Aristotle's biology 



crements of soul or life, possessed by each 

 organism next higher in the universal series. 

 Organic nature presented an ascending scale. 



If this organic world was not an evolution 

 strictly speaking, it was not static. It was 

 alive, in vital process, pressing on toward self- 

 fulfillment through the purposeful power of 

 nature. Each animal was formed and con- 

 ducted to its end by the soul or life which was 

 its purpose and design, its final cause. In like 

 manner each organ was adapted to its function. 

 The plastic power of serviceableness, of utility 

 and use, the formation and existence of all 

 parts as means to ends, with Nature ever work- 

 ing toward an end and doing nothing vainly, — 

 these convictions were launched by the great 

 Stagyrite upon the mighty roles they were to 

 play in all the subsequent thinking of man- 

 kind. For " barren virgins," final causes were 

 to have a large progeny! 



The principles of Aristotle are not dead. 

 Changed scarcely in form, conceptions of the 

 vital power of Nature have ever filled the 

 minds of men and still live in the minds of 

 those men of science for whom mechanics and 

 chemistry cannot explain the world of life. 

 Specific teleological explanations of function 



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