DIDEROT. 117 



The hypothesis of Diderot does not imply his 

 advocacy of an ' internal perfecting tendency, ' for 

 his particles do not arrange themselves in any pre- 

 determined order. It is rather a form of the Survival 

 of the Fittest theory applied, not to entire organisms, 

 but to the particles of which it is composed. Blind 

 and ceaseless trials, such as those imagined by Em- 

 pedocles, Democritus, and Lucretius, are made by 

 these particles, impelled by their rude sensibility. 

 As a sequel of many failures, finally a favourable 

 combination is formed, which persists until a recom- 

 bination is rendered necessary. 



I have met another passage by Diderot, quoted in 

 Morley's biography (II. p. 91), which Morley (not 

 knowing of Empedocles' hypothesis) speaks of as an 

 anticipation of a famous modern theory, referring of 

 course to * Natural Selection.' This is especially 

 valuable because it affords another conclusive proof 

 that the idea of the ' Survival of the Fittest ' must 

 actually be traced back to Empedocles, six centuries 

 before Christ. It is contained in an imaginary 

 dialogue upon the teleological view of Nature 

 between ' Saunderson ' and the ' Professor ' : 



" I may at least ask of you, for example, who told you you 

 and Leibnitz and Clarke and Newton that in the first instances 

 of the formation of animals, some were not without heads and 

 others without feet? I may mention . . . that all the faulty 

 combinations of matter disappeared, and that those individuals only 

 survived whose mechanism implied no important misadaptation 

 (contradiction), and who had the power of supporting and per- 

 petuating themselves." 



