Anarchy is the condition of a society, entity, group of people, or a single person that rejects hierarchy. The term originally meant leaderlessness, but in 1840, Pierre-Joseph Proudhon adopted the term in his treatise What Is Property? to refer to a new political philosophy, anarchism, which advocates stateless societies based on voluntary associations. In practical terms, anarchy can refer to the curtailment or abolition of traditional forms of government.
The word anarchy comes from the ancient Greek ἀναρχία (anarchia), which combines (a), "not, without" and (arkhi), "ruler, leader, authority." Thus, the term refers to a person or society "without rulers" or "without leaders."
The German philosopher Immanuel Kant treated anarchy in his Anthropology from a Pragmatic Point of View as consisting of "Law and Freedom without Force". Thus, for Kant, anarchy falls short of being a true civil state because the law is only an "empty recommendation" if force is not included to make this law efficacious ("legitimation" from "lex timere" = "fearing the law"). For there to be such a state, force must be included while law and freedom are maintained, a state which Kant calls republic.
Kant identified four kinds of government:
Anarchism is a political philosophy that advocates self-governed societies based on voluntary institutions. These are often described as stateless societies, although several authors have defined them more specifically as institutions based on non-hierarchical free associations. Anarchism holds the state to be undesirable, unnecessary, or harmful. While anti-statism is central, anarchism entails opposing authority or hierarchical organisation in the conduct of all human relations, including, but not limited to, the state system.