Abstract: Liberal egalitarian political philosophers have often argued that private property is a legal convention dependent on the state and that complaints about taxation from entitlement theorists are therefore based on a conceptual mistake. But our capacity to grasp and use property concepts seems too embedded in human nature for this to be correct. This essay argues that many standard arguments that property is constitutivelY a legal convention fail, but that the opposition between conventionalists and natural rights theorists is outmoded. In doing this, the essay draws on recent literature in evolutionary biology and psychology. Even though modern property in a complex society involves legal conventions, those conventions should be sensitive to our natural dispositions concerning ownership.