Chapter XII: Conclusion

If we would make a brief summary of the status of Mr. von Osten's horse in the light of these investigations and try to understand what is the bearing upon the question of animal psychology in general, we may make the following statements.

Hans's accomplishments are founded first upon a one-sided development of the power of perceiving the slightest movements of the questioner, secondly upon the intense and continued, but equally one-sided, power of attention, and lastly upon a rather limited memory, by means of which the animal is able to associate perceptions of movement with a small number of movements of its own which have become thoroughly habitual.

The horse's ability to perceive movements greatly exceeds that of the average man. This superiority is probably due to a different constitution of the retina, and perhaps also of the brain.

Only a diminishingly small number of auditory stimuli are involved.

All conclusions with regard to the presence of emotional reactions, such as stubbornness, etc., have been shown to be without warrant. With regard to the emotional life we are justified in concluding from the behavior of the horse, that the desire for food is the only effective spring to action.

The gradual formation of the associations mentioned above, between the perception of movement and the movements of the horse himself, is in all probability not to be regarded as the result of a training-process, but as an unintentional by-product of an unsuccessful attempt at real education, which, though in no sense a training-process, still produced results equivalent to those of such a process.

All higher psychic processes which find expression in the horse's behavior, are those of the questioner. His relationship to the horse is brought about almost wholly by involuntary movements of the most minute kind. The interrelation existing between ideas having a high degree of affective coloring and the musculature of the body, (which is brought to light in this process), is by no means a novel fact for us. Nevertheless, it is possible that this case may be of no small value, on account of the great difficulties which are usually met in the attempt to establish experimentally the more delicate details in this field.

And, returning to the considerations of the first chapter, if we ask what contributions does this case make toward a solution of the problem of animal consciousness, we may state the following: The proof which was expected by so many, that animals possess the power of thought, was not furnished by Hans. He has served to weaken, rather than strengthen, the position of these enthusiasts. But we must generalize this negative conclusion of ours with care,--for Hans cannot without further qualification be regarded as normal. Hans is a domesticated animal. It is possible (though the opposite is usually assumed), that our animals have suffered in the development of their mental life, as a result of the process of domestication. To be sure, in some respects they have become more specialized than their wild kin, (e. g., our hunting dogs), and in their habits they have become adapted largely to suit our needs. This latter is shown by all the anecdotes concerning "clever" dogs, horses, etc. But with the loss of their freedom they have also gradually been deprived of the urgent need of self-preservation and of the preservation of their species, and thus lack one of the greatest forces that make for psychic development. And often their artificial selection and culture has been with a view to the development of muscle and sinew, fat and wool, all at the expense of brain development.[AP] Our horses are, as a rule, sentenced to an especially dull mode of life. Chained in stalls (and usually dark stalls at that,) during three-fourths of their lives, and more than any other domestic animal, enslaved for thousands of years by reins and whip, they have become estranged from their natural impulses, and owing to continued confinement they may perhaps have suffered even in their sensory life. A gregarious animal, yet kept constantly in isolation, intended by nature to range over vast areas, yet confined to his narrow courtyard, and deprived of opportunity for sexual activity,--he has been forced by a process of education to develop along lines quite opposite to his native characteristics. Nevertheless, I believe that it is very doubtful if it would have been possible by other methods, even, to call forth in the horse the ability to think. Presumably, however, it might be possible, under conditions and with methods of instruction more in accord with the life-needs of the horse, to awaken in a fuller measure those mental activities which would be called into play to meet those needs.

[Footnote AP: Buffon,[124] the great naturalist, expresses himself
not less pessimistically in his own brilliant manner: "Un animal
domestique est un esclave dont on s'amuse, dont on se sert, dont on
abuse, qu'on altere, qu'on depaise et que l'on denature."]

