"every inclination or movement is perfected when it achieves its end or attains its term. Hence there is only a perfected will when, given the opportunity, it acts", and acts in such a way as to achieve its end or attain its term.
"omnis inclinatio vel motus perficitur in hoc quod consequitur finem, vel attingit terminum. Unde non est perfecta voluntas, nisi sit talis quae, opportunitate data, operetur."
Thomas Aquinas, Summa theologiae I-II.20.4.Resp., trans. Ralph McInerny (Thomas Aquinas: selected writings, 607). Latin from Corpus Thomisticum.