Plato, Laws 689c

ἔγωγʼ ἂν θείην πόλεώς τε καὶ ἑνὸς ἑκάστου τῶν πολιτῶν, ἀλλʼ οὐ τὰς τῶν δημιουργῶν, εἰ ἄρα μου καταμανθάνετε, ὦ ξένοι, ὃ λέγω. μανθάνομέν τε, ὦ φίλε, καὶ συγχωροῦμεν ἃ λέγεις. τοῦτο μὲν τοίνυν οὕτω κείσθω δεδογμένον καὶ λεγόμενον, ὡς τοῖς ταῦτʼ ἀμαθαίνουσι τῶν πολιτῶν οὐδὲν ἐπιτρεπτέον ἀρχῆς ἐχόμενον καὶ ὡς ἀμαθέσιν ὀνειδιστέον, ἂν καὶ πάνυ λογιστικοί τε ὦσι καὶ πάντα τὰ κομψὰ καὶ ὅσα

All these I would count as the most discordant forms of ignorance, whether in the State or the individual, and not the ignorance of the artisan,—if you grasp my meaning, Strangers. We do, my dear sir, and we agree with it. Then let it be thus resolved and declared, that no control shall be entrusted to citizens thus ignorant, but that they shall be held in reproach for their ignorance, even though they be expert calculators, and trained in all accomplishments and in everything that fosters agility