Though our investigations do not give support to the fantastic accounts of animal intelligence given by Brehms, they by no means warrant a return to Descartes and his theory of the animal-machine (as is advocated by a number of over-critical investigators). We cannot deny the validity of conclusions from analogy without denying at the same time the possibility of an animal psychology--indeed of all psychology. And all such conclusions indicate that the lower forms possess the power of sense-perception, that they, like us, presumably have at their disposal certain images, and that their psychic life is to a large extent also constituted of mere image-associations, and that they too, learn by experience. Also that they are susceptible to feelings of pleasure and of pain and also to emotions, as jealousy, fear, etc., though these may be only of the kind which have a direct relation to their life-needs. We are in no position to deny _a priori_ the possibility of traces of conceptual thought in those forms nearest man in the scale--whether living in their natural manner or under artificial conditions. And even less so since the final word has not yet been spoken regarding the nature of conceptual thinking itself. All that is certain is that nothing of the kind has been proven to occur in the lower forms, and that as yet not even a suitable method of discovering its existence has been suggested. But the community of those elementary processes of mental life which we have mentioned above is in itself enough to connect the life of the lower forms with ours, and imposes upon us the duty of regarding them not as objects for exploitation and mistreatment, but as worthy of rational care and affection.

SUPPLEMENTS

SUPPLEMENT I

MR. VON OSTEN'S METHOD OF INSTRUCTION

[BY C. STUMPF]

The following is a report of the account, which Mr. von Osten gave Professor Schumann and me, of the method which he had used in the instruction of the horse, and which was illustrated by actual demonstrations. I cannot testify, of course, that Mr. von Osten really did adhere to this method throughout the four years in which he tutored the horse, but I will say that I have several good reasons for believing that it was impossible for him to have trumped up this make-believe scheme afterward, merely to mislead us. Among the reasons are the following: He was always ready to give a detailed explanation of any question which we might interpose; the written statements of Major von Keller, who has known Mr. von Osten for a period of fifteen years; the testimony of General Zobel, who became acquainted with the whole process fully a year before any public exhibitions were given; the accounts given by the tenants in Mr. von Osten's house, who for years saw the process of instruction going on in the courtyard of the apartment building,--according to their account his intercourse with the horse was like that with a child at school,--he made much use of the apparatus and never did they notice anything like an habituation to respond to certain signals; and finally the appearance of the apparatus itself--some of which could not be bought at second hand--was most convincing.

The apparatus used for the work in arithmetic consisted mainly of a set of large wooden pins, a set of smaller ones (such as are to be had in toy-shops), a counting-machine, such as is commonly used in the schools, a chart upon which were pasted the numbers from 1 to 100, and finally the digits, cut large and in brass and suspended from a string. For the work in reading Mr. von Osten used the chart shown in the frontispiece of this book. Here we have the letters of the alphabet in small German script with numbers written below which serve to indicate the row, and what place in that row, the letters occupy. For tones, a small, child's organ was used with the diatonic scale C^1 to C^2, and for instruction in colors, a number of colored cloths were used.

The work in arithmetic began by placing a single wooden pin in front of Hans and then commanding him: "Raise the foot!--One!" Here we must assume that the horse had learned to respond to the command to raise the foot during the preceding period, when tapping in general had been taught. In order to get the horse to learn that he was to give only one tap, Mr. von Osten tried to control the tapping by means of holding the animal's foot, just as a teacher tries to aid a pupil in learning to write by guiding his hand. He repeated this exercise so often that finally the single tap was made. And always the right foot was insisted upon. Bread and carrots were the constant rewards.

Two of the pins were now set up and the command given: "Raise the foot!--One, two!" Mr. von Osten again aided the establishment of the proper association by using his hand as before. At the same time the two pins were pointed out, and the order was always without exception from left to right. Gradually it became unnecessary to touch the foot or to point to the pins, and instead the question was introduced: "How many are there?", in order that the horse should become accustomed to these words as an invitation to give the taps when he saw the wooden pins before him.

Then three pins were taken and the words "one, two, three" were spoken, and so on. In naming a number the preceding ones were always named along with it, in order that the normal order might thus be learned at the same time. Later the number alone, without the preceding ones, sufficed to elicit the proper number of taps. The last word of the series thus becomes characteristic of the series as a whole. It differs from all the others, and thus becomes the sign for the whole series of numbers thus named, each of which arises as a memory image at the proper place in the series and is accompanied by a tap of the foot. Thus, Mr. von Osten at any rate had accounted to himself for his success.

