Pierre Joseph Proudhon

But the two most important influences on Courbet's thought were surely Max Buchon (a friend since school days), an author of rural novels and a confirmed, even fanatical, republican (a position that forced him into exile in Belgium for a considerable period), and above all Pierre Joseph Proudhon, the philosopher and revolutionary thinker, most famous perhaps for his statement of 1840, "Qu'est-ce que propriété?"

The Born Rebel Artist Golding, John 2008

Anarchism is an umbrella term covering disparate social and political theories - among them classic or cooperative anarchism (postulated by William Godwin and, later, Pierre Joseph Proudhon), radical individualism (Max Stirner), religious anarchism (Leo Tolstoy), anarcho-communism (Kropotkin) and anarcho-syndicalism, educational anarchism (Paul Goodman), and communitarian anarchism (Daniel Guerin).

Anarchism for a Post-modern Age 2006