Locke legitimized private property through the concept of mixing our labor with objects in nature. Hume accepts the concept of private property, and the concept of justice, from which the legitimization of private property derives, but not as something created by God and grounded in reason. Justice and private property merely functional concepts. If we imagine societies in which everyone is completely unselfish, or resources are unlimited and readily available, we recognize those societies would have no need for these concepts. In war and famine justice is set aside because we understand that people must behave out of self-interest, and we do not blame them for breaking into granaries in order to feed themselves and their families. A virtuous person in a country filled with corrupt, short-sided, selfish people without law and order would be forced to arm himself in order to survive. Rules of equality and justice depend entirely on the context of the particular state.
The masses of poor are harmed by the vanity of the few wealthy in a society. The money wasted on appearances could be used to save lives. A number of societies have existed with moderate equality, such as Sparta and the Agrarian laws of Rome. Societies that seek perfect equality make everyone poor. The most effective have been those who create laws that are beneficial to to the people, on the whole, based on utility.
Private property is a useful concept because we want people to work hard, as well as commerce, because they are both beneficial to society, and contracts because they promote commerce. Little else is necessary for a peaceful society. Because of the nature of the drive for self-interest, we must give private property priority. Self-interest is the only drive that can control self-interest, and the other drives will fall into place once it is under control. Our drives are anti-social, but self-interest quickly controls the other drives because it recognizes that we cannot survive on our own. We never actually act out of public interest. Individual acts may not be self-interested directly, through benevolence, but neither are they directed at the general public’s interest. Therefore we accept that acts of justice, on the whole, are in the private interest, and that property must be stable and fixed by general rules.