CHAPTER VI

GENESIS OF THE REACTION OF THE HORSE

In the preceding discussion we have regarded the achievements of the

horse as well as Mr. von Osten's explanation of them, as matters of

fact. Let us now consider the question: How did the horse come by these

achievements, and how did its master arrive at his curious theory in

explanation of them? Did he indeed seek to instill in the horse's mind

the rudiments of human culture through long years of painstaking

instruction in accordance with the method described in Supplement I

(page 245)? If that is the case, then, of course his hoped-for success

was only seeming, not real. Or did he, as so many critics aver,

systematically train the horse to respond automatically to certain cues,

and propound his theory merely for the purpose of misleading the public?

There might possibly be another alternative, viz.: was there a mixture

of instruction and of training to respond to cues?

The production of the horse's achievements would not require a great

deal of explanation, if it were a case of mere training for the purpose

of establishing certain responses to certain cues. It might be

desirable, however, before deciding in favor of one of these

possibilities, to indicate briefly the process of development, as it

might occur, if the point of view is taken that _bona fide_ instruction

was given.

This development would probably be as follows:--Mr. von Osten, as the

result of theoretical speculation or of a misinterpretation of the facts

of experience, having arrived at the conclusion that the horse possessed

extraordinary capacity, finally undertook to instruct a certain horse

for a period covering three years. This one having died, he, nothing

daunted, undertook the education of another one. What it was that

influenced this old teacher of mathematics to deprive humankind of the

benefit of his extraordinary pedagogical ability and love of teaching,

we do not know. It may be that he had had bitter experience in that

line, or again, mayhap the newness and tremendousness of this other task

stimulated him. His first problem must have been to arouse the interest

of the animal in this process of education. It was hardly to be believed

that Hans would eagerly cooeperate in a process which promised to yield

him no immediate benefit. The teacher sought to overcome this lack of

immediate interest by the means of rewards. To Hans the sweet carrot was

as toothsome a bite as candy is to the child. And since the horse was

furthermore kept on low rations on account of the relatively low amount

of physical exercise he took, the anticipation of the carrots was doubly

enticing.

The first thing that Mr. von Osten sought to teach the horse, according

to his own statement, was the significance of the names of colors and of

the spatial directions such as "up", "down", etc. In the case of

children there is a simple test by means of which we may discover if

they have put any content into these words. The test is: Do they,

themselves, use them correctly? Do they call the blue, blue, and the

red, red? Since the horse could not speak, his instructor had to give

him some means by which he could make himself understood. He taught

Hans to approach the colors and select the cloth of the color wanted. He

also taught him to make those movements of the head or body which

correspond with the expressions: "up", "down", etc.

First of all, Hans had to be taught to bring the cloths. Then began the

pointing out of the different colors, accompanied each time by their

proper names. It is very probable that at first Hans had to be led each

time to each separate colored cloth and taught to raise it or to touch

it with his nose. Later, Mr. von Osten, after having pronounced the name

of the color, remained at his place, with his head and body directed to

the cloth in question and gazing intently at it, in order to see whether

or not the horse was pointing out the right one. Naturally Hans would,

at first, fail a hundred times where he would succeed but once, but

since the horse would receive the anticipated reward in case of success,

he gradually became conscious that this reward was attached to

executions which had some special mark. This special mark would be

expressed in human speech by the statement that the horse would go in

the direction indicated by the position of the instructor's body. For

Hans, of course, this would not take the form of an abstract statement,

but simply of a definite way of seeing and of going and a correlation of

the two in a certain definite manner,--the whole being a process, the

elements of which remained unanalyzed and unaccounted for by Hans. Owing

to the position of the eye, it was possible for him to keep his master

within his field of vision, while he was approaching the cloths. And

only when he had correlated his approach in a certain definite manner

with his visual perception of the master, i. e., only when he had felt

his way, as it were, along the latter's line of vision, did he receive

his reward. A sufficient number of repetitions was all that was

necessary to establish an association in the psychological sense of the

term. In the same manner, dogs will learn, as was indicated on page 177,

to bring an object upon which the master has fixed his gaze, it

mattering little whether or not the name of the object be enunciated.

There is only this difference, that, in the case of the dog it is not

possible to keep the image of the master within the field of vision; but

neither is it necessary, for he has recognized the object before he has

started for it. We must remember, however, that it does not simplify an

attempt at explanation to assume that Mr. von Osten consciously trained

the animal to respond to certain bodily positions of the questioner.

For, even in this case, it would be necessary to explain how it was

possible for him to train the horse to heed the cues.--In the course of

time, the instructor may have noticed that whenever he moved during the

course of a test the horse invariably failed. But he may have regarded

this merely as an incidental distraction and afterward was careful to

remain quiet. As soon as he increased the number of cloths upon the

floor, it was no longer possible for him to give the horse such accurate

directive signs, and the number of errors consequently increased.

Ascribing them to the inattentiveness of his pupil, he sought to

encourage him by such calls as "look out", "look there", "see there",

believing that, thus, he was directing the horse's attention to the

desired color. Without understanding the meaning of the calls, Hans

learned, however, to keep moving just as long as the calling continued,

for if he did this he was regularly rewarded. An association was

established between the call and the impulse to move on. And with these

two associations established, Hans gave the impression of having grasped

the meaning of the color terms.

The origin of the proper movements in response to the terms "up" and

"down" may be explained by the fact that the movements themselves were

practised in a purely external fashion. Thus, whenever the word "left"

was pronounced, the horse's head was pulled to the left by means of the

bridle or the reward was held off to that side. Later, Mr. von Osten,

who looked expectantly at the horse's head, whenever he pronounced the

word would unconsciously move his own head in the direction in which he

desired the horse to turn. This is quite in accord with the words of

Darwin to the effect that whenever we wish an object to move in a

certain direction it is well-nigh impossible for us to inhibit an

unconscious, involuntary movement in that direction. Proof for this may

be found on all sides, in daily experience.[97] Imagine, for instance,

the strain sensations of the bowler or billiard player as he follows the

moving ball. It is impossible to decide whether Mr. von Osten,

consciously continued to image the head movements which he expected the

horse to make or whether these anticipatory images later remained below

the threshold as was always the case with Mr. Schillings and myself (see

page 100). But this question is of little significance, for even

assuming that he always thought of the movement he expected on the part

of the horse, this by no means implies that he was conscious of the

movements on his part, which were associated with the thought process.

Everything up to this point might be explained as the working of simple

memory association, but when we come to problems in counting and

arithmetical calculation, we are in the field of conceptual thought.

Here, again, it was necessary for Mr. von Osten to invent a suitable

means of expression for the horse, and once more this had to be borrowed

from the treasury of gesture-language. Tapping with the hoof was

naturally hit upon as one of the normal, expressive movements of the

horse. This has long been used by trainers, in preparing horses for show

purposes. The method used in training the horse to make this response is

of no import, whether it was by touching his foot with the hand, or

tapping his leg, or by any other means.

