450 Evolution and Modern Fhilosoj^hy 



concerning the evolution of species ; the idea of species would in his 

 eyes absolutely lose its importance if a transition from species to 

 species under the influence of conditions of life were admitted. His 

 disciples (Littr^ Robin) continued to direct against Darwin the 

 polemics which their master had employed against Lamarck. Stuart 

 Mill, who, in the theory of knowledge, represented the empirical or 

 positivistic movement in philosophy — like liis English forerunners 

 from Locke to Hume — founded his theory of knowledge and morals 

 on the experience of the single individual. He sympathised with the 

 theory of the original likeness of all individuals and derived their 

 diflferences, on which he practically and theoretically laid much stress, 

 from the influence both of experience and education, and, generally, 

 of physical and social causes. He admitted an individual evolution, 

 and, in the human species, an evolution based on social progress ; 

 but no physiological evolution of species. He was afraid that the 

 hypothesis of heredity would carry us back to the old theory of 

 "innate" ideas. 



Darwin was more empirical than Comte and Mill ; experience 

 disclosed to him a deeper continuity than they could find ; closer 

 than before the nature and fate of the single individual were shown 

 to be interwoven in the great web binding the life of the species with 

 nature as a whole. And the continuity which so many idealistic 

 philosophers could find only in the world of thought, he showed to 

 be present in the world of reality. 



m, 



Darwin's energetic renewal of the old idea of evolution had its 

 chief importance in strengthening the conviction of this real con- 

 tinuity in the world, of continuity in the series of form and events. 

 It was a great support for all those who were prepared to base their 

 conception of life on scientific grounds. Together with the recently 

 discovered law of the conservation of energy, it helped to produce 

 the great realistic movement which characterises the last third of 

 the nineteenth century. After the decline of the Romantic movement 

 people wished to have firmer ground under their feet and reality now 

 asserted itself in a more emphatic manner than in the period of 

 Romanticism. It was easy for Hegel to proclaim that "the real" 

 was " the rational," and that " the rational " was " the real " : reality 

 itself existed for him only in the interpretation of ideal reason, and 

 if there was anything which could not be merged in the higher unity 

 of thought, then it was only an example of the " impotence of nature 

 to hold to the idea." But now concepts are to be founded on nature 

 and not on any system of categories too confidently deduced djmorl 



