A leading expert in informal logic, Douglas Walton turns his attention in this new book to how reasoning operates in trials and other legal contexts, with special emphasis on the law of evidence. The new model he develops, drawing on methods of argumentation theory that are gaining wide acceptance in computing fields like artificial intelligence, can be used to identify, analyze, and evaluate specific types of legal argument. In contrast with approaches that rely on deductive and inductive logic and rule out many common types of argument as fallacious, Walton&’s aim is to provide a more expansive view of what can be considered &"reasonable&" in legal argument when it is construed as a dynamic, rule-governed, and goal-directed conversation. This dialogical model gives new meaning to the key notions of relevance and probative weight, with the latter analyzed in terms of pragmatic criteria for what constitutes plausible evidence rather than truth.

In the study of forms of legal reasoning, logic and argumentation theory long followed separate tracks. `Legal logicians' tended to focus on a deductive reconstruction of justifying a decision, disregarding the dialectical process leading to the chosen justification. Others instead emphasized the adversarial and discretionary nature of legal reasoning, involving reasonable evaluation of alternative choices, and the use of analogical reasoning. Recently, however, developments in Artificial Intelligence and Law have paved the way for overcoming this separation. Logic has widened its scope to defensible argumentation, and informal accounts of analogy and dialectics have inspired the construction of computer programs. Thus the prospect is emerging of an integrated logical and dialectical account of legal argument, adding to the understanding of legal reasoning, and providing a formal basis for computer tools that assist and mediate legal debates while leaving room for human initiative. This book presents contributions to this development. From a logical point of view it covers topics such as evaluating conflicting arguments, weighing reasons, modelling legal disputes as a dialogue game, the role of the burden of proof, the relation between principles, rules, reasons and facts, and the relation between deductive and nondeductive arguments. Written by leading scholars in the field and building on recent developments in logic and Artificial Intelligence, the chapters provide a state-of-the-art account of research on the logical aspects of legal argument.

Recent work in artificial intelligence has increasingly turned to argumentation as a rich, interdisciplinary area of research that can provide new methods related to evidence and reasoning in the area of law. Douglas Walton provides an introduction to basic concepts, tools and methods in argumentation theory and artificial intelligence as applied to the analysis and evaluation of witness testimony. He shows how witness testimony is by its nature inherently fallible and sometimes subject to disastrous failures. At the same time such testimony can provide evidence that is not only necessary but inherently reasonable for logically guiding legal experts to accept or reject a claim. Walton shows how to overcome the traditional disdain for witness testimony as a type of evidence shown by logical positivists, and the views of trial sceptics who doubt that trial rules deal with witness testimony in a way that yields a rational decision-making process.

After years of teaching law courses to undergraduate, graduate, and law students, Michael Evan Gold has come to believe that the traditional way of teaching – analysis, explanation, and example – is superior to the Socratic Method for students at the outset of their studies. In courses taught Socratically, even the most gifted students can struggle, and many others are lost in a fog for months. Gold offers a meta approach to teaching legal reasoning, bringing the process of argumentation to the fore. Using examples both from the law and from daily life, Gold's book will help undergraduates and first-year law students to understand legal discourse. The book analyzes and illustrates the principles of legal reasoning, such as logical deduction, analogies and distinctions, and application of law to fact, and even solves the mystery of how to spot an issue. In Gold's experience, students who understand the principles of analytical thinking are able to understand arguments, to evaluate and reply to them, and ultimately to construct sound arguments of their own.

This book intends to unite studies in different fields related to the development of the relations between logic, law and legal reasoning. Combining historical and philosophical studies on legal reasoning in Civil and Common Law, and on the often neglected Arabic and Talmudic traditions of jurisprudence, this project unites these areas with recent technical developments in computer science. This combination has resulted in renewed interest in deontic logic and logic of norms that stems from the interaction between artificial intelligence and law and their applications to these areas of logic. The book also aims to motivate and launch a more intense interaction between the historical and philosophical work of Arabic, Talmudic and European jurisprudence. The publication discusses new insights in the interaction between logic and law, and more precisely the study of different answers to the question: what role does logic play in legal reasoning? Varying perspectives include that of foundational studies (such as logical principles and frameworks) to applications, and historical perspectives.

This book, written by a leading expert, and based on the latest research, shows how to apply methods of argumentation to a range of examples.