6 DARWINISM AND PHILOSOPHY 



as a whole is a progressive realization of purpose 

 strictly comparable to the realization of purpose 

 in any single plant or animal. 



The conception of eidoG, species, a fixed form 

 and final cause, was the central principle of knowl 

 edge as well as of nature. Upon it rested the 

 logic of science. Change as change is mere flux 

 and lapse; it insults intelligence. Genuinely to 

 know is to grasp a permanent end that realizes 

 itself through changes, holding them thereby with 

 in the metes and bounds of fixed truth. Completely 

 to know is to relate all special forms to their one 

 single end and good: pure contemplative intelli 

 gence. Since, however, the scene of nature which 

 directly confronts us is in change, nature as 

 directly and practically experienced does not sat 

 isfy the conditions of knowledge. Human ex 

 perience is in flux, and hence the instrumentalities 

 of sense-perception and of inference based upon 

 observation are condemned in advance. Science 

 is compelled to aim at realities lying behind and 

 beyond the processes of nature, and to carry on 

 its search for these realities by means of rational 

 forms transcending ordinary modes of perception 

 and inference. 



There are, indeed, but two alternative courses. 

 We must either find the appropriate objects and 

 organs of knowledge in the mutual interactions 

 of changing things; or else, to escape the infec- 



