HEREDITY AND "PHYSICAL DEGENERATION" 101 



factors, but upon psychical, sociol()<,ncal, super-orf^unic 

 factors. The decliue of nations is not a theme tor 

 the biologist, the student of heredity, hut f(jr the 

 sociologist and the moralist. iUit it is highly 

 necessary for the student of heredity to atlirm, and 

 again and again to affirm, that Ice knows no cause 

 whatever why nations should decay. His study 

 throws no light on the phenomenon, or, rather, it 

 does throw a light upon it by demonstrating that 

 there are no facts or factors of heredity that exphiin 

 it. Hence when the moralist seeks to exphun the 

 causes of national decay he is justitied in his preach- 

 ing by the positive assertion of the biologist that 

 there are no physical facts which explain such de- 

 cadence, and should the historian seek to save 

 himself the trouble of finding the true explanation, 

 and hint that the decay of nations is due to some 

 obscure laws of heredity as yet unclucidated, his 

 listeners must be warned that the student of 

 heredity will countenance no such explanation. In 

 the organic world success makes for more success ; 

 it is not to the facts of the germ-phism, but to the 

 facts of mind and morals, that we must attribute 

 the decline and fall of any empire or nation. Thus 

 a nation may be tottering to its fall, whilst its 

 stalwart sons — " superb specimens of physical man- 

 hood" — are breaking all athletic records. 



One important point remains to bo considered — 

 the alleged cessation of selection. If selection has 

 ceased, then the a priori objection to the belief 

 in a progressive physical degeneration is disp(.).sed 

 of. If there is no selection, plainly, the unLit 



