Abductive Inference in Legal Reasoning: Resolving the Question of Res Ipsa Loquitur’s Procedural Effect

Abstract

AbstractThis chapter examines the relevance of C.S. Peirce’s notion of abductive inference for law and the formation of legal concepts. The importance of this examination comes from the fact that several doctrinal practices in diverse areas of law rely on logical inferences that defy neat explanation under standard forms of deductive or inductive logic. I argue that abduction resolves some of these logical infirmities, providing the logic underlying certain doctrines or conceptual practices common in modern law. My analysis concentrates on the common law tort maxim res ipsa loquitur (‘the thing speaks for itself’). This is for two reasons. First, as much as any legal concept, res ipsa loquitur manifests the form and conditions of abductive inference. Second, though it entered English common law over 150 years ago and remains today a form of inferential reasoning used in negligence cases throughout most of the common law world, res ipsa loquitur is still highly controversial. Several issues affecting its force and effect split courts and prevent it from receiving uniform application across jurisdictions. The most consequential issue is whether it authorizes a burden-shifting presumption of negligence or only a permissible evidentiary inference left to the discretion of the fact-finder. This is the central issue of res ipsa loquitur’s procedural effect. It continues to confound, I argue, in part because of the maxim’s little understood logical foundation in abduction. This chapter aims to unfold that foundation. In doing so, it establishes three propositions: (1) abduction is a suitable form of logic for legal reasoning; (2) abduction is the form of logic used by the English Court of the Exchequer in Byrne v. Boadle and Scott v. London and St. Katherine Docks Co., the birth-cases to the tort maxim res ipsa loquitur; and (3) recognizing abduction as the logic underlying res ipsa loquitur resolves the perennial issue of its procedural effect in favor of the permissible inference theory.KeywordsAbduction/abductive inferenceCommon lawExplanatory hypothesesInductive reasoningNegligence lawPeirce, Charles SandersPresumptions in lawRes ipsa loquitur