INFLUENCE OF ENVIRONMENT 303 



so great an influence on the origin of species 

 or even of life itself much more could it affect 

 the process of development of the individual. 

 It is still popularly supposed that complexion 

 is dependent upon the intensity of light, and 

 stature upon the quantity and quality of food, 

 that sex is determined by food or temperature, 

 mentality by education, and that in general 

 individual peculiarities are due to environ- 

 mental differences. 



Many philosophers of the seventeenth and 

 eighteenth centuries taught that man was the 

 product of environment and education and that 

 all men were born equal and later became un- 

 equal through unequal opportunities. Des- 

 cartes begins his famous "Discourse on 

 Method" with these words: 



"Good sense is, of all things among men, the most 

 equally distributed . . . The diversity of our opin- 

 ions does not arise from some being endowed with a 

 larger share of Reason than others, but solely from 

 this, that we conduct our thoughts along different 

 ways, and do not fix our attention on the same 

 objects." 



The Declaration of Independence merely re- 

 flected the spirit of the age in which it was 