But Hans was not to acquire merely this relatively mechanical process of counting (hardly to be called counting), but he was to acquire also some meaning content for the number terms. For this purpose everything depended upon the concept "and". Only he who can grasp its meaning will be able to understand a number. 2 is 1 _and_ 1, 3 is 2 _and_ 1. Mr. von Osten had someone hold a large cloth before the horse, where the wooden pins usually were placed. He then had the cloth taken up and he would pronounce emphatically the word "and". After this had been done a number of times, he put up two of the pins and obscured them by the cloth. The cloth was again raised and the word "and" pronounced. Then Hans, as a result of his previous instruction (so Mr. von Osten thought) would give two taps at sight of the pins. The thing was repeated with three pins, then with one, and so on, and the horse would always execute the proper number of taps.

Now, five pins were set up, the three to the right being covered by the cloth. The horse tapped twice and Mr. von Osten said "two". Then the cloth was raised, Hans gave three further taps, and Mr. von Osten said "and three" with emphasis.

In this simple manner he tried to get the horse to understand that the three belongs to the two, and that both together make five. The image of the five pins as it was known from previous experience, was to be associated with the combined groups of two and three, and conversely, it was to be reproduced when these groups were presented. Later the cloth and pins were omitted and the question was asked: "How much is two and three?". The horse tapped five times. It had learned how to add. Still this could be regarded only as a mechanical process, if the horse were able to add only those numbers which had been presented together one or more times in the manner just described. And so long as we remained within the first decade, we could get twenty-five binary combinations whose sum does not exceed 10 (counting inverted orders we would have forty-five binary permutations),--all of which might have been practised separately. But as a matter of fact, Mr. von Osten did not take this course, for as he himself says, he allowed Hans to discover a great deal for himself. "Hans had to develop the multiplication table for himself."--With larger numbers and more addends, the number of combinations becomes so great that there can be no doubt they were not practised separately.

Since, after all this preliminary instruction, Hans really began to give solutions of new problems, the master believed that this was proof that he had succeeded in inculcating the inner meaning of the number concepts, and not merely an external association of memory images with certain movement responses. But he always remained within the sphere of the ideas thus developed, and adhered closely to the customary vocabulary and its usage. Every new concept, each additional word was explained anew.

It would not be legitimate to condemn the whole procedure from the very beginning on the ground of the horse's lack of knowledge of language or of its use. It was Mr. von Osten's aim to convey to the horse an understanding of the language, by means of sense-presentations, adequate to give rise to the proper sense-perceptions. Helen Keller and other blind deaf-mutes have been educated to an understanding of the language without the aid of vision and hearing. They have come to it through the sense of touch alone. Everything depends upon whether or not the predisposition for it is present. And it was quite rational that Mr. von Osten should have chosen counting and arithmetical calculation as the processes by which to make his attack upon the animal mind, for as a matter of fact, nowhere else is it so easy to bridge the gap between perception and conception and nowhere else can the sign of success or failure be perceived so readily as in the handling of numbers. It is unfortunate, however, that he did not utilize these same signs for purposes of counter-testing also, as, for instance, by inquiring for the cube root of 729. But he was prevented from doing this by his close adherence to his pedagogical principle and by his unquestioning faith in the soundness of the entire procedure.

In teaching multiplication the counting machine was used. Two of the ten balls on one of the rods were pushed far to the left, thus: 00. "How many are there?" Two taps. "Very well. That is once two." Another group of two was pushed to the left, at a short interval from the first group, thus: 00 00. "How many times two balls are there?" was asked, with a decided movement of the hand toward the two groups. Two taps. "How many, therefore, are two times two?" Four taps.

The horse was supposed to learn the meaning of the word "times" by means of the spatial separation of the groups; he was to be taught to notice and to count the groups, and also the number of units in a single group. Three times two then meant three groups with two units in each group. The horse was supposedly aided by the following factors: the relative nearness of the units belonging to one group, as over against the space interval between the groups themselves; also that the groups were pointed out as wholes in connection with the emphatic enunciation of the words 'once, twice,' etc.; and finally the touching and raising of the horse's foot by means of the hand until all the desired associations of the ideas with one another and with the corresponding tapping movements were quite perfect.

Subtraction was taught in the following manner. Five pins were set up; the horse tapped five times. Mr. von Osten then removed two of them and said emphatically: "I take away,--minus. How many are still standing?" The horse tapped three times. Here, too, there was at first some assistance by means of the hand to get the tapping.

