Mechanism, Vitalism, and Teleology 361 



too narrowly limited to those of human invention. The liv- 

 ing machine is not a single one, as is an engine or a watch, 

 but it'is composed of machines within machines. Every liv- 

 ing body is composed of cells within which are nuclei. The 

 visible differentiations of a body are developed from the 

 portion of the cell outside of the nucleus, but always under 

 the influence 'of the nucleus. The nucleus itself rarely under- 

 goes differentiation, so that there is in every such nucleus 

 a complete machine which under certain conditions may be 

 capable of developing a complete organism, as in the case 

 of development from an egg cell. If this nuclear machine 

 is fragmented or destroyed no regeneration is possible. 

 Therefore the machine-theory of organization does not 

 fail in this case; only Driesch's conception of the vital ma- 

 chine fails because the real organism is more complex than 

 he supposed. 



But even granting Driesch's claims that organisms are 

 equipotential systems capable of complete regeneration 

 after injury, that they differ greatly from machines of 

 human invention, and that they generally respond benefi- 

 cially to stimuli, it does not follow that they are in any 

 respect removed from the field of mechanistic causality. 



In the works of Bergson, Driesch, Thomson and other 

 "neo-vitalists" hundreds of pages are devoted to labored 

 refutations of mechanistic explanations of life and to elo- 

 quent presentations of mystical, allegorical, and unintelli- 

 gible causes. In a notable contribution by Jennings 1 the 

 ground is cleared of mere verbiage and the solid founda- 

 tions of a mechanistic conception of life are laid in eighteen 

 pages. Jennings shows that diversities in life phenomena 

 are accompanied or preceded by diversities in materials, 

 functions, and structures, and that they are not indeter- 



1(< Life and Matter." Johns Hopkins Univ. Circ., 1914. 



