The economist Thomas Sowell’s prodigious output of over 30 books in the last 40 years has seen him writing on topics ranging from the basics of economic thinking to the impact of government programs on minorities to late-talking children. Sowell was born during the Great Depression and raised by his great-aunt. From these humble beginnings, he built a hugely successful and influential career as one of America’s most important economic thinkers. A major theme of his work, expanding on the ideas of F. A. Hayek, is the role knowledge plays in economies and how different institutional arrangements can either help or hinder the beneficial aggregation of dispersed knowledge. Sowell has also written at length about the unintended consequences of state run social programs such as welfare and affirmative action. He argues that many proponents of such plans are often more interested in conspicuously appearing to help than in actually having a positive impact. Some of his most theoretical work can be found in his trilogy of books on the origins of political ideologies. In A Conflict of Visions, Sowell contrasts the “constrained” and “unconstrained” visions of human nature and shows how their conflict informs much seemingly unrelated political debate. Sowell is currently a Rose and Milton Friedman Senior Fellow on Public Policy at the Hoover Institution at Stanford University.