[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—.
[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]
[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 Léonard 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 naïve, 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 Léonard, 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.
[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."
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.