ANCIENT PHILOSOPHY
Two versions of Peri tou mē ontos ptmo by Gorgias, related by an Anonymous Author MXG and by Sextus Empiricus SE, have been alternatively accredited by scholars according to their disposition to seek a doctrine or a rhetorical- communicational dimension respectively with the first tendency prevailing. Comparing the ptmo to the rest of Gorgiasʼ works, we verify and clearly demonstrate how SE manages to convey a precise modus argumentandi. In effect, SE shows Gorgias’ demonstrative reasoning as employing: 1 the application of demonstrandum and quod erat demonstrandum typical of Gorgiasʼ speeches, reinforced by a substantial and abundant use of verbs of explanation and demonstration, especially in comparison to the rest of the same Against the Logicians’ section. Otherwise, MXG reduces this lexicon to the more generic phēmi; 2 the continuous employment of the reductio ad absurdum, like in all of Gorgias’ works; 3 a very refined formulation of the principle of non-contradiction §67, similar to the one seen in Pal. 25. In addition, MXG is accurate in the discussion of some arguments as in the third kephalaion, however, presents as an overcorrected interpreter, more interested in questioning Gorgias than reporting his original text, also directly referring to Zeno, Melissus, and Leucippus. The context of the ptmo in SE’s work the structure presented leads us to believe that SE had the text or at least an accurate summary of the ptmo different from MXG. The aims of this paper are: 1 to demonstrate that SE shows well the Gorgianic demonstrative reasoning and, for this specific reason, he is reliable and valuable resource for us; 2 to hypothesise that SE’s version is based on and independent as yet unknown source.