The Republic

Book I: what is justice?

The Republic is a dialogue narrated by Socrates. He goes down to the port of Piraeus for a religious festival and ends up at the house of Polemarchus, where his father Cephalus, a wealthy old man, lives. The conversation turns to a single question: what is justice? The rest of the work, ten books long, tries to answer it.

Three people offer definitions in Book I, and Socrates tests each one.

• Cephalus suggests that justice means telling the truth and paying back what you owe. Socrates gives a counterexample: if a friend lends you a weapon and then goes mad, you should not return it.
• Polemarchus, his son, says justice means giving each person what is owed: help to friends and harm to enemies. Socrates argues that a just person never makes anyone worse, and that we often misjudge who our friends are.
• Thrasymachus, a sophist, bursts in angrily. He claims that justice is simply the advantage of the stronger. Rulers make laws that benefit themselves and call obedience "justice." He adds that injustice, done on a large enough scale, makes a person happier and more powerful.

Socrates counters with several arguments. A true ruler, like a doctor, serves those in his care. Even a band of thieves needs some justice among its members to work together. And the soul has a function, living well, which it performs only through justice. Thrasymachus falls silent, but Socrates admits that they have argued about justice without first defining it.

Books II and III: the city in speech

Plato's brothers Glaucon and Adeimantus are not satisfied. They want Socrates to prove that justice is good in itself, not only for its rewards.

Glaucon restates the common view. People think justice is a compromise: they would like to do wrong freely, but they fear suffering wrong, so they agree to laws. To make his point, he tells the story of the Ring of Gyges. A shepherd finds a ring that makes him invisible. He uses it to seduce the queen, kill the king and take the throne. Glaucon asks: would anyone stay just if they could act without being seen? Adeimantus adds that parents and poets praise justice only for its reputation and rewards.

Socrates proposes a method. It is easier to read large letters than small ones. A city is like a soul written large. So they will build a city in speech, find justice in it, and then look for the same pattern in the individual.

The first city is simple. People specialize by their natural skills (farmers, builders, weavers) and trade. Glaucon mocks it as a city of pigs, because it lacks comforts. So Socrates allows a luxurious city. Luxury requires more land, which leads to war, which requires a professional army. These soldiers are the guardians. They must be like good watchdogs: gentle with their own people and fierce with enemies.

Educating the guardians

Most of Books II and III concern how to raise the guardians. Their education has two parts: music (stories, poetry and song, which shape the soul) and physical training (which shapes the body).

Socrates proposes strict control of stories. Poets like Homer and Hesiod show gods that lie, fight, change shape and do wrong. These stories would teach children bad character, so they must be censored or rewritten. Stories that make death seem terrible must also go, because guardians must not fear death. Even musical modes and rhythms are limited to those that build courage and self-control.

The guardians who rule must be the best of them. They will live without private property or money, in shared housing, supported by the other citizens. To keep everyone content with their place, Socrates proposes a noble lie, often called the myth of the metals. Citizens will be told that the earth formed them, and that the god mixed gold into rulers, silver into their helpers and bronze or iron into farmers and craftsmen. Children are usually like their parents, but a child born with a different metal must move to the right class.

Book IV: justice in the city and the soul

The finished city has three classes: rulers, auxiliaries (soldiers who enforce the rulers' decisions) and producers (everyone else). Adeimantus objects that the guardians will not be happy without property. Socrates replies that the aim is the happiness of the whole city, not one class.

He then identifies four virtues in the city:

• Wisdom lives in the rulers, who know what is best for the whole.
• Courage lives in the auxiliaries, who hold firm beliefs about what to fear.
• Moderation is the agreement of all classes about who should rule.
• Justice is each class doing its own work and not meddling in the work of others.

Next, Socrates argues that the soul has the same three parts. Reason calculates and seeks truth. Spirit (in Greek, thumos) feels anger, pride and honor. Appetite wants food, drink, sex and money. He shows that these parts are distinct because they can conflict. A thirsty person may refuse to drink because reason says the water is unsafe. He also tells the story of Leontius, who wanted to look at dead bodies outside the city wall and was furious at his own eyes for giving in.

In a just person, reason rules, spirit supports reason, and appetite obeys. Justice is a kind of health of the soul. Injustice is a civil war inside it. Since nobody wants a sick soul, justice is worth having for its own sake.

Books V to VII: philosopher-kings and the Good

Before Socrates can continue, his friends demand details about the guardians' way of life. He responds with three proposals that he calls waves, because each is more shocking than the last.

