Of course a careful study of the negative hallucinations will help us to understand rapport, as will be seen from my remarks on those hallucinations; but the most essential consideration in respect to rapport is the individual influence which certain people can exert over others, which I sound than one he is prepared for. Probably the production of negative sense-delusions in hypnosis is facilitated in a similar way. It must be remembered that the experimenter has acquired ascendancy over the subject and has become an authority for him. The subject is consequently inclined to believe everything he is told by the experimenter; and it is conceivable that negative hallucinations are thereby favoured.

1 Der Rapport in der Hypnose; Leipzig, 1892.

Nevertheless, these two factors, the diversion of the subject's attention and the conviction established in him, do not suffice to explain negative hallucinations. However much he believes the hypnotist, without such motives as would induce belief under normal circumstances (as Bentivegni rightly points out) this does not alone explain such mistakes of sense-perception as are found in negative hallucinations. A completely changed state of consciousness must be added if we wish to understand negative hallucinations; the dream-consciousness again, which helped us to understand positive delusions of the senses. For dream-consciousness is not only distinguished by the reappearance of former memory-images as hallucinations; it is also characterized by the fact that sense-impressions, which under normal circumstances become feelings and perceptions) induce in it no feeling or perception.

Hence, negative hallucinations depend upon the co-operation of various factors: firstly, dream-consciousness which creates the tendency to negative sense-delusions; secondly, the subject's belief in everything the experimenter says, which favours those delusions; thirdly, the mental state which results from this, and which may be regarded as analogous to diversion of the attention.

We can explain the analgesia of some hypnotic subjects in a like manner. It is known that an expected pain is more acutely felt than an unexpected one. The effect of a stimulus may vary very considerably according to the mental attitude of the subject. We see this in operations; the subject feels much more pain when he expects the stroke of the knife than when it takes him unawares; in the latter case he feels hardly any pain at all. It is the same thing with analgesia in hypnosis; but it is still doubtful whether there is ever an entirely spontaneous analgesia without suggestion. In any case, analgesia is more usually induced by suggestion. Here we may take it the subject's mental state has been brought about by his implicit belief in the experimenter, and is much the same as in diversion of the attention. To explain analgesia, however, it is necessary to call in the aid of dream-consciousness, just as we did in the case of negative sense-delusions; for dream-consciousness has a decided tendency to prevent impressions, which would otherwise be painful, from becoming feelings and perceptions.

Be this as it may, the following essential difference exists: as soon as a painful stimulus has acquired a certain degree of intensity it wakes a person from ordinary sleep in spite of dream-consciousness, but does not as a rule terminate a hypnosis; and Rosenbach pointed out long ago in his work, The Reflexes in Sleepy how differently sensory stimuli act in health and disease. We can more readily understand the analgesia of hypnosis when dream-consciousness is associated with the other factors mentioned above.

I now come to the discussion of some phenomena of memory. Only those cases will be considered in which there is a derangement of memory due to hypnosis - i.e. cases in which the subject after waking from hypnosis remembers nothing of what has happened. It is a well-known fact that we forget certain events in ordinary life. We entirely forget mechanical actions, such as the winding of a watch. But some things done with reflection and in perfect consciousness are occasionally forgotten even though we particularly intended to remember them. I will choose an example from my own experience, a thing which we have all doubtless observed in ourselves. I take a book and put it in a particular place so that I may find it when I want it. At last I want it, but I cannot remember where I put it. I think in vain. Only when I replace myself in imagination at the moment when I put it away (a method which every one knows) do I remember where it is. And yet in spite of temporary loss of memory I did not put the book away when I was in a state of loss of consciousness; it was rather that I was at the time in another state of consciousness.

This is in many respects analogous to hypnosis, the events of which are remembered only when the subject is again in the same state of consciousness - i.e.., in a fresh hypnosis. Of course these cases in ordinary life may deprive the mental derangements which occur in hypnosis of much that is strange and mysterious, but they do not afford a satisfactory explanation of the phenomena. I mentioned when discussing the memory before that the subject in hypnosis sometimes remembered all the events of preceding hypnoses, and of his waking life. If we suppose the life of such a being as divided into several periods a, b, c, dt e,f, in the periods at c, e, only the events of those periods will be remembered; so that in period c he will only remember what happened in a, and in period e what happened in a and c. On the other hand, in the periods b, d, ft both what has happened in them and in the periods a, c, e, will be remembered. A phenomenon such as this calls for an explanation.

Max Dessoir endeavours to explain it by his theory of the "Doppel-Ich," or double Ego. He supposes that human personality is a unity merely to our own consciousness, but that it consists really of at least two distinguishable personalities, each held together by its own chain of memories. According to him many actions are performed mechanically though of mental origin - i.e., the agent acts unconsciously for the moment. For example, rubbing the hands when they are cold and even more complicated actions are performed automatically. Max Dessoir relates the following personal experience: - "A friend calls on me with a communication which means that I must go with him at once. I dress myself to go out while he relates the details of a case that is evidently urgent. I put on a clean collar, turn my cuffs, button them on, put my coat on and my latch-key into my pocket although the questions I put to him from time to time show that my attention is directed exclusively to what he is saying. As soon as we get into the street I am seized with the firm conviction that I have left the key behind.