David Schmidtz is Professor of Philosophy, joint Professor of Economics, and Director of the Program of Philosophy of Freedom at the University of Arizona. He is the author of Rational Choice and Moral Agency and co-author, with Robert Goodin, of Social Welfare and Individual Responsibility. He is editor of Robert Nozick and edited, with Elizabeth Willott, Environmental Ethics: What Really Matters, What Really Works. His lectures on justice have taken him to sixteen countries and six continents.