In the first book of the Republic (ca. 380 BCE), the Greek philosopher Plato attempts to establish the nature of justice. This task is a keystone of all Plato’s philosophy, which endeavors to answer the question “How should men live?” In “Of Wealth, Justice, Moderation, and Their Opposites,” Plato’s answer takes a political dimension. He begins by trying to define justice as an exemplary virtue (a specific instance of the most general form of the good itself), which leads to an investigation of the forces that define society and suggest how an ideal state should be constructed. Plato has the character Socrates (not necessarily expressing the actual thoughts of Plato’s great teacher) refute two common ideas of justice that opposed Plato’s own. The first is the “common sense” tradition of Greek culture. The second is that of the Sophists, the leading teachers of Socrates’ generation, who held that the stronger argument is necessarily the most just—in other words, that intellectual might makes right. In later books of the Republic, a work still regarded as one of the most important documents in the history of philosophy, Plato goes on to establish his own idea of justice and how human beings and societies might be transformed by truly serving the ends of justice.