THE SCIENCE OF HAPPINESS 



given new significance, certain ones being developed 

 under a fostering environment till they preponderate 

 as they had never done in a previous generation ; other 

 tendencies being, of course, proportionately pushed 

 into the background. 



Manifestly, then, this new factor of environment is a 

 force to be reckoned with. It is the variable quantity 

 which is introduced into the personal equation of every 

 creature, to be considered along with the fixed quantity, 

 hereditary tendencies. And as this variable can never 

 be exactly the same for any two organisms in the world, 

 it follows that no two personalities can ever be identical. 

 Thus it appears that the diversity of individuals and of 

 races, which is the observed condition of organic nature, 

 has come to pass primarily through environment, not 

 through heredity. 



Now it is manifest why it does make a difference 

 whether one has six or eight ancestors of the third 

 generation, for the two additional ancestors would have 

 brought certain tendencies that had been developed by 

 the specific environment of their particular lines of 

 recent ancestors, which must necessarily have varied 

 somewhat from the tendencies of each of the other 

 ancestors of that or any other generation. The remote 

 or fundamental tendencies, inherited from the common 

 ancestry far removed, would have been the same in all; 

 the points of difference pertain to certain less funda- 

 mental, but scarcely less important, lines of special 

 development. 



And these additional tendencies, as we have seen, 

 are not to be set down to the credit of heredity, but to 



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