The Handbook of Epictetus
Handbook 51.2
Translated by Clint Miller
Right now, then, demand of yourself that you live as a mature person, as one making progress. And let everything that appears best to you be an unbreakable law. If anything laborious presents itself, or pleasant, or glorious, or inglorious, remember: the contest is now, the Olympics are already here, there is no more putting it off – and progress is lost or saved by a single day, by a single act.
ἤδη οὖν ἀξίωσον σεαυτὸν βιοῦν ὡς τέλειον καὶ προκόπτοντα· καὶ πᾶν τὸ βέλτιστον φαινόμενον ἔστω σοι νόμος ἀπαράβατος. κἂν ἐπίπονόν τι ἢ ἡδὺ ἢ ἔνδοξον ἢ ἄδοξον προσάγηται, μέμνησο, ὅτι νῦν ὁ ἀγὼν καὶ ἤδη πάρεστι τὰ Ὀλύμπια καὶ οὐκ ἔστιν ἀναβάλλεσθαι οὐκέτι καὶ ὅτι παρὰ μίαν ἡμέραν καὶ ἓν πρᾶγμα καὶ ἀπόλλυται προκοπὴ καὶ σῴζεται.