Reasoning With Rules

Rule-applying legal arguments are traditionally treated as a kind of syllogism. Such a treatment overlooks the fact that legal principles and rules are not statements which describe the world, but rather means by which humans impose structure on the world. Legal rules create legal consequences, they do not describe them. This has consequences for the logic of rule- and principle-applying arguments, the most important of which may be that such arguments are defeasible. This book offers an extensive analysis of the role of rules and principles in legal reasoning, which focuses on the close relationship between rules, principles, and reasons. Moreover, it describes a logical theory which assigns a central place to the notion of reasons for and against a conclusion, and which is especially suited to deal with rules and principles.

Few areas of human expertise are so well understood that they can be completely reduced to general principles. Similarly, there are few domains in which experience is so extensive that every new problem precisely matches a previous problem whose solution is known. When neither rules nor examples are individually sufficient, problem-solving expertise depends on integrating both. This book presents a computational framework for the integration of rules and cases for analytic tasks typified by legal analysis. The book uses the framework for integrating cases and rules as a basis for a new model of legal precedents. This model explains how the theory under which a case is decided controls the case's precedential effect. The framework for integrating rules and cases is implemented in GREBE, a system for legal analysis. The book presents techniques for representing, indexing, and comparing complex cases and for converting justification structures based on rules and case into natural-language text. This book will interest researchers in artificial intelligence, particularly those involved in case-based reasoning, artificial intelligence and law, and formal models of argumentation, and to scholars in legal philosophy, jurisprudence, and analogical reasoning.

This book constitutes the proceedings of the International Joint Conference on Rules and Reasoning, RuleML+RR 2021, held in Leuven, Belgium, during September, 2021. This is the 5th conference of a new series, joining the efforts of two existing conference series, namely “RuleML” (International Web Rule Symposium) and “RR” (Web Reasoning and Rule Systems). The 17 full research papers presented together with 2 short technical communications papers and 2 abstracts of invited papers were carefully reviewed and selected from 39 submissions.

Demystifying Legal Reasoning defends the proposition that there are no special forms of reasoning peculiar to law. Legal decision makers engage in the same modes of reasoning that all actors use in deciding what to do: open-ended moral reasoning, empirical reasoning, and deduction from authoritative rules. This book addresses common law reasoning when prior judicial decisions determine the law, and interpretation of texts. In both areas, the popular view that legal decision makers practise special forms of reasoning is false.

For centuries, philosophers have been puzzled by the fact that people often respect moral obligations as a matter of principle, setting aside considerations of self-interest. This text shows how rule-following can be understood as an essential element of rational action.

This book provides an accessible and at the same time scientifically rigorous introduction to the principles of logical reasoning.

Legal and moral reasoning share much methodology, and they address similar problems. This volume charts two shared problems: the relation between theory, principles and particular judgments; and the role of facts and factual assertions in normative settings. The relation between 'theory' and 'practice' and between 'principle' and 'particular judgment' has become the subject of much debate in moral philosophy. In the ongoing debate, some moral philosophers refer to legal philosophy for a support of their views on the primacy of 'practice' over 'theory'. According to them, legal philosophy should have a more balanced view in that relation. In the contributions to Part One this claim is critically analysed. The role of the facts is underestimated in discussions on legal reasoning and legal theory, as well as moral reasoning and ethical theory. Factual statements enter into moral and legal discussions not only because they link the conclusion with a rule. They also play a role as background assumptions in supporting a theory. Its focus on the role of facts in normative reasoning makes this book of special interest to scholars of legal and moral argumentation.

This insightful and highly readable Advanced Introduction provides a succinct, yet comprehensive, overview of legal reasoning, covering both reasoning from canonical texts and legal decision-making in the absence of rules. Overall, it argues that there are only two methods by which judges decide legal disputes: deductive reasoning from rules and unconstrained moral, practical, and empirical reasoning.