523. Gurney held the view that the main distinction of kind between his "alert " and his "deep " stage of hypnosis was to be found in the domain of memory, while memory also afforded the means for distinguishing the hypnotic state as a whole from the normal one. As a general rule (though with numerous exceptions), the events of ordinary life are remembered in the trance, while the trance events are forgotten on waking, but tend to recur to the memory on rehypnotisation. But the most interesting part of his observations (see 523 A) consisted in showing alternations of memory in the alert and deep stages of the trance itself; - the ideas impressed in the one sort of state being almost always forgotten in the other, and as invariably again remembered when the former state recurs. On experimenting further, he met with a stage in which there was a distinct third train of memory, independent of the others; - and this, of course, suggests a further doubt as to there being any fixed number of stages in the trance.

The later experiments of Mrs. Sidgwick on the same subject (recorded in 523 B), in which eight or nine distinct trains of memory were found - each recurring when the corresponding stage of depth of the trance was reached - seem to show conclusively that the number may vary almost indefinitely. We have already seen that in cases of alternating personalities the number of personalities similarly varies,1 and the student who now follows or repeats Gurney's experiments, with the increased knowledge of split personalities which recent years have brought, cannot fail to be struck with the analogies between Gurney's artificial light and deep states, - with their separate chains of memory, - and those morbid alternating personalities, with their complex mnemonic cleavages and lacunas, with which we dealt in Chapter II (Disintegrations Of Personality). The hypnotic stages are in fact secondary or alternating personalities of very shallow type, but for that very reason all the better adapted for teaching us from what kinds of subliminal disaggregation the more serious splits in personality take their rise.

1 Besides those mentioned in Chapter II (Disintegrations Of Personality). (especially sections 233 to 236), see a remarkable recent case recorded by Dr. Bramwell in Brain, Summer Number, 1900, on the authority of Dr. Albert Wilson, of Leytonstone. In this case there were sixteen different stages or personalities, with distinct memories and different characteristics.

524. And beneath and between these awakenings into limited, partial alertness lies that profound hypnotic trance which one can best describe as a scientific or purposive rearrangement of the elements of sleep; - a rearrangement in which what is helpful is intensified, what is merely hindering or isolating is removed or reduced. A man's ordinary sleep is at once unstable and irresponsive. You can wake him with a pin-prick, but if you talk to him he will not hear or answer you, until you rouse him with the mere noise. That is sleep as the needs of our timorous ancestors determined that it should be.

Hypnotic sleep, on the contrary, is at once stable and responsive; strong in its resistance to such stimuli as it chooses to ignore; ready in its accessibility to such appeals as it chooses to answer.

Prick or pinch the hypnotised subject, and although some stratum of his personality may be aware, in some fashion, of your act, the sleep will generally remain unbroken. But if you speak to him, - or even speak before him, - then, however profound his apparent lethargy, there is something in him which will hear.1

All this is true even of earlier stages of trance. Deeper still lies the stage of highest interest; - that sleep-waking in which the subliminal self is at last set free, - is at last able not only to receive but to respond; when it begins to tell us the secrets of the sleeping phase of personality, beginning with directions as to the conduct of the trance or of the cure, and going on to who knows what insight into who knows what world afar?

Without, then, entering into more detail as to the varying forms which hypnosis at different stages may assume, I have here traced its central characteristic; - the development, namely, of the sleeping phase of personality in such fashion as to allow of some supraliminal guidance of the subliminal self.

1 I am inclined to think that this is always the case. For a long time the lethargic state was supposed at the Salpêtrière to preclude all knowledge of what was going on; and I have heard Charcot speak before a deeply-entranced subject as if there were no danger of her gathering hints as to what he expected her to do. I believe that his patients did subliminally receive such hints, and work them out in their own hypnotic behaviour. On the other hand, I have heard the late Dr. Auguste Voisin, one of the most persistent and successful of hypnotisers, make suggestion after suggestion to a subject apparently almost comatose, - which suggestions, nevertheless, she obeyed as soon as she awoke.

525. We have here a definition of much wider purview than any which has been habitually applied to the process of hypnotisation or to the state of hypnosis. To test its validity, to explain its scope, we need a survey of hypnotic results much wider in range than any enumeration of the kind at present usual in text-books, - than any mere list of neuromuscular and vaso-motor phenomena provoked, or of maladies cured by hypnotic suggestion. Regarding hypnotic achievements mainly in their mental aspects, I must seek for some broad principle of classification which on the one hand may not be so exclusively moral as to be physiologically untranslatable, - like the distinction between vice and virtue; - or on the other hand so exclusively physiological as to be morally untranslatable, like the distinction between cerebral anaemia and hyperæmia.

Perhaps the broadest contrast which is expressible in both moral and physiological terms is the contrast between check and stimulus, - between inhibition and dynamogeny. Not, indeed, that such terms as check and stimulus can be pressed in detail; it is quite possible, for instance, that the action of what we call inhibitory nerves may give a sense of increased moral activity. Yet the terms do correspond well enough with a deep distinction in our practical education, - the distinction between the checking or countermanding on the one hand of impulses already existent, and the heightening, on the other hand, of existent powers, or the infusion of new impulses. The central power, - the ruling agency within the man which gives the command, - is no doubt the same in both cases. But the common contrast between negative and positive exhortations, - "this you shall not do," "this you shall do," - will help to give clearness to our review of the influences of hypnotism in its bearings on intelligence and character, - its psychological efficacy.