David Gauthier is Distinguished Service Professor Emeritus at the University of Pittsburgh. He previously held postions at the University of Toronto, and has held visiting appointments at UCLA, UC Berkeley, Princeton, UC Irvine, and the University of East Anglia. He is the author of Practical Reasoning: The Structure and Foundations of Prudential and Moral Arguments and their Exemplification in Discourse (OUP, 1963), The Logic of Leviathan: The Moral and Political Theory of Thomas Hobbes (OUP 1969), Morals by Agreement (OUP, 1986), Moral Dealing: Contract, Ethics, and Reason (Cornell, 1990), and Rousseau: The Sentiment of Existence (Cambridge, 2006).