Abstract

This chapter provides guidance in reasoning from precedent and by legal analogy as practiced in a common law context. The goal is to bring jurisprudential theories and descriptive accounts of precedent and legal analogy, philosophical accounts of practical reasoning in terms of argument schemes and critical questions, and computational models of analogical legal reasoning together in a way that should be instructive for law students, but also has practical ramifications for the fields of AI and Law and of Jurisprudence. More specifically, the goal is to identify good patterns of argument associated with precedent and legal analogy and to distill them into argument schema that students, practitioners, and those who develop computational models of legal reasoning can implement. This chapter surveys jurisprudential accounts of the constraints that “following precedent” imposes on a court’s discretion, and formal and descriptive accounts of the kinds of legal arguments one may use to convince a court to follow a precedent, or analogy, or not to do so. Finally, this chapter addresses how to represent these patterns of reasoning in terms of argument schemes that have been offered by AI and Law researchers and briefly addresses application of the schemes in statutory reasoning.