It is possible that many will declare, as being nonsensical, any attempt

to introduce number-concepts[AJ] into an animal's mind, because the

necessary motor basis is lacking. We will not, just at this point, stop

to discuss whether or not it was not possible to develop number-concepts

from purely auditory or visual representations. It is evident, however,

that Mr. von Osten believed that a motor basis of some sort was

essential. In the case of man this basis is found in the enunciation of

the number names (or in the manipulation of the fingers). Mr. von Osten

seemed to think that he was justified in assuming that, even in the case

of the horse, some form of inner articulation of the word-sounds was

possible;--at the same time, in so doing, he did not blink at the

psychological difficulty of this hypothesis. The tapping of the foot was

to be regarded merely as the expression of the process of inner

counting, but not as the motor basis of the process. For this latter

purpose tapping would be quite inadequate, for the number complexes

which arise in the summation process of counting, could not be

differentiated by mere tapping with the foot, any more than a child

could learn to count by employing only one finger. Mr. von Osten

evidently imagined the process was somewhat like this: Whenever Hans was

about to count 5, he would enunciate inwardly the numbers from 1 to 5,

and would accompany each word with a tap of the foot. Since,

furthermore, wooden pins and balls could be used--as in the case of

children--for giving visual content in learning the significance of the

number-terms, it seemed as if all the conditions necessary for the

formation of number-concepts were supplied. However, the most essential

thing had to be presupposed, viz.: that the horse virtually possessed

the general power of forming concepts,[AK] and that all that had been

lacking was the suitable conditions for its development. Mr. von Osten

held tenaciously to this conviction, and it was this conviction that was

the basis for the infinite patience with which the tests had been

pursued.

[Footnote AJ: The author intends to take up the problem of counting,

so-called, on the part of animals and of the principle involved, in

another work soon to be forthcoming.]

[Footnote AK: There are some who believe they are warranted in

concluding the opposite from the structure of the animal's brain

alone. We may say that the brain of the horse, compared with that of

the ape, or even that of the dog, represents a relatively low type

of development. But owing to the rapid changes in the views, often

contradictory, concerning the nature of the nervous structures and

processes underlying the thought process, any conclusion based on

such views would be premature. For this reason we cannot agree with

the French physiologist who was dissecting the brain of a horse and,

struck by its smallness of size, exclaimed: "When I saw your proud

look and beautiful neck, I hesitated a moment before mounting upon

your back. But now that I have seen how small is your brain, I no

longer have any qualm about using you."[98]]

To come now to the learning process itself;--we may assume that, at

first, whenever the horse began to tap in response to commands, he would

receive a reward for this purely mechanical feat. Wooden pins were then

planted on the ground and designated as: one, one two, etc., and each

time someone would raise the horse's foot as many times as the count

demanded (see Supplement I). Then Mr. von Osten would take his stand at

the horse's side and would command him, let us say, to tap 3. Hans

noting merely (from his master's position) that he was expected to tap,

would begin. The instructor, who had bent forward in order to watch the

horse tapping,[AL] would involuntarily straighten up again at the third

tap, without being conscious of it and quite unaware that he was thus

giving a signal. The horse would be startled, and sometimes he would

immediately cease tapping and sometimes not. But it was only in the

first case that he would receive a reward. Thus, unknown to the

instructor, an association became established between the sight of the

upward jerk of the instructor and the act of ceasing to tap. To be sure,

the animal would receive sundry visual impressions from the wooden pins

set up before him and the auditory stimulations of the spoken number

names, on the basis of which, the concepts were to be formed in his

mind. But in this chaos of visual impressions (at times there were two

wooden pins, then three, then four, sometimes there were the pins, at

others, the balls of the counting-machine)--and in the babel of

word-sounds--which evidently meant nothing but noise to him--amidst all

this there was but one constant element: the final movement of the

instructor's body. The moment the horse reacted to this, he would

receive the tidbit at the hands of his overjoyed master, and thus he

became more and more accustomed to attend to this jerk, even after it

had gradually decreased in scope. And the reason again, why this jerk

tended to become less pronounced was that the tests were gradually

becoming more and more successful. For, corresponding to the degree in

which the horse began to react properly, the instructor's tenseness and

excitement tended to decrease, and with this decrease of the emotional

element in the man's consciousness, the accompanying non-voluntary,

expressive movement gradually became less pronounced until it attained

that extraordinary refinement which it possesses to-day. We noticed

also, that whenever the horse, for any reason, had to be trained anew,

Mr. von Osten's movements would, on the whole, become somewhat more

gross, as for instance after the tests with the blinders. There is not a

shadow of a doubt that this increase in the movement's extent was

entirely unintentional, since the horse could not see his master at all

on account of the blinders which had been attached to the trappings.

[Footnote AL: This natural and close connection between the process

of attention and the movement toward the object attended to is

clearly expressed in our English and French terms, derived from the

Latin "tendere ad--," to reach toward--.]

In the same way it is possible to explain the details. Mr. von Osten

himself said that at first Hans had tapped at times with his left foot,

at times with his right, just as he pleased. But later his master taught

him to tap only with the right. Whenever he began with the left, Mr. von

Osten would immediately interrupt him, and he was allowed to add only a

final tap with his left foot. Thus, this additional tap which was

sometimes made with the left foot was but the vestige of an earlier

rudimentary habit. The signal for it was the stooping posture in which

the master remained after the head-jerk had been made. Whenever Mr. von

Osten had given Hans a small number to tap, he would bend forward only a

little. But when he expected a larger number he would bend forward

somewhat more, owing to the desire to observe the tapping more

carefully. From the slight inclination of the master's body the horse

would get the cue that he was expected to tap for a short time only, by

the greater degree of inclination he would know that he was to tap for a

longer period. In the second case he tapped rapidly and did not raise

his foot as high from the ground--evincing a regard for the saving of

energy, which may well be attributed to a horse. And thus arose the

connection between the degree of inclination of the instructor's body

and the horse's rate of tapping.

So, now that the ability to count and solve problems had become

fixed--as the old gentleman thought--he began to instruct the horse in

other branches. Since everything had been translated into terms which

were to be expressed by means of tapping with the foot, and thus really

put into terms of number--which was perhaps natural for an old teacher

of mathematics--the same mechanism was involved in these accomplishments

as in those of counting, etc. Mr. von Osten saw the animal's

intelligence steadily increase, without having the slightest notion that

between his words and the responsive movements of the horse, there were

interpolated his own unconscious movements--and that thus instead of the

much desired intellectual feats on the part of the horse, there was

merely a motor reaction to a purely sensory stimulus. It has been a

common custom of man to posit some extraneous cause for movements

resulting from certain involuntary motions of his own, of which he is

not aware, (witness the divining-rod).[AM] And furthermore, when these

results appear to be rational, the tendency is to seek their cause in

some extraneous intelligence, not his own. Just as the spiritualists

ascribe the "messages" which are revealed to them through table-rapping,

to certain rational spirits, so Mr. von Osten credited the intelligence

of the horse with the result produced by his own involuntary signs--i.

e., with the proper solution of problems.

[Footnote AM: G. Franzius,[99] privy counselor of the admiralty,

master of the dry-dock at Kiel, is responsible for the undeserved

revival of the ancient belief, long buried by science, that the

divining branch is put into motion solely as the result of the

influence of hidden springs or treasures, and without any agency in

the person who is holding it. The untenability of this theory comes

home to us most forcibly when we recall how various are the kinds of

things which have been discovered by means of the branch. First

there is gold and water, which are the only ones mentioned by Mr.

