Pierre Joseph Proudhon was a French political philosopher, social theorist, and economist whose influence on economic theory is significant. In the section "Introduction," his background and influences that shaped his ideas are analyzed. His philosophical and political works are examined to gain a better understanding of his thinking. Special attention is given to his work "What is Property?" in which he presented his critique of capitalism and economic inequality. The comparison of Proudhon with other economists includes a comparison with Adam Smith and Karl Marx, but with a particular focus on Vilfredo Pareto. Proudhon's impact on political and economic practice is explored through an analysis of his social doctrine, the concept of mutualism, and advocacy for federalism and decentralization of power. His influence on the anarchist movement is also emphasized. Proudhon's influence on contemporary economic debates and political movements is also highlighted. His ideas leave a legacy in discussions on justice, equality, and societal organization. The influence of Proudhon is evident in contemporary political and economic movements that deal with social justice and alternative economic systems. Proudhon's thought and ideas continue to be relevant and subject to discussions in contemporary economic and political circles, and his influence extends to contemporary political and economic movements.