The notion of burden of proof and its companion notion of presumption are central to argumentation studies. This book argues that we can learn a lot from how the courts have developed procedures over the years for allocating and reasoning with presumptions and burdens of proof, and from how artificial intelligence has built precise formal and computational systems to represent this kind of reasoning. The book provides a model of reasoning with burden of proof and presumption, based on analyses of many clearly explained legal and non-legal examples. The model is shown to fit cases of everyday conversational argumentation as well as argumentation in legal cases. Burden of proof determines (1) under what conditions an arguer is obliged to support a claim with an argument that backs it up and (2) how strong that argument needs to be to prove the claim in question.

'Douglas Walton has done it again. This important and timely book should be read by everyone concerned with the health and state of argumentation in a world that seems devoid of reasoning.' Ian I. Mitroff, Center for Catastrophic Risk Management, University of California, Berkeley
'Walton's book provides a much-needed firm grasp on two of the 'slipperiest member[s] of the family of legal terms' - burden of proof and presumption - through accessible examples and clear connections to the broader field of argumentation.' Joseph A. Laronge, Trial Attorney and Adjunct Law Professor
'Walton's intellectual tour de force brings together argumentation theory, AI and law to provide a framework within which this most difficult but also highly important issue of argumentation can be addressed.' Burkhard Schafer, University of Edinburgh

Douglas Walton holds the Assumption Chair in Argumentation Studies and is Distinguished Research Fellow of the Centre for Research in Reasoning, Argumentation and Rhetoric at the University of Windsor, Canada. His most recent book is Methods of Argumentation (Cambridge University Press, 2013). Walton's work has been used to prepare better legal arguments and to help develop artificial intelligence. His books have been translated worldwide and he attracts students from many countries to study with him. A festschrift honoring his contributions, Dialectics, Dialogue and Argumentation: An Examination of Douglas Walton's Theories of Reasoning and Argument, edited by C. Reed and C. W. Tindale (2010), shows how his theories are increasingly finding applications in computer science.