Franzius. The water can be thus discovered only when it flows below

ground, say that which is passing through the mains of a city,

whereas the water of the Rhine or the Elbe would have no effect on

the branch. Besides gold, every other kind of metal has been

supposedly located by the branch,--as well as coal, gypsum, ochre,

red-chalk sulphur and petroleum,--according to the desire of the one

searching. Thus, the very same branch that just a moment ago was

influenced by the least bit of underground water, may remain

unaffected by the presence of a large body of water, if in the

meantime I have changed my plan and decide to search for coal or for

gold. But that is not all. The branch will point out a murderer or

the place where a murder has been committed, it will discover the

thief or his trail, as well as the things stolen or merely touched

by him. It will indicate where the boundary-stone that has been

moved, ought to stand. The branch further discloses the sins of the

persons concerning whom it is consulted, as well as their talents

and abilities, the journeys they have made and the wounds they have

received. It will indicate whether or not a person has money and how

much. It can announce what absent persons are doing and what apparel

they are wearing, and of what color it is. It will give information

on theological, medical, zoological, and botanical questions. In

fine, no matter what the question, it will never fail of an

answer.[100, 101]

The impossibility of explaining the phenomena in a purely physical

way was recognized at a very early date. For a long time the

activity of the users of the divining rod seems to have been

restricted to the search for metals. The first (or one of the first)

to raise his voice against it was the learned G. Agricola[102]

(1556), and after him there were many who all wrote more or less

independently of one another. Aside from swindle and chance, it was

usually believed that sorcery of the agency of Beelzebub was

involved, and for that reason the Church has repeatedly forbidden

the use of the divining-rod. But even in the 17th century we find

some who believed that it was imagination alone that moved the

person's hand, and with it the rod,[103, 104] ("fortassis etiam

phantasia manum in motum concitante"); and that points out the

essentials of the solution of the phenomenon, and we will not go

into the matter here in detail. A number of complex psychological

problems arising in connection with it are still waiting to be

solved, but this much appears certain; the staff or branch plays no

other part in the whole process than that which is served by the

three levers in the tests described in Chapter IV (pages 116

ff.),--they simply magnify the expressive movements of the diviner.

And so we can understand why the instruments serving as rod might be

so varied. Hay-forks, pickets, clock-springs and pendulums, scissors

and pliers have been used. A knife and fork or two pipes, fastened

together, an open book, and even a sausage, grasped at both ends and

thus bent together somewhat,--all have served the purpose equally

well. We can understand, too, how some adepts are able to achieve

the same degree of success--for they do succeed beyond a

doubt--without any rod whatever, but simply by placing the index

fingers end to end and bending them somewhat, and even by merely

groping about with hands outstretched or folded before them.[106]]

Two other phenomena may have tended to strengthen Mr. von Osten's belief

in Hans's intelligence. One was the misleading similarity with which the

horse's supposed errors in computation and the poorly adjusted

concentration of the questioner, were expressed. We recall the

difficulty in the case of very high numbers. This might easily be

considered as being due to the horse's ability to work more readily with

small, rather than with large numbers, whereas, as a matter of fact, it

was due solely to the difficulty of the questioner to keep his attention

concentrated upon the number for so long a time. We recall also the

frequency of errors of one unit too few and one unit too many. These

were easily interpreted as miscounts on the part of Hans, but in truth

were the result of the poorly concentrated attention of the questioner.

Added to this was the seeming independence and self-sufficiency of the

horse. Often the number given by him was other than that desired by his

master. Usually Hans was in the wrong in such cases, but sometimes, too,

he was right. At any rate, this served to give the impression of

independence of thought which his master so thoroughly believed he

possessed, and which was the goal of his endeavors--though as a matter

of fact he was farther removed than ever from that goal.

Some may ask: Does not this whole process partake of the essentials of

all training, (though cumbersome and misunderstood, to be sure), and is

there any need of investigating whether or not the actual development

was of the sort here outlined, or whether it actually took the course

common to all training?

In order to answer this question we must determine more specifically

what we mean by the term "training". Usually we take it to mean the

establishment in the animal, of definite habits of motor reaction in

response to certain stimuli purposely selected by the trainer, and

without involving any process of animal consciousness other than

association. Such a conception may be applied also to man, if we assume

that the higher thought processes can be eliminated. If that were the

case, the above definition would not have to be changed, not even with

regard to the word "animal", for we must take it in the antique sense of

"zoon", a signification readopted by modern zoology. The concept may be

widened, however, by omitting the differentia of "purpose", or even

more, by including the habitual association of ideas or images (instead

of movements) with certain sensory stimuli. But in so doing, we must

bear in mind that we are going beyond the usual content which in

everyday practice is put into the term "training". Especially, when we

cease to regard the presence of purpose in the trainer's mind (both in

giving the stimulus as well as in the habituation of the animal to them)

as essential. When this is done, the conception of training really

resolves itself into the much wider conception of habit-building, and

the whole discussion becomes merely a quarrel over words. In order to

obviate this, let us bear in mind that in the following, the word

"training" is always taken in the usual and narrower sense. The term

then is still ambiguous only in so far as it has not merely its original

significance of the _act_ of purposely habituating (a person or an

animal) to perform certain definite movements, but by transference is

also used to denote the _effect_, i. e., the occurrence of the movements

in question. But this does not really detract from the clearness of the

concept itself.

Having cleared up the question of definition, let us return to our

original problem: Does the hypothetical account of the probable

development of the horse's reactions, which is given on pages 213 to

220, represent a case of training? This must be denied decidedly with

regard to the tapping of numbers and the solution of arithmetical

problems. For here the sensory stimuli which were purposely given, i.

e., the wooden pins, the balls, and the spoken words, were intended to

subserve the function of arousing not movement, but thought processes in

the horse; whereas the function of the horse's movements was to give

expression to these thought processes. Of the really effective

stimuli--the slight movements on his part--the master was never

conscious, much less were they purposely made. The same holds true for

the "up" and "down", "yes" and "no", etc., for here also Mr. von Osten

counted upon the rise of the corresponding concepts, and not merely upon

a purely external, mechanical association of meaningless sounds with

certain movement-responses on the part of the horse. This might also

explain the genesis of Mr. von Osten's belief that Hans was able

mentally to put himself in the place of the questioner, (page 19). At

any rate it is very improbable that he, Mr. von Osten himself, clearly

distinguished between the concept: "up" and the sound of the word "up".

When we come to consider the horse's selection of the colored cloths,

and even more his leaping and rearing, we find that the distinction

between "training" and "instruction" vanishes. If we had to deal only

with this class of achievements, we might perhaps say, without fear of

going very far wrong, that the only difference between this and the

ordinary form of training was that Mr. von Osten had intended to train

the horse to respond to auditory signs (words), but had unintentionally

trained him to respond to visual signs instead. But it is not this type

of performance that has become the bone of contention. Just as it would

be misleading to maintain that Mr. von Osten's effort was nothing other

than a case of training, so it also would be unjustifiable to designate

the results of his effort by that name, since the really effective

stimuli were not, as has been pointed out just now, given intentionally.

As far as the horse is concerned, it is a matter of indifference whether

or not really effective stimuli were given intentionally by the

questioner. The animal knows nothing of human purposes and if he were

transferred to a circus, he would find nothing new in the method

employed there, except the use of the whip. We, however, define our

concepts from the human and not from the horse's point of view. We may

definitely say, therefore, that the method described cannot be regarded

as that of training, neither in its application nor in the effect

produced, though in the latter it closely simulates the effects of the

training method.

Having thus differentiated between the methods of instruction and

training, let us now attempt to decide on the basis of such indications

as we may possess, which of the two was actually represented by the

development of the horse's attainments. Surveying the facts which we

have at hand, we may say that there are hosts of reasons why we cannot

assume that it was a case of training. Everything that we know from our

own observation and from the well-attested statements of others, with

regard to the actual process of instruction, weighs against the

assumption. Another evidence of this is the long period of time which

Mr. von Osten required (both in the case of Hans, as well as with his

predecessor), whereas the same end would have been much more speedily

attained if it had been a case of training. A further argument is the

fact that a large horse was selected for the purpose, whereas a small

mare would have been far more suitable, (c. f., "Clever Rosa", page 7).

