Читать книгу Clever Hans (The Horse of Mr. Von Osten) - Oskar Pfungst - Страница 6

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If we would appreciate the interest that has been aroused everywhere by the wonderful horse solving arithmetical problems, we must first consider briefly the present state of the problem of animal consciousness.[C] Animal consciousness cannot be directly gotten at, and the psychologist must therefore seek to appreciate it on the basis of the animal's behavior and with the assistance of conceptions borrowed from human psychology. Hence it is that animal psychology rests upon uncertain foundations with the result that the fundamental principles have been repeatedly questioned and agreement has not yet been attained. The most important of these questions is, "Does the animal possess consciousness, and is it like the human consciousness?" Comparative psychologists divide into three groups on this question.

The one group allows consciousness to the lower forms, but emphasizes the assertion that between the animal and the human consciousness there is an impassable gap. The animal may have sensations and memory-images of sensations which may become associated in manifold combinations. Both sensations and memory images are believed to be accompanied by conditions of pleasure and of pain (so-called sensuous feelings), and these in turn, become the mainsprings of desire. The possession of memory gives the power of learning through experience. But with this, the inventory of the content of animal consciousness is exhausted. The ability to form concepts[D] and with their aid to make judgments and draw conclusions is denied the lower forms. All the higher intellectual, æsthetic and moral feelings, as well as volition guided by motives, are also denied. Among the ancients this view was held by Aristotle and the Stoics; and following them it was taught by the Christian Church. It pervaded all mediæval philosophy, which grew out of the teachings of Aristotle and the Church. It is this philosophy, in the form of Neo-Thomism, which still obtains in the Catholic world.

During the 17th century, even though temporarily, another conception of the consciousness of lower forms came to prevail and was introduced by Descartes, the "Father" of modern philosophy. Far more radical than the earlier conception, it denied to animals not only the power of abstract thought, but every form of psychic life whatever, and reduced the lower form to a machine, which automatically reacted upon external stimuli. This daring view, however, prevailed for only a comparatively short period; but owing to the opposition which it aroused, it gave a tremendous impetus to the study of animal consciousness. Most of the great philosophers following Descartes, such as Locke, Leibniz, Kant, and Schopenhauer, however greatly they may have differed in other points, in this one returned to the Aristotelian point of view.

A third belief avers that animal and human consciousness do not differ in essentials, but only in degree. This conclusion is regularly arrived at by those who regard so-called abstract thought itself, as simply a play of individual sensations and sensation-images, as did the French and British associationists (Condillac and the Mills). The superiority of man accordingly consisted in his ability to form more intricate ideational complexes. Again, this conception of the essential similarity of the human and the animal psyche has also always been arrived at by the materialists (from Epicurus to C. Vogt and Büchner) who impute reason to the animal form as well as to man. The same position is, furthermore, taken by the evolutionists, including those who do not subscribe to the doctrines of materialism. It has almost become dogma with them that there exists an unbroken chain of psychic life from the lowest protozoa to man. Haeckel, preëminently, though not always convincingly, sought to establish such a graded series and thus to bridge the chasm between the human and the animal consciousness.

Two tendencies, therefore, are discernible in animal psychology. The one seeks to remove the animal psyche farther away from the human, the other tries to bring the two closer together. It is undoubtedly true that many acts of the lower forms reveal nothing of the nature of conceptual thinking. But that others might thus be interpreted cannot be denied. But need they be thus interpreted?—There lies the dispute. A single incontrovertible fact which would fulfil this demand, [i.e., proof of conceptual thinking], would, at a stroke, decide the question in favor of those who ascribe the power of thought to the lower forms.

At last the thing so long sought for, was apparently found: A horse that could solve arithmetical problems—an animal which, thanks to long training, mastered not merely rudiments, but seemingly arrived at a power of abstract thought and which surpassed, by far, the highest expectations of the greatest enthusiast.

