Epictetus, Works, book 4, Περὶ ἐλευθερίασ. 71:

‐ Οὔ. ‐ Σὸν οὖν ἐστιν ἔργον τὸ καταφρονεῖν θανάτου ἢ οὐ σόν; ‐ Ἐμόν. ‐ Σὸν ἄρα ἐστὶ καὶ τὸ ὁρμῆσαι ἢ οὔ; ‐ Ἔστω ἐμόν. ‐ Τὸ δ’ ἀφορμῆσαι τίνοσ;