Rights that human beings are taken to possess simply in virtue of being human, independent of any specific government, legal system, or cultural tradition. On the classic liberal account (John Locke, Thomas Paine, Thomas Jefferson), these are rights to life, liberty, and property (or in Jefferson's softened phrase, "the pursuit of happiness") that governments do not create but are instituted to protect — and may be legitimately resisted when they systematically violate them.
The concept's modern career begins with 17th-century natural law theorists (Grotius, Pufendorf) and is fully developed in Locke's Second Treatise, where the state of nature is already governed by a natural moral law that assigns rights prior to any political authority. From there it passes into the American Declaration of Independence, the French Declaration of the Rights of Man and of the Citizen (1789), the classical liberal tradition, and eventually the Universal Declaration of Human Rights (1948).
Critics have been relentless. Jeremy Bentham famously called natural rights "nonsense upon stilts" — rhetorical flourishes dressed up as metaphysics, and dangerous nonsense when deployed to justify revolution. Marx and subsequent radicals argued that the rights tradition articulates the specific interests of bourgeois property owners as if they were universal. Historicist critics from Hegel onward have questioned whether any rights can be meaningfully "natural" rather than embedded in specific historical institutions. Communitarians and virtue ethicists (Alasdair MacIntyre) argue that rights-talk has been overextended and has crowded out richer moral vocabularies.
Defenders have responded in kind: Robert Nozick's Anarchy, State, and Utopia is the sharpest recent statement of rights as "side constraints." The doctrine of human rights — operating in international law, activism, and humanitarian practice — is natural rights under a more modest name. The argument has not been settled in three centuries.