Work · Plato
The Republic
c.375 BCE · Ten books, in dialogue
What is justice — and what would a perfectly just city, and a perfectly just soul, actually look like?
10
Books
~375 BCE
Written
Athens
Set in
The city and the soul
The book’s central move: a city has the same three parts as a soul. Justice is each part doing its own work and not meddling in the others’ — wisdom belongs to the rulers, courage to the soldiers, and temperance holds the whole together.
The shape of the argument
Book I
What is justice? Three answers — and Thrasymachus’ attack — all fail.
Book II
Glaucon revives the challenge, so Socrates builds a city to read justice writ large.
Books II–IV
Three classes, the guardians’ education, and the same three parts found inside the soul.
Book V
Three waves: women guardians, families held in common, and the philosopher-king.
Books VI–VII
The Good, the Sun, the Divided Line, and the Cave — the climb to real knowledge.
Books VIII–IX
City and soul decay through five regimes; the tyrant is the unhappiest man alive.
Book X
Poetry put on trial, and the Myth of Er on how souls choose their next life.
The cast
Socrates — narrates the whole conversation the day after
Cephalus — the contented old host; justice is telling the truth and paying your debts
Polemarchus — Cephalus’ son; justice is giving each person their due
Thrasymachus — the sophist who bursts in: justice is the interest of the stronger
Glaucon — Plato’s brother; presses the Ring of Gyges challenge
Adeimantus — Plato’s brother; argues justice is praised only for its rewards
The famous bits
The Ring of GygesBook II
A ring that turns you invisible — would anyone stay just if they could never be caught?
The Royal LieBook III
A founding myth that sorts citizens into souls of gold, silver, and bronze.
Philosopher-kingsBook V
The claim Socrates calls almost unsayable: cities will not rest until philosophers rule.
The Sun and the GoodBook VI
The highest thing the mind can reach, said to lie beyond being itself.
The Allegory of the CaveBook VII
Prisoners who take the shadows thrown on a wall for the whole of reality.
The Myth of ErBook X
A soldier returns from death to report how souls choose their next lives.