ARISTOTLE. 173 



an epitome of it, made by himself from memory, during a sea voyage 

 from Velia to Rhegium. 



V. On Sophistical Proofs, (i. II.) (?rpt aotyiariKuv eXey^wi/.) 

 An analysis of the possible forms of fallacy in demonstration. This 

 work has a natural connexion with the * Topics,' as Aristotle himself 

 remarks in the beginning of the last chapter of the second book. 



The preceding works taken together complete Aristotle's logical 

 writings, and with Porphyry's Introduction to the ' Categories,' have 

 gone generally in modern times by the name of the ' Organum,' from 

 the circumstance of Aristotle having called logic opyavov opyavw. 

 The philosopher gave this name to the art, because of all others it is 

 the most purely instrumental, that is, the most entirely a means to 

 something else, and the least an end to be desired for its own sake. 

 The term, however, was in subsequent ages misapplied to mean 

 that it was the best of all instruments for the discovery of truth, as 

 opposed to the observation of facts, and the art was correspondently 

 abused. 



VI. Physical Lectures, (i. n. in. iv. v. vi. vn. vm.) (^ucrtfo) 

 ctKpocHTic.) It is a very questionable thing whether this treatise was 

 published by the author as one organic whole. The three last books 

 probably formed a treatise by themselves under the name Trcpt 

 lavj/orfwc;, 1 and the first five another under that of tyvaiKa. Again of 

 these the first one is quite independent of the rest, and is devoted to 

 the discussion of the first principles (ap^ca), 2 to which everything in 

 nature may be resolved. This book is extremely valuable for the 

 history of philosophy before the time of Aristotle. He discusses in it 

 the theories of Melissus, Parmenides, Anaxagoras, Empedocles, and 

 others. The second is taken up with an examination of the ideas of 

 Nature, Necessity, and Chance ; and the next three with the properties 

 of Body, or rather with the analysis of those notions of the under- 

 standing which are involved in the idea of Body. Of this work ab- 

 stracts and syllabuses (fce^aXata KOI avvo^u^) were very early made 

 by the Peripatetic school, 3 and these keeping their attention fixed upon 

 the connexion of a system of dogmas, contributed perhaps much to 

 divert them from the observation of nature, and to keep up that con- 

 fusion between laws of the Understanding and laws of Nature which 

 pervades the whole of the ancient physical speculations. 



VII. On the Heavens, (i. n. m. iv.) (vrept ovpavov.) Alexander 

 of Aphrodisias considered that the proper name for this work was Trtpl 

 Kofffj.ov, as only the first two books are really on the subject of the 

 heavenly bodies and their circular motion. The two last treat on the 



1 Sim pi. ad. Phys. Auscult. f. 216. Diogenes, however, gives a work (irepl 

 Kij'Tjo-eoJs) in two books. This is not conclusive against the opinion quoted in the 

 text. See below, the notice respecting the Rhetoric. 



2 Perhaps it is to this book that the title nepl apx^s, in Diogenes' Catalogue, 

 refers. 



3 Simplicius, Introd. ad Phys. Ausc. vi. and vii. 



