154 Controversial Questions. 



treatment.^ Far too little attention has been paid to the 

 relation between the range of variation of the individual 

 characters and the degree of their adaptation to changing 

 conditions of life; and the whole matter is still very much 

 of a mystery. Here again it is probable that further 

 study will tend to emphasize the fundamental distinction 

 between variability and mutability. 



§ 19. VARIABILITY IN MAN, AND SOCIAL QUESTIONS. 



A noteworthy feature of the last few decades has 

 been the attempt to apply the results of evolutionary in- 

 vestigation to the solution of the great problems of hu- 

 manity and social life. Many have followed along the 

 lines which the great English philosopher Herbert Spen- 

 cer laid down ; and a considerable mass of literature has 

 accumulated on this subject. There are at least two im- 

 portant schools in this field of research. Otto Ammon 

 is the founder of one of them: his method consisted in 

 the application of the results of statistical investigations. 

 The other, and much larger school, is that which aims at 

 the application of biological, and particularly of zoological 

 knowledge to the solution of social problems. 



Ammgn^s method seems to me to be justified by the 

 fruit it has borne; but the writings of biologists in gen- 

 eral and zoologists in particular seem to me to fall short 

 of a desirable standard of lucidity and directness.- 



Many mistakes may in the future be avoided if a clear 



distinction be drawn between mutability and variability 



in the ordinary sense. 



* See Von Rumker, Der wirthschaftliche Mehrwerth, loc cif., 

 pp. 140-141. 



^ A general account of the methods and results of this school, 

 and a bibliograph}- will be found in O. Hertwig's essay, Die Lchre 

 vom Organismus iitid Hire Beziehimg zur Sozialwissenschaft, 1899. 



