What Is Law?


Law is the body of rules created and enforced by social or governmental institutions to regulate behavior. Its precise definition is a matter of longstanding debate, with some considering it to be a science and others viewing it as an art of justice.

There are numerous branches of law, reflecting the diverse aspects of a society. Contract law governs agreements to exchange goods or services, ranging from buying a bus ticket to trading options on the stock market. Criminal law covers crimes such as murder and robbery, with punishments varying from imprisonment to the death penalty. The law also covers civil rights and protection of property, as well as immigration and emigration laws. There is even law governing air travel and the use of force.

Lawyers, judges, and other judicial officers make up the legal profession, which is sometimes referred to as the judiciary. Judges, often referred to as Justices of the Supreme Court or Justices of the lower courts, are the highest judicial authority in each state and territory. Prosecutors and defense attorneys are the other key players in a criminal or civil case. Public defenders are lawyers who represent defendants who cannot afford to hire their own lawyers. Probation officers screen applicants for pretrial release and monitor convicted offenders released under supervision. In civil cases, the person who files a lawsuit is called the plaintiff and the person against whom the lawsuit is filed is the defendant. Those who sue without the help of lawyers are known as pro se, or in Latin, “on one’s own behalf.”

The practice of law is an intricate and complicated affair. Rules and responsibilities of judicial officers are determined by law and tradition, as well as the specifics of each case. A basic element is the principle of stare decisis, which means that decisions of higher courts binding on subsequent cases. The law can be further shaped by the presiding judge, jury instructions, and the judge’s own reasoning.

In a common law system, the decisions of higher courts are acknowledged as “law” on an equal footing with statutes adopted through legislative process and regulations issued by executive branch agencies. In the United States, cases are usually decided by panels of three or more judges. However, some cases are deemed important enough to be heard by the entire court, which is called sitting en banc.