Mechanism, Vitalism, and Teleology 363 



3. Mechanism and Purpose 



The only mechanism of adaptation that has ever been 

 suggested is the elimination of the unfit and the persistence 

 of the fit. Inherited or racial adaptations may be explained 

 as the result of the elimination of unfit individuals ("per- 

 sonal selection" or "Darwinism" in the strict sense), while 

 acquired adaptations and useful responses to new conditions 

 can be accounted for by the elimination of unfit structures 

 and functions within the individual (intra-personal and re- 

 actional selection). Thus the simple mechanical principles 

 of overproduction of varied individuals or reactions and the 

 elimination of the less fit furnish a mechanistic explana- 

 tion of all kinds of fitness in the living world. 



But in man at least, and probably also in some of the 

 higher animals, there is conscious purpose, and the behavior 

 of many lower animals suggests that they also possess some- 

 thing similar to human purpose, though it is probably not 

 accompanied by consciousness. If conscious purpose has 

 evolved during the course of evolution, as it certainly de- 

 velops during the individual development of man, do we 

 not here find a phenomenon which cannot be explained as 

 due to mechanistic causes? And if conscious purpose is non- 

 mechanistic in its origin, is it not probable that "unconscious 

 purpose," such as is manifested in the many apparently pur- 

 posive responses of digestion, respiration, circulation, devel- 

 opment, regulation, and the adaptive behavior of lower or- 

 ganisms, is also non-mechanistic? In short, if we approach 

 this problem of fitness from the standpoint of human con- 

 sciousness rather than from that of the physiology of the 

 lowest organisms, from the top rather than from the bot- 

 tom, do we not find that the mechanistic philosophy fails 

 to furnish an adequate explanation? Mechanism must ac- 



