Ambiguity and Vagueness in Legal Interpretation

Vagueness and ambiguity are key problems in theories of legal interpretation. The article first delimits vagueness and ambiguity and sets it into relation to related phenomena like the generality of legal expressions (1). Vagueness proves to be a multi-faceted phenomenon which can be systematised along three distinctions: vagueness of individuation and classification, degree and combinatory vagueness, and semantic and pragmatic vagueness. For law pragmatic vagueness seems of specific import (2.). As for the origins and accounts of vagueness the different approaches are sorted into logic, ontic, epistemic and semantic accounts with epistemic and semantic accounts showing the closest relations to legal theories of interpretation (3.). The last section argues that vagueness is not a threat to legal interpretation and rule of law values properly understood. It is cautious, though, with regard to some suggested values of vagueness. However, it sees a value of vagueness in reducing decision costs, which cannot be completely accommodated by other semantic features of vague concepts like generality (4.)