οὐ γὰρ πράξιν ἀγαθὴν, ἀλλὰ καὶ εὖ ποεῖν αὐτὴν → it does not suffice to do good–one must do it well
ἀντευποιῶ: ἀντευεργετῶ, Ἀριστ. ἔνθ’ ἀν.