Deontic logics for prioritized imperatives

When a conflict of duties arises, a resolution is often sought by use of an ordering of priority or importance. This paper examines how such a conflict resolution works, compares mechanisms that have been proposed in the literature, and gives preference to one developed by Brewka and Nebel. I distinguish between two cases - that some conflicts may remain unresolved, and that a priority ordering can be determined that resolves all - and provide semantics and axiomatic systems for accordingly defined dyadic deontic operators.