Cicero Quote on Natural Law: Right Reason in Agreement with Nature

Quote

"True law is right reason in agreement with nature; it is of universal application, unchanging and everlasting; it summons to duty by its commands and averts from wrongdoing by its prohibitions." — Cicero, De Re Publica (On the Republic), Book III (51 BCE)

Author

Cicero (106–43 BCE) was the greatest orator of the Roman Republic, a statesman, and the philosopher who transmitted Greek ethics to the Latin world. His account of natural law in the De Re Publica became the classical formulation of the doctrine.

Source

The quotation is from Book III of the De Re Publica (On the Republic), written in 51 BCE. The passage survived the loss of the work through its quotation by Lactantius, and it was recovered with the rest of the work in 1819. The translation follows C.W. Keyes's Loeb edition (1928).

Context

The passage belongs to Cicero's account of justice, and it is the classical statement of the Stoic doctrine of natural law. The Stoics held that the universe is governed by a rational order, the Logos, and that the human reason is a fragment of it. The consequence for law is the doctrine of natural law: there is a law higher than the law of the state, grounded in right reason and nature, and the laws of the state are to be measured against it. The passage states the doctrine with complete precision: the true law is rational, natural, universal, and unchanging, and no statute, no assembly, no sovereign can alter it. The passage was quoted by Lactantius as evidence of the agreement of the pagans with the Christian doctrine of the moral law, and through the Church Fathers and the scholastics it shaped the Western tradition of natural law and, eventually, of natural rights.

Meaning

The quotation states the doctrine of natural law with complete clarity. "True law is right reason in agreement with nature" — the definition: the law is not the command of the sovereign but the deliverance of reason, and the deliverance of reason is in agreement with the natural order. "It is of universal application, unchanging and everlasting" — the properties: the law is the same for all peoples and all times, because reason is the same and nature is the same. "It summons to duty by its commands and averts from wrongdoing by its prohibitions" — the function: the law is the moral law, the standard by which the commands and prohibitions of the state are to be measured. The deeper claim is the Stoic conviction that the human being is a part of a rational order, and that the moral law is not a convention but a fact of nature — the law that the reason of every human being can discover, and against which every human law is to be judged. The quotation is the foundation of the Western tradition of natural law, and it grounds the modern idea of human rights.

Related Wisdom

The quotation belongs to the Stoic philosophy of justice and the tradition of natural law. Its account of the law as right reason in agreement with nature connects to the doctrine of the Logos and to the wider Stoic ethics of the common good. The passage is among the most influential in the history of political philosophy, and it grounds the Stoic wisdom tradition's account of the moral law.