Again, the whip, that sorcerer's rod of all professional trainers, was

here absent. And finally, many traits of character of Mr. von Osten, as

well as his conduct during the whole course of events, militate against

such an assumption. He generously turned the horse over to us, as he had

given it over to Count zu Castell, Count Matuschka and Mr. Schillings.

He eagerly besought a scientific investigation. He had made several

reports to different ministries. All of these acts could only hasten the

denouement. What could have been his motive? Some thought they detected

an effort at pecuniary speculation, and an advertisement of June, 1902,

in the "Militaerwochenblatt", in which Hans was offered for sale, seemed

to confirm the conjecture. Mr. von Osten says that this occurred at a

time when he himself was sick and had become tired of the job. And why

should he not be willing to sell even a thinking horse, since he had

become convinced that any other could be instructed in the same way?

Besides, I have it on good authority that after the publication of the

September report he received several exorbitant offers; to mention only

one of them: a local vaudeville company was ready to pay him 30,000 to

60,000 marks per month. He refused every one of these offers. Some may

say that perhaps he wanted still more. But if he knew that the day of

judgment was close at hand, he also knew that before then, if ever, was

the sunshiny day on which to make his hay. A more auspicious time he

could never hope to see again.--Let us add, once more, that he never

charged admission to any of Hans's performances, although there were

many who were anxious to see the horse, and many enthusiasts had come

from a great distance. And finally, he was an old man, unmarried and

entirely alone, a property owner, but a man whose wants were few and

very simple--and his Hans was almost his sole companion. Is it possible

that such a man, one who had all the pride of gentle birth, would become

a trickster in his old age, all for the love of money?

The unreliability of Mr. von Osten's signs is good proof of their

involuntary nature. Anyone who had seen him work with the horse could

not have helped noticing that he certainly did not have complete control

over the animal, and was not able, at a given moment, to make Hans

perform a certain feat, as would have been the case if the process had

been one of "training". Again and again Hans failed to make the right

count. Before a large audience, one time, it took four tests to get him

to tap properly up to 20, and in all four I could note clearly that it

was Mr. von Osten who, by his involuntary premature movements, was the

innocent cause of the failure. On another occasion, after Hans had done

some beautiful work in fractions, in the presence of a large number of

spectators, the master asked him the simple question: "Where is the

numerator in a fraction?"--The answer was first: "to the left", and

then, after a severe reprimand: "down" (below), and finally: "up"

(above). He often made just such incorrect movements of the head. In the

color-selecting tests the average of error was quite unpredictable. With

an equal number of tests, on one day, half would be successful, on

another, four fifths, on a third, one-tenth. Often Hans appeared to be

"indisposed" for days at a time. The color tests would often end in

expressions of rage on the part of Mr. von Osten and in consequence Hans

would become startled and would then storm about the courtyard so that

it was dangerous to try to approach him. Some may object that all this

was mere comedy and that possibly Mr. von Osten prevented some of the

tests from turning out successfully. But this objection is to be met by

the statement that very often failure would occur just when it was

particularly desirable to have the tests appear in a favorable light

before a large and enthusiastic assemblage of visitors. After such

failures he would be downcast on account of Hans's contrariness. It is

also significant that Mr. von Osten's percentage of error, corresponds

very closely with my percentage of error in the "non-voluntary" tests,

(page 84f.), whereas he never was able to obtain the errorless results

which I obtained in my "voluntary" experiments.

But we must be careful not to confuse non-voluntary movement and lack of

knowledge of the movement. And again we must distinguish between

knowledge of the grosser and the finer signals. Mr. von Osten was aware

of the grosser movements, and talked quite freely concerning them, but

in so doing, showed that he was quite unaware of their true function. He

undertook to show us what we already knew--that, when he remained

standing perfectly erect, he could elicit no sort of response from Hans.

Furthermore, that whenever he continued to bend forward, Hans would

always respond incorrectly and with very high numbers. He knew, also,

that Hans was distracted in his operations every time the questioner

resumed the erect posture while the tapping was in progress. This he

demonstrated to us on one occasion in the following manner. He said to

Hans: "You are to count to 7; I will stand erect at 5". He repeated the

test five times, and each time Hans stopped tapping when the master

raised his body. Several such tests resulted in the same way. Mr. von

Osten, however, believed this to be a caprice of the horse and at first

declared that he would yet be able to eliminate it, but later became

resigned to it as an irremediable evil. Mr. von Osten was also aware

that the questioner ought not move while the horse was approaching a

colored cloth, and cautioned me in regard to it, though I had already

noted as much. And finally, he also knew what influence his calls had

while the horse was selecting the cloth, and he told me that it was of

great assistance to Hans to be admonished frequently, since thus his

attention was brought to bear upon the proper cloth. Yet, when we

requested Mr. von Osten to desist calling, since he was thereby

influencing the horse in the choice of the cloth, he answered: "Why

that's just what I wish to do!"--But though the statement that he was

aware of the nature of these grosser signs is thus seen to be true, it

by no means necessarily implies that he had purposely trained the animal

to respond to them. In these observations of his he had builded better

than he knew--he evidently had no notion of their scientific

significance. But the same thing might happen to those who were supposed

to be somewhat less naive, as is shown by the experience of Mr.

Schillings, who quite unconsciously, for many months had been giving not

only the finer, but also the grosser signs, and never guessed the true

nature of affairs until I explained it to him. Nor was it an easy matter

for me to get at the facts involved in the process, although it now all

appears so very simple.

On the other hand, it is also true that Mr. von Osten knew nothing

whatever of the finer, more minute signals, such as the final jerk, the

head-movement upward, downward, etc., and it is difficult to conceive

how he might have gained any knowledge of them. We might perhaps

conceive of four possible sources. He might have come upon them by

chance. But it is extremely improbable that in the million of possible

forms of signaling he should have hit upon those that at the same time

represent the natural expressive movements. Or he might have derived a

knowledge of them through a study of the pertinent literature. I have

searched diligently for such a source, in both the old and the modern

literature, but in vain. From the sixteenth century on, there is a

series of accounts of horses that were able to spell and to solve

problems in arithmetic, and the reports on learned dogs go back even to

the time of Justinian, in the middle of the sixth century.[107] All of

these animals were kept for purpose of speculation and were exhibited

for pecuniary reasons only. Nor does one read that any person could work

with these animals off-hand, which was the characteristic feature of the

Osten horse.[AN] In many cases we find mention made of the signs to

which the animals reacted. Thus for the beginning or stopping of the

animal's scraping or tapping, the signals were respectively raising and

lowering of the eyes on the part of the trainer,[113] lowering and

raising of the whip[114] or of the arm, stepping forward and

backward,[115] and as a closing signal a slight bending forward.[116]

