In defence of deontic diversity

摘要

The normative terms of natural language have a variety of usages, and their logical properties differ between these usages. Some of the differences are difficult to discern in natural language, but may be easier to keep apart with the more precise tools of a formal language. We can therefore use the resources of deontic logic to discover and distinguish among different meanings of the deontic terms in natural language. Some of the ingrained disagreements among deontic logicians may also be resolvable if we recognize that the different viewpoints correspond to different meanings of the normative terms of ordinary language. This is illustrated with the diversity in the meanings of both prescriptive and permissive predicates.