Human Action: A Treatise on Economics.

Human Action is the single most important work by Ludwig von Mises and one of the most influential economic works of the twentieth century. First published by Yale University Press in 1949, it presents his comprehensive theory of praxeology, the study of human action and choice, and mounts a rigorous defense of free-market capitalism and methodological individualism against socialism and central planning. A foundational text of the Austrian School, it profoundly shaped libertarian and free-market thought, influencing figures from Friedrich Hayek to Murray Rothbard, and remains a landmark treatise on economics and human liberty. "It should become the leading text of everyone who believes in freedom, in individualism, and in the ability of a free-market economy not only to outdistance any government-planned system in the production of goods and services for the masses, but to promote and safeguard... those intellectual, cultural, and moral values upon which all civilization ultimately rests" (Henry Hazlitt).