The signals for beginning and ceasing to bark in the case of dogs, were

the trainer's commands to "speak", and, at the same time, his looking at

the dog, and then looking away for a closing sign;[117] or a

mouth-movement on the part of the trainer and then a withdrawing of the

left hand which had been resting on the hip.[118] Among the signals for

nodding and shaking the head we find the following mentioned: raising

and lowering the hand or arm[119] or the whip;[120] a movement of the

hand toward the horse's nose, as a signal for nodding, and an

arm-movement as a signal for shaking the head.[121] For this last, we

find recommended also a slight breathing upon the animal,[122] and--in

the case of dogs--a mouth-movement simulating blowing, or a turn of the

fingers.[123] (We will not dwell upon the many signals for selecting

objects, which are mentioned, since we have already discussed this point

on page 230f). In all these instances it is plain that we have to do

with purely voluntary and "artificial" signals. The only example of

involuntary signs which Mr. von Osten could have found in literature,

was that of Huggins's dog, which need not be considered here, since, as

was said on page 177, the really effective signs in that case were not

discovered. A third means by which Mr. von Osten might have gained a

knowledge of the involuntary, natural expressive signs, would have been

by observing others. If he had had opportunity of observing another von

Osten and another Hans, he might have gotten at the secret. But since

this was not the case, this possibility vanishes. A fourth possibility

is self-observation. We would then have to assume that Mr. von Osten at

first really tried to educate the horse to think, but soon recognized

the fruitlessness of such an attempt. At the same time, he then would

have noticed his own involuntary movements and their effect upon the

horse, and having noted them, voluntarily reduced their extent and

utilized them in the training process. But here also there is much that

militates against this assumption when we consider how great is the

difficulty of consciously refining movements which at first were rather

coarse, unless it be by the adjustment of the proper degree of

concentration of attention, a subtlety of method of which we could

hardly believed Mr. von Osten capable. We must remember, also, that in

the first publication regarding Hans which, by the way, marks the

beginning of his career, ("Das lesende und rechnende Pferd," by

Major-General E. Zobel, in the "Weltspiegel" of July 7, 1904), we may

read the following: "He (Mr. von Osten) is always willing to have the

horse undergo an examination on the part of a stranger, and promises

that after Hans has become fairly well acquainted he will display the

same degree of efficiency as he displays with the master, himself."

This occurred at a time when Mr. Schillings, the man who was destined to

prove the truth of the statement, had not yet appeared on the scene. How

was Mr. von Osten to know beforehand that every questioner, who might

appear, would execute the same movements that he himself had used? We

would recall also that not one in the great multitude of persons who

worked successfully with the horse in the absence of Mr. von Osten, had

noticed, even in the slightest measure, any of these movements in

themselves. The position and repute of these persons vouches for their

veracity,--among them were the writer of the article just mentioned, the

Count zu Castell, Count Matuschka, Count von Eickstedt-Peterswaldt,

General Koering, Dr. Sander, Mr. H. Suermondt and Mr. H. von

Tepper-Laski. Some of these gentlemen were quite unwilling to believe

that they executed such movements. This happened in the case of Mr. von

Tepper-Laski, who had visited Hans ten times and who had, during the

course of these visits, frequently worked alone with the horse and had

received correct responses. Count Eickstedt, too, although he was one of

those who had been made acquainted with the nature of the movements

involved before being allowed to visit the horse, was unable to note

them either in his observation of Mr. von Osten, or of himself, when, in

compliance with his own wish, he was left alone with Hans. Nor did any

of the laboratory subjects, some of whom were well trained in

introspection, discover the true nature of affairs. They were thoroughly

astonished when the facts of the case were explained to them. And I,

also, as was mentioned on page 100, did not become aware of my own

movements, until I had noted those of Mr. von Osten. In fine, everything

would indicate that we have here not an intention to deceive the

public, but a case of pure self-deception.[AO]

[Footnote AN: There is only one, and I believe it is only a seeming

exception to be found in the literature on the subject. We are told

that about the year 1840 a French revenue official named Leonard had

two hunting dogs that, besides other things, were able to play at

dominoes, and this not only with their master, but with anyone and

without the master's assistance. The owner had educated them simply

for the fun of it, and not for pecuniary gain. This statement is

made by both writers who, apparently independently of one another,

have discussed the case, Youatt[108] and de Tarade.[109] De Tarade

himself played with them, and gives directions how to teach dogs to

play the game. But his exposition is so naive, and even ridiculous,

for those who know anything about the subject, that we do not

believe it necessary to attempt a detailed refutation. Youatt never

saw the animals. But he tells us that not only the dog's partner,

but also the master, sat at the game. Youatt's assertion, however,

that "not the slightest intimation could have been given by Mr.

Leonard to the dog," but that the animal carried on the game by

means of its own observation and calculation, appears to me a rather

bold statement. After my own experience with dogs, I firmly believe

this to have been impossible. Hachet-Souplet,[110] who shares my

conviction, explains the matter as follows: the dog would simply

place a domino having the number of eyes named by his partner, thus

the 6 adjacent to the 6, the 3 to the 3, etc. But even so a great

deal would have to be attributed to the dog, (although in that case

real counting would by no means be absolutely necessary, for an

association between the number term and the total picture of the

corresponding group of eyes would suffice.) But we must note that

neither of the writers mentions that the numbers were always called

aloud by the partner. After the failure of the experiments of Sir

John Lubbock,[111] we must doubt very much if a dog is able to match

one domino with another having the same number of eyes. We are

therefore inclined to believe that this dog continually received

signs from its master. These signs probably were visual, perhaps

also auditory, and they were by no means involuntary. For in a book

on the training of animals, which Leonard, the owner of the dogs,

has published, and in which he describes minutely the method by

which they had been trained in their various accomplishments, he

does not mention with so much as a syllable the game of dominoes, a

thing which he certainly would have dwelt upon, if he had believed

in the animals' power of independent thought. He would not have

remained silent concerning this greatest--though only

apparent--achievement of his educational endeavors. But his whole

book is evidence that he was too wise to have thus deceived himself,

and our only alternative is to believe that he was playing a joke on

his credulous admirers.]

[Footnote AO: P. Wasmann, S. J. in the third edition of his book,

"Instinkt und Intelligenz im Tierreich" (Freiburg, Herder, 1905),

discusses the case of Hans and quotes from a letter I wrote him

concerning the matter. In the quotation an error has crept in, which

I would here correct. The statement is ascribed to me that "Hans

differs from other horses only in his extraordinary power of

observation, an unintentional by-product of intentional training,"

whereas in my letter I said: "unintentional by-product of

intentional education."]

This self-deception is easily understood when we consider the two

predominent characteristics of the man: the pedantry of the pedagogue,

and his proneness to be possessed by a single idea, which is a

peculiarity of those of an inventive turn of mind. Adhering closely to a

preformed plan, he carefully and narrowly circumscribed the scope and

order of instruction. He would not go on to the number 5 if he were not

thoroughly convinced that the 4 had been completely mastered, nor would

he go on to a more difficult problem in multiplication, until he felt

certain that Hans was entirely proficient in the problems of the simpler

sort. If he had ever put a question to Hans before its regular order, he

would have discovered, to his amazement, that there really existed no

difficulties for Hans, and also that the horse really required no

appreciable time to acquire new material. Mr. von Osten would have had a

like experience if he had asked Hans concerning the value of Chinese

coins or the logarithm of 1000. However, he never did anything of the

kind, but always adhered closely to his plan. He required the questioner

to say: "2 and 2", and never "2 plus 2". Nor were capitals or Latin

script to be used in the written material. And if upon request he did

so, he did it, without faith in the result, and hence there was

failure. And so he declared that "if you use Latin script Hans becomes

confused and will be out of sorts for several weeks thereafter." Mr. von

Osten is, and ever will remain, the schoolmaster, and will never become

the psychologist, the "soul-vivisectionist". Who would work a child with

such puzzling questions? and Hans was to him like a child. Thus the old

man believed himself to be a witness of a continuous, organic

development of the animal soul--a development which in reality had no

other existence than in his own imagination.

