test the influence of sounds upon motor reactions to visual stimuli. Frogs, like most other amphibians, reptiles and fishes, are attracted by any small moving object and usually attempt to seize it.

They never, so far as I have noticed, feed upon motionless objects, but, on the other hand, will take almost anything which moves.

Apparently the visual stimulus of movement excites a reflex. A very surprising thing to those who are unfamiliar with frog habits is the fear which small frogs have of large ones. Put some green frogs or small bull frogs into a tank with large bull frogs, and the little ones will at once show signs of extreme fear; they jump about in the most excited manner and try hard to escape. The cause of their fear soon appears, since it is usually only a few minutes until the little ones are swallowed by their wide-mouthed, cannibalistic fellows.

It is, moreover, well known that a bit of red flannel fastened to a hook attracts frogs and is an excellent method of capturing them. Red seems to be the color which they most readily notice.

This tendency of the frog to attempt to seize any moving object I made use of to test the value of sounds. By placing a frog in a gla.s.s aquarium which was surrounded by a screen, back of which I could work and through a small hole in which I was able to watch the animal without being noticed by it, and then moving a bit of red cardboard along one side of the aquarium, I could get the frog to jump at it repeatedly. In each attempt to get the moving object, the animal struck its head forcibly against the gla.s.s side of the aquarium. There was, therefore, reason to think that a few trials would lead to the inhibition of the reaction. Experiment discovered the fact that a hungry frog would usually jump at the card as many as twenty times in rapid succession.

In this reaction to a visual stimulus there appeared good material for testing audition. I therefore arranged a 500 S.V. tuning fork over the aquarium and compared the reactions of animals to the visual stimulus alone, with that to the visual stimulus when accompanied by an auditory stimulus. The tuning-fork sound was chosen because it seemed most likely to be significant to the frog. It is similar to the sounds made by the insects upon which frogs feed. For this reason one would expect that the sight of a moving object and the sound of a tuning-fork would tend to reenforce one another.

The experiments were begun with observations on the effects of moving objects on the respiration. In case of a normal rate of 54 respirations per minute sight of the red object caused an increase to 58. Then the same determination was made for the auditory stimulus.

The tuning-fork usually caused an increase in rate. In a typical experiment it was from 65 per minute to 76. The observations prove conclusively that the 500 S.V. sound is heard. My attention was turned to the difference of the environment of the ear in its relation to hearing. Apparently frogs hear better when the tympanum is partially under water than when it is fully exposed to the air.

Having discovered by repeated trials about how vigorously and frequently a frog would react to the moving red card, I tried the effect of setting the fork in vibration a half minute before showing the card. It was at once evident that the sound put the frog on the alert, and, when the object came into view, it jumped at it more quickly and a greater number of times than when the visual stimulus was given without the auditory. This statement is based on the study of only two animals, since I was unable to get any other frogs that were in the laboratory at the time to take notice of the red cardboard. This was probably because of the season being winter. I venture to report the results simply because they were so definite as to point clearly to the phenomenon of the reenforcement of the visual-stimulus reaction by an auditory stimulus.

Concerning the influence of this combining of stimuli on the reaction time, I am only able to say that the reaction to the moving object occurred quicker in the presence of the auditory stimulus. When the red card was shown it was often several seconds before the frog would notice it and attempt to get it, but when the sound also was given the animal usually noticed and jumped toward the moving card almost immediately.

Unfortunately I have thus far been unable to get chronoscopic measurements of the reaction times in this reenforcement phenomenon. I hope later to be able to follow out the interesting suggestions of these few experiments in the study of reenforcement and inhibition as caused by simultaneously given stimuli.

A few observations made in connection with these experiments are of general interest. The frog, when it first sees a moving object, usually draws the nict.i.tating membrane over the eye two or three times as if to clear the surface for clearer vision. Frequently this action is the only evidence available that the animal has noticed an object.

This movement of the eye-lids I have noticed in other amphibians and in reptiles under similar conditions, and since it always occurs when the animals have need of the clearest possible vision, I think the above interpretation of the action is probably correct.

Secondly, the frog after getting a glimpse of an object orients itself by turning its head towards the object, and then waits for a favorable chance to spring. The aiming is accurate, and as previously stated the animal is persistent in its attempts to seize an object.

