Plato, Laws 689a

τίς οὖν ἡ μεγίστη δικαίως ἂν λέγοιτο ἀμαθία; σκοπεῖτε εἰ συνδόξει καὶ σφῷν λεγόμενον· ἐγὼ μὲν δὴ τὴν τοιάνδε τίθεμαι. ποίαν; τὴν ὅταν τῴ τι δόξαν καλὸν ἢ ἀγαθὸν εἶναι μὴ φιλῇ τοῦτο ἀλλὰ μισῇ, τὸ δὲ πονηρὸν καὶ ἄδικον δοκοῦν εἶναι φιλῇ τε καὶ ἀσπάζηται. ταύτην τὴν διαφωνίαν λύπης τε καὶ ἡδονῆς πρὸς τὴν κατὰ λόγον δόξαν ἀμαθίαν φημὶ εἶναι τὴν ἐσχάτην, μεγίστην δέ, ὅτι τοῦ πλήθους ἐστὶ τῆς ψυχῆς·

What kind of ignorance would deserve to be called the greatest? Consider whether you will agree with my description; I take it to be ignorance of this kind,— What kind? That which we see in the man who hates, instead of loving, what he judges to be noble and good, while he loves and cherishes what he judges to be evil and unjust. That want of accord, on the part of the feelings of pain and pleasure, with the rational judgment is, I maintain, the extreme form of ignorance, and also the greatest because it belongs to the main mass of the soul,—