Introduction. The Mercantilist School. The Physiocratic School. The Classical School: Forerunners. The Classical School: Adam Smith. The Classical School: Thomas Malthus. The Classical School: David Ricardo. The Classical School: Bentham, Say, Senior, And Mill. The Rise of Socialist Thought. Marxian Socialism. The German Historical School. The Marginalist School: Forerunners. The Marginalist School: Jevons, Menger, Von Wieser, And Bohm-Bawerk. The Marginalist School: Edgeworth and Clark. The Neoclassical School: Alfred Marshall. The Neoclassical School: Monetary Economics. The Neoclassical School: The Departure from Pure Economics. Mathematical Economics. The Institutionalist School. Welfare Economics. The Keynesian School: John Maynard Keynes. The Keynesian School: Developments Since Keynes. Theories of Economic Development and Growth. The Chicago School: The New Classicalism. Conclusions.