text: Many facets of human civilization have been influenced by anarchist theory, critique, and praxis.Etymology, terminology, and definition The etymological origin of anarchism is from the Ancient Greek anarkhia, meaning "without a ruler", composed of the prefix an- ("without") and the word arkhos ("leader" or "ruler").The suffix -ism denotes the ideological current that favours anarchy.Anarchism appears in English from 1642 as anarchisme and anarchy from 1539; early English usages emphasised a sense of disorder.Various factions within the French Revolution labelled their opponents as anarchists, although few such accused shared many views with later anarchists.Many revolutionaries of the 19th century such as William Godwin (1756–1836) and Wilhelm Weitling (1808–1871) would contribute to the anarchist doctrines of the next generation but did not use anarchist or anarchism in describing themselves or their beliefs.The first political philosopher to call himself an anarchist () was Pierre-Joseph Proudhon (1809–1865), marking the formal birth of anarchism in the mid-19th century.Since the 1890s and beginning in France, libertarianism has often been used as a synonym for anarchism and its use as a synonym is still common outside the United States.Some usages of libertarianism refer to individualistic free-market philosophy only, and free-market anarchism in particular is termed libertarian anarchism.While the term libertarian has been largely synonymous with anarchism, its meaning has more recently been diluted by wider adoption from ideologically disparate groups, including both the New Left and libertarian Marxists, who do not associate themselves with authoritarian socialists or a vanguard party, and extreme cultural liberals, who are primarily concerned with civil liberties.Additionally, some anarchists use libertarian socialist to avoid anarchism's negative connotations and emphasise its connections with socialism.