Roy Kreitner teaches courses on private law, legal history, and law and political thought at Tel-Aviv University’s Law School, where he has been on the faculty since 2001. He received an S.J.D. from Harvard Law School, an LL.B. and an M.A. (Comparative Literature & Semiotics) from Tel-Aviv University, and an A.B. from Brown University. He has been a Visiting Professor at the University of Virginia and at the University of Toronto. He is the author of Calculating Promises: The Emergence of Modern American Contract Doctrine (Stanford University Press, 2007). During 2009-2010 he was a fellow at The Radcliffe Institute for Advanced Study at Harvard University and an American Council of Learned Societies Fellow. In 2010-2011 he was a visiting researcher at the Institute for Global Law and Policy at Harvard Law School. For their patience in discussing the ideas presented here, he wishes to thank Christine Desan, Chris Tomlins, David Grewal, and Mickey Zar.