ARISTOTLE 



framework of his thought), but also, in the Appendix, 

 accounts of his theory of the universe and movement 

 (without which parts of Books II and IV cannot be 

 understood) and of the functions of ^ ('/[*</> urov Ylvev/xa,'* 

 an essential factor in his doctrine of generation. On 

 Aristotle the principle that, for the most part, Aristotle is his 

 interpretlr! ^^'^ t)est interpreter, these accounts are compiled 

 almost entirely from passages taken direct from 

 Aristotle's own treatises. 

 Aristotle' In reading Aristotle's scientific works, it is important 

 ^^^ sors! '^ot only to recognize how great were the advances 

 which he himself made in natural history, both in 

 - practical observation and in theory, but also to re- 

 member that his work was a continuation and an 

 expansion of what had been begun by previous 

 scientific workers.'' Those to whom he most fre- 

 quently refers by name are three : Anaxagoras, 

 Empedocles, and Democritus, besides several refer- 

 ences to theories which can be traced in the 

 Hippocratic treatises " ; and the fact that he often 

 quotes them in order to disagree with them should 

 not lead us to underrate their achievement. It is not 

 possible here to give any adequate account of these 

 predecessors of his, and for details about them the 

 reader must be referred to the standard works on 



» The doctrine of SIl was older than Aristotle (see Jaeger ; 

 references given Introd. § 46, n.), but in this volume I am 

 concerned only with Aristotle's presentation of it. 



'' Aristotle calls them collectively ^volkoI. or <l)vaioX6yoi, 

 " physiologers," i.e., writers on " Nature," " natural " 

 scientists. See 741 b 10, n. 



" There are also, of course, reftrences to theories stated by 

 Plato, to which attention is called in the notes ; but Plato is 

 not mentioned bv name. See also K. Prachter, Platon 

 Praformist? in Philologus, LXXXIII (1937), 18-30. 



xvi 



