92 Heredity and Social Progress 



accompaniment of each mental phenomenon. 

 Have not memory, will, sensation, and other 

 psychic contrasts a physical background, and 

 are they not at bottom distinct or similar only 

 so far as they have the same or different physi- 

 cal antecedents ? Psychic effects cannot be 

 more complex than their physical causes. 

 When, therefore, we know the deeds the body 

 can do, we know the psychic variety the mind 

 can manifest. Any greater complexity is not 

 real but apparent. 



In the simplest form of life, the surplus 

 energy due to assimilation creates more cells 

 and greater complexity of form. This natural 

 growth is bilateral, and action due to sur- 

 plus energy is rhythmic. There is a rising 

 tide of activity on one side when there is 

 a falling tide on the other. The conscious 

 effect of the latter is memory, and that of the 

 former is will. There are not in structure a 

 storehouse for memories and a distinct mech- 

 anism to start bodily movements. When we 

 see the antecedents of a movement and not 

 its consequents, we call them will ; when we 

 are conscious of the consequents and not of 



