Kenneth R. Westphal is Professor of Philosophy at Bogaziçi Üniversitesi, Istanbul. His research concerns the character and scope of rational justification in non-formal, substantive domains, including both theoretical philosophy (epistemology, history, and philosophy of science) and moral philosophy (ethics, social, political. and legal philosophy). This, his fifth monograph, is his first published by the Clarendon Press; others are issued by Cambridge University Press, Vittorio Klostermann, and Hackett Publishing Co. He has edited four collections of research and published nearly 150 research articles, in such journals as Synthese, Dialogue, Journal of the History of Philosophy, Philosophical Inquiries, Journal for the History of Analytic Philosophy, HOPOS, and Jurisprudence. His article, 'Kant on the State, Law, and Obedience to Authority in the Alleged 'Anti-Revolutionary' Writings' (1992, rpt. 2006) received the 1994 George Armstrong Kelly Prize.