Samuel C. Rickless is Professor of Philosophy at the University of California, San Diego. Educated at Harvard (BA, 1986) and Balliol College, Oxford (BPhil 1988), he earned his PhD in philosophy at the University of California, Los Angeles, in 1996. After five years of teaching at Florida State University, he joined the UCSD philosophy department in 2001. He is the author of Plato's Forms in Transition (CUP, 1997), and articles on a variety of subjects in the history of philosophy, including Socrates' theory of virtue; Plato's theory of forms; Plato's method of definition; the Cartesian Circle; early modern theories of primary and secondary qualities; Locke's theory of knowledge, rejection of innate ideas, and philosophy of action; Hume's account of the passions; and Kant's argument for the Categorical Imperative. His research interests extend to normative ethics, constitutional law, and philosophy of language. He is at work on a book on Locke for Wiley-Blackwell's Great Minds series.