V 



PREFACE be 



subject of the elective affinities is closely allied to 

 that of sexual selection. By more than one authority 

 it is questioned whether the importance of sexual 

 selection was not overrated by Darwin ; and there is 

 in fact great difficulty in explaining upon the score 

 of utility alone such variations of structure as the 

 peacock's tail, while in all species, including man, 

 the inferior types find partners without difficulty, and 

 are, upon the whole, as productive as the superior 

 ones. It would thus appear that sexual selection is 

 swallowed up in natural selection. At the same time, 

 men may be trusted to reason about their own feel- 

 ings more accurately than they can about those of 

 any other species, and the existence of sexual pre- 

 ferences in the human race will hardly be denied. 

 In connexion with a theory of psychological evolu- 

 tion, the elective affinities which are a form of mental 

 selection acquire a new and scientific importance. 



London, July 1889. 



