The Republic

Not a word for a building, but for an idea: the common good, the public thing, a government that belongs to its people.

Plato imagined an ideal republic governed by philosophers. Cicero grounded the concept in Roman political reality: a republic is the property of the people, and a people is not any random gathering but an association united by agreement about justice and a partnership for the common good. When that agreement breaks down, the republic dies, no matter what name the state still carries. He wrote this as the Roman Republic was dying around him.