A Century of Science 25 



Darwin. The vast treasures of theory and ex- 

 ample which he had accumulated were given to 

 the world, the notion of special creations was ex- 

 ploded, and the facts of phylogenetic evolution won 

 general acceptance. 



Under the influence of this great achievement, 

 men in every department of science began to work 

 in a more philosophical spirit. Naturalists, aban- 

 doning the mood of the stamp collectors, saw in 

 every nook and corner some fresh illustration of 

 Darwin's views. One serious obstacle to any gen- 

 eral statement of the doctrine of evolution was 

 removed. It was in 1861 that Herbert Spencer 

 began to publish such a general systematic state- 

 ment. His point of departure was the point 

 reached by Baer in 1829, the change from homo- 

 geneity to heterogeneity. The theory of evolution 

 had already received in Spencer's hands a far more 

 complete and philosophical treatment than ever 

 before, when the discovery of natural selection 

 came to supply the one feature which it lacked. 

 Spencer's thought is often more profound than 

 Darwin's, but he would be the first to admit the 

 indispensableness of natural selection to the suc- 

 cessful working-out of his own theory. 



The work of Spencer is beyond precedent for 

 comprehensiveness and depth. He began by show- 



