Legal reasoning and argumentation

Abstract

Reasoning and argumentation occur in many legal contexts, but most theory focuses on adjudication. Normative theories of reasoning in adjudication approximate to a rationalist model, which postulates that the main aim of adjudication is the correct application of legal norms to facts proved to be true. Much reasoning in “easy cases” may be deductive, but most theories address “hard cases”, where some doubt arises about the major premise, or the categorization of the minor premise, or its evidential support. Reasoning about questions of law and of fact is generally treated separately, even though the distinction is problematic. Rationalist theories of reasoning about questions of law may differ about priority rules, validity, and weight; what constitutes a hard case; and whether substantive reasons are an integral part of the law. Critics may question their narrow focus on adjudication and on Western systems, particular models of rationality, whether rationality in adjudication is possible, the determinacy of legal norms, whether cases are inherently easy or hard, and whether highly abstract theories of reasoning capture the complexities of actual discourses of argumentation. Rationalist theories of factual reasoning differ among themselves about the nature of inferential reasoning, whether standard examples fit inductive (Baconian) or mathematical (Pascalian) theories of probability, and whether “atomistic” models can accommodate “holistic” ideas of narrative coherence. Rationalist theories also face skeptical challenges. Links between normative theories and actual discourses have been intermittent, with some notable exceptions. More work is needed to integrate these diverse inquiries and to explore the implications of modern technology and artificial intelligence.