LIFE AND MIND 



I began by saying that there were three kinds of 

 changes in matter the physical, the chemical, and 

 the vital. But if we follow up this idea and declare 

 that there are three kinds of force also, claiming this 

 distinction for the third term of our proposition, we 

 shall be running counter to the main current of re- 

 cent biological science. "The idea that a peculiar 

 * vital force* acts in the chemistry of life," says Pro- 

 fessor Soddy, "is extinct." 



"Only chemical and physical agents influence the 

 vital processes," says Professor Czapek, of the Uni- 

 versity of Prague, "and we need no longer take 

 refuge in mysterious 'vital forces' when we want to 

 explain these." 



Tyndall was obliged to think of a force that 

 guided the molecules of matter into the special forms 

 of a tree. This force was in the ultimate particles 

 of matter. But when he came to the brain and to 

 consciousness, he said a new product appeared that 

 defies mechanical treatment. 



The attempt of the biological science of our time 

 to wipe out all distinctions between the living and 

 the non-living, solely because scientific analysis re- 

 veals no difference, is a curious and interesting phe- 

 nomenon. 



Professor Schafer, in his presidential address 



before the British Association in 1912, argued that 



all the main characteristics of living matter, such 



as assimilation and disassimilation, growth and 



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