Note 3 — Chapter XXII · MENON.
Reading edition
Plato, Menon, p. 71 D. ἀκεῖνον μέντοι νῦν ἐῶμεν, ἐπειδὴ καὶ ἄπεστιν. Sokrates sets little value upon opinions unless where the person giving them is present to explain and defend: compare what he says about the uselessness of citation from poets, from whom you can ask no questions, Plato, Protagor. p. 347 E.