THE LAW OF SUBSTANCE. 237 



Not only the growth and the nutrition of plants and 

 animals, but even their functions of sensation and 

 movement, their sense-action and psychic life, depend 

 on the conversion of potential into kinetic energy, and 

 vice versa. This supreme law dominates also those 

 elaborate performances of the nervous system which 

 we call, in the higher animals and man, "the action 

 of the mind." 



Our monistic view, that the great cosmic law 

 applies throughout the whole of nature, is of the 

 highest moment. For it not only involves, on its 

 positive side, the essential unity of the cosmos and 

 the causal connection of all phenomena that come 

 within our cognizance, but it also, in a negative way, 

 marks the highest intellectual progress, in that it 

 definitely rules out the three central dogmas of meta- 

 physics — God, freedom, and immortality. In assigning 

 mechanical causes to phenomena everywhere, the law 

 of substance comes into line with the universal law of 

 causality. 



