[Footnote A: "Frankfurter Zeitung" of September 22, 1904: "Concerning the question whether the horse was given some sort of aid, Professor Stumpf expressed himself freely. He said: 'We were careful to state in our report that the intentional use of the (actual) means of training, on the part of the horse's teacher, is out of the question, ... nor are there involved any of the known kinds of unconscious, involuntary aids. Our task was completed after we had ascertained that no tricks or aids of the traditional sort were being employed'." After some remarks on unconscious habituation and self-training on the part of animals, the writer arrives at the conclusion that "the horse of Mr. von Osten has been educated by its master in the most round-about way, in accordance with a method suited for the development of human reasoning powers, hence in all good faith, to give correct responses by means of tapping with the foot. But what the horse really learned by this wearisome process was something quite different, something that was more in accord with his natural capacities,--he learned to discover by purely sensory aids which are so near the threshold that they are imperceptible for us and even for the teacher, when he is expected to tap with his foot and when he is to come to rest."] But how did it come to pass that the commission should deny completely the presence of intentional signals, while, as regards the unintended, it excluded only those which were of the known sort? The report clearly shows that the decision as to the absence of voluntary signals was based not merely upon the fact that no such signals had been detected by the most expert observers, but also upon the character of the two men who exhibited the horse, upon their behavior during the entire period, and upon the method of instruction which Mr. von Osten had employed. In the case of unintentional signs, on the other hand, one had to deal with the fact with which physiologists and experimental psychologists are especially familiar, viz., that our conscious states, without our willing it--indeed, even in spite of us--are accompanied by bodily changes which very often can be detected only by the use of extremely fine graphic methods. The following is a more general instance: every mother, who detects the lie or divines the wish in the eyes of the child, knows that there are characteristic changes of facial expression, which are, nevertheless, very difficult of definition.[B] [Footnote B: "From the productions of the 'thought-readers' we see how slight and seemingly insignificant the unconscious movements may be, which serve as signs for a sensitive re-agent. But in this case no contact is necessary. There would have to be some sort of visible or audible expression on the part of the questioner. No proof for this has as yet been advanced."