For background information about Plato, recently discussed dialogues (including Books 1-5 of The Republic), and recommended editions of his works, see the meetup announcements for April and May.
The second half of The Republic includes three famous analogies and an assessment of various types of governance. The analogies are the Analogy of the Sun, the Analogy of the Divided Line, and the Allegory of the Cave. Although ostensibly different, the analogies reinforce the same Platonic theme--the world of the senses is illusory, that of the Forms true.
The Allegory of the Cave is a philosophical fable, universally regarded as Plato's most effective. It is set in a dark cave where prisoners look at a wall and see shadows of objects; the shadows represent our imperfect knowledge of the world, gained primarily through the senses. One man breaks away, leaves the cave and enters a world of light. Initially blinded by it, he slowly sees objects as they really are rather than as shadows. The source of the light is the sun, representative of the highest of all Forms, the form of Goodness; it is through Goodness that all true knowledge is obtained. The man returns to the cave and attempts to explain to others what he has seen, but they do not believe him. He exemplifies the philosopher who has attained the highest level of wisdom; to him is given the responsibility of ruling.
The four types of governance Plato critiques are Timocracy, Oligarchy, Democracy, and Tyranny. He explains why he finds each deficient: Timocracy (rule by the military) because it values honor rather than justice; Oligarchy because it privileges the rich at the expense of the poor; Democracy because everyone, regardless of how uninformed they may be, can vote, making them ripe for demagogues; and Tyranny because it can only be maintained by murder, terror, and bribery. Plato’s animus towards Oligarchy and Democracy can be traced in large part to his experience as an Athenian. What is novel about this analysis is that it is psychological as well as historical, the rulers' values a response to poor education or unhealthy parenting.
Plato's psychological theories are foundational in The Republic. He argues that if justice is achieved at a societal level, primarily through class stratification, then harmony at the individual level will follow. His Tripartite Theory of Soul makes the symbiotic relationship explicit: just as social harmony is achieved when people work productively within their social class, so harmony at the individual level is achieved when reason is allowed to regulate biological impulses. A rough symmetry becomes apparent when the two levels are juxtaposed: Guardian=Reason; Soldier=Spirited; Worker=Appetitive. In such an ideal environment citizens act more virtuously, practice more justice, and ultimately achieve what the Greeks believed to be the primary objective of life, Eudaimonia (Happiness).
The following resources provide analyses, bibliographies, lecture notes, and videos.
Wikipedia: “Plato”, “Theory of Forms”, "Problem of Universals", “The Republic (Plato)”, "Form of the Good", “Allegory of the Cave,” “Analogy of The Divided Line”, “Analogy of the Sun”, "Ship of State", "Myth of Er", "Ring of Gyges", "Philosopher King", "Plato's Tripartite Theory of Soul", "Pythagoreanism", "Musica Universalis" [Harmony of the Spheres], "Plato's Five Regimes", "Laws (Dialogue)", "List of Speakers in Plato’s Dialogues”
Stanford Encyclopedia of Philosophy: "Plato", “Plato’s Myths”, “Plato’s Ethics and Politics in The Republic”, “The Laws' Relation to the Republic", “Callicles and Thrasymachus”
Internet Encyclopedia of Philosophy: “Plato”, "Plato: The Republic”, "Thrasymachus", “Plato: Political Philosophy”
Plato Quotes from Goodreads and Wikiquote
"Introduction" to The Republic by Plato", trans. by Benjamin Jowett.
Stanley Rosen. “Introduction” in Plato’s Republic: A Study.” Yale University Press, 2005: 1-6.
Jyl Gensler. “How to Know the Good: The Moral Epistemology of Plato’s Republic.” The Philosophical Review 114.4 (October 2005), pp. 471-496.
Eric Brown. “The Unity of the Soul in Plato’s Republic.” In Plato and the Divided Self. Ed. By Rachel Barney et al. Cambridge University Press, 2004: 53-74.