XII. THE PAIN-SCREAM OF FROGS.

While making measurements of the frog's reaction time to electrical stimulation, I noticed that after a few repet.i.tions of a 2-volt, .0001-ampere stimulus an animal would frequently make a very peculiar noise. The sound is a prolonged scream, like that of a child, made by opening the mouth widely. The ordinary croak and grunt are made with closed or but slightly opened mouth. The cry at once reminds one of the sounds made by many animals when they are frightened. The rabbit, for example, screams in much the same way when it is caught, as do also pigs, dogs, rats, mice and many other animals. The question arises, is this scream indicative of pain? While studying reaction time I was able to make some observations on the relation of the scream to the stimulus.

First, the scream is not given to weak stimuli, even upon many repet.i.tions. Second, it is given to such strengths of an electrical stimulus as are undoubtedly harmful to the animal. Third, after a frog has been stimulated with a strong current (two volts), until the scream is given with almost every repet.i.tion, it will scream in the same way when even a weak stimulus is applied. If, for instance, after a two-volt stimulus has been given a few times, the animal be merely touched with a stick, it will scream. It thus appears as if the strong stimulus increases the irritability of the center for the scream-reflex to such an extent that even weak stimuli are sufficient to cause the reaction. Are we to say that the weak stimulus is painful because of the increased irritability, or may it be concluded that the reflex is in this case, like winking or leg-jerk or the head-lowering and puffing, simply a forced movement, which is to be explained as an hereditary protective action, but not as necessarily indicative of any sort of feeling. Clearly if we take this stand it may at once be said that there is no reason to believe the scream indicative of pain at any time. And it seems not improbable that this is nearer the truth than one who hears the scream for the first time is likely to think.

The pain-scream is of interest in this consideration of auditory reactions because it increases the range of sounds which we should expect frogs to hear if we grant the probability of them hearing their own voices.

It may be worth while to recall at this point the fact that a whistle from the human lips--the nearest approach to the pain-scream among the sounds which were used as stimuli in the experiments on respiration--caused marked inhibition of respiration. Perhaps this fact may be interpreted in the light of the pain-scream reaction. I may add that I have never seen a frog give a motor reaction to the pain-scream. Thinking it would certainly alarm the animals and cause them to make some movement which would serve for reaction-time measurements, I made repeated trials of its effects, but could never detect anything except respiratory changes.

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STUDIES IN PSYCHOLOGICAL THEORY.

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THE POSITION OF PSYCHOLOGY IN THE SYSTEM OF KNOWLEDGE.

BY HUGO MuNSTERBERG.

The modern efforts to bring all sciences into a system or at least to cla.s.sify them, from Bacon to Spencer, Wundt and Pearson have never, if we abstract here from Hegel, given much attention to those questions of principle which are offered by the science of psychology. Of course the psychological separation of different mental functions has often given the whole scheme for the system, the cla.s.sification thus being too often more psychological than logical. Psychology itself, moreover, has had for the most part a dignified position in the system; even when it has been fully subordinated to the biological sciences, it was on the other hand placed superior to the totality of mental and moral sciences, which then usually have found their unity under the positivistic heading 'sociology.' And where the independent position of psychology is acknowledged and the mental and moral sciences are fully accredited, as for instance with Wundt, psychology remains the fundamental science of all mental sciences; the objects with which philology, history, economics, politics, jurisprudence, theology deal are the products of the processes with which psychology deals, and philology, history, theology, etc., are thus related to psychology, as astronomy, geology, zoology are related to physics.

There is thus nowhere a depreciation of psychology, and yet it is not in its right place. Such a position for psychology at the head of all 'Geisteswissenschaften' may furnish a very simple cla.s.sification for it, but it is one which cannot express the difficult character of psychology and the complex relations of the system of mental sciences.

The historical and philological and theological sciences cannot be subordinated to psychology if psychology as science is to be coordinated with physics, that is, if it is a science which describes and explains the psychical objects in the way in which physics describes and explains the physical objects. On the other hand, if it means in this central position of mental sciences a science which does not consider the inner life as an object, but as subjective activity needing to be interpreted and subjectively understood, not as to its elements, but as to its meaning, then we should have two kinds of psychology, one which explains and one which interprets. They would speak of different facts, the one of the inner life as objective content of consciousness, as phenomenon, the other of the inner life as subjective att.i.tude, as purpose.

The fact is, that these two sciences exist to-day. There are psychologists who recognize both and keep them separated, others who hold to the one or the other as the only possible view; they are phenomenalists or voluntarists. Mostly both views are combined, either as psychological voluntarism with interposed concessions to phenomenalism or as phenomenalism with the well-known concessions to voluntarism at the deciding points. Further, those who claim that psychology must be phenomenalistic--and that is the opinion of the present writer--do not on that account hold that the propositions of voluntarism are wrong. On the contrary: voluntarism, we say, is right in every respect except in believing itself to be psychology.

