This book is an abstract of Human Action, a treatise on economics, the magnum opus of Ludwig von Mises, a central author of the "Austrian" school and one of the greatest thinkers in economics. Published in 1949, the original work has nearly a thousand pages. Although traditionally obscured by the neoclassical mainstream, the Austrian tradition is faithful to the ideas that have prevailed from the origins of economic thinking until the beginning of the twentieth century. It embodies a realistic conception of the economic discipline, rejecting the reductionist model of homo oeconomicus and the study of equilibrium states in order to focus on the processes of change and on the causal relations between events. Those ideas form a more solid foundation for the study of the market, of money, of economic crises, of enterprise and of modern industrial structures than the neoclassical paradigm. They are gradually being rediscovered by economists and increasingly validated by the evolution of the real world. Human Action exposes those idées in a systematic way, in a language accessible to all, and beyond its economic aspect, is in addition a particularly eloquent defense of freedom. As such, it should be part of the library of any "honest man".