It is the act of an ill-instructed man to blame others for his own bad condition; it is the act of one who has begun to be instructed, to lay the blame on himself; and of one whose instruction is completed, neither to blame another, nor himself.
Απαιδεύτου ἔργον τὸ ἄλλοις ἐγκαλεῖν ἐφ᾿ οἷς αὐτὸς πράσσει κακῶς· ἠργμένου παιδεύεσθαι τὸ ἑαυτῷ· πεπαιδευμένου τὸ μήτε ἄλλῳ μήτε ἑαυτῷ.
Original text (Ancient Greek)