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On the Commonwealth

Cicero

Roman republicanism

Cicero's great work of political philosophy and the most influential Roman statement of republican government and natural law. Modeled on Plato but rooted in Roman experience, it defends the mixed constitution as the most stable and just form of state, defines the commonwealth (res publica) as the property of the people bound by shared law and common good, and argues for a true law of nature that no human decree may rightly violate. A vital bridge from Greek philosophy to the modern republican and natural-rights traditions.

About the author

Roman statesman, orator, and philosopher (106–43 BC), the supreme prose stylist of Latin and a defender of the Roman Republic in its dying decades. Consul, and later a victim of the political violence he opposed, Cicero transmitted Greek philosophy to Rome and to posterity; his political and ethical works profoundly shaped the republican and natural-law traditions.

Synopsis

In a dialogue partly surviving (including the famous 'Dream of Scipio'), Cicero argues that the best constitution mixes monarchy, aristocracy, and democracy, as Rome's did; that a commonwealth exists only where the people are united by agreement on law and a partnership for the common good; and that true law is right reason in accord with nature, eternal and universal, binding on all peoples and rulers alike.

Core passage idea

Paraphrase · Public domain

Cicero defines a commonwealth as the property of the people — an association united not by any bond but by agreement on justice and a partnership for the common good — and holds that true law is right reason in harmony with nature.

Cicero's definitions — the republic as the people's shared concern, and law as natural reason binding all — transmitted Greek and Stoic ideas to Rome and, through Rome, to the founders of modern republics. His mixed constitution and natural law shaped Western constitutionalism for two millennia.

To avoid a bubble

Pair with Augustine, who in City of God challenged Cicero's definition of the just commonwealth, and with realists like Machiavelli who admired Rome but doubted that justice and virtue, rather than power and fortune, sustain republics.

Reading note

Survives only in part; read what remains together with the 'Dream of Scipio' that closes it. Pair it with Polybius on the mixed constitution and with Cicero's On Duties for his ethics of public life.

Best paired with

Polybius, The Histories; Cicero, On Duties.

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