1. Women can be guardians. Men and women differ in strength, but not in the nature relevant to ruling. So women with the right nature receive the same education and duties.
2. Guardians share spouses and children. There are no private families. Mating is arranged by the rulers through rigged lotteries, and children are raised in common so that no one knows their own parents.
3. Philosophers must rule. The city will never be well governed until philosophers become kings, or kings become philosophers.

Socrates explains what a philosopher is. Most people love sights, sounds and opinions. The philosopher loves knowledge of what truly is: the unchanging Forms, such as Beauty itself or Justice itself, rather than their changing copies.

Book VI offers the ship of state image. The sailors fight to take the helm, each claiming to know how to steer, while the true navigator, who studies the stars and weather, is mocked as a useless stargazer. This is why real philosophers seem useless in actual cities.

The highest object of knowledge is the Form of the Good. Socrates says he cannot describe it directly, so he uses three images. In the Sun analogy, the sun makes things visible and helps them grow. Likewise, the Good makes things knowable and gives them their being. The Divided Line ranks types of awareness: images and shadows at the bottom, then physical things, then mathematical objects, and finally the Forms, grasped by pure reason.

The Allegory of the Cave

Book VII contains the most famous image. Prisoners sit chained in a cave, facing a wall. Behind them, a fire casts shadows of objects onto the wall. The prisoners think the shadows are reality. One prisoner is freed. He turns, sees the fire, and is dragged up into the sunlight. At first he is blinded. Slowly he sees reflections, then real things, and finally the sun itself. If he goes back down, his eyes struggle in the dark. The prisoners laugh at him and might kill him if he tried to free them.

The cave stands for ordinary life, and the ascent for philosophical education. The philosopher's study follows a long sequence: arithmetic, geometry, astronomy and harmonics, then dialectic, the method of reasoning toward the Forms. After years of practical service, the best reach the Good at around age fifty. They then take turns ruling. They do not want power, which is exactly why they can be trusted with it. They must be compelled to go back into the cave.

Books VIII and IX: how cities and souls decline

Socrates now describes four worse types of city, each with a matching type of person. Each one grows out of the one before.

• Timocracy is ruled by the love of honor and victory, like a military state.
• Oligarchy is ruled by the rich. Wealth becomes the measure of worth, and the city splits into rich and poor.
• Democracy arises when the poor take power. It values freedom and treats all desires as equal. Socrates describes it as colorful and attractive, but disordered.
• Tyranny grows from democracy's excess of freedom. A popular leader takes power and becomes a tyrant.

The tyrannical person is the most unhappy. He is ruled by lawless desires, lives in fear, and cannot trust anyone. Socrates gives three arguments that the just life is happier. The tyrant's soul is enslaved. The philosopher has tasted all three kinds of pleasure (of reason, honor and appetite) and is the best judge of them. And the pleasures of reason are truer and purer. He even calculates, half in jest, that the just king lives 729 times more pleasantly than the tyrant.

He closes with an image of the soul as a many-headed beast (appetite), a lion (spirit) and a small human (reason). The just person feeds the human and tames the beast.

Book X: poetry and the Myth of Er

The last book returns to poetry. Socrates argues that imitative poets copy appearances, which are themselves copies of the Forms. He uses the example of a bed: there is the Form of a bed, the bed a carpenter makes and the painting of a bed. The painter and the poet are two steps removed from the truth. Poetry also stirs up emotions that reason should control. So imitative poetry is banned from the ideal city, except hymns to the gods and praise of good people.

Socrates then argues that the soul is immortal and describes the rewards of justice after death through the Myth of Er. Er, a soldier killed in battle, revives on his funeral pyre and reports what he saw. Souls are judged, rewarded or punished, and then choose their next lives. Many choose badly, led by habit or desire. Odysseus, cured of ambition, chooses the quiet life of a private citizen. The lesson is that philosophy prepares a soul to choose well.

What the critics say

The ideal city is deeply controversial. Karl Popper, in The Open Society and Its Enemies (1945), attacked it as a blueprint for totalitarian rule, citing censorship, the noble lie and rigid classes. Aristotle had already criticized its abolition of private property and family. Other scholars argue that the city is mainly an analogy for the soul, not a political program, and the dialogue itself raises doubts about whether such a city could exist.

Who should read it

The Republic suits anyone interested in the roots of Western political thought, education and ethics. It rewards slow reading in a good modern translation, ideally alongside a guide or commentary.