I shall be silent here on the physiological theories, as I shall come to them later on; they may be looked upon as most unsatisfactory hypotheses. At all events, if we are to understand the phenomena of hypnosis, it is essential first of all to establish the fundamental facts of mental life, and to remember at the same time that now one, now another, of these facts, now several of them together, will have to be considered.

After these preliminary remarks I go on to discuss the separate phenomena of hypnosis; the functional disturbances of voluntary movement first, because there is no hypnotic state without them. They are almost always the first symptom, even when there are other changes. The effect of expectant attention explains their onset. But to understand this more readily the hypnosis should be induced by slow degrees, as in this case the motor disturbances are plainer.

To produce any motor disturbance by suggestion in a subject, X., who is in a perfectly normal state, we must first of all make him believe in the possibility of such an effect. Consequently we shall the sooner attain our end if X. has seen a number of similar experiments performed on other persons. The possibility of influencing people in this way is, for example, much greater just after they have witnessed hypnotic performances. But belief in the possibility alone of the effect taking place does not as a rule suffice. It is more generally necessary to fix the subject's attention as far as possible on the coming on of the motor disturbance; or, as Fechner and Wundt express it, to place the expectation of the disturbance in the range of his inner perceptive. The better we succeed in doing this, the easier will it be to induce motor disturbances by means of suggestion. It is certain that some people have a peculiar disposition which facilitates the attainment of the desired result. But such a disposition can be created by external conditions; in this respect the surroundings, moral influence, and the manner and appearance of the experimenter play a great part. •.

Supposing we have succeeded in paralyzing the subject's arm. The appearance of one symptom facilitates the following of others, because it increases the subject's conviction of his susceptibility to suggestion. A mental state ensues which Pierre Janet calls tnisere psychique, a feeling of weakened willpower which favours the acceptance of later suggestions - for example, paralysis of the speech, the legs, etc.

This enables us to understand the gradual development of the disturbances of the muscular functions. This development is in many cases identical with that of hypnosis, which is often merely an inhibition of the voluntary muscular functions. Many methods used to induce hypnosis are alike in one particular - they direct the subject's attention to some change in the functions of the muscles. The method of the Nancy school consists chiefly in making the subject expect the closing of his eyes as strongly as possible, though certainly this method also aims at producing the dream-consciousness. However, the latter is an additional moment, and is not an absolute necessity. As we saw in our classification of hypnoses, there are numerous cases without any evidence whatever of dream-consciousness. On the other hand, it is evident that when special stress is laid on the closing of the eyes, the dream-consciousness may be unintentionally suggested as well. We may begin with any other member of the body just as well as with the eye. For example, an arm or a leg loses its power to move when I concentrate the attention of the subject on the loss of power to move.

In fact, it is quite unnecessary to begin with the eyes, as the school of Nancy does; we can begin with any member, as Max Dessoir rightly insists. Of course, we should naturally begin with that abnormality which is most easily induced, because the acceptance of later suggestions is favoured by the abnormality already induced.

This principle of the effects of expectant attention illustrated above is nowhere shown more plainly than in the voluntary movements. Modern psychology teaches us how easily a movement is induced by the idea of it, without any voluntary action. Here we have apparently the same effect produced when the subject himself has the idea of the movement as when the experimenter arouses the idea in hypnosis. But in the latter case not only is the idea aroused, but the expectation of its fulfilment as well, and this further favours the movement being carried out.

I now come to the discussion of sense-delusions; first of all, of the positive kind. Are we not exposed to such delusions otherwise than in hypnosis ? Take first a very simple example of Max Dessoir's. If a man who is wide awake is told, "A rat is running behind you," he will have a mental image of a rat for a moment - i.e., there is already a trace of hallucination, even though he is convinced that there is no rat.

Modern psychology, following such men as Dugald Stewart and Taine, generally supposes that every idea includes an image - e.g., the idea of a knife includes the image of a knife. As, further, every central image tends to externalize itself, as Stuart Mill in particular has explained, when an idea is aroused, there is always a tendency to externalize the corresponding image - i.e., there is a tendency to hallucination. We have thus a tendency to take remembered images for real objects (Binet, Fere). Many interesting details on this process are given by Sourian in La Suggestion dans l'Art.

But even if the ideas of waking life are associated with a trace of hallucination, there is a great difference between the effect of an idea suggested in hypnosis and that of the corresponding idea in waking life. In normal waking life a man can convince himself of the inaccuracy of a statement by means of his senses; and, apart from this, an idea in itself has not the same tendency that it has in hypnosis to develop into a hallucination which dims the judgment. The difference may only be quantitative, but must not be disregarded. It is a necessary condition for the production of a sense-delusion in hypnosis that an idea be connected with the corresponding image. "The power possessed by hallucination of producing conviction depends upon the fact that we invariably refer the reproduction of our impressions to the sensory region from which they sprang; indeed, we not only localize them in this way, but even to a certain extent thus project them into space."