Stumbled across the article Plato: The Republic on the Internet Encyclopedia of Philosophy.
The dialogue explores two central questions. The first question is “what is justice?” Socrates addresses this question both in terms of political communities and in terms of the individual person or soul. He does this to address the second and driving question of the dialogue: “is the just person happier than the unjust person?” or “what is the relation of justice to happiness?” Given the two central questions of the discussion, Plato’s philosophical concerns in the dialogue are ethical and political.
I haven’t had the time to read this whole article, yet. Perhaps if I had read this back in my college freshman course in humanities, I might have actually passed the course. Of course, there was no internet back then. More’s the pity.