Steven M. Duncan (1954-) earned his Ph.D. from the University of Washington in 1987 and taught at various colleges and universities for nearly forty years before retiring in December, 2015 after having taught at Bellevue College since 1999. He is the author of a over twenty books, including The Proof of the External World (Wipf and Stock, 2008) and How Free Will Works (Wipf and Stock, 2011). He completed a series of monographs on topics in analytic metaphysics, a four-volume work on epistemology called The Nature of Inquiry and, more recently, three related volumes on Christian Philosophy. Visit his Amazon author page for details.