Logic, Duty, Virtue

Abstract

Deonticlogic, "the logic of ethics," can apply to various moral theories. for example, those based on the concepts of virtue or on duty. A scholastic-style "square of opposition" isuseful in displaying logical relationships among moral notions or"operators" such as ought and may. The system may be constructed with a single operator and the nothers may be added to parallel other expressions in ordinary language. Two principies are given to explain super erogation, the case of good but non obligatory acts or habits and to suggest a basic logic of virtue.