There are some topics Plato returns to again and again in his dialogues. Sometimes he does this to reiterate the same reply, sometimes to introduce a novel answer, and sometimes to address the question in a novel way. Among the questions Plato repeatedly addresses is: what is the nature of justice? What kind of thing is it, and how—if at all—is it in a person's interest to be just? And how does a person become just? As many scholars read Plato, early attempts at answering this question are largely unsuccessful, hampered by the early Plato's allegiance to distinctively Socratic modes of philosophy, the most notable example of this failed approach being found in the Gorgias. On this view, the Republic represents Plato's progression from the early, largely negative Socratic ethics and the introduction of his better, more mature account of justice, built on the foundation of a highly un-Socratic metaphysical theory. This dissertation argues, by contrast, that there is more than this to be said for the Gorgias—deeply Socratic work though it is—and that the Republic, for all the ways it represents a new developmental stage in Plato's philosophical career, is fundamentally continuous with the Gorgias on the question of justice. The dissertation works toward this conclusion from both ends. The argument starts by showing of the Gorgias that it has more to say about justice than is sometimes thought, even as it preserves the central ethical content of so distinctively Socratic a work as the Apology. Finally, I show of the Republic that, mature work though it is, we find in the essential features of its characterization of justice a clear continuity with the Socratic account of virtue in the Gorgias and Apology.