Specialization and the division of labor are two important forms of social interaction that allow two or more individuals to do what an isolated individual cannot do. Both are means to increase the production of goods and services. Specialization is the case where an individual (firm, organization or country) focuses on the production of a specific good (or group of goods). It can increase the amount of goods that can be produced. It also requires some form of social institution to coordinate the process. If one individual produces food and the other clothing, the two individuals must interact if both are to have food and clothing. This interaction may be facilitated through an institution such as the market or a transfer based on kinship, marriage, religion or government authority. Plato suggests that the city-state is a social construct that is used to facilitate specialization and to improve the welfare of the members of that state. In The Republic , Plato [427-347 B.C.] suggests specialization as an explanation of the origins of the city-state. Plato describes a conversation between Socrates and a group of students. They are pondering the nature of justice. They conclude that justice is each person doing that which they are best suited to do. The person best suited to be a baker should be a baker: the person best suited to be a shepherd should be a shepherd. Once individuals specialize, the city-state arises to facilitate the transfer of goods and the necessary interactions among the individuals. [ The Republic , Book II] Plato tries to identify the characteristics of the ideal society. One of the focal points is justice that is achieved by “each person doing what they are best suited to do.” Social interaction is required because each person depends on the other members of the community. He devises a meritocracy that is lead by philosopher kings. To prevent nepotism and greed from influencing these philosopher kings, Plato does not allow the philosopher kings to hold private property rights, all of their property is held in common.