: Natural Law School The Natural Law School of jurisprudence postulates that the law is based on what is "correct." Natural law philosophers emphasize a moral theory of law that is, law should be based on morality and ethics. Natural law is "discovered" by humans through the use of reason and choosing between good and evil. The law is not a series of calculating machines where definitions and answers come tumbling out when the right levers are pushed. William O. Douglas Dissent, A Safeguard of Democracy (1945) Examples Documents such as the U.S. Constitution, the Magna Carta, and the United Nations Charter reflect this theory. Historical School The Historical School of jurisprudence believes that the law is an aggregate of social traditions and customs that have developed over the centuries. It believes that changes in the norms of society will gradually be reflected in the law. To these legal philosophers, the law is an evolutionary process. Example Historical legal scholars look to past legal decisions (precedent) to solve contemporary problems.