Sources of legal indeterminacy

Author: Quentin du Plessis

ISSN: 1996-2177
Affiliations: Johannesburg Bar
Source: South African Law Journal, Volume 138 Issue 1, p. 115-151


Traditional analyses characterise or identify vagueness and ambiguity as the sole or primary sources of legal indeterminacy. In this article, I identify and characterise various other sources of legal indeterminacy. In addition to the semantic indeterminacy of vagueness and ambiguity, philosophers of language have identified conversational, pragmatic, and contextual indeterminacy, each of which is capable of generating a ‘hard case’ as applied to the legal sphere. Nor is all legal indeterminacy linguistic in nature. Following Henry Prakken, I identify non-monotonicity, or the fact that legal inferences are defeasible, as a final source of legal indeterminacy. Each source of legal indeterminacy thus identified includes case-law examples to aid in the discussion.