Natural law

Natural law, body of law supposed to be innate, discoverable by natural human reason, and common to all people. Under this philosophy, human or positive law, though changeable and culturally dependent, must—if truly just—be derived from the principles of natural law. The concept was rooted in Greek philosophy and Roman law. Particularly in the Christian philosophy of Thomas Aquinas, natural law—the sense of right and wrong implanted in humans by God—is contrasted with revealed law. It lay behind Hugo Grotius's ideas on international law (17th century). It was used as a basis for ethics, morality, and even for protests against tyranny by Spinoza, Leibniz, Locke, Rousseau, and many others, but with the development of scientific philosophies in the 19th century, natural law largely lost its influence.

See also: Aquinas, Saint Thomas.