Heredity of Instincts. 23 



heat, and light ; nor would the reduction of all psychical phenomena 

 to motion bar the separate study of instinct, sensation, imagination, 

 will, etc. In any case, therefore, the question remains, What is 

 instinct ? 



Instinct is an unconscious form of intelligence, determined by 

 the organization. 



We intend to give in another place (Part III. chap. i. 2) a 

 detailed exposition of unconscious psychological phenomena, and 

 to insist upon a class of facts that have been somewhat overlooked, 

 though they probably contain much instruction for us. For the 

 present, we would merely observe that, besides the conscious action 

 of the mind, there is also an unconscious action, with a far wider 

 sphere ; that consciousness is an habitual, though not necessary, 

 accompaniment of our mental life; that perhaps every one of these 

 phenomena instinct, sensation, perception, memory, etc. is by 

 turns conscious and unconscious. This consideration will 

 probably aid us to throw light on the problem of instinct. 



Suppose a highly civilized people, among whom the division of 

 labour is carried to great lengths ; that it contains architects, poets, 

 engineers, musicians, all incapable of any work save that which 

 constitutes the specialty of each ; that the architect can only 

 build houses, and only a certain kind of house ; the engineer only 

 bridges, and such or such a kind of bridge ; that the poet can only 

 make verses let us suppose, further, that each of them works 

 unconsciously. These acts will certainly be regarded as instinctive, 

 and we may compare the architect to the beaver, the engineer to 

 the bee and the ant, the weaver to the spider, the carpenter to 

 the termite. The only characteristic of instinct wanting would 

 be innateness. This hypothesis exhibits the metamorphosis of 

 intellectual acts into instincts : we had only to restrict intelligence 

 within narrow limits and to deprive it of consciousness ; we had to 

 take away its suppleness and its manifold aptitudes, to impoverish, 

 and, so to speak, to prune it. 



But this is only an hypothesis which might properly enough 

 be rejected. To look more closely at the question, we take a 

 familiar fact, one known to all somnambulism. The sleep- 

 walker walks, runs, waits at table, like Gassendi's valet, writes 

 verses, copies music, composes and revises sermons, solves pro- 