And now what was it that this wonderful horse could do? The reader may accompany us to an exhibition which was given daily before a select company at about the noon hour in a paved courtyard surrounded by high apartment houses in the northern part of Berlin. No fee was ever taken. The visitor might walk about freely and if he wished, might closely approach the horse and its master, a man between sixty and seventy years of age. His white head was covered with a black, slouch hat. To his left the stately animal, a Russian trotting horse, stood like a docile pupil, managed not by means of the whip, but by gentle encouragement and frequent reward of bread or carrots. He would answer correctly, nearly all of the questions which were put to him in German. If he understood a question, he immediately indicated this by a nod of the head; if he failed to grasp its import, he communicated the fact by a shake of the head. We were told that the questioner had to confine himself to a certain vocabulary, but this was comparatively rich and the horse widened its scope daily without special instruction, but by simple contact with his environment. His master, to be sure, was usually present whenever questions were put to the horse by others, but in the course of time, he gradually responded to a greater and greater number of persons. Even though Hans did not appear as willing and reliable in the case of strangers as in the case of his own master, this might easily be explained by the lack of authoritativeness on their part and of affection on the part of Hans, who for the last four years had had intercourse only with his master.

Our intelligent horse was unable to speak, to be sure. His chief mode of expression was tapping with his right forefoot. A good deal was also expressed by means of movements of the head. Thus "yes" was expressed by a nod, "no" by a deliberate movement from side to side; and "upward," "upper," "downward," "right," "left," were indicated by turning the head in these directions. In this he showed an astonishing ability to put himself in the place of his visitors. Upon being asked which arm was raised by a certain gentleman opposite him, Hans promptly answered by a movement to the right, even though seen from his own side, it would appear to be the left. Hans would also walk toward the persons or things that he was asked to point out, and he would bring from a row of colored cloths, the piece of the particular color demanded. Taking into account his limited means of expression, his master had translated a large number of concepts into numbers; e.g.:—the letters of the alphabet, the tones of the scale, and the names of the playing cards were indicated by taps. In the case of playing cards one tap meant "ace," two taps "king," three "queen," etc.

Let us turn now to some of his specific accomplishments. He had, apparently, completely mastered the cardinal numbers from 1 to 100 and the ordinals to 10, at least. Upon request he would count objects of all sorts, the persons present, even to distinctions of sex. Then hats, umbrellas, and eyeglasses. Even the mechanical activity of tapping seemed to reveal a measure of intelligence. Small numbers were given with a slow tapping of the right foot. With larger numbers he would increase his speed, and would often tap very rapidly right from the start, so that one might have gained the impression that knowing that he had a large number to tap, he desired to hasten the monotonous activity. After the final tap, he would return his right foot—which he used in his counting—to its original position, or he would make the final count with a very energetic tap of the left foot—to underscore it, as it were. "Zero" was expressed by a shake of the head.

But Hans could not only count, he could also solve problems in arithmetic. The four fundamental processes were entirely familiar to him. Common fractions he changed to decimals, and vice versa; he could solve problems in mensuration—and all with such ease that it was difficult to follow him if one had become somewhat rusty in these branches. The following problems are illustrations of the kind he solved.[E] "How much is ⅖ plus ½?" Answer: 9/10. (In the case of all fractions Hans would first tap the numerator, then the denominator; in this case, therefore, first 9, then 10). Or again: "I have a number in mind. I subtract 9, and have 3 as a remainder. What is the number I had in mind?"—12. "What are the factors of 28?"—Thereupon Hans tapped consecutively 2, 4, 7, 14, 28. "In the number 365287149 I place a decimal point after the 8. How many are there now in the hundreds place?"—5. "How many in the ten thousandths place?"—9. It will be noticed, therefore, that he was able to operate with numbers far exceeding 100, indeed he could manipulate those of six places. We were told that this, however, was no longer arithmetical computation in the true sense of the term; Hans merely knew after the analogy of 10 and 100 that the thousands take the fourth place, the ten-thousands the fifth, etc. If an error entered into Hans' answer, he could nearly always correct it immediately upon being asked: "By how many units did you go wrong?"