Voluntarism, we say, is the interpretative account of the real life, of immediate experience, whose reality is understood by understanding its meaning sympathetically, but we add that in this way an objective description can never be reached. Description presupposes objectivation; another aspect, not the natural aspect of life, must be chosen to fulfill the logical purposes of psychology: the voluntaristic inner life must be considered as content of consciousness while consciousness is then no longer an active subject but a pa.s.sive spectator. Experience has then no longer any meaning in a voluntaristic sense; it is merely a complex of elements. We claim that every voluntaristic system as far as it offers descriptions and explanations has borrowed them from phenomenalistic psychology and is further filled up by fragments of logic, ethics and aesthetics, all of which refer to man in his voluntaristic aspect. We claim, therefore, that such a voluntaristic theory has no right to the name psychology, while we insist that it gives a more direct account of man's real life than psychology can hope to give, and, moreover, that it is the voluntaristic man whose purpose creates knowledge and thus creates the phenomenalistic aspect of man himself.

We say that the voluntaristic theory, the interpretation of our real att.i.tudes, in short teleological knowledge, alone can account for the value and right of phenomenalistic psychology and it thus seems unfair to raise the objection of 'double bookkeeping.' These two aspects of inner life are not ultimately independent and exclusive; the subjective purposes of real life necessarily demand the labors of objectivistic psychology. The last word is thus not dualistic but monistic and the two truths supplement each other. But this supplementation must never be misinterpreted as meaning that the two sciences divide inner experience, as if, for instance, the phenomenalistic study dealt with perceptions and ideas, the voluntaristic with feelings and volitions. No, it is really a difference of logical purpose of treatment and thus a difference of points of view only; the whole experience without exception must be possible material for both. There is no feeling and no volition which is not for the phenomenalist a content of consciousness and nothing else. There is, on the other hand, no perception and no idea which is not, or better, ought not to be for the voluntarist a means, an aim, a tool, an end, an ideal. In that real life experience of which the voluntarist is speaking, every object is the object of will and those real objects have not been differentiated into physical things under the abstract categories of mechanics on the one hand, and psychical ideas of them in consciousness on the other; the voluntarist, if he is consistent, knows neither physical nor psychical phenomena.

Phenomenalist and voluntarist thus do not see anything under the same aspect, neither the ideas nor the will.

This difference is wrongly set forth if the ant.i.thesis to voluntarism is called intellectualism. Intellectualism is based on the category of judgment, and judgment too is a ideological att.i.tude. Phenomenalism does not presuppose a subject which knows its contents but a subject which simply _has_ its contents; the consciousness which has the thought as content does not take through that the voluntaristic att.i.tude of knowing it and the psychologist has therefore no reason to prefer the thought to the volition and thus to play the intellectualist. If the psychologist does emphasize the idea and its elements, the sensations, it is not because they are vehicles of thought but because their relations to physical objects make them vehicles of communication. The elements of ideas are negotiable and thus through their reference to the common physical world indirectly describable; as the elements of ideas are alone in this position, the psychologist is obliged to consider all contents of consciousness, ideas and volitions alike, as complexes of sensations.

The ant.i.thesis is also misinterpreted, or at least wrongly narrowed, if it is called voluntarism _versus_ a.s.sociationism. Recent discussions have sufficiently shown that the principle of a.s.sociation is not the only possible one for phenomenalistic theories. If a.s.sociationism is identified with objective psychology, all the well-founded objections to the monopoly of the somewhat sterile principle of a.s.sociation appear as objections to phenomenalism in psychology, and voluntaristic theories, especially those which work with the teleological category of apperception, are put in its place.

But without returning to apperceptionism we can overcome the one-sidedness of a.s.sociationism if full use is made of the means which the world of phenomena offers to theory. The insufficiency of a.s.sociationism disappears if the content of consciousness is considered as variable not only as to quality and intensity but also as to vividness. This variation of vividness, on the other hand, is no exception from the psychophysical parallelism as soon as the psychical process is considered as dependent not only upon the local and quant.i.tative differences of the sensory process but also upon the motor function of the central physical process. The one-sidedness of the physiological sensory theories has been the hidden reason for the one-sidedness of a.s.sociationism. The sensory-motor system must be understood as the physical basis of the psychophysical process and the variations in the motor discharge then become conditions of those psychical variations of vividness which explain objectively all those phenomena in whose interest a.s.sociationism is usually supplemented by apperceptionism. The a.s.sociation theory must thus be given up in favor of an 'action-theory'[1] which combines the consistency of phenomenalistic explanation with a full acknowledgment of the so-called apperceptive processes; it avoids thus the deficiency of a.s.sociationism and the logical inconsistency of apperceptionism.

