This book restates the importance of the study of the history of ideas, in the context of the writings of economists. After an initial statement, a case study involving five methodological detours is considered. This is followed by an analysis of a flawed attempt to remedy the manifest deficiencies of the static general equilibrium model. A general overview of classical economics is followed by an account of the world of Alfred Marshall who did so much to bridge the gap between classical and neo-classical economics. The work of two great historians of economics, Edwin Cannan and J.R. McCulloch, is discussed, as well as that of Paul Samuelson who while a leading theorist has defied the narrow essentialism now fashionable, and remained a scholar. There are also three chapters dealing with one of the most learned writers on economics, Friedrich Hayek. Illustrated by discussions of methodological and historical issues, the book will be essential reading for economists, researchers and students of the history of economic thought.