Hans, furthermore, was able to read the German readily, whether written or printed. Mr. von Osten, however, taught him only the small letters, not the capitals. If a series of placards with written words were placed before the horse, he could step up and point with his nose to any of the words required of him. He could even spell some of the words. This was done by the aid of a table devised by Mr. von Osten, in which every letter of the alphabet, as well as a number of diphthongs had an appropriate place which the horse could designate by means of a pair of numbers. Thus in the fifth horizontal row "s" had first place; "sch" second, "ss," third, etc.; so that the horse would indicate the letter "s" by treading first 5, then 1, "sch," by 5 and 2, "ss" by 5 and 3. Upon being asked "What is this woman holding in her hand?" Hans spelled without hesitation: 3, 2; 4, 6; 3, 7; i.e., "Schirm" (parasol). At another time a picture of a horse standing at a manger was shown him and he was asked, "What does this represent?" He promptly spelled "Pferd" (horse) and then "Krippe" (manger).

He, moreover, gave evidence of an excellent memory. In passing we might also mention that he knew the value of all the German coins. But most astonishing of all was the following: Hans carried the entire yearly calendar in his head; he could give you not only the date for each day without having been previously taught anew, but he could give you the date of any day you might mention. He could also answer such inquiries as this: "If the eighth day of a month comes on Tuesday, what is the date for the following Friday?" He could tell the time to the minute by a watch and could answer off-hand the question, "Between what figures is the small hand of a watch at 5 minutes after half-past seven?" or, "How many minutes has the large hand to travel between seven minutes after a quarter past the hour, and three quarters past?" Tasks that were given him but once would be repeated correctly upon request. The sentence: "Brücke und Weg sind vom Feinde besetzt" (The bridge and the road are held by the enemy), was given to Hans one day and upon the following day he tapped consecutively the 58 numbers which were necessary for a correct response. He recognized persons after having seen them but once—yes, even their photographs taken in previous years and bearing but slight resemblance.

A corresponding high degree of sensory activity seemed to accompany these astonishing feats of memory and reason. Although the horse is not usually credited with a very keen sense of vision, Hans was able to count the windows of distant houses and the street urchins climbing about on neighboring roofs. He had an ear for the most subtle nuances of the voice. He caught every word—no matter how softly it was spoken—so that we were not allowed to whisper the answer to a problem, even when standing at a distance of several yards, since it would be equivalent—so Mr. von Osten declared—to giving the result to the horse.

Musical ability also comes into the category of Hans' accomplishments. He possessed, not only an absolute tone consciousness—a gift granted to few of us in the human world—which enabled him to recognize a note sounded or sung to him as c, d, etc. (within the once accented scale of c-major), but also an infallible feeling for intervals, and could therefore determine whether two tones, sounded simultaneously, composed a third or fifth, etc. Without difficulty he analyzed compound clangs into their components; he indicated their agreeableness or disagreeableness and could inform us which tones must be eliminated to make consonance out of dissonance. C, d and e were given simultaneously and Hans was asked: "Does that sound pleasant?" He shook his head. "What tone must be omitted to make it pleasant?" Hans trod twice—indicating tone "d." When the seventh chord, d-f-a-c, was sounded, he shook his head disapprovingly. He evidently was old-fashioned in his musical tastes and not agreeably disposed toward modern music, so he indicated by tapping that the seventh, c, would have to be eliminated; thus changing the seventh chord to a minor chord in order to obtain harmony. When asked what tones might not be given simultaneously with the fourth and sixth, Hans indicated consecutively the third, fifth and seventh; that the first might be added, he was ready to admit. Finally, he was familiar with not less than thirteen melodies and their time.

