CHAPTER XXXIII 



MECHANISM AND VITALISM 



Myself when young did eagerly frequent 

 Doctor and Saint and heard great argument 



About it and about; but evermore 

 Came out by the same door wherein I went. 



— Omar Khayyam. 



In the previous pages an attempt has been made to explain as 

 many as possible of the life processes in the known terms of phys- 

 ics and chemistry. The question must have thus arisen in the 

 reader's mind whether life is anything more than physics and 

 chemistry. This brings us back for our last chapter to the dis- 

 cussion of questions of philosophy, which, we must remember, 

 is after all the mother of science. 



The Problem. — The question at issue is fairly clear-cut. The 

 vitalists hold that life is more than mechanics and that there is 

 a distinct gap between the organic and the inorganic worlds. 

 This doctrine is known as vitalism. The mechanists, on the other 

 hand, believe that all life phenomena may be explained by the 

 physical and chemical constitution of living matter. This doc- 

 trine, known as mechanism, has been summed up by Pearl in his 

 own statement of faith as follows: "Living things, whether single- 

 celled or many-celled organisms, are essentially only physico- 

 chemical machines of extraordinary complexity, but regardless 

 of their degree of complexity only amenable to and activated in 

 accordance with, physical and chemical laws and principles. " 

 The question stated briefly remains: Is life more than physics 

 and chemistry? The vitalists maintain that it is and the mecha- 

 nists that it is not. 



From the beginning, the vitalists have been asked by the mech- 

 anists to describe or name some characteristic possessed by living 

 things which was not equally the attribute of the inorganic or 

 nonliving world. Up until 1828, it was thought that only organ- 

 isms could make the compounds so characteristic of organic 

 matter. In that year Wohler synthesized urea, a distinctly ani- 

 mal product, and from that day to this, the synthesis of organic 



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