Definition: It granted its owner the power to become invisible at will.
Purpose: A just man and an unjust man will act the same given a Ring of Gyges. Once in possession of this ring, the man can act unjustly with no fear of reprisal. No one can deny, Glaucon claims, that even the most just man would behave unjustly if he had this ring. He would indulge all of his materialistic, power-hungry, and erotically lustful urges. This tale proves that people are only just because they are afraid of punishment for injustice. No one is just because justice is desirable in itself.
Auxiliary
Definition: Providing supplementary or additional help and support. Their role is to aid rulers by carrying out and enforcing their decisions.
Purpose: Proper education for guardians, he introduces the third and final class of the just society: rulers. The best from this group will be chosen out as rulers, and only they will now be termed “guardians,” while the rest will remain as warriors and will be termed “auxiliaries.”
Aporia
Definition: a deadlock, where no further progress is possible and the interlocutors feel less sure of their beliefs than they had at the start of the conversation. An irresolvable internal contradiction.
Purpose: In Book I, Socrates and those (Adeimantus, Cephalus, another brother of Plato, and the young nobleman Polemarchus) he engages in dialogue with, go back and forth debating on “what is justice?” but Plato does not answer the question. In Plato’s early dialogues, aporia usually spells the end. The Republic moves beyond this deadlock.
Producers
Definition: The producing class is the largest class of society; it is a catch-all group that includes all professions other than warrior and ruler. Framers and craftsmen are producers, as are merchants, doctors, artists, actors, lawyers, judges, and so forth.
Purpose: Plato divides his just society into three classes: the producers, the auxiliaries, and the guardians. They focus exclusively on producing whatever it is that they are best suited to produce.
Sophist
Definition: the general educators hired as tutors to the sons of the wealthy. They regarded law and morality as conventions.
Purpose: Thrasymachus shows us the criminal result of the confusion of defining justice: the Sophist’s campaign to do away with justice, and all moral standards, entirely. Justice, he says, is nothing more than the advantage of the stronger. Because it does not pay to be just, the rational thing to do is ignore justice entirely.
Philosopher-King
Definition: The philosopher-king is the ruler of the kallipolis. Also called guardians, philosopher-kings are the only people who can grasp the Forms, and thus the only people who can claim actual knowledge. Since the philosopher-king yearns after truth above all else, he is also the most just man.
Purpose:
Guardians
Definition: The guardians, we are told, all live together in housing provided for them by the city. Guardians receive no wages and can hold no private wealth or property. They are supported entirely by the city through the taxation of the producing class.
Purpose:
Kallipolis
Definition: Kallipolis is the Greek term for Plato’s just city.
Hades
Definition: The place of dead souls.
Purpose: Heroes must never be presented as fearing death or as preferring slavery to death. Hades must never be presented as a frightening place.
The Myth of the Metals
Definition: Every citizen is born out of the earth of the State and every other citizen is his brother or sister. Yet God has framed them differently, mixing different metals into their soul: gold for the rulers, silver for the auxiliaries, and brass or iron for the husbandmen and craftsmen.
Purpose: To ensure that there is never controversy over who should rule, Socrates suggests telling all citizens a useful fiction that all citizens of the city were born out of the earth. This fiction persuades people to be patriotic. They have reason to swear loyalty to their particular