In division four balls were first pushed to the left end of the rod, thus: 0000. "How many balls are there to the left?" Four taps. They were now divided into two pairs, thus: 00 00. Pointing to the units of one group, the teacher asks: "There are always how many in the group?" Two taps. Three groups were formed, thus: 00 00 00. "There are now how many balls to the left?" Six taps. "And there are always how many in each group?", (pointing at them). Two taps. "And how often is two contained in six?", (pointing to the groups consecutively). Three taps, etc.

The ideas of 'part', of 'whole', and of 'being contained' were illustrated by means of a chalk line which was interrupted in one or more places by erasure.

In all these operations Mr. von Osten adhered strictly to the rule, and required others to do so too, that the number upon which the operation was performed, must be mentioned first. Thus, one was not to say, "take 3 away from 7", but "from 7 take away 3." Otherwise, he believed, Hans would become easily confused. Also one was not allowed to say "to multiply", but to "take" a certain number so many "times". He, himself, never departed from this practice.

We will not go into the details of the method by which Hans was taught the meaning of the number signs, of the signs of operation, of the numbers above 10, or the significance of "digits", "tens", etc. Only this,--when in problems in addition the sum was greater than 10, the 10 was first tapped and then the remainder of the number added to the 10. Thus: "You are to add 9 and 5. How much must you add to the 9 to have 10?" One tap. "But now, you were to add not merely 1, but 5; how much have you still to add to the 10?"--Four taps. In like manner, whenever the addends were below 20 or 30 and the sum above 20 or 30, Mr. von Osten would ask for the 20 or 30 taps first. He thought that he was thus giving his pupil an ever firmer grasp upon the principle of the structure of our number system, in which all higher numbers are constituted of tens and digits. For the same reason he used at first, instead of the words 'eleven' and 'twelve' ('elf' and 'zwoelf' in the German), expressions which in English might be rendered as 'one-teen' and 'two-teen' ('einzehn' and 'zweizehn' in the German); and only later, after the animal had seemingly mastered the meaning in question, did Mr. von Osten replace them by the usual forms.

All this was beautifully conceived and might perhaps form the basis for the instruction of primitive races. But it is of immediate interest for us only because it enables us to better understand the origin of the conviction under which Mr. von Osten and his followers labored.

SUPPLEMENT II

THE REPORT OF SEPTEMBER 12, 1904

"The undersigned came together for the purpose of investigating the question whether or not there is involved in the feats of the horse of Mr. von Osten anything of the nature of tricks, that is, intentional influence or aid, on the part of the questioner. After a careful investigation they are unanimously agreed that such signs are out of the question under the conditions which were maintained during this investigation. This decision in no wise takes into account the character of the men exhibiting the horse, and who are known to most of the undersigned: In spite of the most attentive observation, nothing in the way of movements or other forms of expression which might have served as a sign, could be discovered. In order to obviate involuntary movements on the part of those present, one series of tests was made with only Mr. Busch present. Among these tests were some in which, according to his professional judgment, the possibility of tricks of the sort commonly used in training, was excluded. Another series of tests was made in such a way that the correct answers to the questions which Mr. von Osten put to the horse, were unknown to the questioner. From previous observation the greater number of the undersigned also know of a large number of cases in which, during the absence of Mr. von Osten and Mr. Schillings, other persons were likewise able to obtain correct responses from the horse. Among these were some cases in which the questioner did not know the correct solution of the problem or was mistaken about it. And lastly, several of the undersigned have become acquainted with the method which Mr. von Osten used, which has little in common with methods of training, and is patterned after the instruction given in the elementary schools. As a result of these observations the undersigned are of the opinion that unintentional signs of the kind which are at present familiar, are likewise excluded. They are unanimously agreed that this much is certain: This is a case which appears in principle to differ from any hitherto discovered, and has nothing in common with training, in the usual sense of that word, and therefore is worthy of a serious and incisive investigation.

BERLIN, September 12, 1904.

PAUL BUSCH, Circus-manager.
OTTO, COUNT ZU CASTELL-RUeDENHAUSEN.
DR. A. GRABOW, member of the schoolboard, retired.
ROBERT HAHN, Teacher, Municipal schools.
DR. LUDWIG HECK, Director of the Zooelogical Garden.
DR. OSCAR HEINROTH, Assistant in the Berlin Zooelogical Garden.
DR. RICHARD KANDT.
MAJOR F. W. VON KELLER, retired.
MAJOR-GENERAL TH. KOeRING, retired.
DR. MIESSNER, Assistant in the Royal Veterinary College.
PROF. NAGEL, Head of the department of sense-physiology in the
Physiological Institute of the University of Berlin.
PROF. C. STUMPF, Director of the Psychological Institute, Member of
the Academy of Sciences.
HENRY SUERMONDT."

