Are the just happier than the unjust? In Plato' s Republic, Thrasymachus argues that they aren't, that justice is simply the advantage of the stronger. Though Socrates apparently refutes him, Plato's brothers, Glaucon and Adeimantus, take up his argument anew, challenging Socrates to show them that justice really does better further happiness than injustice. The nature of this renewed challenge and the reason for it are hotly debated problems. Equally problematic is the question of whether...