Sufferers from ordinary neurasthenia exhibit similar phenomena when being hypnotized; this is accounted for by the excitement which the act of hypnotizing sets up in such persons.

In dealing with auto-suggestion we must also bear in mind that there are certain variations in susceptibility to the experimenter's suggestions. One declares at one moment that his name is Moll, and does what I command him; directly after he is himself again, without any certain or apparent cause. Like many other subjects, he says afterwards that he perceives two opposing wills in himself, and that sometimes one, and sometimes the other, conquers.

I have been careful to distinguish between auto-suggestion proper and those forms which are really external suggestions. This is a distinction upon which Hirschlaff has rightly insisted. Many cases of external suggestion seem to be instances of autosuggestion, a phenomenon which plays a great part in training, to which I shall now direct my remarks. The slightest sign suffices to make a subject repeat, later on, any action which has once been induced in hypnosis by means of external suggestion - i.e., he responds just as he did to a definite suggested idea. When a hypnotic has been trained it is hardly necessary for the experimenter to state what he wishes to be done - a gesture will suffice. For example, let a man's arm be paralyzed by verbal suggestion, then, later on, the experimenter will only have to give the slightest sign and the paralysis will reappear without being specially suggested. It may happen that the experimenter, either by his voice or by some slight* movement, unintentionally directs the subjects to exhibit certain phenomena which could only be primarily induced by definite verbal suggestion. In this we have one of the chief sources of error, because the subject is inclined to . obey the experimenter's intentions, and thus unintentionally misleads him.

The subject is also greatly influenced by his surroundings, and by watching other subjects (Bertrand). Imitation is also of great importance here. I hypnotize X., and suggest that he cannot speak, at the same time inadvertently touching his left stioulder with my right hand. Y., in hypnosis, sees this, and every time I touch his left shoulder with my right hand he, too, is unable to speak. Y. believes this is the signal for loss of speech. In this case I gave the signal (touching the shoulder) unintentionally. We often give the signal unintentionally, but easily overlook the fact that we are at the same time suggesting something, and this leads to the phenomenon produced being erroneously attributed to the signal instead of to the idea suggested. Consequently at each subsequent experiment the hypnotist is, without suspecting it, educating the subject to respond more and more readily to a given signal - i.e., there is unintentional training, if I may be allowed the expression, and, moreover, the particular symptom induced by the training becomes more and more pronounced.

We must, therefore, invariably consider the question of training. All the phenomena of hypnosis may be interpreted falsely by any one who overlooks this point. This refers in particular to on-lookers at hypnotic experiments. When hypnotic experiments are shown to outsiders, subjects are as a rule selected who have gone through a hypnotic training in some particular direction, and as the directions are various, the results also are various. The experimenter A. keeps in view a particular symptom, a, and reinforces it at each experiment; in the same way experimenter B. cultivates symptom b. In the first case a is fully developed, and b receives little attention; and in the second case the reverse happens. The Breslau investigators, for example, developed the imitative movements, while others did the same with the effects of the movements on the feelings (suggestions d'attitude). He who only regards the final results and pays no attention to their gradual evolution will be inclined to believe that the two parties of investigators are engaged with different things; though it is in reality only differences in training which give a different appearance to states which were primarily identical.

Each experimenter now only demonstrates such symptoms as he has cultivated by training, especially as this training commonly produces most interesting phenomena; the heightening of certain faculties in particular. The outsider is unaware that this is a mere result of hypnotic training, and is misled. Children who repeat to strangers the piece of poetry they know best, do exactly the same thing. Experimenters produce certain objective symptoms by means of training, and any one seeing them for the first time is apt to make mistakes. But every experimenter produces different objective symptoms - one, for example, a lasting catalepsy, another a perfect echolalia. These things strike the stranger who knows nothing about the previous . training. The question of training is of immense importance. Many have suspected simulation because of the apparent variety of hypnotic states. This variety is really only the result of different training, if we put aside differences of character. In this respect the experimenter influences the development of the hypnosis. Unimportant phenomena such as echolalia are developed as much as possible, and are at last wrongly considered to be essential hypnotic phenomena.

By training the subject learns, as it were, to "read" the experimenter's thoughts.

We meet something very similar, but under different circumstances, in the training of animals, in which, as we know, it plays an important part. It was through overlooking this fact that Stumpf, a well-known Berlin psychologist, was led to attest in the case of the horse, "Clever Hans," that the only possible explanation of the animal's power to calculate, read, etc., lay in the admission of telepathic communications passing between the owner and the horse. As we shall see later on, Stumpf failed to see the tiny signals to which the horse responded.