Where does private property begin, why does it arise, and how does it affect society? In the book "What is Property? A Study of the Principle of Law and Government" by the famous anarchist Pierre-Joseph Proudhon, there are answers to these questions. The author expresses his advanced views on the essence of property, considering it as a fundamental principle of society. The book provokes the reader to think about justice, the possibility of coexistence and interaction of people in the conditions of ownership. Using logical reasoning and analysis of social relations, Proudhon reveals the deep principles of law and private property. This book has become a classic work of anarchist theory and philosophy that continues to provoke intellectual debate and spread new ideas about social interaction.