Pierre-Joseph Proudhon (15 January 1809 – 19 January 1865) is a French politician, mutualist philosopher, economist, and socialist.

He is a member of the French Parliament and the first person to call himself an "anarchist".

He is considered among the most influential theorists and organizers of anarchism.

After the events of 1848, he begins to call himself a federalist.

Proudhon, who was born in Besançon, is a printer who teaches himself Latin in order to better print books in the language.

His best-known assertion is that Property is Theft!, contained in his first major work, What is Property?

Or, an Inquiry into the Principle of Right and Government (Qu'est-ce que la propriété?

Recherche sur le principe du droit et du gouvernement), published in 1840.

The book's publication attracts the attention of the French authorities.

It also attracts the scrutiny of Karl Marx, who starts a correspondence with its author.

The two influence each other: they meet in Paris while Marx is exiled there.

Their friendship finally ends when Marx responded to Proudhon's The System of Economic Contradictions, or The Philosophy of Poverty with the provocatively titled The Poverty of Philosophy.

The dispute becomes one of the sources of the split between the anarchist and Marxian wings of the International Working Men's Association.

Some, such as Edmund Wilson, have contended that Marx's attack on Proudhon had its origin in the latter's defense of Karl Grün, whom Marx bitterly disliked, but who had been preparing translations of Proudhon's work.

Proudhon favors workers' associations or cooperatives, as well as individual worker/peasant possession, over private ownership or the nationalization of land and workplaces.

He considers that social revolution could be achieved in a peaceful manner.

In The Confessions of a Revolutionary, Proudhon asserts that “Anarchy is Order Without Power”, the phrase which much later inspires, in the view of some, the anarchist circled-A symbol, today "one of the most common graffiti on the urban landscape."

(Marshall, Peter.

Demanding the Impossible.

Fontana, London.

1993. p. 558) He unsuccessfully tries to create a national bank, to be funded by what becomes an abortive attempt at an income tax on capitalists and stockholders.

Similar in some respects to a credit union, it would have given interest-free loans.