Not only in the high degree of development of the senses and the intellect, but also in that of the feeling and the will, did Hans possess a decided individuality. Being of a high-strung and nervous temperament and governed by moods, he evinced strong likes and dislikes, and frequently displayed an annoying stubbornness—a fact often dwelt upon by Mr. von Osten. He had never felt the whip, and therefore often persisted in wilfully answering the simplest questions incorrectly and a moment later would solve, with the greatest ease, some of the most difficult problems. Whenever any one asked a question without himself knowing the answer, Hans would indulge in all sorts of sport at the questioner's expense. We were told that the sensitive animal could easily perceive the questioner's ignorance and would therefore lose confidence in, and respect for, him. It was felt to be desirable, however, to have just such cases with correct responses. Often, too, Hans would persist in giving what seemed an incorrect reply, but which was later discovered to be correct. On the other hand it was useless to try to get answers upon topics of which he knew nothing. Thus he ignored questions put in French or Latin and became fidgety, thereby showing the genuineness of his achievements; but upon topics with which he was familiar he could not be led astray. Indeed, there was nothing but language lacking to make him almost human and the intelligent animal was declared by experienced educators to be at about the stage of development of a child of 13 or 14 years.

This wonderful horse, which in the opinion of its friends was the means of deciding in the affirmative the old, old, question of the rationality of the lower forms and thus changing radically the existing Weltanschauung, aroused world-wide interest. A flood of articles appeared in the newspapers and magazines, two monograph[1, 2] attempts at explanation were devoted to him.[F] He was made the subject of popular couplets, and his name was sung on the vaudeville stage. He appeared upon picture post-cards and upon liquor labels, and his popularity was shown by his reincarnation in the form of children's playthings. Many personages of note who had seen the horse's exhibitions, declared, some of them in public statements, that they were now convinced. Among these, besides Mr. Schillings, were naturalists of note; e.g.: the African explorer Prof. G. Schweinfurth, Dr. Heinroth and Dr. Schäff, the director of the zoological garden in Hanover; there were likewise horse-fanciers of first-rank, such as General Zobel, and the well-known hippological writer Major R. Schoenbeck. Again, the well-known zoölogist, K. Möbius, writing in the "National-zeitung" declared he was convinced of the horse's power to count and to solve arithmetical problems. He also said that he believed the horse's memory and acute power of sense-discrimination to be at the root of the matter. Those who gleaned all their knowledge of the horse from newspaper reading were satisfied to arrest judgment, or, on the other hand, became indignant at the supposed imposition on the part of the gentleman of leisure and at the gullibility of the public. Some would of course attempt explanations on the basis of older facts. Here we have two points of view.

Some tried to explain the whole thing on the basis of purely mechanical memory and would thus allow the title "learned" but not "intelligent" Hans. If, for instance, he was able to indicate the component of a clang of three tones, it was not because he had the power to analyze the tone-complex, but because he was able to see the stops of the harmonica and was accustomed to give one tap for every stop which was closed. If he was able to tell time by the watch, it was not because he read it, but because he was always asked at the same hour of the day (which, of course, was contrary to fact) and because he had learned by heart the necessary number of taps. They also said that his manifold arithmetical achievements were merely the expression of a remarkable memory; that in the animal brain, lying fallow for centuries, there was stored up a tremendous amount of energy, which here had been suddenly released. They justified their point by calling to mind, in this connection, the wonderful memory of primitive races. The authors of the two monographs already mentioned, Zell and Freund, adopted this 'mnemotechnic' interpretation, and the latter considered that he had disposed definitely of the problem in designating the horse—a "four-legged computing machine."

