CHAPTER FIVE 

 Lamarck 



THE doctrine of evolution in its broad sense cov- 

 ers a very large field of science and its influence 

 extends to almost every human activity. Before be- 

 ginning the discussion of evolution as a modern scien- 

 tific theory and its bearing on thought in general, the 

 particular purpose of this study should be stated 

 clearly and should be kept in mind by the reader. 



In the first place, I accept the general doctrine of 

 the evolution of organisms as a deductive theory on 

 the same grounds that I subscribe to the atomic theo- 

 ry of matter. It is the most satisfactory rational 

 theory to account for those relations between existing 

 flora and fauna which undoubtedly exist. But this is 

 not equivalent to accepting the metaphysical hy- 

 potheses which attempt to give the causes and meth- 

 ods of evolution, nor does it mean that the biological 

 theory of evolution can be applied with success to the 

 problems of man's mental and spiritual nature. We 

 are certain of the long duration of the earth, and that 

 it has been inhabited by a long succession of plant and 

 animal forms which were different in the past, and 

 which are at present linked together by an heredity 

 that varies in a greater or less degree from generation 

 to generation. Such a belief is the common property 



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