xxxiv STUDIES IN THE EVOLUTION OF ANIMALS 



but the coarse commonplace assumption, upon which every act of 

 our daily lives is based, that we may conclude from an effect 

 to the pre-existence of a cause competent to produce that effect. 



' Zadig was able to do this because he perceived endless minute 

 differences (and likenesses) where untrained eyes discern nothing ; 

 and because the unconscious logic of common sense compelled him 

 to account for these effects by the causes he knew to be competent 

 to produce them.' 



