The term "liberalism" comes from the Latin word liber meaning "free." Mises defines liberalismas "the liberal doctrine of the harmony of the rightly understood interests of all members of a free society founded on the principle of private ownership of the means of production." This book presents the theoretical and practical arguments for liberalism in the classical tradition.

The foundation of liberalism, Mises says, rests on an understanding and appreciation of private property, social cooperation, the freedom idea, ethics and morality, democracy, and the legitimate role of government. Liberalism is not a political party; it is a system of social organization. The liberal program aims at securing equality under law and freedom of opportunity for everyone to make their own choices and decisions, so long as they do not interfere with the equal rights of others; it offers no special privileges to anyone. Under liberalism, the role of government would be limited to protecting the lives, property, and freedom of its citizens to pursue their own ends and goals. Mises is more specific here than elsewhere in applying the liberal program to economic policy, domestic and foreign. Also in this book, Mises contrasts liberalism with other conceivable systems of social organization such as socialism, communism, and fascism.

Ludwig von Mises (1881–1973) was the leading spokesman of the Austrian School of Economics throughout most of the twentieth century. He earned his doctorate in law and economics from the University of Vienna in 1906. In 1926, Mises founded the Austrian Institute for Business Cycle Research. From 1909 to 1934, he was an economist for the Vienna Chamber of Commerce. Before the Anschluss, in 1934 Mises left for Geneva, where he was a professor at the Graduate Institute of International Studies until 1940, when he emigrated to New York City. From 1948 to 1969, he was a visiting professor at New York University.