This chapter explores the constitutional ramifications of the French Revolution’s transformation of the old regime of property. It reinterprets the abolition of feudalism as part of the revolutionaries’ larger attempt to draw a conceptual and legal line of demarcation between property and power. Their double aim was to make property truly private by stripping from it all attributes of public authority and to make power truly public by eliminating its former patrimonial characteristics. The attempt to implement this demarcation in practice was still underway decades after the Revolution had formally ended feudalism. Over time, it largely succeeded. From this distinction between property and power flowed some of the key conceptual binaries – the political and social, state and society, public and private, sovereignty and property – through which we still apprehend the world. The abolition of feudalism was thus much more than simply the eradication of an archaic form of property. Rather, it played an essential role in shaping the conceptual building blocks from which modernity was built.