244 SCIENCE AND IMMORTALITY 



to other parts of the body in which existence for 

 some purpose is apparent. And it is argued that 

 where all things happened as if they were made 

 for some purpose, being aptly united by chance 

 they were preserved, but such as were not aptly 

 made, these were lost, and still perish according to 

 what Empedocles says concerning the bull-species 

 with human heads. This, therefore, and similar 

 reasoning, may lead some to doubt on this subject. 



" It is, however, impossible that these parts 

 should arise in this manner, for these parts, and 

 everything which is produced in Nature, are either 

 always or for the most part thus (adaptively) pro- 

 duced, and this is not the case with anything which 

 is produced by fortune or chance, even as it does 

 not appear to be fortune or chance that it frequently 

 rains in winter. ..." " Similarly, it may be 

 argued that there should be an accidental genera- 

 tion of the germs of things ; but he who asserts this 

 subverts Nature herself, for Nature produces these 

 things which, being continually moved by a certain 

 principle contained in themselves, arrive at a 

 certain end." 



There is the whole point : Does Nature produce 

 these things which, being continually moved by a 

 certain principle contained in themselves^ arrive at a 

 certain end ; or does the end depend on the selection 

 by environment of variations offered for selection } 



