μὴ τὴν ὄψιν καλλωπίζου, ἀλλ' ἐν τοῖς ἐπιτηδεύμασιν ἴσθι καλός → Don't beautify your face, but be beautiful in your habits (Thales, in Diog. Laertius 1.37)
la cualidad en sí