[1] H. Munsterberg, 'Grundzuge der Psychologie.' Bd. I., Leipzig, 1900, S. 402-562.

Only if in this way the sciences of voluntaristic type, including all historical and normative sciences, are fully separated from phenomenalistic psychology, will there appear on the psychological side room for a scientific treatment of the phenomena of social life, that is, for sociology, social psychology, folk-psychology, psychical anthropology and many similar sciences. All of them have been in the usual system either crowded out by the fact that history and the other mental sciences have taken all the room or have been simply identified with the mental sciences themselves. And yet all those sciences exist, and a real system of sciences must do justice to all of them. A modern cla.s.sification has perhaps no longer the right as in Bacon's time to improve the system by inventing new sciences which have as yet no existence, but it has certainly the duty not to ignore important departments of knowledge and not to throw together different sciences like the descriptive phenomenalistic account of inner life and its interpretative voluntaristic account merely because each sometimes calls itself psychology. A cla.s.sification of sciences which is to be more than a catalogue fulfills its logical function only by a careful disentanglement of logically different functions which are externally connected. Psychology and the totality of psychological, philosophical and historical sciences offer in that respect far more difficulty than the physical sciences, which have absorbed up to this time the chief interest of the cla.s.sifier. It is time to follow up the ramifications of knowledge with special interest for these neglected problems. It is clear that in such a system sciences which refer to the same objects may be widely separated, and sciences whose objects are unlike may be grouped together. This is not an objection; it indicates that a system is more than a mere pigeon-holing of scholarly work, that it determines the logical relations; in this way only can it indeed become helpful to the progress of science itself.

The most direct way to our end is clearly that of graphic representation wherein the relations are at once apparent. Of course such a map is a symbol and not an argument; it indicates the results of thought without any effort to justify them. I have given my arguments for the fundamental principles of the divisions in my 'Grundzuge der Psychologie' and have repeated a few points more popularly in 'Psychology and Life,' especially in the chapter on 'Psychology and History.' And yet this graphic appendix to the Grundzuge may not be superfluous, as the fulness of a bulky volume cannot bring out clearly enough the fundamental relations; the detail hides the principles. The parallelism of logical movements in the different fields especially becomes more obvious in the graphic form.

Above all, the book discussed merely those groups which had direct relation to psychology; a systematic cla.s.sification must leave no remainder. Of course here too I have not covered the whole field of human sciences, as the more detailed ramification offers for our purpose no logical interest; to subdivide physics or chemistry, the history of nations or of languages, practical jurisprudence or theology, engineering or surgery, would be a useless overburdening of the diagram without throwing new light on the internal relations of knowledge.

Without now entering more fully into any arguments, I may indicate in a few words the characteristic features of the graphically presented proposition. At the very outset we must make it clear that phenomena and voluntaristic att.i.tudes are not coordinated, but that the reality of phenomena is logically dependent upon voluntaristic att.i.tudes directed towards the ideal of knowledge. And yet it would be misleading to place the totality of phenomenalistic sciences as a subdivision under the teleological sciences. Possible it would be; we might have under the sciences of logical att.i.tudes not only logic and mathematics but as a subdivision of these, again, the sciences which construct the logical system of a phenomenalistic world--physics being in this sense merely mathematics with the conception of substance added. And yet we must not forget that the teleological att.i.tudes, to become a teleological science, must be also logically reconstructed, as they must be teleologically connected, and thus in this way the totality of purpose-sciences might be, too, logically subordinated to the science of logic. Logic itself would thus become a subdivision of logic. We should thus move in a circle, from which the only way out is to indicate the teleological character of all sciences by starting not with science but with the strictly teleological conception of life--life as a system of purposes, felt in immediate experience, and not as the object of phenomenalistic knowledge. Life as activity divides itself then into different purposes which we discriminate not by knowledge but by immediate feeling; one of them is knowledge, that is, the effort to make life, its att.i.tudes, its means and ends a connected system of overindividual value. In the service of this logical task we connect the real att.i.tudes and thus come to the knowledge of purposes: and we connect the means and ends--by abstracting from our subjective att.i.tudes, considering the objects of will as independent phenomena--and thus come to phenomenalistic knowledge. At this stage the phenomenalistic sciences are no longer dependent upon the teleological ones, but coordinated with them; physics, for instance, is a logical purpose of life, but not a branch of logic: the only branch of logic in question is the philosophy of physics which examines the logical conditions under which physics is possible.