SUPPLEMENT III

AN ABSTRACT FROM THE RECORDS OF THE SEPTEMBER-COMMISSION[AQ]

[Footnote AQ: A few days after the 12th of September I made the
present abstract from the original records of the Commission, which
I have here abbreviated somewhat. (See page 8). Referring once more
to the misunderstanding mentioned on page 3, I would say that the
closing sentence of the report is here re-given literally as it then
appeared. C. St.]

The important meetings occurred on the 11th and 12th of September and both of them extended over four hours. The greatest difficulty was occasioned by the condition laid down by Mr. von Osten: that we were to work without him from the very beginning. In a certain sense this condition had been met once before when Mr. Schillings appeared upon the scene, a man whose fairness ought to be doubted by none. He came utterly skeptical, and yet in the course of a week he learned to handle the horse and received responses regularly. However, since the public had begun to doubt Mr. Schillings also, another person had to attempt the role of questioner. Count zu Castell tried to do this and practised for some days before the meetings, but his success--although of no small moment--was not great enough to be convincing.

In apprising Mr. von Osten of this fact we caused a veritable catastrophe. He declared in a most decisive manner that he would have to insist upon the condition he had imposed, since the public demanded it, and he could never assist in any tests, until he had been cleared of the suspicion of having descended to the use of tricks. If it should take weeks to accustom the horse to a new questioner, there would be no alternative but to wait that length of time.

A happy circumstance helped us out of our difficulty. We had chanced in our discussion to mention the experience of Dr. Miessner, a member of the commission, who on the day before had gone to witness an exhibition of the mare "Clever Rosa", and who believed that he had succeeded in discovering the tricks involved. There was a sudden change in Mr. von Osten's attitude. He expressed his willingness to undergo the most stringent examination and agreed to anything in the way of conditions of control, challenging even the proven ability of Dr. Miessner. "I have neither whip nor rod, as had the man in the exhibition, and agree to any precautionary measures you may care to take."

After he had gone, the commission decided to ask him to have the horse perform one of the more common, simple, feats. They were going to watch him very closely. Different members were assigned the task of attending to different parts of his body (head, eyes, right hand, left hand, etc.) while Mr. Busch, since he was the most proficient in the detection of tricks, was to regard the total behavior of the man.

The exhibitions included the indication of the day of the week by means of taps, the day just past, the day ahead, its date, arithmetical problems, and the counting of rings strung upon a rod. Messrs. Grabow and Hahn interpolated a few tests themselves, in which they did the questioning. All tests were successful.

Mr. von Osten withdrew, and in comparison of notes which followed, Mr. Busch, as well as all the others, declared that they had discovered nothing of the nature of a visible sign. Mr. Busch said that he had also kept an eye on the spectators and had noticed nothing there. Nevertheless, he desired to see Mr. von Osten go through one series with no one else but himself (Busch) present.

This was done, and on this occasion a number of tests were made in the recognition of colored cloths. The horse was required to indicate, by tapping, the place in the series which the cloth occupied and was then asked to bring the green or the red, as the case might be, in his mouth. Furthermore, he was asked to approach that one of the five gentlemen standing at a distance, whose photograph had been shown him. Then he was requested to spell the words "Rat" and "Busch" according to the method which he had been taught. Nearly all of these tests were likewise successful.

In the conference which followed, Mr. Busch again declared that he had noticed no trace of a sign; he maintained that, in the selecting of colored cloths (especially when they were placed so closely together) and in the approach toward a person, there was no possibility whatever that some trick was being used.

During the session of September 12th, Mr. von Osten agreed to two sets of experiments.

1. Another man was to put the question to the horse. Mr. von Osten himself was to stand, back to back to the questioner and to bend forward, so that he was effectually hidden from the horse's view, yet could, by means of occasional calls, make his presence known to the animal. The assumption was that it would be conducive to success if the horse knew that the master was present and was awaiting the answer, and yet at the same time the possibility of receiving a sign was obviated.

