restrictions on how those privileges may be exercised." Property rights Left-libertarians generally uphold self-ownership and oppose strong private property rights, instead supporting the egalitarian distribution of natural resources. Other left-libertarians believe that neither claiming nor mixing one's labor with natural resources is enough to generate full private property rights and maintain that natural resources ought to be held in an egalitarian manner, either unowned or owned collectively. Political scientist Peter Mclaverty notes it has been argued that socialist values are incompatible with the concept of self-ownership when this concept is considered "the core feature of libertarianism" and socialism is defined as holding "that we are social beings, that society should be organised, and individuals should act, so as to promote the common good, that we should strive to achieve social equality and promote democracy, community and solidarity." However, political philosopher Nicholas Vrousalis has also argued that "property rights [...] do not pass judgment as to what rights individuals have to their own person [...] [and] to the external world" and that "the nineteenth-century egalitarian libertarians were not misguided in thinking that a thoroughly libertarian form of communism is possible at the level of principle." Economics Other left-libertarians make a libertarian reading of progressive and social-democratic economics to advocate a universal basic income. Building on Michael Otsuka's conception of "robust libertarian self-ownership", Karl Widerquist argues that a universal basic income must be large enough to maintain individual independence regardless of the market value of resources because people in contemporary society have been denied direct access to enough resources with which they could otherwise maintain their existence in the absence of interference by people who control access to resources. Schools of thought Anarchism Anarchism is a political philosophy that advocates stateless societies characterized by self-governed, non-hierarchical, voluntary institutions. It developed in the 19th century from the secular or religious thought of the Enlightenment, particularly Jean-Jacques Rousseau's arguments for the moral centrality of freedom. In France, revolutionaries began using anarchiste in a positive light as early as September 1793. Pierre-Joseph Proudhon was the first self-proclaimed anarchist (a label he adopted in his treatise What Is Property?) and is often described as the founder of modern anarchist theory. Proudhon's opposition to the state, organized religion, and certain capitalist practices inspired subsequent anarchists and made him one of the leading social thinkers of his time. However, French anarchist Joseph Déjacque castigated Proudhon for his sexist