pSmith's Wealth of Nations, Marx's Capital and Keynes's General Theory are three paradigmatic texts which are foundational to any study of economics or political economy. Although they have long been abundantly quoted and commented on, these Great Books paradoxically are being read less and less, as the price of their success. The aim of this book is to encourage the reader to re-read these Texts, by providing theoretical and conceptual entries in the spirit of a reasoned dictionary. Hence the return to these works in the text, in statu nascendi, in order to shed light on their complexities, to loosen the imperialism of received ideas, and to underline their topicality from a theoretical point of view and for the understanding of contemporary economic issues. For example, Adam Smith's view of the need to add a liberal state to the system of natural liberty, Marx's view of the ability of the capitalist system to overcome temporarily but periodically its contradictions, or Keynes' view o