130 Heredity and Social Progress 



to their power of resistance against it, and to 

 their developing force acting on other persons, 

 or on external conditions. 



To determine the truth of this distinction 

 we must start from the economic conditions 

 upon which life depends. An economic sur- 

 plus is followed, first, by organic growth and 

 then by emotional changes that disturb present 

 adjustment, and force an entrance into a new 

 environment where the new characters find a 

 field of activity, and bring about a new adjust- 

 ment. But an economic deficit blocks the first 

 step in this series of changes. It not only pre- 

 vents the formation of new tissues and organs, 

 but it hardens those already in use and con- 

 fines the flow of nervous currents to increas- 

 ingly definite channels ; it therefore aids in the 

 formation of acquired characters which help the 

 individual in his own adjustment to present 

 conditions, but are not inherited by his de- 

 scendants. A deficit does not develop new 

 natural characters ; it can become a cause 

 of progress only by conscious means, and 

 through agencies which must be evoked anew 

 in each generation. With it is handed down, 



