204 EVOLUTION 



the most superficial details of physiological 

 activity it becomes unsatisfactory; and it 

 breaks down completely when applied to 

 fundamental physiological problems, such as 

 that of reproduction." 



THEORIES OF VITALISM. A constructive 

 and comprehensive endeavour to formulate 

 a doctrine of vitalism is that of Dr. Hans 

 Driesch's recent Aberdeen Gifford Lectures, 

 in which the author, working from his stand- 

 point as an experimental embryologist, ad- 

 vances technical proofs of the " autonomy 

 of life," and of its specific distinctiveness 

 from the not-living. He advances an elabor- 

 ate threefold argument to show how the 

 interpretation of a living creature as a 

 machine breaks down, both in regard to its 

 functioning and its development; and he 

 seeks to show that it is necessary to postulate 

 an immaterial autonomous factor, or " en- 

 telechy " which punctuates the transforma- 

 tions of energy that go on within the body. 

 This " entelechy " is the living creature's 

 innermost secret, in fact its directive soul. 



Another clear and comprehensive exposi- 

 tion of a theory of Vitalism will be found in 

 Bergson's " Creative Evolution." Bergson 

 dwells on the close resemblance between the 

 life of the organism and our own personal 



