DEFINITION of Natural Law

Natural law is a theory that says there is a set of rules inherent in human behavior and human reasoning that governs human conduct. Natural law is preexisting and is not created in courts by judges. Many schools of thought think that is passed to man through a divine presence. Philosophers and theologians throughout history have differed in their interpretations of natural law, but in theory, natural law should be the same throughout time and across the world because it is based on human nature, not on culture or customs.


The opposite of natural law is "positive law" or "man-made law." Positive law may be based on natural law, but not the other way around. Positive or man-made laws include laws such as the speed at which individuals may drive on the highway and the age at which individuals may legally purchase and consume alcohol. While natural law typically applies to philosophy, it is also extensively used in theoretical economics.

Example of Natural Law

An example of natural law, as interpreted by Thomas Hobbes, is that judges should be impartial. A widely recognized nod to natural law and its concepts is present in the Declaration of Independence in the statement that " ... all men are created equal, that they are endowed by their creator certain unalienable rights ... " Other major philosophers of natural law include Aristotle, Thomas Aquinas and Lysander Spooner.