150 CREATIVE EVOLUTION CHAP. 



instinct than instinct has of intelligence ; for the power 

 to give shape to crude matter involves already a superior 

 degree of organization, a degree to which the animal 

 could not have risen, save on the wings of instinct. So, 

 while nature has frankly evolved in the direction of 

 instinct in the arthropods, we observe in almost all the 

 vertebrates the striving after rather than the expansion 

 of intelligence. It is instinct still which forms the basis 

 of their psychical activity ; but intelligence is there, and 

 would fain supersede it. Intelligence does not yet 

 succeed in inventing instruments ; but at least it tries to, 

 by performing as many variations as possible on the 

 instinct which it would like to dispense with. It gains 

 complete self-possession only in man, and this triumph 

 is attested by the very insufficiency of the natural means 

 at man s disposal for defence against his enemies, against 

 cold and hunger. This insufficiency, when we strive to 

 fathom its significance, acquires the value of a pre 

 historic document ; it is the final leave-taking between 

 intelligence and instinct. But it is no less true that 

 nature must have hesitated between two modes of 

 psychical activity one assured of immediate success, 

 but limited in its effects ; the other hazardous, but 

 whose conquests, if it should reach independence, 

 might be extended indefinitely. Here again, then, the 

 greatest success was achieved on the side of the greatest 

 risk. Instinct and intelligence therefore represent two 

 divergent solutions, equally fitting^ of one and the same 

 problem. 



There ensue, it is true, profound differences of 

 internal structure between instinct and intelligence. 

 We shall dwell only on those that concern our present 

 study. Let us say, then, that instinct and intelligence 

 imply two radically different kinds of knowledge. But 



