The Republic poses questions that endure: What is justice? What form of community fosters the best possible life for human beings? What is the nature and destiny of the soul? What form of education provides the best leaders for a good republic? What are the various forms of poetry and the other arts, and which ones should be fostered and which ones should be discouraged? How does knowing differ from believing? Several characters in the dialogue present a variety of tempting answers to those questions. Cephalus, Polemarchus, Thrasymachus, and Glaucon all offer definitions of justice. Socrates, Glaucon, and Adeimantus explore five different forms of republic and evaluate the merit of each from the standpoint of goodness. Two contrasting models of education are proposed and examined. Three different forms of poetry are identified and analyzed. The difference between knowing and believing is discussed in relation to the objects of each kind of thinking.
