 Philosophical discussion of justice begins with Plato, who treats the topic in a variety of dialogues, most substantially in Republic. There Plato offers the first sustained discussion of the nature of justice (dikaiosune) and its relation to happiness, as a departure from three alternatives receiving varying degrees of attention. First, there is a traditionalist conception of justice (speaking the truth and paying your debts). Second, Plato has Socrates rebut the Sophist conception of justice which built on a distinction between nature (phusis) and convention (nomos) As Plato has this conception articulated by Thrasymachus in Book I, justice is simply the “advantage of the stronger,” not tracking anything like the sort of value attributed to it by traditionalists. Finally, Plato has Socrates confront a conventionalist conception of justice that anticipates modern contractarian views, in which justice — forbearing preying on others in exchange for not being preyed on by them — is a “second-best alternative,” not as good as being able to prey at will upon others, but better than being the prey of others. These last two challenges give rise to the central question of the book: to whose advantage is justice? Would we really be better off being unjust if we could get away with it? Plato’s negative answer to that question is the project of the balance of the work.