 Though private property is a system of individual decision-making, it is still a system of social rules. The owner is not required to rely on her own strength to vindicate her right to make self-interested decisions about the object assigned to her: if Jennifer’s employees occupy the steel factory to keep it operating despite her wishes, she can call the police and have them evicted; she does not have to do this herself or even pay for it herself. So private property is continually in need of public justification—first, because it empowers individuals to make decisions about the use of scarce resource in a way that is not necessarily sensitive to others’ needs or the public good; and second, because it does not merely permit that but deploys public force at public expense to uphold it.