Plato: Republic I

What is the true nature of dikaiosyne (justice)? In the dialogue that forms Book I of The Republic Socrates meets the arguments first of Polemarchus, that justice means speaking the truth and paying one's dues in the broadest sense; then of Thrasymachus, that it is nothing more than the power which the strong exercise over the weaker members of society. In reality, Book I concludes, justice, self-control (sophrosyne), and virtue (arete) are 'natural'; the city which displays them is most truly free; the individuals who possess them will achieve their true destiny.