Douglas J. Den Uyl is Vice President of Educational Programs at Liberty Fund, Inc. He has published essays or books on Spinoza, Smith, Shaftesbury, Mandeville and others. His most recent books include the co-authorship with Douglas B. Rasmussen of the 2006 book Norms of Liberty and God, Man and Well-Being: Spinoza's Modern Humanism in 2008. He co-founded (with Douglas Rasmussen) the American Association for the Philosophic Study of Society, The North American Spinoza Society, and The International Adam Smith Society. He taught Philosophy and was Department Chair and Full Professor at Bellarmine College (now Bellarmine University) before coming to Liberty Fund.

Douglas B. Rasmussen is Professor of Philosophy at St. John's University in New York City. He is the author of numerous articles in various philosophical journals and books as well as coauthor (with Douglas J. Den Uyl) of Liberty and Nature, Liberalism Defended, and Norms of Liberty (which has been translated into Portuguese and Spanish). His research interests are in ethics, political philosophy, epistemology, ontology, and political economy.