[Footnote 11: Analyt. Post. II. iv. p. 91, a. 12: [Greek: tau=ta me\n ou)=n me/chri tou/tou diêporê/sthô]. One would think, by these words, that [Greek: to\ diaporei=n] (or the dubitative treatment) finished here. But the fact is not so: that treatment is continued for four chapters more, to the commencement of ch. viii. p. 93.] [Footnote 12: Analyt. Post. II. iv. p. 91, a. 12-32: [Greek: tau=ta d' a)na/gkê antistre/phein; ei) ga\r to\ A tou= G i)/dion, dê=lon o(/ti kai\ tou= B kai\ tou=to tou= G, ô(/ste pa/nta a)llê/lôn.--lamba/nei ou)=n o(\ dei= dei=xai; kai\ ga\r to\ B e)/sti ti/ e)stin a)/nthrôpos.] Themistius, pp. 72, 73: [Greek: to\n a)podeiknu/nta to\ ti/ ê)=n ei)=nai tou= a)nthrô/pou, a)/llo ti dei= prolabei=n tou= au)tou= to\ ti/ ê)=n ei)=nai.--ou(= ga\r bou/letai to\n o(rismo\n a)podei=xai, tou/tou prolamba/nei tina\ o(rismo\n ei)=nai chôti\s a)podei/xeôs.] M. Barthélemy St. Hilaire, notes, p. 205:--"Il faut donc, pour conclure par syllogisme que A est la définition essentielle de C, que A soit la définition essentielle de B, et que B soit lui-même la définition essentielle de C. Mais alors la définition de la chose sera dans le moyen terme lui-même, avant d'être dans la conclusion; en effet, la mineure: B est la définition essentielle de C, donne la définition essentielle de C, sans qu'il soit besoin d'aller jusqu'**à la conclusion. Donc la démonstration de l'essence ainsi entendue est absurde."] If you cannot obtain Definition as the conclusion of syllogistic Demonstration, still less can you obtain it through the method of generic and specific Division; which last method (as has been already shown in the Analytica Priora) is not equal even to the Syllogism in respect of usefulness and efficacy.[13] You cannot in this method distinguish between propositions both true and essential, and propositions true but not essential; you never obtain, by asking questions according to the method of generic subdivision, any premisses from which the conclusion follows by necessity. Yet this is what you ought to obtain for the purpose of Demonstration; for you are not allowed to enunciate the full actual conclusion among the premisses, and require assent to it. Division of a genus into its species will often give useful information, as Induction also will;[14] but neither the one nor the other will be equivalent to a demonstration. A definition obtained only from subdivisions of a genus, may always be challenged, like a syllogism without its middle term. [Footnote 13: Analyt. Post. II. v. p. 91, b. 12, seq.; Analyt. Prior. I. xxxi. p. 46, a. 31. Aristotle here alludes to the method pursued by Plato in the Sophistes and Politicus, though he does not name Plato: [Greek: ê( dia\ tô=n diaire/seôn o(do/s], &c.] [Footnote 14: Analyt. Post. II. v. p. 91, b. 15-33: [Greek: ou)de\ ga\r o( e)pa/gôn i)/sôs a)podei/knusin, a)ll' o(/môs dêloi= ti.] Compare Themistius, p. 74.]