SCIENCE AND REVOLUTION 



pervaded the entire universe ; that all forms were 

 in constant flow, and that " struggle is the father 

 of all things," thus expressing the idea of Dar- 

 win in regard to a struggle for existence. 



A little later, Empedokles developed these ideas 

 still more. In his didactic poem, he sings: 

 " Long, long ago, whether boy or girl, I may 

 have been in a flower, a bird, or a fish . . ," 

 Hate and love were to him the two active princi- 

 ples which determined the evolution of all things. 

 This is an embryonic conception of the subse- 

 quent theory of atomic interaction by attraction 

 and repulsion. And it is remarkable that Em- 

 pedokles believed in a development of all forms 

 by purposeless interaction and thus indicated the 

 problem, which Darwin solved in his " Origin of 

 Species," the problem: How can purposeful 

 forms arise mechanically without the control of 

 some universal guiding mind? 



With the victorious conclusion of the Persian 

 wars, the industries and wealth of Athens grew 

 apace. With them grew also the distinction of 

 classes and the intensity of the class struggles. 

 The small property owners, representing the prin- 

 ciples of " Democracy " (only among freemen, 

 however), opposed the aristocratic tendencies of 

 the wealthier freemen. And these struggles are 