2. Another man in Mr. von Osten's absence was to ask the horse to tap a certain number. Then the questioner was to leave, and Mr. von Osten, returning, was to ask the horse to perform some arithmetical process with the number which was thus unknown to the master. Mr. von Osten said that he thought that this method was somewhat risky, since the horse would be aware that he, Mr. von Osten, did not know the number, and might therefore be in a humor to play some prank.

The questions of the first sort were answered with but very few errors. Mr. Hahn and Count zu Castell asked simple questions in arithmetic. When Mr. von Osten withdrew into the stable, the count put several other problems, among them the counting of persons and of windows, all of which were solved correctly.

Between the first and second series of tests the following experiments were interpolated. The names of six members of the commission were written upon six slates respectively, which were then suspended from a string. Mr. von Osten pointed to one of the men and asked: "On which of the slates is this gentleman's name to be found?" The correct number was tapped in every case. The command to approach the slate in question was also obeyed as a rule, although this was not as uniformly successful as tapping.

In the conference which followed, Mr. Busch declared that the feats appeared inconceivable to him; and again none of the men had noted anything in the way of signs.

Now followed the second series of tests mentioned above. In order to be sure to get the correct responses, Mr. Schillings, who up to this point had not been present at any of the experiments, was asked to put the questions to the horse. Mr. von Osten went into the house, accompanied by a member of the commission. And again, Mr. Schillings would go out before the second part of the test, without having met Mr. von Osten.

Five tests were made in this way. They were not attended by such amazing success as were the preceding ones, but nevertheless the results were surprising. The horse nearly always repeated the number itself, instead of performing the operation required. Since, however, Mr. Schillings, owing to a misunderstanding, had, in the first two cases, said to the horse: "You are to repeat this number for Mr. von Osten", the errors might appear to be a result of this request.

At the final discussion, the result of which was the unanimous declaration which was given for publication, not only the data obtained during these two sessions, but also the earlier experiences of some of the members of the commission were taken into consideration. None of the tests witnessed could be referred to chance or to the use of tricks. Count zu Castell pointed out that in the course of eight days he had elicited forty correct responses from the horse, among them some in regard to which he himself had been momentarily in error. Other members recalled the many instances in previous exhibitions, during which both Mr. Schillings and Mr. von Osten were absent, when questions were put to the horse by others. The commission also had access to a detailed account written by Professor Stumpf on Mr. von Osten's method of instruction, based on the explanations and demonstrations which Mr. von Osten had himself given. As a result of these considerations the commission felt under obligations to give public expression to its conviction. In the report it limited itself, however, to the purely negative side--principally in denying the use of tricks,--and expressed no opinion with regard to the actual genesis of the horse's accomplishments, since it believed that there was great possibility that other factors were involved which ought to be carefully investigated.

SUPPLEMENT IV

THE REPORT OF DECEMBER 9TH, 1904

Together with Dr. E. von Hornbostel and Mr. O. Pfungst, I have tried during the past few weeks to find an explanation of the accomplishments of the horse 'Hans' by the experimental method. We had access to the horse in the absence of the master and groom. The results are as follows:

The horse failed in his responses whenever the solution of the problem that was given him was unknown to any of those present. For instance, when a written number or the objects to be counted were placed before the horse, but were invisible to everyone else, and especially to the questioner, he failed to respond properly. Therefore he can neither count, nor read, nor solve problems in arithmetic.

The horse failed again whenever he was prevented by means of sufficiently large blinders from seeing the persons, and especially the questioner, to whom the solution was known. He therefore required some sort of visual aid.

These aids need not, however,--and this is the peculiarly interesting feature in the case,--be given intentionally. The proof for this is found in the fact that in the absence of Mr. von Osten the horse gave correct replies to a large number of persons; and to be more specific, Mr. Schillings and later Mr. Pfungst, after working with the horse for a short time, regularly received correct answers, without their being in any way conscious of having given any kind of signal.

So far as I can see, the following explanation is the only one that will comport with these facts. The horse must have learned, in the course of the long period of problem-solving, to attend ever more closely, while tapping, to the slight changes in bodily posture with which the master unconsciously accompanied the steps in his own thought-processes, and to use these as closing signals. The motive for this direction and straining of attention was the regular reward in the form of carrots and bread, which attended it. This unexpected kind of independent activity and the certainty and precision of the perception of minimal movements thus attained, are astounding in the highest degree.

