70 Heredity and Instinct 



actions of a creature which are useful to him will survive 

 in the species ; for in so far as he imitates actions which 

 are injurious, he will aid natural selection in killing himself 

 off. So intelligence, and the imitation which copies it, 

 will set the direction of the development of the complex 

 instincts even on the Darwinian theory ; and in this sense 

 we may say that consciousness is a 'factor' without resort- 

 ing to the vague postulates of * self-adaptation,' ' growth- 

 force,' ' will-effort,' etc., which have become so common of 

 late among the advocates of the new vitalism. 



2. The same consideration may give the reason in part 

 that instincts are so often coterminous with the limits of 

 species. Similar creatures find similar uses for their 

 intelligence, and they also find the same imitative actions 

 to be to their advantage. So the interaction of these 

 conscious factors with natural selection brings it about 

 that the structural definition which characterizes species, 

 and the functional definition which characterizes instinct, 

 largely keep to the same lines. 



