  Despite the abstract and deeply controversial nature of metaethics, its central concerns arise naturally — perhaps even inevitably — as one reflects critically on one's own moral convictions. So it is no surprise that, in Plato's Republic, Polemarchus’ claim that being a just person enhances one's life developed quickly into a decidedly metaethical discussion of the origin and nature of justice. Early in Book I, for instance, Thrasymachus defends the idea that justice is whatever is in the interest of the stronger, arguing that morality is a human creation designed by the rich and powerful to control and exploit others. A myth for the weak-minded, arranged for the advantage of a few, justice imposes burdens most have reason to set aside. So Thrasymachus argues. Glaucon follows up, in Book II, with an alternative, and less cynical, proposal. While he too sees morality as a human creation, he sees it as a salutary solution to the serious problems we would otherwise face. He argues that people naturally find themselves unable successfully to ensure that their own wills will rule while, simultaneously, being subject regularly to the will of others.  The principles of justice are, he thinks, reasonably introduced and enforced by all as a good way to ensure peace and stability in society. Socrates, in contrast, rejects the idea that justice is a human invention and argues instead that justice provides independent and eternal standards against which human practices, conventions, and institutions can be judged. These different views will likely have implications for what value justice might have. At the same time, though, accepting one or the other view of the nature of justice is compatible with a range of substantive views about what, specifically, justice consists in and about its value.  