Libertarianism (Latin: liber, “free”) is a political philosophy that upholds liberty as its principal objective. Libertarians seek to maximize autonomy and freedom of choice, emphasizing political freedom, voluntary association, and the primacy of individual judgment.^[1][2]

Libertarians generally share a skepticism of authority; however, they diverge on the scope of their opposition to existing political and economic systems. Various schools of libertarian thought offer a range of views regarding the legitimate functions of state and private power, often calling to restrict or even to wholly dissolve coercive social institutions. Rather than embodying a singular, rigid systematic theory or ideology, libertarianism has been applied as an umbrella term to a wide range of sometimes discordant political ideas through modern history.

Some libertarians advocate laissez-faire capitalism and strong private property rights,^[3]such as in land, infrastructure, and natural resources. Others, notably libertarian socialists,^[4] seek to abolish capitalism and private ownership of the means of production in favor of their common or cooperative ownership and management.^[5][6] An additional line of division is between minarchists and anarchists. While minarchists think that a minimal centralized government is necessary, anarchists propose to completely eliminate the state.^[7][8]

The term libertarianism originally referred to a philosophical belief in free will but later became associated with anti-state socialism and Enlightenment-influenced^[9][10] political movements critical of institutional authority believed to serve forms of social domination and injustice. While it has generally retained its earlier political usage as a synonym for either social or individualist anarchism through much of the world, in the United States it has since come to describe pro-capitalist economic liberalism more so than radical, anti-capitalist egalitarianism. In the Stanford Encyclopedia of Philosophy, libertarianism is defined as the moral view that agents initially fully own themselves and have certain moral powers to acquire property rights in external things.^[11] As individualist opponents of social liberalism embraced the label and distanced themselves from the word liberal, American writers, political parties, and think tanks adopted the word libertarian to describe advocacy of capitalist free market economics and a night-watchman state.