ii THE NATURE OF INSTINCT 177 



planation. Yet it is doubtful whether science, with 

 its present methods of explanation, will ever succeed in 

 analysing instinct completely. The reason is that 

 instinct and intelligence are two divergent develop 

 ments of one and the same principle, which in the one 

 case remains within itself, in the other steps out of 

 itself and becomes absorbed in the utilization of inert 

 matter. This gradual divergence testifies to a radical 

 incompatibility, and points to the fact that it is im 

 possible for intelligence to reabsorb instinct. That 

 which is instinctive in instinct cannot be expressed 

 in terms of intelligence, nor, consequently, can it be 

 analysed. 



A man born blind, who had lived among others 

 born blind, could not be made to believe in the 

 possibility of perceiving a distant object without first 

 perceiving all the objects in between. Yet vision 

 performs this miracle. In a certain sense the blind 

 man is right, since vision, having its origin in the 

 stimulation of the retina by the vibrations of the light, 

 is nothing else, in fact, but a retinal touch. Such is 

 indeed the scientific explanation, for the function of 

 science is just to express all perceptions in terms of 

 touch. But we have shown elsewhere that the philo 

 sophical explanation of perception (if it may still be 

 called an explanation) must be of another kind. 1 Now 

 instinct also is a knowledge at a distance. It has the 

 same relation to intelligence that vision has to touch. 

 Science cannot do otherwise than express it in terms of 

 intelligence ; but in so doing it constructs an imitation 

 of instinct rather than penetrates within it. 



Any one can convince himself of this by studying 

 the ingenious theories of evolutionist biology. They 



1 Mature et m/moire, chap. i. 



