IV. 



EXHAUSTIVENESS. TIME GIVEN TO INVESTI- 

 GATIONS. TREATMENT OF OBJECTIONS. 



THE theories with which Darwin dealt were 

 so general, and the facts that had to be 

 handled as evidence were so vast in number, 

 that probably no man was ever exposed to 

 greater temptation to collect his evidence pro- 

 miscuously from all quarters, picking up in 

 each field what was already known, and sup- 

 plementing it by a few test observations. But 

 he never contented himself with sketching 

 theories and adorning them with dashes of 

 evidence. 



He made himself invincible by the exhaust- 

 iveness with which he determined the quality 

 of his evidence. The great confidence which \ 

 scientific men have had in him has been due | 

 to the fact that he did not leave it to them to . , 

 test the theories which he presented. He con- 

 vinced the world of the truth of a doctrine 

 which others had striven in vain for fifty years 

 to establish. To my mind one of the chief 



