Natural law first appeared in ancient Greek philosophy,[2] and was referred to by Roman philosopher Cicero. It was subsequently alluded to in the Bible,[3] and then developed in the Middle Ages by Catholic philosophers such as Albert the Great and his pupil Thomas Aquinas. During the Age of Enlightenment, the concept of natural laws was used to challenge the divine right of kings, and became an alternative justification for the establishment of a social contract, positive law, and government – and thus legal rights – in the form of classical republicanism. Conversely, the concept of natural rights is used by others to challenge the legitimacy of all such establishments.
The idea of human rights derives from theories of natural rights.[4] Those rejecting a distinction between human rights and natural rights view human rights as the successor that is not dependent on natural law, natural theology, or Christian theological doctrine.[4] Natural rights, in particular, are considered beyond the authority of any government or international body to dismiss. The 1948 United Nations Universal Declaration of Human Rights is an important legal instrument enshrining one conception of natural rights into international soft law. Natural rights were traditionally viewed as exclusively negative rights,[5] whereas human rights also comprise positive rights.[6] Even on a natural rights conception of human rights, the two terms may not be synonymous.
The concept of natural rights is not universally accepted, partly due to its religious associations and perceived incoherence. Some philosophers argue that natural rights do not exist and that legal rights are the only rights; for instance, Jeremy Bentham called natural rights "simple nonsense".[7]