Plato, Epinomis 974e

ὡς εἰσὶ μὲν ἀναγκαιόταται σχεδὸν ἀληθῶς τε πρῶται, ὁ δὲ ἐπιστήμων αὐτῶν γιγνόμενος, εἰ καὶ κατʼ ἀρχὰς ἔδοξέν τις εἶναί ποτε σοφός, οὔκουν νῦν γε οὔτε σοφὸς εἶναι δοξάζεται

are about the most necessary and truly the first, yet he who acquires a knowledge of them, though in the beginning he may have been regarded as wise in some sort, is now not reputed wise at all, but rather incurs reproach