u.i ADAPTATION AND PROGRESS 101 



embryonic state, can no longer abide together when they 

 grow stronger. If one could speak, otherwise than meta- 

 phorically, of an impulse toward social life, it might be said 

 that the brunt of the impulse was borne along the line of 

 evolution ending at man, and that the rest of it was col- 

 lected on the road leading to the hymenoptera: the so- 

 cieties of ants and bees would thus present the aspect 

 complementary to ours. But this would be only a manner 

 of expression. There has been no particular impulse 

 towards social life; there is simply the general movement 

 of life, which on divergent lines is creating forms ever new. 

 If societies should appear on two of these lines, they ought 

 to show divergence of paths at the same time as community 

 of impetus. They will thus develop two classes of char- 

 acteristics which we shall find vaguely complementary 

 of each other. 



So our study of the evolution movement will have to 

 unravel a certain number of divergent directions, and to 

 appreciate the importance of what has happened along 

 each of them — in a word, to determine the nature of the 

 dissociated tendencies and estimate their relative pro- 

 portion. Combining these tendencies, then, we shall get 

 an approximation, or rather an imitation, of the indivisible 

 motor principle whence their impetus proceeds. Evo- 

 lution will thus prove to be something entirely different 

 from a series of adaptations to circumstances, as mechan- 

 ism claims; entirely different also from the realization of a 

 plan of the whole, as maintained by the doctrine of finality. 



That adaptation to environment is the necessary con- 

 dition of evolution we do not question for a moment. 

 It is quite evident that a species would disappear, should 

 it fail to bend to the conditions of existence which are im- 

 posed on it. But it is one thing to recognize that outer 



