I am grateful to Donald Ainslie, Lisa Austin, Michael Blake, Abraham Drassinower, David Dyzenhaus, George Fletcher, Robert Gibbs, Louis-Philippe Hodgson, Sari Kisilevsky, Dennis Klimchuk, Christopher Morris, Scott Shapiro, Horacio Spector, Sergio Tenenbaum, Malcolm Thorburn, Ernest Weinrib, Karen Weisman, and the Editors of Philosophy & Public Affairs for comments, and audiences in the UCLA Philosophy Department and Columbia Law School for their questions.