In his famous Wager, Blaise Pascal (1623–62) offers the reader an argument that it is rational to strive to believe in God. Philosophical debates about this classic argument have continued until our own times. This volume provides a comprehensive examination of Pascal's Wager, including its theological framework, its place in the history of philosophy, and its importance to contemporary decision theory. The volume starts with a valuable primer on infinity and decision theory for students and non-specialists. A sequence of chapters then examines topics including the Wager's underlying theology, its influence on later philosophical figures, and contemporary analyses of the Wager including Alan Hájek's challenge to its validity, the many gods objection, and the ethics of belief. The final five chapters explore various ways in which the Wager has inspired contemporary decision theory, including questions related to infinite utility, imprecise probabilities, and infinitesimals. 'Given the importance of Pascal's wager, both intrinsically and in terms of its historical influence, this book is an important contribution to the literature.' B. T. Harding, Choice Presents a comprehensive examination of Pascal's Wager, its underlying theology, philosophical influence, and role in contemporary decision theory. Paul Bartha is Professor and Head of the Department of Philosophy, University of British Columbia, Vancouver. He is the author of By Parallel Reasoning: The Construction and Evaluation of Analogical Arguments (2010). Lawrence Pasternack is Professor of Philosophy at Oklahoma State University. His publications include Routledge Philosophy Guidebook to Kant on Religion within the Boundaries of Mere Reason (2013).