Meditations 3.12.1

Ἐὰν τὸ παρὸν ἐνεργῇς ἑπόμενος τῷ ὀρθῷ λόγῳ, ἐσπουδασμένως, ἐρρωμένως, εὐμενῶς, καὶ μηδὲν παρεμπόρευμα, ἀλλὰ τὸν ἑαυτοῦ δαίμονα καθαρὸν ἑστῶτα τηρῇς, ὡσεὶ καὶ ἤδη ἀποδοῦναι δέοι· ἐὰν τοῦτο συνάπτῃς μηδὲν περιμένων μηδὲ Φεύγων, ἀλλὰ τῇ παρούσῃ κατὰ Φύσιν ἐνεργείᾳ καὶ τῇ ὧν λέγεις καὶ Φθέγγῃ ἡρωικῇ ἀληθείᾳ ἀρκούμενος, εὐζωήσεις. ἔστι δὲ οὐδεὶς ὁ τοῦτο κωλῦσαι δυνάμενος.

If you do what lies before you according to right reason, earnestly, firmly, and with goodwill; if you allow no sideline, but keep your divine guardian standing pure, as though you had to give it back this instant; if you hold to this, waiting for nothing and fleeing nothing, content with your present action according to nature and with heroic truth in everything you say and utter, you will live well. No one can prevent this.