The movements which call forth the horse's reaction, are so extremely slight in the case of Mr. von Osten, that it is easily comprehensible how it was possible that they should escape the notice even of practised observers. Mr. Pfungst, however, whose previous laboratory experience had made him keen in the perception of visual stimuli of slightest duration and extent, succeeded in recognizing in Mr. von Osten the different kinds of movements which were the basis of the various accomplishments of the horse. Furthermore, he succeeded in controlling his own movements, (of which he had hitherto been unconscious), in the presence of the horse, and finally became so proficient that he could replace these unintentional movements by intentional ones. He can now call forth at will all the various reactions of the horse by making the proper kind of voluntary movements, without asking the relevant question or giving any sort of command. But Mr. Pfungst meets with the same success when he does not attend to the movements to be made, but rather focuses, as intently as possible, upon the number desired, since in that case the necessary movement occurs whether he wills it or not. In the near future he will give a special detailed report of his observations, which gives promise of becoming a valuable contribution to the study of involuntary movements. Also he will give an account of our tests and of the mechanism of the various accomplishments of the horse. We must also defer, till then, the disproof of certain seemingly relevant arguments in favor of the horse's power of independent thought.

Some defenders of the view which maintains the horse's rationality may urge that it was only through our experiments that the animal became trained and spoiled in so far as the ability to think is concerned. They are refuted in this, however, by the fact that the horse still continues to solve problems involving decimal fractions and to determine calendar dates for Mr. von Osten, as brilliantly as ever, as is shown by his recent demonstration before a large group of spectators. That these results are now being achieved in a manner essentially different from formerly is nothing but a bare assertion.

On the other hand, now that the possibility has been established that these wonderful results may be obtained in all their complexity by means of intentional signs, many will question whether Mr. von Osten did not himself train the horse from the very beginning to respond to these signs. No one has the right, however, to charge an old man, who has never had a blemish on his reputation, with having invented a most refined network of lies, if the facts can be explained in a satisfactory manner in some other rational way. And this can be done in this case. For we have seen that there is another alternative, other than the theory that the horse can think or the assumption that tricks have been employed.

And now, aside from the specific results obtained, what is the scientific and philosophic import of the whole affair?--For one thing, the revolution in our conception of the animal mind, which had been hoped for by some, and feared by others, has not taken place. But a conclusion of an opposite character is justified. If such unexampled patience and high pedagogical excellence as was daily brought to bear by Mr. von Osten during the course of four long years, could not bring to light the slightest trace of conceptual thinking, then the old assertion of the philosophers that the lower forms are incapable of such thinking, finds corroboration in the results of these experiments so far as the animal scale up to and including the ungulates is concerned. For this reason the tremendous effort put forth by Mr. von Osten, is not, in spite of the self-deception under which he labors, lost to science. If anyone has the courage to try the experiment with the dog or the ape, the insight which we have now gained will enable him to beware of one source of error which hitherto has not been noticed.

In the face of much misapprehension which has arisen, I wish once more to say emphatically that the committee of September 12th in no wise declared itself to be convinced that the horse had the power of rational thinking. The committee restricted itself entirely to the question whether or not tricks were involved, and, intentionally and rightly referred the positive investigation to a purely scientific court. I would also report that for some time Mr. Schillings has been convinced, by his own observations, of the horse's lack of reason, and when he was apprised of our conclusion in the matter, he embraced it without wavering. I have no intention of taking part in any discussion which may arise in the press as a result of the present report. Unless they wish to confine themselves to mere guesswork, the defenders of other views will not shrink from the task of basing their criticism upon careful methodical experimentation, and they will keep a detailed record of their results day by day; for statements based solely upon memory, without specific report of experimental conditions, prove nothing.

PROF. CARL STUMPF.

December 9th, 1904.

TABLE OF REFERENCES

(The names of the authors of anonymous works are placed in parenthesis.)

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3. HANSEN, F. C. C. and A. Lehmann. Ueber unwillkuerliches Fluestern. Philosophische Studien, edited by W. Wundt, Leipsic, 1895, Vol. 11, pp. 471 ff.

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