12 THE FAMILY AND THE NATION 



the divine, fit habitations in which they can expand 

 and develop till they are worthy of a sublimer sphere. 

 We cannot fix exactly the bodily or mental character 

 of any future individual, but we can (and do whether 

 we will or no) control the average future qualities 

 of the race, both in mind and body. Individually we 

 can deal only with probabilities ; statistically we are 

 responsible for certainties. 



Let us pass then to inquire how far selection, 

 natural or artificial, has been the means of developing 

 the race, how far it is still acting and in what direc- 

 tions, what will be the effect of that action, and 

 whether it can be controlled in any way to favour the 

 preponderance of all the best physical, mental, and 

 moral qualities. 



For selection to play its part in any community, 

 three conditions are necessary. Firstly, the individuals 

 which compose the race must vary one from the other. 

 Secondly, those variations must tend to be inherited, so 

 that the individuals possessing them tend to transmit 

 them to their offspring. Thirdly, the individuals with 

 certain kinds of variation must reproduce themselves 

 faster than the rest of the community. 



Unless individuals vary, selection has nothing to 

 work upon. Unless the variations be such that they 

 are transmitted to descendants, its work produces no 

 effect. Hence our first inquiry is directed to the laws 

 of variation in mankind, in regard both to physical and 

 to mental qualities ; our second to the transmission of 

 variations from parent to offspring — the central problem 

 of heredity. 