One point only may at once be mentioned in this connection. While we have coordinated the knowledge of phenomena with the knowledge of purposes we have subordinated mathematics to the latter. As a matter of course much can be said against such a decision, and the authority of most mathematicians would be opposed to it. They would say that the mathematical objects are independent realities whose properties we study like those of nature, whose relations we 'observe,' whose existence we 'discover' and in which we are interested because they belong to the real world. All that is true, and yet the objects of the mathematician are objects made by the will, by the logical will, only, and thus different from all phenomena into which sensation enters. The mathematician, of course, does not reflect on the purely logical origin of the objects which he studies, but the system of knowledge must give to the study of the mathematical objects its place in the group where the functions and products of logical thought are cla.s.sified. The arithmetical or geometrical material is a free creation, and a creation not only as to the combination of elements--that would be the case with many laboratory substances of the chemist too--but a creation as to the elements themselves, and the value of the creation, its 'mathematical interest,' is to be judged by ideals of thought, that is, by logical purposes. No doubt this logical purpose is its application in the world of phenomena, and the mathematical concept must thus fit the world so absolutely that it can be conceived as a description of the world after abstracting not only from the will relations, as physics does, but also from the content.

Mathematics would then be the phenomenalistic science of the form and order of the world. In this way mathematics has a claim to places in both fields: among the phenomenalistic sciences if we emphasize its applicability to the world, and among the teleological sciences if we emphasize the free creation of its objects by the logical will. It seems to me that a logical system as such has to prefer the latter emphasis; we thus group mathematics beside logic and the theory of knowledge as a science of objects freely created for purposes of thought.

All logical knowledge is divided into Theoretical and Practical. The modern cla.s.sifications have mostly excluded the practical sciences from the system, rightly insisting that no facts are known in the practical sciences which are not in principle covered by the theoretical sciences; it is art which is superadded, but not a new kind of knowledge. This is quite true so far as a cla.s.sification of objects of knowledge is in question, but as soon as logical tasks as such are to be cla.s.sified and different aspects count as different sciences, then it becomes desirable to discriminate between the sciences which take the att.i.tude of theoretical interest and those which consider the same facts as related to certain human ends. But we may at first consider the theoretical sciences only. They deal either with the objectified world, with objects of consciousness which are describable and explainable, or with the subjectivistic world of real life in which all reality is experienced as will and as object of will, in which everything is to be understood by interpretation of its meaning. In other words, we deal in one case with phenomena and in the other with purposes.

The further subdivision must be the same for both groups--that which is merely individual and that which is 'overindividual'; we prefer the latter term to the word 'general,' to indicate at once that not a numerical but a teleological difference is in question. A phenomenon is given to overindividual consciousness if it is experienced with the understanding that it can be an object for every one whom we acknowledge as subject; and a purpose is given to overindividual will in so far as it is conceived as ultimately belonging to every subject which we acknowledge. The overindividual phenomena are, of course, the physical objects, the individual phenomena the psychical objects, the overindividual purposes are the norms, the individual purposes are the acts which const.i.tute the historical world. We have thus four fundamental groups: the physical, the psychological, the normative and the historical sciences.

Whoever denies overindividual reality finds himself in the world of phenomena a solipsist and in the world of purposes a sceptic: there is no objective physical world, everything is my idea, and there is no objective value, no truth, no morality, everything is my individual decision. But to deny truth and morality means to contradict the very denial, because the denial itself as judgment demands acknowledgment of this objective truth and as action demands acknowledgment of the moral duty to speak the truth. And if an overindividual purpose cannot be denied, it follows that there is a community of individual subjects whose phenomena cannot be absolutely different: there must be an objective world of overindividual objects.

In each of the four groups of sciences we must consider the facts either with regard to the general relations or with regard to the special material; the abstract general relations refer to every possible material, the concrete facts which fall under them demand sciences of their own. In the world of phenomena the general relations are causal laws--physical or psychical laws; in the world of purposes theories of teleological interrelations--normative or historical; the specific concrete facts are in the world of phenomena objects, physical or psychical objects, in the world of purposes acts of will--specific norms or historical acts. If we turn first to phenomena, the laws thereof are expressed in the physical sciences, by mechanics, physics, chemistry, and we make mechanics the superior as chemistry must become ultimately the mechanics of atoms. In the psychological sciences the science of laws is psychology, with the side-branch of animal psychology, while human psychology refers to individuals and to social groups. Social psychology, as over against individual psychology, is thus a science of general laws, the laws of those psychological phenomena which result from the mutual influence of several individuals.