Jeffery Zavadil. "Medical Metaphors in Plato's Political Philosophy." (chapter in doctoral dissertation written by one of our members)
Stephen Halliwell. "The Life-and-Death-Journey of the Soul: Interpreting the Myth of Er." In Cambridge Companions Online. Ed. by G. R. F. Ferrari. Cambridge University Press, 2013, pp. 445-473.
Rachana Kamtekar. “Ethics and Politics in Socrates’ Defense of Justice.” In Plato’s Republic: A Critical Guide. Ed. Mark L. McPherran. Cambridge University Press, 2013, pp. 65-82.
Sheldon Wein. "Plato's Moral Psychology." The Paideia Project On-Line: Twentieth World Congress of Philosophy Boston, Massachusetts U.S.A. (10-15 August 1998).
Robert Heinaman. "Why Justice Does Not Pay in Plato's Republic." The Classical Quarterly 54.2 (2004), pp. 379-393.
H. P. P. Lotter. "The Significance of Poverty and Wealth in Plato's Republic." South African Journal of Philosophy 22.3 (2003), pp. 189-206.
Ralph Wedgwood. "The Coherence of Thrasymachus." (author is Professor of Philosophy, University of Southern California).
Theodore Scaltsas. "The Ontology of Knowledge and Belief in Republic V." Edinburgh Research Archive (30 August 2007).
Teja Srinivas. “The Relationship of Philosophy and Art in Plato’s Republic.” Hey Zeus: The Yale Undergraduate Journal of Classics 5 (Spring 2004), pp. 36-43.
David Sachs. “A Fallacy in Plato’s Republic.” The Philosophical Review 72.2 (April 1963), pp. 141-158.
Melissa Lane. “Comparing Greek and Chinese Political Thought: The Case of Plato’s Republic." Journal of Chinese Philosophy 36:4 (December 2009), pp. 585–601.
Yuhwen Wang. "The Ethical Power of Music: Ancient Greek and Chinese Thoughts." Journal of Aesthetic Education 38.1 (Spring 2004), pp. 89-104.
Bernard Suzanne. "Plato and the Existence of God." (The author is an independent scholar who runs the well-regarded blog "Plato and his dialogues"; in 1999 the English version was frozen and the blog continued in French).
"Plato Study Guide" and "Plato Guide: Republic" by Professor M. Gregory Oakes, Dept. of Philosophy, Wintrop University (latter provides key questions about each book).
"Plato’s Republic" by Professor Philip A. Pecorino, Dept. of Social Sciences, Queensborough Community College.
“Plato’s Republic” by Professor G. J. Mattey, Dept. of Philosophy, University of Calfornia at Davis.
“Plato’s Republic: Some of the Main Arguments and Issues” by Professor Brandon C. Look, Dept. of Philosophy, University of Kentucky.
"Plato and the Form of the Good" by Professor Phillip McReynolds, Dept. of Philosophy, Gonzaga University.
"The Form of the Good" (a handout provided by Routledge Publishing).
"Plato: The Failure of Democracy" (author unknown; text appears on a philosophy forum administered by Frostburg State University).
Videos and Podcast
"Plato's Cave" (animated re-telling of the allegory).
"Plato's Cave", an interview with Simon Blackburn, a Plato scholar and Professor of Philosophy at the University of North Carolina at Chapel Hill.
“Ain’t No Sunshine: The Cave Allegory of Plato’s Republic” and "Last Judgments: Plato, Poetry and Myth" (podcasts) by Professor Peter Adamson, Dept. of Philosophy, King’s College London.
"Appearance and Reality: Plato's Divided Line" by Professor Judith V. Grabiner, Dept. of Mathematics, Pitzer College.
“Bertrand Russell on Plato’s Republic” (audiobook recording of Bertrand Russell's chapter on Plato's Republic, contained within his "History of Western Philosophy (1945).
"Plato's Republic" by Professor Mark Navin, Dept. of Philosophy, Oakland University.