How should we regulate the U.S. financial system after the financial crisis when we face the task with a radically inadequate understanding of what went wrong and what effect proposed regulations will likely have? This paper explores three quite different approaches to regulating in the face of severe uncertainty: the libertarianism of Friedrich Hayek, the conservatism of Michael Oakeshott, and the liberalism of John Maynard Keynes. Each man thought deeply about the problem of how uncertainty affects human affairs, but each came to different conclusions about how to address such uncertainty. The paper outlines the core, immensely useful insights of each theorist. The paper then outlines the even more useful and persuasive critiques that each launches at the other two. From