Epictetus, Works, book 2, Τίσ οὐσία τοῦ ἀγαθοῦ. 18:

ἢ ἄλλα σοι ἐρεῖ ἐκεῖνοσ ἢ ταῦτα; ἀλλ’ εἰ μὲν τὸ ἄγαλμα ἦσ τὸ Φειδίου, ἡ Ἀθηνᾶ ἢ ὁ Ζεύσ, ἐμέμνησο ἂν καὶ σαυτοῦ καὶ τοῦ τεχνίτου καὶ εἴ τινα αἴσθησιν εἶχεσ, ἐπειρῶ ἂν μηδὲν [ἂν] ἀνάξιον ποιεῖν τοῦ κατασκευάσαντοσ μηδὲ σεαυτοῦ μηδ’ ἐν ἀπρεπεῖ σχήματι φαίνεσθαι τοῖσ ὁρῶσι·