564. The group of sleep-waking cases which we may next discuss illustrate a natural evolution of the faculty of the sleeping phase of personality. The subliminal self, exercising in sleep a profounder influence over the organism than the supraliminal can exert, may also be presumed to possess a profounder knowledge of the organism, - of its present, and therefore of its future, - than the supraliminal self enjoys.

I refer in 564 A to two cases in which the somnambulic personality is discerned throughout as a wiser self - advising a treatment, or at least foreseeing future developments of the disease with great particularity. Of course in such a case prediction is often simply a form of suggestion; the symptom occurs simply because it has been ordained beforehand. In the case of cures of long-standing disease the sagacity which foresees probably co-operates with the control which directs the changes in the organism.

565. The next stage is a very important one. We come to the manifestation in spontaneous sleep-waking states of manifestly supernormal powers, - sometimes of telepathy, but more commonly of clairvoyance or telæsthesia. Unfortunately these cases have been, as a rule, very insufficiently observed (see, e.g., the case of Mollie Fancher, in 236 A). Still, it appears that in spontaneous somnambulism there is frequently some indication of supernormal powers, though the observers - even if competent in other ways - have generally neglected to take account of the hyperæsthesia and heightening of memory and of general intelligence that often accompany the state. I quote, however, from Dr. Dufay (in 565 A) a case which does not seem open to these objections, and give some references to other cases.

566. Before leaving this subject of spontaneous sleep-waking states, I ought briefly to mention a form of trance with which we shall have to deal more at length in a later chapter. I speak of trance ascribed to spirit-possession. As will be seen, I myself fully adopt this explanation in a small number of the cases where it is put forward. Yet I do not think that spirit-agency is necessarily present in all the trances even of a true subject of possession. With all the leading sensitives - with D. D. Home, with Stainton Moses, with Mrs. Piper and others - I think that the depth of the trance has varied greatly on different occasions, and that sometimes the subliminal self of the sensitive is vaguely simulating, probably in an unconscious dream-like way, an external intelligence. This hypothesis suggested itself to several observers in the case especially of D. D. Home, with whom the moments of strong characterisation of a departed personality, though far from rare, were yet scattered among tracts of dreamy improvisation which suggested only the utterance of Home's subliminal self (see Chapter IX (Trance, Possession And Ecstasy).). However we choose to interpret these trances, they should be mentioned in comparison with all the other sleep-waking states.

They probably form the best transition between those shallow somnambulisms, on the one hand, which are little more than a vivid dream, and those profound trances, on the other hand, in which the native spirit quits, as nearly as may be, the sensitive's organism, and is for the time replaced, as nearly as may be, by an invading spirit from that unseen world.

567. This brief review of non-hypnotic somnambulisms has not been without its lessons. It has shown us that the supernormal powers which we have traced in each of the preceding chapters in turn do also show themselves, in much the same fashion, in spontaneous sleep-waking states of various types. We must now inquire how far they occur in sleep-waking states experimentally induced.

And here the very fact of induction suggests to us a question specially applicable to the hypnotic state itself. Is hypnosis ever supernormally induced? Can any one, that is to say, be thrown into hypnotic trance by a telepathic impact ? or, to phrase it more generally, by any influence, inexplicable by existing science, which may pass from man to man?

The question which I thus attack at a comparatively late point of my discussion has given rise to more of heated controversy than any other in the history of my subject. A battle which seemed internecine raged for years between the partisans of "mesmeric effluence," on the one hand, and the partisans of a purely physiological or a purely 'suggestive " causation of hypnosis on the other. The victory gradually fell to the latter of these groups, and when Edmund Gurney and I first wrote on hypnotism, some twenty years ago, hardly a single hypnotist supported us in our question as to the real discomfiture of the old, or "mesmeric," hypothesis.

I do not say that even now much change has occurred in the then general opinion. Yet efflux of time, and certain considerations set forth in earlier sections of this chapter, may now enable us to a certain extent to see round the former controversy, to concede to each side the establishment of certain definite theses, and to suggest limitations of the field still open to dispute.

In the first place one may say that of the anti-mesmeric schools of opinion, the "purely physiological" school has on the whole failed, the "purely suggestive " school has triumphantly succeeded. The school of Nancy, reinforced by hypnotists all over Europe, has abundantly proved that "pure suggestion " (whatever that be) is the determining cause of a very large proportion of hypnotic phenomena. That is beyond dispute; and the two other schools, the "pure physiologists" and the "mesmerists" alike, must now manage to prove as best they can that their favourite methods play any real part in the induction of any case of hypnosis. For to the pure suggestionist, monotonous stimulation and mesmeric passes are alike in themselves inert, are alike mere facilitations of suggestion, acting not directly on the patient's organism, but rather on his state of mental expectation.

I reply that there is absolutely no need to go as far as this. In admitting suggestion as a vera causa of hypnosis, we are recognising a cause which, if we really try to grasp it, resolves itself into subliminal operation, brought about we know not how. So far, therefore, from negativing and excluding any obscure and perhaps supernormal agency, the suggestion theory leaves the way for any such agency broadly open. Some unknown cause or other must determine whether each suggestion is to "take" or no; and that unknown cause must presumably act somehow upon the subliminal self. We should have something like a real explanation of suggestion, if we could show that a suggestion's success or failure was linked with some telepathic impact from the suggester's mind, or with some mesmeric effluence from his person.

I know well that in many cases we can establish no link of this kind. In Bernheim's rapid hospital practice there seems no opportunity to bring the hypnotist's will, or the hypnotiser's organism, into any effective rapport with the subject. Rather, the subject seems to do all that is wanted for himself almost instantaneously. He often falls into the suggested slumber almost before the word "Dormez! " has left the physician's mouth. But on the other hand, this is by no means the only type of hypnotic success. Just as in the mesmeric days, so also now there are continual instances where much more than the mere command has been needed for effective hypnotisation. Persistence, proximity, passes - all these prove needful still in the practice even of physicians who place no faith at all in the old mesmeric theory.