for capitalism to function. Rothbard also wrote a piece published posthumously entitled "Are Libertarians 'Anarchists'?" in which he traced the etymological roots of anarchist philosophy, ultimately coming to the conclusion that "we find that all of the current anarchists are irrational collectivists, and therefore at opposite poles from our position. That none of the proclaimed anarchist groups correspond to the libertarian position, that even the best of them have unrealistic and socialistic elements in their doctrines". Furthermore, he wrote: "We must therefore conclude that we are not anarchists, and that those who call us anarchists are not on firm etymological ground, and are being completely unhistorical. On the other hand, it is clear that we are not archists either: we do not believe in establishing a tyrannical central authority that will coerce the noninvasive as well as the invasive. Perhaps, then, we could call ourselves by a new name: nonarchist". Anarchist view Conversely, anarchists do not believe that anarcho-capitalism can be considered to be a part of the anarchist movement due to the fact that anarchism has historically been an anti-capitalist movement and see anarchism as fundamentally incompatible with capitalism because capitalism produces an economic hierarchy. Throughout its history, anarchism has been defined by its proponents in opposition to capitalism which they believe can be maintained only by state violence. Anarchists follow Pierre-Joseph Proudhon in opposing ownership of workplaces by capitalists and aim to replace wage labor with workers' associations. Anarchists also agree with Peter Kropotkin's comment that "the origin of the anarchist inception of society [lies in] the criticism [...] of the hierarchical organisations and the authoritarian conceptions of society" rather than in simple opposition to the state or government. They argue that the wage system is hierarchical and authoritarian in nature and consequently capitalism cannot be anarchist. Individualist anarchists, including Tucker and Spooner who Rothbard claimed as anarcho-capitalist influences, considered themselves "fervent anti-capitalists [who see] no contradiction between their individualist stance and their rejection of capitalism". Many defined themselves as socialists. Those early individualist anarchists defined capitalism in various ways, but it was often discussed in terms of usury: "There are three forms of usury, interest on money, rent on land and houses, and profit in exchange. Whoever is in receipt of any of these is a usurer". Excluding these, they tended to support free trade, free competition and varying levels of private property such as mutualism based