Plato, Laws 819d

μήκη καὶ πλάτη καὶ βάθη, περὶ ἅπαντα ταῦτα ἐνοῦσάν τινα φύσει γελοίαν τε καὶ αἰσχρὰν ἄγνοιαν ἐν τοῖς ἀνθρώποις πᾶσιν, ταύτης ἀπαλλάττουσιν. ποίαν δὴ καὶ τίνα λέγεις ταύτην; ὦ φίλε Κλεινία, παντάπασί γε μὴν καὶ αὐτὸς ἀκούσας ὀψέ ποτε τὸ περὶ ταῦτα ἡμῶν πάθος ἐθαύμασα, καὶ ἔδοξέ μοι τοῦτο οὐκ ἀνθρώπινον ἀλλὰ ὑηνῶν τινων εἶναι μᾶλλον θρεμμάτων, ᾐσχύνθην τε οὐχ ὑπὲρ ἐμαυτοῦ μόνον,

The next step of the teachers is to clear away, by lessons in weights and measures, a certain kind of ignorance, both absurd and disgraceful, which is naturally inherent in all men touching lines, surfaces and solids. What ignorance do you mean, and of what kind is it? My dear Clinias, when I was told quite lately of our condition in regard to this matter, I was utterly astounded myself: it seemed to me to be the condition of guzzling swine rather than of human beings, and I was ashamed, not only of myself, but of all the Greek world.