74 THE FAiMILY AND THE NATION 



person and of character are equally necessary for the 

 perfection of mankind. We may hope in future that 

 such qualities will appear in pedigrees alongside the 

 more showy honours which come to him who possesses 

 and knows how to use ability of intellect. 



All these desirable qualities are, from the point of 

 view of heredity, essentially different from some of the 

 bad qualities hitherto considered, in that they depend 

 on the conjunction of a great many factors. Such a 

 conjunction must be very hard to trace in the hereditary 

 process, where possibly each character may descend 

 independently, or different characters may be linked 

 together, or be incompatible, in far more complicated 

 ways than we have traced in the qualities of plants and 

 animals. Our present knowledge is quite insufficient 

 to enable us to predict how a complex combination of 

 factors making up the personality of an able or charm- 

 ing man or woman will reappear in their offspring. 

 We can but follow empirical lines of inquiry, and reach 

 certain general conclusions to be discussed later. 



Many undesirable qualities tendencies to disease, 

 insanity, feeble -mindedness, deformity depend on 

 the inheritance of some one definite pathological 

 condition, which can be traced, as we have seen, from 

 generation to generation, sometimes in accord with 

 regular Mendelian principles. Here our knowledge is 

 surer, and a much safer guide. We know that a certain 

 proportion of the children of unsound parents will 

 possess the unsoundness. We can calculate the effect 

 on the race of allowing numbers of such parents to 

 marry. 



But, notwithstanding the complication of the pro- 



