Note 28 — Chapter VI · ANALYTICA PRIORA II.
Reading edition
Analyt. Prior. II. xvii. p. 65, a. 38: ὃ πολλάκις ἐν τοῖς λόγοις εἰώθαμεν λέγειν, &c. That the Reductio ad Absurdum was sometimes made to turn upon matters wholly irrelevant, we may see from the illustration cited by Aristotle, p. 65, b. 17.