338 Heredity and Environment 



philosophy. Is it not a fact that the possibilities of our inheritance 

 depend for their realization upon development, one of the most 

 important factors of which is use, functional activity in response 

 to stimuli? Is it not a fact that in many animals behavior is 

 modifiable and that impulses may be inhibited and controlled ? Is 

 it not a fact that experience, intelligence, will are factors in hu- 

 man behavior and that by means of these men are often able to 

 choose between alternatives and so to control their own activi- 

 ties as well as external phenomena? Is it not a fact that our ca- 

 pacities are very much greater than our habitual demands upon 

 them? Is it not a fact that belief in our responsibility energizes 

 our lives and gives vigor to our mental and moral fiber? Is it not 

 a fact that shifting all responsibility from men to their heredity 

 or to that part of their environment which is beyond their con- 

 trol helps to make them irresponsible? 



This debilitating philosophy in which everything is predeter- 

 mined, in which there is no possibility of change or control, in 

 which there is hypertrophy of intellect and atrophy of will, is a 

 symptom of senility whether in men or nations. We need to re- 

 turn to the joys of a childhood age in which men believed them- 

 selves free to do, to think, to strive, in which life was full of 

 high endeavor and the world was crowded with great emprise. 

 We need to think of the possibilities of development as well as of 

 the limitations of heredity. Chance, heredity, environment have 

 settled many things for us; we are hedged about by bounds 

 which we cannot pass, but those bounds are not so narrow as we 

 are sometimes taught and within them we have a considerable 

 degree of freedom and responsibility. 



"That which we are we are, 

 One equal temper of heroic hearts 

 Made weak by time and fate, but strong in will 

 To strive, to seek, to find, and not to yield." 



