Epictetus, Works, book 4, Πρὸσ τοὺσ μαχίμουσ καὶ θηριώδεισ. 29:

Ἐτεοκλέα καὶ Πολυνείκη τὸ πεποιηκὸσ οὐκ ἄλλο ἢ τοῦτο, τὸ δόγμα τὸ περὶ τυραννίδοσ, τὸ δόγμα τὸ περὶ φυγῆσ, ὅτι τὸ μὲν ἔσχατον τῶν κακῶν, τὸ δὲ μέγιστον τῶν ἀγαθῶν.