Reasoning By Precedent

Abstract

This thesis develops a novel account of judicial common-law reasoning by precedent. If a new case is relevantly similar to a precedent case, judges are generally bound to follow the decision made in the precedent case. Important differences between cases can justify deciding the new case differently. The literature offers two main approaches to reasoning by precedent. According to rule-based-approaches, every case is decided by either following an existing rule or establishing a new one. I show that rule-based approaches are untenable. Analogy-based approaches claim that similarities and differences between two cases are determined through reasoning by analogy. These approaches are problematic because some similarity or difference can always be found between two cases. Accounts suggested so far cannot explain how precedents can provide significant guidance to judges. My dissertation salvages analogy-based approaches by supplementing them with insights from argumentation theory. Analogies contain a figurative part that is used to make someone see the analogy‘s literal part in a new way. An arguer can manipulate her interlocutor‘s perception of the literal part through the way she describes the figurative part by rhetorically drawing attention to those similarities that she considers relevant. Arguments by analogy use this to convince interlocutors of conclusions about the literal part. I propose to see judges in the role of interlocutors, evaluating arguments by precedent. The opinion that documents the precedent case from the point of view of the former judge is the figurative part of an analogy. The literal part is the new case. They form an analogical argument for repeating the precedent decision. The judge evaluates the argument by considering a number of critical questions. If all the critical questions can be answered, the precedent is applicable and must be followed. Otherwise, the precedent is either not applicable or has to be distinguished.