Anarchism

Anarchism is a political philosophy which considers the state undesirable, unnecessary, and harmful, and instead promotes a stateless society, or anarchy. It seeks to diminish or even abolish authority in the conduct of human relations. Anarchists may widely disagree on what additional criteria are required in anarchism. The Oxford Companion to Philosophy says, "there is no single defining position that all anarchists hold, and those considered anarchists at best share a certain family resemblance."

Etymology and terminology
For more information, see Anarchist terminology

The term anarchism derives from the Greek ἄναρχος, anarchos, meaning "without rulers", from the prefix ἀν- (an-, "without") + ἀρχή (archê, "sovereignty, realm, magistracy") + -ισμός (-ismos, from the suffix -ιζειν, -izein "-izing"). There is some ambiguity with the use of the terms "libertarianism" and "libertarian" in writings about anarchism. Since the 1890s from France, the term "libertarianism" has often been used as a synonym for anarchism and was used almost exclusively in this sense until the 1950s in the United States; its use as a synonym is still common outside the United States. Accordingly, "libertarian socialism" is sometimes used as a synonym for socialist anarchism, to distinguish it from "individualist libertarianism" (individualist anarchism). On the other hand, some use "libertarianism" to refer to individualistic free-market philosophy only, referring to free-market anarchism as "libertarian anarchism"