66 PERIOD III. 



pervades the whole animal kingfdom — a belief that he 

 could never have adequatel}^ supported by facts ; Baer 

 long afterwards (1828) searched in vain for evidence on 

 this very point, while Darwin in 1859 admitted that his 

 arguments and facts only proved common descent for 

 each separate phylum of the animal kingdom ;^ he 

 inferred from analogy that probably all the organic 

 beings which have ever lived on this earth have 

 descended from some one primordial form.^ Elsewhere 

 Buffon makes bold to declare that Nature in her youthful 

 vigour threw off a number of experimental forms of life, 

 some of which were approved and adopted, while others 

 were allowed to survive in order to give mankind a wider 

 conception of her projects. There is generally some 

 gleam of truth in Buffon's most fantastic speculations, but 

 we often wish that he could have attended to the warning 

 of Bossuet : " Le plus grand dereglement de I'esprit est 

 de croire les choses parce qu'on veut qu'elles soient." 



Against all his shortcomings we must set the fact 

 that Buffon strove to interpret the present by the 

 past, the past by the present, geology by astronomy, 

 geographical distribution by the physical history of the 

 continents. One of his maxims expresses the funda- 

 mental thought of Lyell's Principles of Geology : " Pour 

 juger de ce qui est arrive, et meme de ce qui arrivera, 

 nous n'avons qu'^ examiner ce qui arrive." 



Hard-and-fast distinctions are the marks of imperfect 

 theory. Early philosophers distinguished hot and cold, 

 wet and dry, light and dark, male and female, as things 

 different in kind. In later times organic and inorganic, 

 animal and vegetable, the activities of matter and the 

 activities of mind, have been sharply separated. But as 



\ 



* Life and Letters, Vol. II., p. 212. 

 "^ Origin of Species, ed. i., p. 484. 



