174 MARRIAGE AND HEREDITY 



is not regarded as theft. "Writers who condemn 

 marriage as an institution might with equal justice 

 attack the law of property. Both are conventional ; 

 both have been developed with a view to general 

 convenience, whatever hardship they may inflict 

 upon individuals. What we are now elucidating are 

 certain aspects of the natural law, of which marriage 

 is a conventional regulation. 



That physical attractiveness in the parents is 

 advantageous to the offspring admits of no doubt ; 

 and moral attractiveness, elective affinity, sympathy, 

 or whatever we may call the ineffable sentiment that 

 blends two natures into one, is plainly intended to 

 fulfil a similar purpose. The evidence upon this 

 point, it is true, is a little vague, chiefly because the 

 experiment and observation from which it is derived 

 have necessarily been limited. But as far as it goes 

 it tells in favour of the theory which a sense of the 

 perfection and completeness of Nature's plan suggests. 

 Burdacli confidently declares that love unions are 

 more beneficial to the species than others.^ He 

 admits that illegitimate children do not exhibit any 

 superiority as a rule. This is, however, to be ac- 

 counted for by the greater anxiety, and even hardship, 

 * Burdach's Traitd de Physiologie (tvauslated from the German). 



