[Footnote 139: The second and third books of Dexippus's Dialogue contain his answers to many of the objections urged by Plotinus. Aristotle, in the Categoriæ (Dexippus says), accommodates himself both to the received manner of speaking and to the simple or ordinary conception of [Greek: ou)si/a] entertained by youth or unphilosophical men--[Greek: ou)/te ga\r peri\ tô=n o)/ntôn, ou)/te peri\ tô=n genô=n tê=s prô/tês ou)si/as nu=n au)tô=| pro/keitai le/gein; stocha/zetai ga\r tô=n ne/ôn toi=s a(plouste/rois e)pakolouthei=n duname/nôn] (p. 49). Compare also pp. 50-54, where Dexippus contrasts the more abstruse handling which we read in the Physica and Metaphysica, with the more obvious and unpretending thoughts worked out by Aristotle in the Categoriæ. Dexippus gives an interesting piece of advice to his pupil, that he should vary his mode of discussing these topics, according as his companions are philosophical or otherwise--[Greek: e)gô\ me\n ou)=n, ô)= kale\ ka)gathe\ Se/leuke, dogmatikô/teron pro\s Plôti=non a)pantô=, su\ de/, e)pei\ bathu/terai/ pôs ei)si\n ai( lu/seis au(=tai, pro\s me\n tou=s e)k philosophi/as o(rmôme/nous tai=s toiau/tais a)pantê/sesi chrô=, pro\s de\ tou\s o)li/ga e)pistame/nous tô=n dogma/tôn tai=s prochei/rois chrô= dialu/sesin, e)kei=no le/gôn, _o(/ti peri\ po/da poiei=sthai e)/thos ta\s a)kroa/seis A)ristote/lei;_ dio\ kai\ nu=n ou)de\n e)/xôthen e)peisa/gei tô=n a)nôte/rô keime/nôn philosophêma/tôn], &c. (pp. 50, 51).] Galen also recognizes five Categories; but not the same five as Plotinus. He makes a new list, formed partly out of the Aristotelian ten, partly out of the Stoic four:--[Greek: Ou)si/a, poso/n, poio/n, _pro/s ti_, pro/ ti pô\s e)/chon].[140] [Footnote 140: Schol. ad Categor. p. 49 a. 30.] . . . . . . The latter portion of this Aristotelian treatise, on the Categories or Predicaments, consists of an Appendix, usually known under the title of 'Post-Predicamenta;'[141] wherein the following terms or notions are analysed and explained--_Opposita_, _Prius_, _Simul_, _Motus_, _Habere_. [Footnote 141: Andronikus and other commentators supposed the Post-Predicamenta to have been appended to the Categoriæ by some later hand. Most of the commentators dissented from this view. The distinctions and explanations seem all Aristotelian.] Of _Opposita_, Aristotle reckons four modes, analogous to each other, yet not different species under the same genus:[142]--1. _Relative-Opposita_--_Relatum_ and _Correlatum_. 2. _Contraria_. 3. _Habitus_ and _Privatio_. 4. _Affirmatio_ and _Negatio_.