J.— PSYCHOLOGY. 191 



all th© processes by which one mind acts on or is acted on by another 

 unwittingly. He supposed that in the course of mental evolution 

 epicritic characters displaced the early protopathic characters of 

 instinctive beha-viour owing to the incidence! of gregarious life, 

 especially among insects, and owing to the appearance and development) 

 of intelligence, especially in man. The suggestion inlierent in gi'e- 

 garious behaviour implies some graduation of mental and bodily activity 

 — an instinctive and unwitting discrimination distinct from the witting 

 discrimination of intelligence. Suggestion, in primitive gregarious 

 beha.viour, as also in th© dissociated state of hypnosis, and in its allied 

 form, ordinary sleep, is prevented if witting processes be active; it ' is 

 a process of the unconscious,' said Rivers. Both within the herd and 

 during hypnosis, which he believed to be fundamentally of a collective 

 nature, sensibility is heightened, so that the organism may be able 

 to react to minute and almost imperceptible stimuli. Were he here 

 to-day Elvers would have carried this co'nception of the evolution O'f 

 gregarious life still further by distinguishing between the more lowly 

 leaderless herd and the herd wliich has acquired a definite leader. He 

 would have traced the development of the new affect of submission 

 and of the new behaviour of obedience to the leader, and he would 

 doubtless have accredited the leader with the higher affects of superiority 

 and felt prestige, with th© higher cognition that comes of intuitive 

 foresight, and with the higher behaviour of intuitive adaptation, 

 initiative, and command. I expect, toO', that he would have sketched 

 th© development of still later forms Oif social activity, complicated by 

 the interaction and combination of intellectual and instinctive processes 

 — the witting deliberations and decisions on the part of the leader, and 

 th© intellectual understanding of the reasons for their confidenc© in him 

 and for their appropriate beha.viour on the part of those who' are led. 



But it would be idle further to speculate on the ideas of which we 

 have been robbed by Rivers 's untimely death. Let us rather console 

 ourselves with the vast amount of valuable and suggestive material 

 which he has left behind and with the stimulating memories of one 

 who, despite the fact that his health was never robust, devoted himself 

 unsparingly to scientific work and to the claims of any deserving human 

 beings or of any deserving human© cause that were made upon him. 

 There are, no doubt, some who believe tTiat Rivers 's earlier experimental 

 psychological work — on vision, on the effects of drugs, and on cutaneous 

 sensibility — is likely to be more lasting than his later speculations on the 

 nature of instinct, the unconscious, dreams, and the psychoneuroses. No 

 on© can doubt the scientific permanence of his investigations in the 

 laboratory or in the field ; they are a standing monument to us of 

 thoroughness and accuracy combined with criticism and genius. But 

 even those whoi hesitate to suppose that at some definite period in mental 

 evolution intelligence suddenly made its appearance and was gi'afted on 

 to instinct, or that epicritic sensibility was suddenly added to a mental 

 life which had before enjoyed only protopathic sensibility — even those 

 who may not see eye to eye with Rivers on these and other fundamental 

 views on which much of his later work rested, will be foremost in 

 recognising the extraordinarily stimulating, suggestive, and fruitful 

 1022 1> 