Added to this pedantry was an extraordinary uncritical attitude of mind,

induced by his obsession by one favorite idea, which blinded him to all

objections. He met objectionable observations on the part of others in

one of two ways. One method was by attributing to Hans certain

remarkable qualities, such as an extraordinary keenness of hearing and a

wonderful power of memory, or again, certain defects, such as moodiness

and stubbornness,--which as a matter of fact, were only so many

back-doors by which he might escape from the necessity of offering

adequate explanations. When Hans was able to give off-hand a gentleman's

name which he had heard years before, it was called a case of

extraordinary memory. When the horse insisted that 2 times 2 was 5, he

maintained that it was an example of animal stubbornness. There was

still a simpler method of overcoming inconvenient objections and that

was by ignoring them altogether. The number 1, the simplest and most

fundamental in the system of numbers, was one of the most difficult for

Hans. (Page 67f.). Mr. von Osten was aware of this, but thought little

of it. During the very first visit of Professor Stumpf, Mr. von Osten

asked the horse: "By how much must you increase the numerator of the

fraction 7/8, in order to get a whole number?" Hans repeatedly answered

incorrectly and always tapped numbers that were too great. The same

question was then asked concerning the fraction 5/8, and immediately

there was a correct response, (the favorite number 3). Mr. von Osten

said very naively: "In the case of the difference of 1, he always goes

wrong. It was just what I expected." Mr. von Osten still relates that

the distinction between right and left created far greater difficulty

for Hans than all of the work in fractions, and that even to-day it is

not thoroughly established; also, that the selection of colored cloths

is often a failure still, although it was one of the first things in

which he was given instruction. It appears never to have dawned upon Mr.

von Osten that the arts in which Hans seemed to excel, also formed the

standing repertoire of so many trained horses, regarding whom it was

well-known that they owed all of their cleverness to the training given

them by their masters. This fact alone should have induced him to make

some form of critical investigation.

When Hans suddenly became a celebrity, and he, himself, the object of an

enthusiastic following, the whole affair evidently took Mr. von Osten

off his feet. Strangers took the further instruction of the horse in

charge, and the rate and degree of Hans's progress became disconcerting.

One day it came to pass that the horse even understood French, and the

old gentleman, whose apostolic exterior had always exerted a high degree

of suggestion upon his admirers, in turn fell captive to the spell of

retroactive mass-suggestion. He no longer was uneasy concerning the most

glaring kinds of failure. On one occasion he even insisted upon the

completion of a series of tests in which procedure was "without

knowledge", which promised no results whatever. "The animal's

stubbornness must be broken," he commented. On the other hand, he

regarded every criticism as a form of personal insult. And once he

showed a member of the committee of the Society for the Protection of

Animals the door, because the man, without having looked at his watch,

wanted to show it to Hans and ask him the time. Many other critics had

similar experiences.

Summarizing the remarks of this chapter, our judgment must be as

follows: It is in the highest degree improbable that Mr. von Osten

purposely trained the horse to respond to certain cues. It is also

improbable that he knew that in every test he was giving signals,

(although I can form no judgment concerning what happened after the

publication of the latest report). To assume the contrary would land us

in the midst of insoluble contradictions of the many ascertained facts

in the case. The explanation here essayed, however, should prevent that.

To be sure, we, must then reckon with curious inner contradictions in

Mr. von Osten's character. But such contradictions are to be found, upon

earnest analysis, in nearly every human character. And Mr. von Osten may

say with the poet: "Ich bin kein ausgekluegelt Buch. Ich bin ein Mensch

mit seinem Widerspruch."

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.

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fuer praktische Tierheilkunde, Stuttgart, 1904, Bd. 16, Heft 1, pp. 31

ff.

38. BERLIN, R. Ueber die Schaetzung der Entfernungen bei Tieren.

Zeitschrift fuer vergleichende Augenheilkunde, Wiesbaden, 1891,

Bd. 7, Heft 1, pp. 5 f.

39. THE SAME. Ueber ablenkenden Linsen-Astigmatismus und seinen Einfluss

auf das Empfinden von Bewegung. Ditto, 1887, Bd. 5, Heft 1, pp. 7 ff.

40. SCHLEICH, G. Das Sehvermoegen der hoeheren Tiere. Tuebingen, F.

Pietzcker, 1896, p. 24.

41. KOeNIGSHOeFER. Ueber das Aeugen des Wildes. Monatshefte des Allgemeinen

Deutschen Jagdschutz-Vereins, Berlin, 1898, Jahrg. 3, No. 17, pp. 250 f.

42. ZUeRN, J. Vergleichend histologische Untersuchungen ueber die Retina

und die Area centralis retinae der Haussaeugetiere. Archiv fur Anatomie

und Physiologie, Anatomische Abteilung, Leipsic, 1902, Supplementary

volume, pp. 116 ff.

43. HIRSCHBERG, J. Zur vergleichenden Ophthalmoskopie. Archiv fur

Anatomie und Physiologie, Physiologische Abteilung, Leipsic, Jahrg.

1882, p. 96.

44. BERLIN, R., see 39, p. 4.

45. THE SAME. Ueber den physikalisch-optischen Bau des Pferdeauges.

Zeitschrift fur vergleichende Augenheilkunde, Leipsic, 1882, Jahrg.

1, Heft 1, p. 32.

46. BAYER, J. Tieraerztliche Augenheilkunde. Vol. 5 of the "Handbuch der

Tieraerztlichen Chirurgie und Geburtshilfe" by J. Bayer und E. Froehner.

Vienna und Leipsic, W. Braumueller, 1900, p. 459.

47. THE SAME. Ditto, p. 475.

48. RIEGEL, see 37, p. 35.

48a. SCHWENDIMANN, F. Untersuchungen ueber den Zustand der Augen

bei scheuen Pferden. Archiv fuer wissentschaftliche und praktische

Tierheilkunde, Berlin, 1903, Bd. 29, Heft 6, p. 566.

48b. BERLIN, R. Refraktion und Refraktionsanomalien von Tieraugen.

Tageblatt der 52. Versammulung deutscher Naturforscher und Aerzte in

Baden-Baden, 1879, p. 348. See also 45, pp. 28 f. and 39, p. 13.

49. THE SAME, see 39, p. 9.

50. BAYER, J., see 46, pp. 460 f.

51. ZUeRN, J., see 42, p. 114.

52. CHIEVITZ, J. H. Ueber das Vorkommen der Area centralis retinae in den

vier hoeheren Wirbeltierklassen. Archiv fuer Anatomie und Physiologie,

Anatomische Abteilung, Leipsic, 1891, Heft 4-6. p. 329.

53. ZUeRN, J., see 42, p. 140.

54. KOeNIGSHOeFER, see 41, pp. 251 ff.

55. TENNECKER, S. V. Bemerkungen und Erfahrungen ueber den Charakter

und das Temperament, sowie ueber die geistigen Eigenschaften des Pferdes

ueberhaupt. Beitraege zur Natur- und Heilkunde, von Friedreich und

Hesselbach, Wuerzburg, 1825, Vol. 1, pp. 110 f.

56. ZBORZILL, E. Die mnemonische Dressur des Hundes. Berlin, S. Mode

(1865), p. 21.

57. MUeLLER, AD. und K. Tiere der Heimat. 3rd Edition, Cassel, Th.

Fischer, 1897, Book 1, p. 70.

58. HUTCHINSON, W. N. Dog Breaking. 6th Edition, London, J. Murray,

1876, pp. 105 f.

59. HUGGINS, LADY M. Kepler: a Biography. Cited by Sir J. Lubbock, On

the Senses, Instincts, and Intelligence of Animals. London, Kegan Paul,

Trench and Co., 1888, pp. 284 f. (The original was published privately

and never put on the market. Hence it was not accessible for me.)

