442 HEREDITY AND ENVIRONMENT 



But granting the impossibility of predicting 

 the character of children it may well be asked 

 if good general advice may not be given re- 

 garding the choosing of a mate. Many people 

 have thought so, and if all that has been said 

 or written on this subject were to be gathered 

 together I suppose that there would not or 

 should not be room for it in all the libraries of 

 the world. It is generally admitted that few 

 lines are wholly free from hereditary defects 

 and the question has often been asked what 

 the eugenical practice should be in such cases. 

 Of course people with really serious hereditary 

 defects should not have children. If the de- 

 fects are slight Davenport has suggested that 

 they may be either disregarded or weakness 

 in any character may be mated with strength 

 in that character. That people with only slight 

 hereditary defects should not marry at all is a 

 counsel of perfection. 



On the other hand it would be a dangerous 

 rule to propose that persons having really 

 serious hereditary defects should be mated 

 with those who are strong in those characters 

 on the ground that in general strength in a 



