[19] Topic. I. ii. p. 101, b. 3: ἐξεταστικὴ γὰρ οὖσα πρὸς τὰς ἁπασῶν τῶν μεθόδων ἀρχὰς ὁδὸν ἔχει.
[20] Metaphys. Γ. iii. p. 1005, a. 20-b. 10; Γ. ii. p. 1004, b. 15-30.
[21] Topic. I. iii. p. 101, b. 5: ἕξομεν δὲ τελέως τὴν μέθοδον, ὅταν ὁμοίως ἔχωμεν ὥσπερ ἐπὶ ῥητορικῆς καὶ ἰατρικῆς καὶ τῶν τοιούτων δυνάμεων. τοῦτο δ’ ἐστὶ τὸ ἐκ τῶν ἐνδεχομένων ποιεῖν ἃ προαιρούμεθα. οὔτε γὰρ ὁ ῥητορικὸς ἐκ παντὸς τρόπου πείσει, οὔθ’ ὁ ἰατρικὸς ὑγιάσει· ἀλλ’ ἐὰν τῶν ἐνδεχομένων μηδὲν παραλίπῃ, ἱκανῶς αὐτὸν ἔχειν τὴν ἐπιστήμην φήσομεν.
The word ἐπιστήμην in the last line is used loosely, since Aristotle, in the Rhetorica (p. 1369, b. 12), explicitly states that Rhetoric and Dialectic are not to be treated as ἐπιστήμας but as mere δυνάμεις.
[22] Rhetoric. I. i. p. 1355, a. 17.
The subject-matter of dialectic debate, speaking generally, consists of Propositions and Problems, to be propounded as questions by the assailant and to be admitted or disallowed by the defendant. They will relate either to Expetenda and Fugienda, or they must bear, at least indirectly, upon some point of scientific truth or observed cognition.[23] They will be either ethical, physical, or logical; class-terms which Aristotle declines to define, contenting himself with giving an example to illustrate each of them, while adding that the student should collect other similar examples, and gradually familiarize himself with the full meaning of the general term, through such inductive comparison of particulars.[24]
[23] Topic. I, xi. p. 104, b. 2.
[24] Topic. I. xiv. p. 105, b. 20-29: αἱ μὲν γὰρ ἠθικαὶ προτάσεις εἰσίν, αἱ δὲ φυσικαί, αἱ δὲ λογικαί. — ποῖαι δ’ ἕκασται τῶν προειρημένων, ὁρισμῷ μὲν οὐκ εὐπετὲς ἀποδοῦναι περὶ αὐτῶν, τῇ δὲ διὰ τῆς ἐπαγωγῆς συνηθείᾳ πειρατέον γνωρίζειν ἑκάστην αὐτῶν, κατὰ τὰ προειρημένα παραδείγματα ἐπισκοποῦντα.
This illustrates Aristotle’s view of the process of Induction and its results; the acquisition of the import of a general term, through comparison of numerous particulars comprehended under it.
The term logical does not exactly correspond with Aristotle’s λογικαί, but on the present occasion no better term presents itself.