It is necessary in this place to warn once more most emphatically against the time-honored confusing of this conception with that of unconscious-ness. That we do not have any recollection of a certain epoch of our lives or certain things which we have experienced does not prove in the least that we were unconscious of them at the time. This holds good even if the amnesia dates back as far as the occurrence. But, still, we have, as a rule, no other proof that a person was unconscious than his amnesia can give. One almost admits, thus, that it is impossible to prove absolute unconsciousness. One can only speak of a veiling of the consciousness, which is based on chaotic dissociation. As a rule, a person during the period of a deep veiling of the consciousness is amnesic, but not always. And, conversely, one can render some people at will amnesic of perfectly clear conceived experiences and periods of life by means of suggestion. Amnesia of a certain period of time does not necessarily include irresponsibility during this period, although it is the rule, apart from suggestion.

Our conclusion as to the unconsciousness even in cases of deep sleep and of coma, in which, for example, a patient suffering from some brain disturbance does not show any reaction even when the cornea is touched, is only an indirect one. We usually attempt to verify our conclusion by making out that amnesia existed. There is no such thing as a direct inspection into the consciousness of other people.

When one succeeds in producing amnesia for the time of the hypnosis in a person by suggestion, one has gained a considerable power, for one can thus interrupt, inhibit, or reestablish his superconscious linkings at will, and can produce contrast actions, which are of the greatest value for the results of later suggestions. One can especially cause him to forget everything which could offer him opportunity to ponder over and to destroy the action of the suggestion, and cause him only to remember those things which assist the action of the suggestion. It is true that at times amnesia is lost, and the remembrance returns spontaneously. But this occurs only in incomplete cases. By means of suggestion, one is able, not only to limit the amnesia to the single perceptions and conceptions, but one can extend it and allow it to embrace past and future time. However, the suggestibility, which is increased by amnesia, has this disadvantage - that very highly suggestible persons, as we have Been, are very easily subjected to any influence, so that the quickly achieved therapeutic results are very rapidly destroyed by deleterious contrary influences, and thus recurrences are produced.

Amnesia, therefore, plays a very important part in hypnosis. I will illustrate its importance by a single example: I attempted to produce anaesthesia by suggestion in an attendant who had toothache. I only partly succeeded. The extraction of the tooth was nevertheless carried out. He awakened, cried out, seized the hand of the medical officer, and hindered him. I quietly went on suggesting, after the tooth was taken out, that he would sleep well, had not felt anything at all, would forget all when he awoke, and that he had not had any pain. He actually went quietly to sleep, and was completely amnesic when he awoke. He imagined, therefore, that he had not felt anything, and was very grateful and glad about the painless extraction. Later on I made inquiries of him through third persons, toward whom he would have had absolutely no reason whatsoever to conceal the truth. He told everybody that he had not felt anything, and for thirteen years after he had left the asylum, and had an engagement in the town of Zurich, be adhered to this statement, In. contradistinction to this case, I have allowed teeth to be drawn from persons who were quite awake, and who had been rendered perfectly anaesthetic by suggestion. These persons, who were otherwise cowards as far as pain was concerned, laughed during the extraction, and did not feel anything. It was only the becoming conscious of the impression of the memory of the pain which was limited or inhibited in the first case, while in the second case it was the becoming conscious of the peripheral stimulation itself during the moment when it took place.

A peculiar case takes up a position between these two cases: A very capable nurse was very frightened of a tooth extraction, although she was fairly suggestible. Nevertheless, I hypnotized her. But she resisted the application of the forceps during the hypnosis. I was able to render the tooth anaesthetic, in spite of the fact that she protected herself with both hands. She awoke with a slight cry when the tooth came out. She declared at once and spontaneously in astonishment that she had felt nothing else than the tooth lying loose in her mouth. She had not had the least pain, and not even a trace of tenderness after the extraction. But she still remembered experiencing much fear. In this case the anaesthesia bad succeeded, but I had not been able to remove the fear.

The following experiments, which I have carried out several times with two different persons, appear to me to be of special importance. One of them possesses an extremely noble character from an ethical point of view, and has a high ideal of veracity. In this way the least degree of exaggerating In order to please me is excluded with absolute certainty. I suggested anaesthesia for various parts of the body when she was fully awake. Then I asked her to close her eyes, and took sufficient care that she could not see the field of my operation by peeping from under her lids. I pricked the hypnotized person in three or more definite places. She assured mo that she felt nothing, and did not know what I was doing. I then made her go to sleep, and suggested a current to her that would bring back the feeling in such a way that she would know exactly after she had awakened what I had been doing with her. When she awakened I asked her what I had done to her. At first she had difficulty in remembering, and then she found the places where I had pricked her approximately. However, on repeating the experiment carefully, altering the number of pricks and the situations, I succeeded better. She found the places exactly, and knew definitely that I had pricked her. It might be argued that the rough irritation of the sensory nerves, which had lasted somewhat longer, still persisted, and was perceived afterwards by the reassociated conscious brain activity. In order that I might meet this argument, I repeated the same experiment, only using the sense of hearing instead, and made the wide awake somnambulist perfectly deaf to certain sounds. Later on I caused the unconceived acoustic impression which had been deposited in the brain to be conceived by means of suggestion. The somnambulists were able to tell me exactly each time what I had been doing. I then asked both of them how they could explain this, and each of them answered, quite independently of the other, that they almost believed that I could use witchcraft. They had neither felt nor heard anything at all when I pricked thorn or made the noises, and later on they suddenly regained the full recollection of the pricks and sounds. It was absolutely inexplicable to them. Bernheim has carried out similar experiments, dealing with negative hallucinations with equally good results. It appears to me that this proves that the usual reflection of our superconsciousness does not stand in any definite relationship to the intensity and quality of the cerebral activity, and that the cutting off and reintroducing of the reflection of the superconsciousness depends more on associative inhibitions and connections. At all events, this experiment demonstrates that the remembrance of a sensation which is obviously only effected in the hypoconsciousness can later on bo transferred to the chain of the super-consciousness, even after a complete anesthesia, which is controlled during waking consciousness. This cannot be due to a suggested falsification of the memory, because the somnambulists detailed the quality and kind of impressions quite correctly, although I had naturally carefully avoided giving the least hint of this in the suggestion. Engrains, which are apparently unconsciously effected, may therefore be ecphorized consciously by association later on.

Dr. O. Vogt has repeated similar experiments for the hearing, sight, and feeling. Simple touches, which were not felt, have been correctly specified even after many hours. Every one of the persons declared that they had absolutely no sensation, but that they now remembered the stimuli quite distinctly. When asked how this could be possible, they either said that they could not understand it or that Vogt must have suggested it to them.