110 ORGANISM AND ENVIRONMENT 



chemistry — an attempt which, in view of the facts of 

 physiology can only end in certain failure. They 

 assume as self-evident, for instance, that what they 

 are dealing with is "living matter." In reality these 

 two words contradict one another. What we interpret 

 as being in the sense ordinarily current, "matter," 

 cannot be also interpreted as living. 



Why has physiology failed to free herself from this 

 misunderstanding? The fact of organic regulation 

 has been evident enough from early times, and, except 

 in more or less recent text-books, has received promi- 

 nent attention from physiological writers. Various 

 causes have, I think, contributed, and I should like now 

 to refer to one which is specially prominent. 



The physiologists who laid most stress on organic 

 regulation adopted the theory known as Vitalism — 

 a theory which, though unorthodox, is still very much 

 alive, and of which the eminent experimental embryol- 

 ogist, Hans Driesch, is probably the best-known living 

 representative. The vitalistic theory is that although 

 matter and energy are, whether outside or inside of the 

 body, just what current physical and chemical con- 

 ceptions describe them as, yet in the living body they 

 are guided by what older physiologists called the "vital 

 spirit," "vital force," or "vital principle," and what 

 Driesch 1 calls "entelechy." As is well known, Driesch 

 discovered the fact that if the constituent cells of an 

 embryo in its earliest stages of development are dis- 



x The clearest and shortest exposition of Driesch's argu- 

 ment is, I think, contained in his recent book, The Problem 

 of Individuality, London, 1914. 



