There are, moreover, other states, both spontaneous and induced, analogous to sleep, and these will form the subject of the fifth chapter, that on Hypnotism. Hypnotism, however, does not mean trance or somnambulism only. It is a name, if not for the whole _ensemble_, yet for a large group of those artifices which we have as yet discovered for the purpose of eliciting and utilising subliminal faculty. The results of hypnotic suggestion will be found to imitate sometimes the subliminal uprushes of genius, and sometimes the visions of spontaneous somnambulism; while they also open to us fresh and characteristic accesses into subliminal knowledge and power. Further than this point our immediate forecast need not go. But when we have completed the survey here indicated, we shall see, I think, how significant are the phenomena of hysteria in any psychological scheme which aims at including the hidden powers of man. For much as the hysteric stands in comparison to us ordinary men, so perhaps do we ordinary men stand in comparison with a not impossible ideal of faculty and of self-control. But apart from these broader speculations, it has become evident that disturbances of personality are not mere empty marvels, but psycho-pathological problems of the utmost interest:--no one of them exactly like another, and no one of them without some possible _aperçu_ into the intimate structure of man. The purpose of this book, of course, is not primarily practical. It aims rather at the satisfaction of scientific curiosity as to man's psychical structure; esteeming _that_ as a form of experimental research which the more urgent needs of therapeutics have kept in the background too long. Yet it may not have been amiss to realise thus, on the threshold of our discussion, that already even the most delicate speculations in this line have found their justification in helpful act; that strange bewilderments, paralysing perturbations, which no treatment could alleviate, no drug control, have been soothed and stablished into sanity by some appropriate and sagacious mode of appeal to a _natura medicatrix_ deep-hidden in the labouring breast. CHAPTER III GENIUS Igneus est ollis vigor et cœlestis origo Seminibus, quantum non noxia corpora tardant Terrenique hebetant artus moribundaque membra. --VIRGIL.