In accordance with Roman Catholic theology, Aquinas argues that humans can neither wish nor do good without divine grace. However, "doing good" here refers to doing good per se: man "can" do, moved by God even then but "only" in the sense in which even his nature depends on God's moving, things that happen to be good in some respect, and are not sinful, though if he has not grace, it will be without merit, and he will not succeed in it all the time. Therefore, happiness is attained through the perseverance of virtue given by the Grace of God, which is not fully attained on earth; only at the beatific vision. Notably, man cannot attain true happiness without God.