These reflect the nature of the soul. The soul has three parts. Justice consists of the proper interplay of the three parts of the soul. Society and Ethics In Plato's Republic, society mirrors the individual soul. And the virtues of society mirror the virtues of the individual soul.
Society has three groups.
Justice in society is the proper conformity of the three groups to their social roles. Each group has its own place, according to its natural abilities. The aristocrats are to rule wisely, and the other groups are to obey and to do their own tasks. This will promote the happiness of the city and of its members. The GOOD is not an object of sense.