In his classic work, The Republic, Plato puts forth a definition of justice that would be considered rather counterintuitive today. He argues that justice in both the state and the individual is basically "minding one's own business", or performing the function for which one is best suited and not interfering with others doing the same. This essay will explore why Plato thinks this is the case and how his definition is different from most people's idea of justice today.
Plato begins by saying that the ideal state must have the four traditional virtues of wisdom, courage, self-discipline and justice. Furthermore, he argues, the first three qualities are present in the state because they are present in the individual citizens of the state. In other words, because the Guardians are wise and the Auxiliaries are brave, the state is thereby both wise and brave. The state can be said to have self-discipline insofar as there is agreement among the three classes (Guardians, Auxiliaries, and businessmen), about who should rightfully rule. Having identified these three virtues within the state, Plato concludes that whatever quality is left over without a label must be the quality which makes the others possible: justice.
Plato maintains that justice is the requirement set forth at the beginning of the dialogue, that one man should do the one job for which he is naturally best fitted and should not try to do anyone else's job. That is, "Justice consists in minding your own