CHAPTER I 



VARIOUS THEORIES OF THE ORGANISM 

 NEO-VITALISTIC THEORY 



To the primitive man all the phenomena of nature were de- 

 termined and controlled by some agent or agents essentially similar 

 to himself, but as his knowledge of the world increased, the con- 

 trast between living and non-living things forced itself upon him 

 and the idea of a special vital principle of some sort arose. In the 

 mind of different thinkers this principle has taken various forms, 

 and the attempt has been made again and again in the history of 

 thought to show that some such principle is absolutely indispen- 

 sable for any adequate conception of life. A century ago the idea 

 of vital force dominated biological thought. 



Within recent years the same idea has reappeared in a somewhat 

 changed though not essentially different form. Particularly in 

 Germany a group of investigators has arisen who believe that they 

 have found new evidence in the facts of experimental biology for 

 the existence of a vital principle. The chief exponent of these ideas 

 is Driesch ('08) who has developed the Aristotelian idea of entele- 

 chies in a somewhat modified form. The entelechy is something 

 which acts in a purposive way and constructs the organism for a 

 definite end and controls its functioning after it is constructed. 

 The physico-chemical processes are simply means to the end. 



Since the neo-vitalistic hypotheses profess to find their founda- 

 tion to a greater or less extent in the facts of experimental biological 

 investigation, they have a claim on the attention of biologists which 

 purely speculative hypotheses do not have. But a critical examina- 

 tion of the works of Driesch and other neo-vitalists discloses the 

 fact that their hypotheses actually rest, not upon facts, but upon 

 certain undemonstrated and at present undemonstrable assump- 

 tions. Driesch's so-called " proofs of the autonomy of vital pro- 

 cesses" are not proofs at all, because each of them involves in one 

 way or another the assumption of what it is supposed to prove. At 

 present it is as impossible to prove as to disprove the existence of a 



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