THE ORIGIN OF LIFE. 33 



engineer, but with a broken machine which cannot 

 be mended. Life is thus only an abstraction from 

 the properties of living things, just as aquosity would 

 be an abstraction from the properties of water. 



This mechanical theory of life is not at present 

 open to direct argument. The dynamics of proto- 

 plasm may be studied carefully ; it may perhaps be 

 shown that all the activities of protoplasm are easily 

 explained as the result of chemical and physical 

 forces. Already scientists are beginning to compre- 

 hend how the movements of protoplasm, which have 

 proved so puzzling, are intelligible as the results of 

 chemical change, whereby the density of the sub- 

 stance is altered, and consequently its shape. In- 

 deed appearances seem to indicate that perhaps all 

 the activities of protoplasm may be explained thus 

 easily. But all of this fails to reach the real ques- 

 tion at issue, which asks for the directive cause of 

 these changes. The only direct argument would 

 be to manufacture protoplasm and have it begin to 

 assimilate food, or to show in some other way that 

 a purely automatic machine is a possibility, which 

 shall, as organisms do, supply itself with its own con- 

 ditions of activity. Until this is done the mechani- 

 cal theory can only be an inference from the general 

 tendency of scientific advance. 



The Origin of Life. 



It is very plain that our verdict in regard to the 

 origin of life in the world will depend largely upon 

 what position we assume on the question just dis- 

 cussed. If we assume that life is a distinct force 

 3 



