§12.17.1Εἰ μὴ καθήκει, μὴ πράξῃς· εἰ μὴ ἀληθές ἐστι, μὴ εἴπῃς.
If it is not fitting, do not do it; if it is not true, do not say it.
ἡ γὰρ ὁρμή σου ἔστω εἰς τὸ πᾶν ἀεὶ ὁρᾶν, τί ἐστιν αὐτὸ ἐκεῖνο τὸ τὴν φαντασίαν σοι ποιοῦν, καὶ ἀναπτύσσειν διαιροῦντα εἰς τὸ αἴτιον, εἰς τὸ ὑλικόν, εἰς τὴν ἀναφοράν, εἰς τὸν χρόνον, ἐντὸς οὗ πεπαῦσθαι αὐτὸ δεήσει.
For let your impulse always be directed to seeing in everything what that very thing is which produces the impression on you, and to analyzing it by dividing it into its cause, its matter, its relation, and the time within which it must cease.