III. FUKTHEE PKOBLEMS OF HYPNOTISM. (I.) 1

By EDMUND GUENEY. IT is difficult to get a satisfactory definition of what consti- tutes 'hypnotic trance '. If we begin at the bottom of the scale with animals that have been subjected to certain processes of fixation and manipulation the only phenomena open to observation are immobility and anaesthesia ; animals present nothing corresponding to what I have called the " alert stage " (see MIND No. 33) less accurately, I think, described as the somnamlulic stage of hypnotism. It would be pedantic, perhaps, to refuse to call their state one of hypnotisation, when it has been produced by means similar to those employed to hypnotise human beings, and when their condition appears analogous to the deeper or comatose stage of human trance ; still it would obviously be impossible to accept immobility and anaesthesia as affording a sufficient definition of a hypnotic condition, for at that rate a deeply chloroformed patient would be 'hypnotised'. And when we turn to human beings, there seem to be strong reasons against taking the ground of definition from any physical symptoms. Analgesia, diminished sensibility of the con- junctiva, &c., are not distinctive, and are not constant. Increased muscular irritability and catalepsy are frequently absent in ' subjects ' who manifest the most interesting psychical phenomena ; moreover, these muscular peculiarities are common to certain affections generally called hypnotic and to certain affections generally called hysterical, and for no purpose is a definition of hypnotism more needed than to distinguish it from morbid affections to preserve a state whose most interesting features may be observed at a minute's notice in strong and healthy young men, from any necessary association with the idea of lesion or chronic instability. ' Inhibition of inhibitory functions ' is the sufficient, though clumsy, description of the immediate ground of many hypnotic phenomena, including mechanical imitations of gesture, mechanical continuance of particular muscular movements and diminished reaction-time ; but this ground is clearly too general to found a definition upon the same sort of inhibition being involved in a 1 See MIND ix. 110, 477 (Nos. 33, 36).