Another group would not even allow Hans the glory of a wonderful memory. He knew nothing. Rather was he to be regarded as a stupid Hans, and totally dependent upon signs or helps given by his master. Only a very few believed, however, that such signs—the nature of which was quite unknown or regarding which only vague unsubstantiated suppositions were advanced—were given unintentionally. Most of the critics openly averred that we here had to do with intentional control, in other words, with tricks. But not only did stupid orthodoxy dispose of the matter in this way, but also the enlightened, who believe everything unusual to be contrary to reason. They put the Hans problem on a level with spiritualism, and were convinced that if the veil were removed a crass imposition would be revealed. Professional trainers who regarded themselves as well informed did not hesitate to give expression to this same view, even though they had observed Hans inadequately or not at all.

The defenders of this second point of view were not at a loss to point out the signs supposed to be given to Hans. One of these believed he had discovered the primary means for giving these signs in the slouch hat of Mr. von Osten. It was no accident, they said, that Mr. Schillings wore a slouch hat when he experimented with the horse. It is sufficient to note that Mr. Schillings was usually bare-headed or wore only a cap when he tested the horse. Another accused, in like fashion, the long coat of the experimenter; a third, who "had had opportunity to observe Hans on several occasions," declared with equal certainty that the cue lay in the movements of the hand as it was thrust into the pocket filled with carrots. One circus-star declared, that the trick lay in eye movements, another such star declared it lay in the movements of the hand. A sixth discovered that the signs were "manifold" and adds, "to be sure, the trainer must have a fund of such signs in order to prevent embarrassment." Such a hypothesis is itself, it would seem, one of embarrassment. On the other hand, there were many first-class observers who vainly tried to discover regularly recurring signs; among them the only professional trainer—who had devoted any satisfactory length of time to the horse and had also sought diligently for the signs in question—said, "I was fully convinced that I would be able to explain the problem in this way, but I was mistaken." The president of the "Internationale Artisten Genossenschaft," a person who knew all the usual means of control in trick performances, went over to the other side as a result of his observations.

There were others who sought for auditory signs. The opinion was expressed that "Hans was unable to answer the simplest question such as 'What is two plus three?' whenever the questioner's tone of voice differed from that of the master's." Another put chief stress upon the changing inflection; furthermore, a "high degree of auditory sensitivity" was often offered in explanation.

The sense of smell was also made to bear some burdens. With its help, for instance, Hans was believed to be able to recognize the photograph of some one present, supposing, of course, that the person had carried the picture about with him, thus allowing it to be impregnated with his peculiar personal odor. One even suggested that the heat radiating from the questioner's body and the electric stimulus conducted underground to Hans's foot were sufficient explanation for his remarkable feats.

Even the so-called N-rays, of one-day fame, which were supposed to radiate from the human brain when in activity, were offered as a solution. A similar thing may have been in the mind of the "natural philosopher" who even after the publication of the December report, wrote as follows in one of the journals: "On the basis of most careful control, I have come to the conclusion, that the brain of the horse receives the thought-waves which radiate from the brain of his master; for mental work is, according to the judgment of science, physical work." Of the same character are the explanations of two others, one of whom declares that Hans was acting "under the magnetic influence of man", while the other declared that "hypnotic suggestion is involved", and, ignoring attested facts, tells us that, "The horse can execute the commands of another only when the master, with whom it is 'en rapport', wills that it shall obey." We may close the catalogue of explanations with one more, which, in spite of its vagueness, found many defenders, viz: suggestion. Without defining this conception more specifically and without the slightest notion of the peculiar difficulties which it involves (L. Loewenfeld in his "Handbuch des Hypnotismus" [Wiesbaden, 1901, pp. 35ff.] cites twenty different definitions of the term given by as many authors) a critic writes: "The astounding phenomenon of an animal apparently possessing human reason is to be attributed solely to suggestion". Having referred to a dog trained for the vaudeville-stage, the gentleman concludes that, "our intelligent horse, as well as the dog, is simply of fine nervous organization and hence highly susceptible to suggestions".

What was to be done, with this mass of conflicting explanations? Everyone considered his own opinion the only correct one, without, however, being able to convince anyone else. The need here was not simple affirmation, but proof.