Plato, Meno 86d

ἢ ὡς φύσει ἢ ὡς τίνι ποτὲ τρόπῳ παραγιγνομένης τοῖς ἀνθρώποις τῆς ἀρετῆς. ἀλλʼ εἰ μὲν ἐγὼ ἦρχον, ὦ Μένων, μὴ μόνον ἐμαυτοῦ ἀλλὰ καὶ σοῦ, οὐκ ἂν ἐσκεψάμεθα πρότερον εἴτε διδακτὸν εἴτε οὐ διδακτὸν ἡ ἀρετή, πρὶν ὅτι ἐστὶν πρῶτον ἐζητήσαμεν αὐτό· ἐπειδὴ δὲ σὺ σαυτοῦ μὲν οὐδʼ ἐπιχειρεῖς ἄρχειν, ἵνα δὴ ἐλεύθερος ᾖς, ἐμοῦ δὲ ἐπιχειρεῖς τε ἄρχειν καὶ ἄρχεις, συγχωρήσομαί σοι—τί γὰρ χρὴ ποιεῖν; —ἔοικεν οὖν σκεπτέον

or as arriving to them in some other way which I should be glad to know. Had I control over you, Meno, as over myself, we should not have begun considering whether virtue can or cannot be taught until we had first inquired into the main question of what it is. But as you do not so much as attempt to control yourself—you are so fond of your liberty— and both attempt and hold control over me, I will yield to your request—what else am I to do?