What is law?

There are two definitions of law. It can refer to: (1) a system of rules or (2) a specific rule enacted by a government body, organization, or agency. In the United States, the primary source of law is the U.S Constitution. The Constitution is the standard by which all other rules, laws, or actions are measured. Following the Constitution, the other sources of law are, in order of hierarchy, Treaties and Federal Statutes, Federal Administrative Rules, State Constitutions, State Statutes, and State Administrative Rules. The through-line throughout these sources of law is court interpretation of those sources. U.S. Courts are common law courts, meaning U.S. Courts have inherited the principle of stare decisis, the principle that the basis of a decision in a preceding case is followed in subsequent cases to afford litigants a reasonable expectation of how the case will be decided. To the extent that the Courts determine “what the law is,” Marbury v. Madison, 5 U.S. 137, 177, 2 L. Ed. 60 (1803), American judges both create and apply the law.