Note 111 — II.
Reading edition
Ibid. viii. p. 113, b. 15-26: ἐπεὶ δ’ αἱ ἀντιθέσις τέσσαρες, σκοπεῖν ἐκ μὲν τῶν ἀντιφάσεων ἐκ τῆς ἀκολουθήσεως καὶ ἀναιροῦντι καὶ κατασκευάζοντι· λαμβάνειν δ’ ἐξ ἐπαγωγῆς, οἷον εἰ ὁ ἄνθρωπος ζῷον, τὸ μὴ ζῷον οὐκ ἄνθρωπος· ὁμοίως δὲ καὶ ἐπὶ τῶν ἄλλων — ἐπὶ πάντων οὖν τὸ τοιοῦτον ἀξιωτέον.
Aristotle’s declaration, that this great logical rule can only be proved by Induction, deserves notice. I have remarked the same thing about his rules for the conversion of propositions, in the beginning of the Analytica Priora. See above, p. 145, seq.