The work begins by methodically dismantling the conventional justifications for property, asserting that neither first occupation nor civil law can establish a valid right of domain. Proudhon argues that the earth is a natural and gratuitous gift to all humanity, making territorial appropriation an inherent injustice. He examines labor as the supposed efficient cause of property, demonstrating instead that true labor leads naturally to equality rather than private accumulation. The argument proceeds through a series of logical propositions proving that property is impossible because it demands something for nothing and creates economic conditions where production costs more than it is worth.
The author analyzes the psychological exposition of justice, showing how human laws have historically served to protect privilege rather than equity. By contrasting possession with absolute property, the text distinguishes between the legitimate right to use the means of production and the illegitimate claim to own them exclusively. The consequences of this distinction are explored through the mechanics of wages, exchange, and inheritance, revealing how accumulated capital exploits collective labor. Finally, Proudhon outlines the third form of society, wherein individual liberty and the balance of forces are preserved not through the abolition of labor, but through the elimination of property and the realization of universal equality.