COSMIC PHILOSOPHY 



lection. Mr. Mivart habitually thus alludes to 

 him. In fact, however, Mr. Darwin^s merits 

 are twofold. He was the first to marshal the 

 arguments from classification, embryology, mor- 

 phology, and distribution, and thus fairly to 

 establish the fact that there has been a deriva- 

 tion of higher forms from lower ; and he was 

 also the first to point out the modus operandi of 

 the change. The first of these achievements by 

 itself would have entitled him to associate his 

 name with the development theory ; though it 

 was only by the second that the triumph of the 

 theory was practically assured. Just as, in as- 

 tronomy, the heliocentric theory was not re- 

 garded as completely established until the forces 

 which it postulated were explained as identical 

 with forces already known, so the development 

 theory possessed comparatively little value as a 

 working hypothesis so long as it still remained 

 doubtful whether there were any known or 

 knowable causes sufficient to have brought about 

 the phenomena which that theory assumed to 

 have taken place. It was by pointing out ade- 

 quate causes of organic evolution that Mr. Dar- 

 win established the development theory upon 

 a thoroughly scientific basis. 



As Lyell explained all past geologic phe- 

 nomena as due to the slow action of the same 

 forces which are still in action over the earth*s 

 surface and beneath its crust, so Mr. Darwin, 



lO 



