The Republic: Book 1 Summary & Analysis

Socrates walks to the Athens harbor, the Piraeus, with Glaucon, Plato's brother. Socrates and Glaucon are invited to Polemarchus' house by Polemarchus and Adeimantus. They join Thrasymachus and Polemarchus' father, Cephalus. Socrates asks Cephalus if age is as much a hardship as people say. Cephalus says old age brings peace from appetites and passions and is not much harder to bear than youth. Socrates says Cephalus may bear old age well, not because of the way he lives, but because Cephalus is wealthy. Cephalus says that wealth lets one live a just life since a wealthy man does not need to fear owing money or not having enough to sacrifice to a god.

Socrates asks if one can always say that doing right is just speaking truth and paying back what is owed? For instance, if a friend loans us a weapon, but then becomes insane and asks for it back—ought we to return the weapon? Surely that is not a right action. Cephalus agrees that would not be the right action, then excuses himself because he has to attend to the sacrifice.

Polemarchus disagrees with Socrates and cites the poet Simonides who said that it is just to give to each what is owed to him. Simonides, says Polemarchus, meant that friends owe it to their friends to do well by them, and never harm them, and enemies are owed harm. Socrates observes that people make mistakes, thinking an enemy a friend and vice versa, thus the just man could unintentionally help enemies and harm friends. Polemarchus redefines a friend as one who is truly useful. The just man must harm those who are both bad and enemies.

Socrates points out that when humans are harmed they become worse in terms of human virtues, just as the behavior of a horse who is harmed becomes worse. Socrates' example leads Polemarchus to agree that it is not the proper function of justice to harm anyone, friend or foe. It is the function of an unjust man to cause harm.

Thrasymachus, unwillingly quiet, interrupts, loudly. He says instead of asking foolish questions and refuting each answer, Socrates should tell them what he thinks justice is. Thrasymachus offers to define justice if they will pay him. Since Socrates has no money, the others pay his share. Thrasymachus says justice is nothing more than whatever gives advantage to "the stronger."

Socrates says the crafts rule over and are stronger than the things which they are crafts of—medicine over the body, horse breeding over the horse, a captain over his sailors. Socrates concludes that no knowledge seeks what is advantageous to itself, it seeks what is best for the weaker object that is subject to it. A sea captain seeks whatever is beneficial to his sailors, and a ruler seeks what is beneficial for his subjects.

Thrasymachus angrily asserts that a just man always gets less than an unjust man. Justice, says Thrasymachus, benefits the strong. He adds that tyrants, the most unjust, are the happiest and richest because of their tyranny. Victims of tyranny, those most unwilling to do injustice, are the most wretched. Men oppose injustice because they are afraid of being harmed by it, not because they fear engaging in it. Thrasymachus tries to leave, but is stopped by the others.

Socrates points out that the "ruler," in various professions, like a doctor and his patients, does what is best for his subjects and is given wages. Yet political rulers earn no wages and so do not benefit themselves. Socrates concludes that good men rule out of fear of having a worse ruler forced upon them. This leads Socrates to consider Thrasymachus' assertion that the life of an unjust man is better than that of a just man.

Thrasymachus says that injustice is not only more profitable, but that injustice is virtuous and wise. Socrates says that it is the ignorant man who thinks he knows better than the doctor, the non musical person who thinks he knows more than the musician. Even thieves have a degree of just behavior, else they would always rob each other. Thrasymachus unwillingly agrees.

Thrasymachus asserts that an unjust city would enslave other cities. Socrates responds that in an unjust city, everyone is unjust. Soldiers in an unjust army are unhappy and unable to unite against an enemy, as just men could. An unjust individual is in a constant state of unrest, always dissatisfied, and his own enemy.

Socrates considers whether the just have a happier life than the unjust. Since the gods are just, the unjust are enemies of the gods. Anything with a function also has a virtue. Eyes perform their function by the virtue of sight and ears by the virtue of hearing. The specific function of the soul is life, and it can not perform that function without its accompanying virtue of justice.

Socrates adds that a person with a bad soul will rule poorly, while one with a good soul will rule well. Consequently the just man is happy, the unjust unhappy. Injustice is always inferior and less profitable than justice since injustice creates misery. Socrates says although he knows justice is wisdom and virtue, he still doesn't know what justice is. Thrasymachus leaves, still insisting that his definition of justice is the correct one.