Book SummaryThe Republic, by Plato

1-Page Summary1-Page Book Summary of The Republic

Through dramatic scenes, metaphors, and arguments, The Republic defines justice, the human soul, the ideal society, and the foundational structure of the universe itself. Ancient Athenian philosopher Plato intertwines these complicated topics to argue that living morally is good for its own sake. Writing in 375 BCE during the decline of the Athenian empire, Plato critiques his society while providing an alternative set of values based on philosophy, truth, and knowledge. In our guide to the The Republic, we’ll outline Plato’s main arguments in five parts:

• Part 1: The Challenge to Justice sets up Plato’s overall project of proving that living justly and morally is good for its own sake.
• **Part 2:...

The Republic Summary Part 1: The Challenge to Justice (Books I-II)

Plato starts The Republic by establishing his main thesis: Justice, or acting morally, is good for its own sake. He opens with the philosopher Socrates and his student Glaucon taking a trip to the port of Athens, which gets interrupted when the wealthy merchant Cephalus demands they visit him. After a brief discussion on old age and wealth, Socrates questions Cephalus’s perspective and the old man departs. Then, Socrates and the remaining young men discuss the definition of justice.

(Shortform note: Socrates was an ancient Athenian philosopher and Plato’s primary philosophical mentor and teacher. In Plato’s works, he’s almost always the primary character delivering Plato’s philosophical ideas. However, scholars are uncertain of how closely Plato sticks to the teachings of Socrates—Socrates never wrote any philosophy of his own, and historical accounts of him besides those of Plato are relatively scarce.)

The discussion of justice contains the following points:

1. A conventional definition of justice that proves insufficient
2. A definition of justice as “might is right” that describes justice as a tool for...

The Republic Summary Part 2: Creating the Ideal City (Books II-VI)

To answer his challenge, Socrates sets out to first describe the perfectly just man. He suggests that the soul of a man is a lot like a society—both can be described as ”just,” and both are made up of components working together to form a cohesive whole. In addition, Socrates says, justice is easier to observe and describe on the scale of an entire society than it is in the life of an individual. Therefore, he describes a perfectly just society to serve as an analogy for a perfectly just individual.

Part 2 of our guide will discuss the perfectly just city described in Books II-VI of The Republic.

(Shortform note: It might seem like a big leap in logic to assume that an individual is analogous to a society. Many scholars agree—the validity of the “city-soul analogy” is a common topic of discussion and debate. Critics argue that Socrates makes this analogy without offering a definition of justice that could reasonably apply to both individuals and cities. In other words, he assumes justice applies to both before he knows what justice is. Defenders of the analogy argue that the rest of _The...

The Republic Summary Part 3: The Philosopher-Rulers (Books V-VII)

After discussing the overall structure of the ideal city, Socrates discusses who will lead it. He argues that philosophers make the best leaders, and describes a class of philosopher-rulers: a select group of protectors who act as the moral leaders and guides of the ideal city. These rulers are emblematic of the city itself and provide a model of a perfectly just life—the kind of life Socrates must prove is preferable in order to win the challenge.

In books V through VII of The Republic, Socrates uses three allegories to show why philosophers are ideal rulers:

1. The allegory of the ship shows why philosophers have the character of an ideal ruler.
2. The allegory of the divided line explains why an ideal ruler needs philosophical knowledge.
3. The allegory of the cave describes how a philosopher uses their knowledge to rule.

(Shortform note: The way Plato describes ruling is closer to moral or spiritual leadership than our modern idea of a high-ranking politician. Philosopher-rulers don’t spend all their time on technical management of law and state. Instead, they provide the [ideals and goals that those beneath them should strive...

The Republic Summary Part 4: Inferior Cities (Books VIII-IX)

Once Socrates has described the nature of the ideal city, he acknowledges that it will inevitably deteriorate over time. He explains that in the world of objects, change is inevitable. Since the city is already perfect, any change will be negative—and even the smallest negative changes will eventually accumulate into a broader decline.

Socrates describes this decline in terms of four inferior cities, each worse than the last:

1. Timocracy: a society structured around honor and ambition
2. Oligarchy: a society structured around wealth
3. Democracy: a society structured around personal freedom
4. Tyranny: a society structured around oppression and mob rule

In addition, he offers a personality representative of each, just as the philosopher-ruler represents the values of the ideal city. This continues his analogy of justice in society and justice in an individual. Part 4 of our guide will explain the nature of each inferior city and man, how they come to be, and why they’re inferior to the ideal city or philosopher-ruler.

(Shortform note: Many scholars interpret this section as Plato’s acknowledgment that [the ideal city is not and cannot ever be...

The Republic Summary Part 5: Answering the Challenge (Book X)

After outlining the nature of just and unjust societies and how they correspond to individuals, Socrates returns to the original challenge: proving that a just person lives a better life than an unjust person. To answer this challenge, he shows how the philosopher-ruler—the representative of the perfectly just city—is better off in life and death compared to the representatives of the inferior cities.

(Shortform note: While Plato answers The Republic’s major question, this isn’t always the case in his work. Only some of Plato’s dialogues—specifically ones written during his “middle period,” which includes dialogues like The Republic and Symposium—provide accounts of Plato’s specific beliefs. The others end on an ambiguous note with the characters failing to find any answers. Scholars suggest that during his middle period, Plato began to develop philosophical theories independent of Socrates’s more ambiguous style. This may explain his shift in style.)

The Preferable Life

Socrates argues that the philosopher-ruler lives the best life of the individuals he has described. Because the...

Shortform Exercise: Consider Your View of Justice

Reflect on how you feel about Plato’s arguments on the inherent value of justice.

If you had the ring of Gyges and could turn invisible, would you use it to get away with misbehavior or morally dubious acts? Why?