60. LUBBOCK, SIR J. Ditto, p. 285.

61. ROUHET, G. L'entrainement complet et experimental de l'homme avec

etude sur la voix articulee, suivi de recherches physiologiques et

pratiques sur le cheval. Paris, Libraires associes, and Bordeaux, Feret

et fils, 1902, pp. 517 ff.

62. LIPPS, TH. Zur Psychologie der Suggestion. Leipsic, J. A. Barth,

1897, pp. 5 f.

63. ZELL, TH. See 1, pp. 40 f.

64. ZBORZILL, E. See 56, p. 23.

65. BEARD, G. M. Physiology of Mind-Reading. Popular Science Monthly,

New York, February 1877. Vol. 10, p. 472. Reprint in the Journal of

Science, and Annals of Astronomy, Biology, Geology, etc., London, 1881,

Series 3, Vol. 3, p. 418.

66. BABINET. Les tables tournantes au point de vue de la mecanique et de

la physiologie. Revue des deux mondes, Paris, 1854, Twenty-fourth year,

Vol. 5, pp. 409 f.

67. TOLSTOI, L. N. Anna Karenina.

68. GOLDBECK. Besitzen die Tiere, speziell Hunde, Verstand oder nicht?

Deutsche tieraerztliche Wochenschrift, Hannover, 1902, Jahrg. 10, No. 20,

p. 202.

69. MENAULT, E. L'intelligence des animaux. 4th Edition, Paris, Hachette

et Cie., 1872, p. 233.

70. LEBON, G. L'equitation actuelle et ses principes. 3rd Edition,

Paris, Firmin-Didot et Cie., 1895, pp. 120 and 288.

71. LOISET, B. Praktischer Unterricht in Kunstdarstellungen mit Pferden.

New edition. Stuttgart, Schickhardt u. Ebner, 1884, pp. 69 f. and 98 ff.

72. BAUCHER, F. Dictionnaire raisonne d'equitation. 2nd Edition, Paris,

chez l'auteur, 1851, pp. 291 ff.

73. ARNIM, V. Praktische Anleitung zur Bearbeitung des Pferdes an der

Longe. 2nd Edition, Leipsic, Zuckschwerdt und Co., 1896, pp. 18 f. and

39 f.

74. MEEHAN, J. The Berlin "Thinking" Horse. Nature, London. 1904, Vol.

70, No. 1825, p. 602.

75. SPOHR. Die Logik in der Reitkunst. Part 2. Pamphlet No. 32 in the

Series: "Unsere Pferde." Stuttgart, Schickhardt und Ebner, 1904, p. 29

f.

76. REDDING, T. B. The Intelligence of a Horse. Science, New York, 1892,

Vol. 20, No. 500, pp. 133 f.

77. SPOHR. Die naturgemaesze Gesundheitspflege der Pferde. 4th Edition,

Hannover, Schmorl u. v. Seefeld Nachf., 1904, p. 164.

78. DECROIX, E. Projet de langage phonetique universel pour la conduite

des animaux. Bulletin de la Societe nationale d'Acclimatation de France,

Paris, 1898, Forty-fourth Year, pp. 241 ff.

79. NOIZET, GENERAL. Etudes philosophiques. Paris, H. Plon, 1864, Vol.

1, pp. 471 ff.

80. BEARD, G. M. See 65, Vol. 10, p. 471.

81. LEBON, G. See 70, p. 120.

82. FLUeGEL, O. Das Seelenleben der Tiere. 3rd Edition, Langensalza, H.

Beyer und Soehne, 1897, pp. 50 f.

83. LANDOIS, H. Ueber das musikalische Gehoer der Pferde. Zeitshrift fuer

Veterinaerkunde, Berlin, 1889, Jahrg. 1, No. 6. pp. 237 ff.

84. FOVEAU DE COURMELLES. Les facultes mentales des animaux, Paris, J.

B. Bailliere et fils, 1890, p. 142.

85. ZUeRN, F. A. Die intellektuellen Eigenschaften (Geist und Seele) der

Pferde. Pamphlet 8 of the Series: "Unsere Pferde." Stuttgart,

Schickhardt und Ebner, 1899, p. 26.

86. FILLIS, J. Tagebuch der Dressur. Translated from the French by J.

Halperson and G. Goebel. Stuttgart, Schickhardt und Ebner, 1906, pp.

322 f.

87. ATHENAEUS. Dipnosophistae. Book 12, 520 c. Edited by G. Kaibel.

Leipsic, B. G. Teubner, 1890, Vol. 3, pp. 148 f.

88. AELIANUS, CL. De natura animalium. Book 16, 23. Edited by R.

Hercher. Leipsic, B. G. Teubner, 1864, Vol. 1, p. 401.

89. JULIUS AFRICANUS, S. [Greek: Kestohi], chapter 14. In: Veterum

Mathematicorum Opera. Paris, Typographia Regia, 1693, P. 293.

90. GUENON, A. Influence de la musique sur les animaux et en particulier

sur le cheval. (Chalons-sur-Marne), 1898, pp. 83 ff.

91. LEPINAY. L'hypnotisme chez le cheval. Revue de l'hypnotisme, Paris,

1903, Eighteenth Year, No. 5, pp. 152 f.

92. FILLIS, J. Grundsaetze der Dressur und Reitkunst. Translated from the

French by G. Goebel. 3rd Edition, Stuttgart, Schickhardt und Ebner,

1905, pp. 10 f.

93. MANOUVRIER, L. Mouvements divers et sueur palmaire consecutifs a des

images mentales. Revue philosophique, Paris, 1886, Vol. 22, pp. 204 ff.

94. GASPARIN, CTE A. DE. Des tables tournantes, du surnaturel en general

et des esprits. 2nd Edition, Paris, E. Dentu, 1855, Vol. 1, Part 1.

95. RIVERS, W. H. R. and E. KRAEPELIN. Ueber Ermuedung and Erholung.

Psychologische Arbeiten, edited by E. Kraepelin, Leipsic, 1895, Vol. 1,

pp. 636f.

96. (CARPENTER, W. B.). Spiritualism and its Recent Converts. Quarterly

Review, London, 1871, Vol. 131, No. 262, p. 312.

97. DARWIN, CHAS. See 7, p. 48.

98. SAINT-ANGE, DE. Cours d'hippologie. 2nd Edition, Paris, chez Dumaine

et chez Leneveu and Saumur, chez Mlle. Niverlet et chez Mlle. Dubosse,

1854, Vol. 1, p. 101.

99. FRANZIUS, G. Die Wuenschelrute. Zentralblatt der Bauverwaltung,

Berlin, 1905, Jahrg. 25, No. 74, pp. 461 f.

100. MENESTRIER, CL. FR. La philosophie des images enigmatiques. Lyon,

J. Guerrier, 1694, pp. 483 f.

101. (LEBRUN, P.). Histoire critique des pratiques superstitieuses, qui

ont seduit les peuples et embarasse les scavans. Paris (et Amsterdam),

1702, p. 42.

102. AGRICOLA, G. De re metallica libri XII, eiusdem de animantibus

subterraneis liber. Basel, Froben, 1556, Book 2, pp. 27 f.

103. SCHOTT, C. Magia universalis naturae et artis. Wuerzburg, J. G.

Schoenwetters Erben, 1659, Part 4, Book 4, p. 430.

104. THE SAME. Physica curiosa, sive mirabilia naturae et artis.

Wuerzburg, 1662, Part 2, Book 12, p. 1532.

