Such is the antithesis between _notiora naturâ_ (or _simpliciter_) and _notiora nobis_ (or _quoad nos_), which Aristotle recognizes as a capital point in his philosophy, and insists upon in many of his writings. The antithesis is represented by Example and Induction, in the point of view--_quoad nos_--last mentioned; by Syllogism or Deduction, in the other point of view--_naturâ_. Induction (he says),[68] or the rising from particulars to universals, is plainer, more persuasive, more within the cognizance of sensible perception, more within the apprehension of mankind generally, than Syllogism; but Syllogism is more cogent and of greater efficacy against controversial opponents. What he affirms here about Induction is equally true about the inference from Example, that is, the inference from one or some particulars, to other analogous particulars; the rudimentary intellectual process, common to all human and to many animal minds, of which Induction is an improvement and an exaltation. While Induction will be more impressive, and will carry assent more easily with an ordinary uncultivated mind, an acute disputant may always deny the ultimate inference, for the denial involves no contradiction. But the rightly constructed Syllogism constrains assent;[69] the disputant cannot grant the premisses and deny the conclusion without contradicting himself. The constraining force, however, does not come into accurate and regulated working until the principles and conditions of deductive reasoning have been set forth--until the Syllogism has been analysed, and the characteristics of its validity, as distinguished from its invalidity, have been marked out. This is what Aristotle teaches in the Analytica and Topica. It admits of being set out in regular figure and mode--forms of premisses with the conclusion appropriate to each; and the lesson must be learnt before we can know how far the force of deductive reasoning, which begins with the _notiora naturâ_, is legitimately binding and trustworthy. [Footnote 68: Aristot. Topica, I. xii. p. 105, a. 13-19: [Greek: e)pagôgê\ de\ ê( a)po\ tô=n kath' e(/kaston e)pi\ ta\ katho/lou e)/phodos; oi(=on ei) e)/sti kubernê/tês o( e)pista/menos kra/tistos kai\ ê(ni/ochos, kai\ o(/lôs e)sti\n o( e)pista/menos peri\ e(/kaston a)/ristos. e)/sti d' ê( me\n e)pagôgê\ pithanô/teron kai\ saphe/steron kai\ kata\ tê\n ai)/sthêsin gnôrimô/teron, _kai\ toi=s polloi=s koino/n_; o( de\ sullogismo\s biastikô/teron kai\ pro\s tou\s a)ntilogikou\s e)nerge/steron.] Also the same treatise. VI. iv. p. 141, b. 17. The inductive interrogations of Sokrates relating to matters of common life, and the way in which they convinced ordinary hearers, are strikingly illustrated in the Memorabilia of Xenophon, especially IV. vi.: [Greek: polu\ ma/lista ô(=n e)gô\ oi)=da, o(/te le/goi, tou\s a)kou/ontas o(mologou=ntas parei=chen] (15). The same can hardly be said of the Platonic dialogues.]