In the summer of 1951, Mises, as he did every year, gave a series of lectures at the Foundation for Economic Education. Bettina Bien Greaves took word for word shorthand notes at those lectures and they are transcribed in this collection. The nine lectures included here cover the foundations of economics, the nature of economics, socialism, the achievements of capitalism, and three lectures devoted to monetary theory, inflation, and business cycles. Delivered just two years after the publication of Human Action, these lectures are Mises the teacher in his prime, making economics understandable for the interested citizen.