500. Preliminary survey of the chapter. I first show that hypnotism is an experimental development of the sleeping phase of personality. Then, reviewing the various accredited modes of inducing hypnotic effects, I show that these resolve themselves into suggestion and self-suggestion; and, further, that suggestion from hypnotisers resolves itself, in its turn, into self-suggestion; and I define suggestion as a successful appeal to the subliminal self.

Analysing, in the next place, the main achievements of hypnotism, I find that these seem all of them to imply an increased subliminal vitalisation of the organism; and, again, that self-suggestion is exercised most effectively when it is supported by strong faith in some external vitalising or succouring power. I conclude that man's spirit does actually draw in energy from some spiritual environment; and that "by Grace we are saved through Faith".

501. Our study of sleep in the last chapter, even more than our study of genius in the chapter preceding, has suggested the desirability of reproducing and consolidating by experiment some part of that sporadic and spontaneous faculty which has come to the surface especially in vision and sleep-waking states.

502. Yet at the same time, if it were not for the knowledge which hypnotism has almost accidentally brought to us, we should find it hard to devise any appropriate scheme of experiment. Important lesson conveyed by the fact that a phenomenon so easily produced and so impressive as the hypnotic trance should have remained virtually unknown until so recent a period.

503. Hypnotism has now, in fact, been discovered, and has opened an easy road of exploration. Yet we should realise beforehand that we are only likely to reach experimentally such portions of our subliminal being as hysteria and somnambulism have affected in their spontaneous and sporadic way. We shall probably reach, so to say, only " middle-level centres " of the subliminal self.

504. These reflections, at any rate, show that hypnotism is no disconnected or extraneous insertion into experimental psychology, but rather a summary name for a group of necessary, although empirical and isolated, attempts to bring under control that range of submerged faculty which has already from time to time risen into our observation.

505. Mesmer showed broadly that a profound nervous change, often therapeutic, would often follow upon an obscure stimulus which he regarded as a specific effluence passing from hypnotiser to subject.

506. De Puységur developed this nervous change into its most important phase, namely, induced somnambulism, and in this phase obtained indications of supernormal faculty.

507. Elliotson and Esdaile, using mesmeric passes, effected remarkable cures, with deep anaesthesia under surgical operations.

508. Braid and Fahnestock showed that hypnotic results could be produced without passes by suggestion and self-suggestion.

509. Charcot, by strongly defending a definite, but mistaken, conception of hypnotism, gave a fresh impulse to its study. 509 A. Bramwell's criticism of Charcot.

510. Liébeault, Bernheim, and other hypnotists representing what was at first identified with "the Nancy School," but is now the generally accepted view, insisted that hypnotic phenomena are wholly due to suggestion and self-suggestion, but left these terms unexplained.

511. On a closer analysis it is seen that "suggestibility " means nothing more than increased internal responsiveness of the organism, which is the result which we wish to effect, not the means by which we effect it.

512. This plasticity, or readier response of the organism to our desire for its modification, is, in fact, aimed at by the use of various nervous stimuli, massive or specialised. Drugs afford a form of massive stimulus which is sometimes effective. 512 A. Chloroform may sometimes act simply as a suggestion (Herrero's cases). 512 B. Voisin's view of chloroform as facilitating attention. 512 C. Influence of opium in adding force to self-suggestion: Case of Dr. Parsons.

513. Sudden shock has also been tried, but the resultant "cataplexy" is not identical with hypnotic trance. 513 A. Bramwell on hypnosis in animals. 513 B. Mesmerisation of animals regarded as a test of existence of mesmeric effluence. 513 C. Liébeault on hypnotisation of infants.

514. Hypnotic trance is induced in some hysterical persons by pressure on certain patches of skin called hypnogenous zones. This method, however, seems to be merely a form of hysterical self-suggestion.

515. Monotonous stimulation (as used by Voisin, Braid, etc.), has some predisposing effect, but its apparent effect may often be more truly referred to suggestion.

516. And mesmeric passes involve too little monotonous stimulation to be thus explicable. Their effect must be due either to suggestion or to some influence or effluence akin to telepathy.

517. All forms of nervous stimulation, resulting in increased plasticity, tend thus to resolve themselves into the unexplained efficacy of " suggestion," while, on the other hand, unless there exist some influence or effluence of unknown type, suggestion by hypnotisers can mean little more than self-suggestion.

518. Self-suggestion is itself capricious and unintelligible; although it is in practice observed to work more readily along certain main lines. 518 A. Fahnestock and Delboeuf on self-suggestion. 518 B. Bramwell and the elder Despine on the same. 518 C. Forel's experience. 518 D. Wingfield's experiments in self-suggestion.

519. I define suggestion as " successful appeal to the subliminal self "; and thus, in the first place, I present the puzzle of the capriciousness of successful suggestion as part and parcel of the larger problem of the relationships of the supraliminal and the subliminal self.

520. This conception should throw light on the phenomena of hypnotism. In the first place, since the subliminal self is specially concerned with the sleeping phase of personality, we may expect that hypnotism will involve some developed form of sleep.