This chapter discusses the most famous hypothesis about the development of property law: that Western social evolution was determined by a passage “from slavery to feudalism,” from the ownership of humans in the slave economies of Antiquity to the ownership of land in the feudal economies of the Middle Ages. That hypothesis was embraced by Marx, Weber, Bloch, and many others, but has been rejected today, because it rested on claims about economic history that have been proven dubious. The chapter argues that there was truth in the classical hypothesis, but that it should be reinterpreted as an account of transformation in the legal imagination. The chapter investigates the origins of the classic theories, and makes the case that the classic thinkers erred by mistaking the imaginative orientations in the legal sources for the economic realities.