οὐ γὰρ πράξιν ἀγαθὴν, ἀλλὰ καὶ εὖ ποεῖν αὐτὴν → it does not suffice to do good–one must do it well
subs.
See vice.
Bitterness: P. and V. πικρότης, ἡ.
Of horse: P. χαλεπότης, ἡ (Xen.).