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.