190 THE LAW OF BIRTHS AND DEATHS 



So stupendous economic problems have to be grappled 

 with in the near future. 



But let us assume that the power to secure fertilisation 

 at will is achieved, and that the economic problems 

 involved can also be successfully dealt with. It will then 

 be necessary to classify the population according to ability. 

 From the class of highest all-round efficiency, both mental 

 and physical, we should desire the largest proportion of 

 children ; from the class next in order of efficiency a 

 smaller proportion ; and so on in a diminishing proportion 

 until we reach the unfit, from whom we should desire as 

 few children as possible. There would be no need for a 

 stud farm system or a special selection for special points. 

 The only selection needed would be for general efficiency, 

 and Nature could then be left to design her own superman. 

 But to obtain these results it would be necessary to 

 approach each married couple individually for a given 

 number of children at carefully regulated intervals, and 

 assent would only be obtained if the necessary economic 

 guarantees could be given. These conditions being granted, 

 there would be little fear of a refusal in the vast 

 majority of cases in a healthily organised society. Public 

 opinion is a powerful force, selection to assist in the con- 

 tinuation of the race would be one of the highest compli- 

 ments Society could bestow, and a clear realisation of 

 all the bearings of the problem would do the rest. 



The hypotheses which have been worked out may be 

 briefly summarised. They are : 



(1) That the decline in the birthrate is mainly due 

 to a natural law which adjusts the degree of fertility 

 to suit the deathrate of the race. 



(2) That the variation in the degree of animal 

 fertility in response to the direct action of the environ- 



