448 HEREDITY AND ENVIRONMENT 



of our personalities were born with us and can- 

 not be changed except within relatively nar- 

 row limits. "The leopard cannot change his 

 spots nor the Ethiopian his skin," and "though 

 thou shouldst bray a fool in a mortar with a 

 pestle yet will not his foolishness depart from 

 him." Race, sex, mental capacity are de- 

 termined in the germ cells, perhaps in the 

 chromosomes, and all the possibilities of our 

 lives were there fixed, for who by taking 

 thought can add one chromosome, or even one 

 determiner to his organization? 



/The thought of this age has been pro- 

 foundly influenced by such considerations. 

 We formerly heard that "all men were created 

 free and equal"; we now learn that "all men 

 are created bound and unequal." We were 

 once taught that acts, if oft repeated, become 

 habits, and that habits determine character; 

 hereditarians of the stricter sort now teach that 

 acts, habits and character were foreordained 

 from the foundation of the family. We once 

 thought that men were free to do right and 

 wrong, and that they were responsible for 

 their deeds; now we learn that our reactions 



