302 ELEMENTS OF GENERAL SCIENCE 



from the product. What are we doing to make sure that the 

 next generation of men and women shall be physically, intel- 

 lectually, and morally as effective as the laws of heredity will 

 enable us to make them ? 



328. Controlling human environment. No one of us can now 

 determine what our own heredity shall be. That has been 

 settled for us. We can decide, in a measure, what shall be the 

 heredity of those to come after us. We can do much toward 

 changing our environment so that defects in our own heredity 

 may not lead to results so undesirable as might otherwise be. 



A weakened body may often be strengthened by judicious 

 care and exercise, so that a hereditary weakness may be almost 

 or entirely overcome. We can curb a hereditary tendency until 

 it is almost or quite inoperative. We can create for ourselves 

 new and artificial environments which shall enable us to turn 

 a harmful or worthless hereditary tendency into efficiency and a 

 high type of usef ulness. It is a heavy task to stem the tide of na- 

 ture, and he who would do it must prepare for an effort in which 

 some have failed and some have succeeded. It is worth the 

 effort, for what is better than to turn weakness into efficiency ? 



