xxi EVOLUTION OF EVOLUTION THEORIES 421 



and outside the guild of those who dexterously wield the 

 razor, and in so doing observe the horoscope of the 

 organism. Of protoplasm, in regard to which modern 

 biology says so much and knows so little, he was not 

 ignorant, for did he not study the marvels of the state 

 known as " aggregation " ? 



But it is not for special research that men are most 

 grateful to Darwin. Undoubtedly, if clear insight into 

 the world around us be esteemed in itself of value, the 

 author of Insectivorous Plants, The Fertilisation oj Orchids, 

 The Movements oj Plants, The Origin oj Coral Reefs, The 

 Formation oj Vegetable Mould, etc., runs no risk of being 

 forgotten. But though our possession of these results 

 swells the meed of praise, we usually regard them as 

 outside of Darwin's real work, which, as every one knows, 

 was his contribution to the theory of organic life. 



This contribution was threefold (a) He placed the 

 theory of descent on a sure basis ; (b) he shed the light 

 of this doctrine on various groups of phenomena ; and (c) 

 he tackled the problem of the factors in evolution. 



(a) The man who makes us believe a fact is to us 

 more important than the original discoverer. And so 

 Darwin gets credit for inventing the theory of descent, 

 which in principle is as old as clear thought itself, and in 

 its biological application was stated a hundred years 

 before the publication of the Origin oj Species (1859). 

 The conception was no new one, but Darwin first made 

 men believe it. The idea was not his, but he gave it to 

 many. He did not originate ; he established. He 

 converted naturalists to an evolutionary conception of 

 the organic world. 



(b) Having got people to believe the theory of descent, 

 the theory of development out of preceding conditions,- 

 Darwin went on to show how the conception would 

 illumine all facts to which it was applicable. In his 

 work on the expression of emotions, and in scattered 

 chapters, he showed how the light might be shed upon the 

 secrets of mental activity. Whenever it was seen that 

 the doctrine could justify itself in regard to general organic 

 life, it was eagerly seized as an organon for the explora- 



