AbstractA property right, the standard view maintains, is a proper subset of the most complete and comprehensive set of incidents for full ownership of a thing. The subsidiary assumption is that the pieces that are property rights compose the whole that is ownership or property, i.e., that property rights explain property. In reversing the standard view I argue that (1) a custom of intelligent and meaningful human action explains property and that (2) as a custom, property is a historical process of selecting actions conditional on the context. My task is to explain how a physical world of human bodies with minds that feel, think, know, and want gives rise to a custom of property with meaning and purpose. Property is primary because ideas are primary.