105. ZEIDLER, J. G. Pantomysterium, oder das Neue vom Jahre in der

Wuenschelruthe, etc. Hall in Magdeburg (Halle a. S.), Renger, 1700,

Chap. 2. p. 47.

106. BARRETT, W. F. On the so-called Divining Rod, or Virgula Divina.

Proceedings of the Society for Psychical Research, London, 1897, Vol.

13, pp. 177 f.

107. THEOPHANES. Chronographia. Paris, Typographia Regia, 1655, pp.

189 f.

108. YOUATT, W. The Dog. London, Ch. Knight and Co., 1845, pp. 108 ff.

109. TARADE, E. DE. Traite de l'elevage et de l'education du chien.

Paris, E. Lacroix (1866), pp. 113 ff.

110. HACHET-SOUPLET, P. Die Dressur der Tiere. Translated from the

French by O. Marschall v. Bieberstein, Leipsic, O. Klemm, 1898, pp.

36 f.

111. LUBBOCK, SIR J. See 59, pp. 280 f.

112. LEONARD, A. Essai sur l'education des animaux, le chien pris pour

type. Lille, Leleux, 1842, pp. 81-185.

113. MEEHAN, J. See 74, p. 602.

114. FRANCONI (GAeRTNER). Die Dressur der Kunstpferde. Jahrbuch fur

Pferdezucht, Pferdekenntnis, Pferdehandel usw. auf das Jahr 1835, Weimar

und Ilmenau, 1835, Jahrg. 11, p. 329.

115. LOISET, B. See 71, p. 130.

116. HACHET-SOUPLET, P. See 110, p. 91.

117. KNICKENBERG, F. Der Hund und sein "Verstand." Coethen (Anhalt), P.

Schettlers Erben, 1905, pp. 129 f.

118. LANG, R. Geheimnisse zur kuenstlichen Abrichtung der Hunde, revised

edition. Augsburg and Leipsic, A. Baeumer, pp. 46 f.

119. FRANCONI (GAeRTNER). See 114, pp. 326 f.

120. TENNECKER, S. V. Erinnerungen aus meinem Leben. Altona, I. F.

Hammerich, 1838, Vol. 1, pp. 21 f. (The name of the author is

erroneously given on the title page as F. v. Tennecker.)

121. LOISET, B. See 71, p. 132.

122. D----. Ueber die Abrichtung der kleinen Kunstpferde zu dem Zaehlen

mit dem Fusse, Kopfschuetteln und dgl. Zeitung fuer die Pferdezucht, den

Pferdehandel, die Pferdekenntnis usw., Tuebingen, 1804, Vol. 4, p. 51.

123. LANG, R. See 118, pp. 52 f.

124. BUFFON, CTE DE, et L. DAUBENTON. Histoire naturelle, generale et

particuliere. Paris, Imprimerie royale, 1753, Vol. 4, p. 169.

Angell's Text-book of General Psychology.

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Transcriber's Notes

Illustrations have been moved near the relevant section of the text.

Inconsistent use of spacing has been retained for page numbers followed

by "f" or "ff", and for "i.e." / "i. e.", "e.g." / "e. g.", and

"c.f." / "c. f." Inconsistent use of commas following "i.e.", "e.g.",

and "c.f." has also been retained. Inconsistent use of single and

double quotes around words and the placing of punctuation either

within or external to quotes has been left as-is. Capitalization

inconsistencies and grammatical errors relating to subject/verb

agreement were also retained.

Inconsistent hyphenation, accents, and use of separate words have been

retained for "any one" / "anyone", "arm movement" / "arm-movement",

"backstep" / "back-step", "blind spot" / "blind-spot", "by the way" /

"by-the-way", "counting machine" / "counting-machine", "divining rod" /

"divining-rod", "ear movements" / "ear-movements", "eye movement(s)" /

"eye-movement(s)", "eyebrows" / "eye-brows", "first rank" / "first-rank",

"four fifths" / "four-fifths", "Hans problem" / "Hans-problem", "head

jerk" / "head-jerk", "head movement(s)" / "head-movement(s)",

"hoped for" / "hoped-for", "memory images" / "memory-images",

"movement impulse" / "movement-impulse", "movement responses" /

"movement-responses", "number concepts" / "number-concepts", "number

terms" / "number-terms", "psychophysical" / "psycho-physical", "some

one" / "someone", "sound waves" / "sound-waves", "thought processes" /

"thought-processes", "tieraugen" / "tier-augen", "time measurements" /

"time-measurements", "training process" / "training-process", "vaudeville

stage" / "vaudeville-stage", "well disposed" / "well-disposed", "well

known" / "well-known", "well trained" / "well-trained" "zoologist" /

"zooelogist", "Zoological" / "Zooelogical".

There is no direct reference to Table of Reference item 105 or 112

within this book.

Here is a list of the minor typographical corrections made:

- Bracket removed following "1904" on Page vii

- "VI" changed to "IV" on Page vii

- Hyphen added between "September" and "Commission" on Page vii

- "vice versa" italicized on Page 20

- Double quote added after "'Hans'?" on Page 36

- "elasping" changed to "elapsing" on Page 50

- Bracket removed following "utility." on Page 58

- "Futhermore" changed to "Furthermore" on Page 67

- "wtih" changed to "with" on Page 77

- Comma removed after "Problems" on Page 78

- Comma removed after "errors" on Page 82

- Comma removed after "errors" on Page 82

- "reponse" changed to "response" on Page 83

- Comma changed to period after "one" on Page 83

- Period added after "Mr" on Page 89

- Comma added after "continuously" on Page 91

- "preceive" changed to "perceive" on Page 98

- Double quote added before "Inhalt" on Page 115

- "concrn" changed to "concern" on Page 116

- "of" changed to "is" on Page 122

- "is" changed to "of" on Page 122

- Period removed after "I" on Page 127

- "to to" replaced by "to" on Pages 135 and 136

- Period added after "50cm" on Page 138

- Double quote added after "you?" on Page 146

- Double quote removed after "Perseverationstendenz" on Page 150

- Comma removed from before "continued" on Page 154

- "proceesses" changed to "processes" on Page 156

- em-dash changed to hyphen between "soixante" and "six" on Page 159

- "baguette")" changed to "baguette)"" on Page 160

- "role" changed to "role" on Page 161

- "asociate" changed to "associate" on Page 162

- "taks" changed to "takes" on Page 162

- em-dash changed to hyphen before "lens" on Page 170

- Double quote added before "streifenfoermige" on Page 173

- "satisfactury" changed to "satisfactory" on Page 174

- "thought" changed to "though" on Page 174

- "explantion" changed to "explanation" on Page 179

- Comma added after "Another" on Page 188

- "53" changed to "73" on Page 192

- Apostrophe changed to comma between "84" and "85" on Page 198

- "detail" changed to "details" on Page 206

- "Ostens'" changed to "Osten's" on Page 209

- "expectpectantly" changed to "expectantly" on Page 216

- Comma changed to period after "stimuli" on Page 224

- "suppossed" changed to "supposed" on Page 231

- Double quote added after "himself" on Page 235

- "diminshingly" changed to "diminishingly" on Page 240

- "acounts" changed to "accounts" on Page 243

- Single quote moved from before "twice," to after it on Page 250

- Double quote removed from before "How" on Page 251

- "af" changed to "of" on Page 255

- Period removed after "found?" on Page 258

- "Von" changed to "von" on Page 263

- Period removed after "Stuttgart" on Page 272

- Comma changed to period after "Botany" on Page 279