With the domestication of animals, herding, and animal husbandry came private property. To ensure security of private property the monogamous, patriarchal family was created to ensure that man s belongings stayed within his biological offspring. Women s oppression is linked to private property and the creation of the monogamous, patriarchal family for protection of family stuff through bloodline. In Classical Liberal political philosophy the private sphere is made up of a biologically determined social unit. The public realm, on the other hand, is a complicated, bustling arena of human social and political interaction wherein the laws of justice and equality are necessary for the pursuit of freedom.
Justice governs the public realm where adult men deal with adult men by making rational decisions.
The private realm contains no such decision-making, and deals solely with instinct and is so governed by natural law. Justice, equality, and freedom are possible only in the public spheres. Some contemporary liberal theory assumes that the patriarchal family is itself a just unit and focuses its concern for justice in the private realm on household income. In this sense, families are treated as social and economical units. There might be injustice or inequality between families, but not within families.