『The Republic』要約

Plato’s The Republic is a foundational work of Western philosophy, composed around 375 BCE as a Socratic dialogue. The principal narrator is Socrates, who discusses justice with interlocutors including Glaucon, Adeimantus, Polemarchus, and Thrasymachus at the house of Cephalus in the Piraeus, the port of Athens. The central question—what is justice, and why should one be just—expands into an inquiry into the ideal city-state, or kallipolis, and the nature of the human soul. A distinctive framework is the analogy between the city and the soul: justice in the city consists of each class performing its proper function, and justice in the soul consists of reason ruling, spirit supporting reason, and appetite obeying. This yields the theory of the tripartite soul. Another famous framework is the Allegory of the Cave, in which prisoners mistake shadows on a wall for reality; escape represents philosophical education and ascent to the Form of the Good. The divided line and the myth of Er also appear. Socrates proposes that the guardian class should live communally, without private property or nuclear families, and that philosophers must rule as “philosopher-kings” until political power and philosophy coincide. The dialogue also examines degenerate constitutions—timocracy, oligarchy, democracy, and tyranny—and argues that tyranny is the most unjust regime and the unhappiest life. Glaucon’s challenge, the ring of Gyges, raises whether anyone would remain just if invisible and unaccountable. The Republic is not a political blueprint but an extended argument linking ethics, epistemology, and politics.