Epictetus, Discourses 1.18 (DIORISIS sentence 891)

— μηδαμῶς, ἀλλʼ ἐκεῖνο μᾶλλον τοῦτον τὸν πεπλανημένον καὶ ἐξηπατημένον περὶ τῶν μεγίστων καὶ ἀποτετυφλωμένον οὐ τὴν ὄψιν τὴν διακριτικὴν τῶν λευκῶν καὶ μελάνων, ἀλλὰ τὴν γνώμην τὴν διακριτικὴν τῶν ἀγαθῶν καὶ τῶν κακῶν μὴ ἀπολλύναι;