Note 21 — Chapter IX · TOPICA. I.
Reading edition
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.