22 ARE THE EFFECTS OF USE INHERITED? 



and Mr. Wallace concludes that Mr. Spencer's 

 insuperable difficulty is " wholly imaginary." 



The extract concerning a somewhat similar 

 " class of difficulties," which Mr. Spencer quotes 

 from his Principles of Biology^ is faulty in its 

 reasoning, 1 though legitimate in its conclusion 

 concerning the increasing difficulty of evolution 

 in proportion with the increasing number and 

 complexity of faculties to be evolved. But this 

 increasing difficulty of complex evolution is only 

 overcome by some favourably-varying individuals 

 and species not by all. And as the difficulty 



1 Mr. Spencer weakly argues that an advantageous attribute 

 (such as swiftness, keen sight, courage, sagacity, strength, &c.) 

 cannot be increased by natural selection unless it is " of greater im- 

 portance, for the time being, than most of the other attributes" ; 

 and that natural selection cannot develop any one superiority when 

 animals are equally preserved by "other superiorities." But as 

 natural selection will simultaneously eliminate tendencies to slow- 

 ness, blindness, deafness, stupidity, &c., it must favour and improve 

 many points simultaneously, although no one of them may be of 

 greater importance than the rest. Of course the more complicated 

 the evolution the slower it will be ; but time is plentiful, and 

 the amount of elimination is correspondingly vast. 



