Etymology, terminology and definition
The etymological origin of anarchism derives from ancient Greek word anarkhia. Anarkhia meant "without a ruler" as it was composed by the prefix a (i.e. "without") and the word arkhos (i.e. leader or ruler). The suffix -ism is used to denote the ideological current that favours anarchism. The first known use of this word was in 1642. Various factions within the French Revolution labelled opponents as anarchists although few shared many views of later anarchists. There would be many revolutionaries of the early 19th century who contributed to the anarchist doctrines of the next generation, such as William Godwin and Wilhelm Weitling, but they did not use the word anarchist or anarchism in describing themselves or their beliefs.
The first political philosopher to call himself an anarchist was Pierre-Joseph Proudhon, marking the formal birth of anarchism in the mid-19th century. Since the 1890s and beginning in France, the term libertarianism has often been used as a synonym for anarchism and its use as a synonym is still common outside the United States. On the other hand, some use libertarianism to refer to individualistic free-market philosophy only, referring to free-market anarchism as libertarian anarchism.
While opposition to the state is central, defining anarchism is not an easy task as there is a lot of talk among scholars and anarchists on the matter and various currents perceive anarchism slightly differently. Hence, it might be true to say that anarchism is a cluster of political philosophies opposing authority and hierarchical organization (including the state, capitalism, nationalism and all associated institutions) in the conduct of all human relations in favour of a society based on voluntary association, freedom and decentralisation, but this definition has the same shortcomings as the definition based on etymology (which is simply a negation of a ruler), or based on anti-statism (anarchism is much more than that) or even the anti-authoritarian (which is an a posteriori conclusion). Major elements of the definition of anarchism include: a) the will for a non-coercive society; b) the rejection of the state apparatus; c) belief that human nature allows humans to exist in or progress toward such a non-coercive society; and d) a suggestion on how to act to pursue the ideal of anarchy.