Corresponding to these three elements in human nature there are three classes in the social organism-Philosopher class or the ruling class which is the representative of reason; auxiliaries, a class of warriors and defenders of the country is the representative of spirit; and the appetite instinct of the community which consists of farmers, artisans and are the lowest rung of the ladder. Thus, weaving a web between the human organism and the social organism, Plato asserts that functional specialization demands from every social class to specialize itself in the station of life allotted to it. Justice, therefore to Plato is like a manuscript which exists in two copies, and one of these is larger than the other. It exists both in the individual and the society. But it exists on a larger scale and in more visible form in the society. Individually "justice is a 'human virtue' that makes a man self consistent and good: Socially, justice is a social consciousness that makes a society internally harmonious and good."
Justice is thus a sort of specialization. It is simply the will to fulfill the duties of one's station and not to meddle with the duties of another station, and its habitation is, therefore, in the mind of every citizen who does his duties in his appointed place. It is the original principle, laid down at the foundation of the State, "that one man should practice one thing only and that the thing to which his nature was best adopted". True justice to Plato, therefore, consists in the principle of non-interference. The State has been considered by Plato as a perfect whole in which each individual which is its element, functions not for itself but for the health of the whole. Every element fulfils its appropriate function. Justice in the platonic state would, therefore, be like that harmony of relationship where the Planets are held together in the orderly movement. Plato was convinced that a society which is so organized is fit for survival. Where man are out of their natural places, there the co-ordination of parts is destroyed, the society disintegrates and dissolves. Justice, therefore, is the citizen sense of duties.