Epictetus, Works, book 4, Πρὸσ τοὺσ μαχίμουσ καὶ θηριώδεισ. 20:

καὶ ὀδμὴν ἔχειν αὐτὸ δεῖ καὶ γεῦσιν· οὐκ ἀρκεῖ ἡ ἐκτὸσ περιγραφή. οὐκοῦν οὐδὲ πρὸσ τὸν ἄνθρωπον ἡ ῥὶσ ἐξαρκεῖ καὶ οἱ ὀφθαλμοί, ἀλλ’ ἂν τὰ δόγματα ἔχῃ ἀνθρωπικά.