Plato, Laws 905c

γιγνώσκειν δὲ αὐτήν, ὦ πάντων ἀνδρειότατε, πῶς οὐ δεῖν δοκεῖς; ἥν τις μὴ γιγνώσκων οὐδʼ ἂν τύπον ἴδοι ποτέ, οὐδὲ λόγον συμβάλλεσθαι περὶ βίου δυνατὸς ἂν γένοιτο εἰς εὐδαιμονίαν τε καὶ δυσδαίμονα τύχην. ταῦτα εἰ μέν σε πείθει Κλεινίας ὅδε καὶ σύμπασα ἡμῶν ἥδε ἡ γερουσία, περὶ θεῶν ὡς οὐκ οἶσθα ὅτι λέγεις, καλῶς ἄν σοι θεὸς αὐτὸς συλλαμβάνοι· εἰ δʼ ἐπιδεὴς ἔτι λόγου τινὸς ἂν εἴης, λεγόντων ἡμῶν

how it contributes to the All. And surely, O most courageous of men, thou canst not but suppose that this is a thing thou must needs learn. For if a man learns not this, he can never see even an outline of the truth, nor will he be able to contribute an account of life as regards its happiness or its unhappy fortune. If Clinias here and all our gathering of elders succeed in convincing thee of this fact, that thou knowest not what thou sayest about the gods, then God Himself of His grace will aid thee; but shouldest thou still be in need of further argument, give ear to us while we argue with the third unbeliever,