Note 346 — VII.
Reading edition
Topic. VII. p. 152, a. 5-30: σκοπεῖν δὲ καὶ ὧν θάτερον μάλιστα λέγεται ὁτιοῦν, εἰ καὶ θάτερον τῶν αὐτων τούτων κατὰ τὸ αὐτὸ μάλιστα λέγεται, καθάπερ Ξενοκράτης τὸν εὐδαίμονα βίον καὶ τὸν σπουδαῖον ἀποδείκνυσι τὸν αὐτόν, ἐπειδὴ πάντων τῶν βίων αἱρετώτατος ὁ σπουδαῖος καὶ ὁ εὐδαίμων· ἓν γὰρ τὸ αἱρετώτατον καὶ τὸ μέγιστον· &c.
Aristotle remarks that Xenokrates here carried his inference too far: that the application of the same superlative predicate to A and B affords indeed a presumption that they are Idem numero, but not a conclusive proof thereof; that the predicate might be applied in like manner, if B were a species comprised in A as genus.
Xenokrates made the mistake of drawing an affirmative conclusion from syllogistic premisses in the Second figure.