Deontic Logic

Abstract

In discussions on moral norms we tend to assume that a reasonable system of norms should have certain structural properties. Obligations should be consistent, so that a person cannot be morally required both to visit her father in his home and to stay out of the town where he lives. Certain norms imply other norms; someone who has a duty to mow her neighbor's lawn also has permission to enter her garden in order to do so. Deontic logic is the discipline that attempts to systematize such structural properties of systems of norms. Along with decision theory, the logic of preference, and game theory and rational choice, deontic logic is one of the disciplines that apply formal rigor to moral reasoning and to the subject matter of moral philosophy in general ( see Preference; Game Theory and rational choice; Moral Reasoning).