Vague expressions are omnipresent in natural language. If a law contains vague terms, the question whether it applies to a particular case often lacks a clear answer. This places the law at odds with rule-of-law values. One of the fundamental pillars of the rule of law is legal certainty. The determinacy of the law enables people to use it as a guide and it puts judges in a position to decide impartially. Vagueness poses a threat to these ideals. In borderline cases, the law seems to be indeterminate and thus incapable of serving its core rule of law value. In the philosophy of language, vague ... More

Vague expressions are omnipresent in natural language. If a law contains vague terms, the question whether it applies to a particular case often lacks a clear answer. This places the law at odds with rule-of-law values. One of the fundamental pillars of the rule of law is legal certainty. The determinacy of the law enables people to use it as a guide and it puts judges in a position to decide impartially. Vagueness poses a threat to these ideals. In borderline cases, the law seems to be indeterminate and thus incapable of serving its core rule of law value. In the philosophy of language, vagueness has become one of the hottest topics of the past two decades. Linguists and philosophers have investigated what distinguishes ‘soritical’ vagueness from other kinds of linguistic indeterminacy, such as ambiguity, generality, open texture, and family resemblance concepts. The literature discusses the logical, semantic, pragmatic, and epistemic aspects of these phenomena. Legal theory has hitherto paid little attention to the differences between the various kinds of linguistic indeterminacy grouped under the heading of ‘vagueness’, let alone to the various theories that try to account for these phenomena. The volume brings together leading scholars who are working on the topic of vagueness in philosophy and in law, collecting essays in the respective fields and fostering a dialogue between philosophers and legal scholars. It depicts how philosophers conceive vagueness in law from their theoretical perspective and how legal theorists make use of philosophical theories of vagueness.