PROUDHON'S COLLECTED WORKS
What is Property (1840)
Qu'est-ce que la propriété
System of Economical Contradictions: or, the Philosophy of Misery (1846)
(Etext Version from Project Gutenberg) or broken into chapters
The Malthusians: Le Représentant du Peuple, 10th August 1848.
Celebration of Sunday [pdf]
General Idea of Revolution (1851)
Shawn Wilber's revised translation:
THE STATE: Its Nature, Object, and Destiny. Translated from the Voix du Peuple of December 3, 1849, by Benj. R. Tucker.
"The Coming Era of Mutualism," The Spirit of the Age, I, 7 (August 18, 1849), 107-8.
Proudhon's Solution of the Social Problem (excerpts). Edited by Henry Cohen. Vanguard Press, 1927.
Correspondance de P.J. Proudhon
"Etre Gouverne", from: Idée Générale de la Révolution au XIXe Siècle
A Letter To M. Blanqui. Paris, April 1, 1841.
Interest and Principal: A Loan is a Service,
Letter addressed to Frederic Bastiat in The Voice of the People, 1849.
Interest and Principal: The Circulation of Capital, Not Capital Itself, Gives Birth to Progress,
Letter addressed to Frederic Bastiat in The Voice of the People, 1849.
Interest and Principal: The Origin of Ground Rent, Letter addressed to Frederic Bastiat in The Voice of the People, 1849.
Interest and Principal: Arguments Drawn from the Operations of the Bank of France, Letter addressed to Frederic Bastiat in The Voice of the People, 1849.
The Philosophy of Progress [pdf] [html version]
The causes of oppression [pdf in french] Excerpts in html
La guerre et la paix: recherches sur le principe et la Constitution Du Droit Des Gens, [pdf in French] [pdf English trans. of Preface]
Les Confessions d'un révolutionaire pour servire à l'histoire de la Révolution de Févier. [pdf in French]
Several letters between Bastiat and Proudhon can be found on the Bastiat site.