This is a new translation of one of the classics of the traditions of anarchism and socialism. Pierre-Joseph Proudhon was a contemporary of Marx and one of the most acute, influential, and subversive critics of modern French and European society. What is Property? (1840) has become a classic of political thought through its wide-ranging and deep-reaching critique of private property as at once the essential institution of Western culture and the root cause of greed, corruption, political tyranny, social division, and violation of natural law.