In deontological ethics an action is considered morally good because of some characteristic of the action itself, not because the product of the action is good. Deontological ethics holds that at least some acts are morally obligatory regardless of their consequences for human welfare. Descriptive of such ethics are such expressions as “Duty for duty’s sake,” “Virtue is its own reward,” and “Let justice be done though the heavens fall.”

Teleological theories differ on the nature of the end that actions ought to promote. Eudaemonist theories (Greek eudaimonia, “happiness”), which hold that ethics consists in some function or activity appropriate to man as a human being, tend to emphasize the cultivation of virtue or excellence in the agent as the end of all action. These could be the classical virtues—courage, temperance, justice, and wisdom—that promoted the Greek ideal of man as the “rational animal”; or the theological virtues—faith, hope, and love—that distinguished the Christian ideal of man as a being created in the image of God.