Definitions in Law

Abstract

Definitions play a fundamental role in legal discourse, which can be identified in its two basic functions: avoiding ambiguity in interpretation, and warranting the application of a law to a case. Definitions can be both standpoints of argumentative discussions, in which the meaning of a rule is challenged, and premises of inferences supporting a legal decision. Definitions are analyzed in this paper in relation to the twofold role they play in legal argumentative discussions. Examining arguments about definitions in legal cases, the most important types of argument (such as argument from expert opinion, or from consequences) used to support a definition are compared, and their relevance and probative force evaluated. It is also shown how the communicative relevance of different types of definitions (such as operational or inductive definition) depends on the inferences they warrant and their argumentative function, such as applying rules to cases, or explaning obscure concepts.