Law is a set of rules that are created and enforced by social or governmental institutions to regulate behavior. Its precise definition is a matter of longstanding debate. It is often described as a science and as the art of justice. Laws may be made by a legislature, resulting in statutes; by the executive branch of government, resulting in decrees and regulations; or established by judges through case law, in common law jurisdictions. They may be private or public, civil or criminal, or both.
A law is a set of rules that form a framework to ensure a peaceful society. If the laws are broken, sanctions can be imposed to punish offenders. The legal system is a complex web of procedures and powers that are used to enforce the laws, resolve disputes, and protect individuals and businesses. This system is regulated by the state and federal governments, and it covers a wide variety of activities, from employment and family law to criminal law and intellectual property.
A more narrow definition of law focuses on the rules that dictate human action and conduct. This view, which is generally associated with John Austin, argues that the law is a set of commands, backed by the threat of sanction, issued by a sovereign. Such laws, he argued, must be obeyed, since they are the “precepts by which man, the noblest of all sublunary creatures, endowed with reason and free will, is commanded to act.”
People who ascribe to this view argue that laws are necessary for order and security in society and that they have a natural and inalienable morality. They are also concerned that the state should provide a minimum level of protection to its citizens.
Those who subscribe to the utilitarian theory of law argue that it is important for society to have a system of laws that is consistent, predictable and easy to understand. They also believe that a system of laws should be enforced with minimal interference from the political process.
Many states have their own systems of law, which can differ greatly from the system in the rest of the country. Some have adopted the civil law tradition of France or Germany, while others have based theirs on English common law and judicial decisions. Some states have their own particular religious or customary laws, while others have a largely secular legal system.
Federal law consists of the Constitution, statutes, regulations, and case law that governs the national government. Historically, it has centered on areas of activity for which the Constitution explicitly granted power to the federal government, such as the military, money (especially foreign and domestic), mail, and tariffs. However, a number of broad interpretations of the Commerce and Spending Clauses of the Constitution have expanded federal power to encompass many more areas of law. For example, the United States now has a large body of federal laws on aviation, telecommunications, railroads, pharmaceuticals, antitrust, and trademarks. There are also a number of federal courts that hear cases that pertain to these subjects.