In his "Theory of Property" (1866), Pierre-Joseph Proudhon subjects capitalist property to a scientific and political fundamental critique. Its relevance becomes particularly evident where he characterizes it as an instrument of growing economic and political power and as a subject of increasingly sharp intra-societal conflicts. With this critique, Proudhon connects his concept of a socially oriented organization of property within an economy based on the principle of reciprocity, which is brought into discussion with the present translation.