Law is the system of rules that a society or government develops in order to deal with crime, business agreements, social relationships and other matters of public interest. It has been variously described as an art and science, with the precise definition of law a longstanding subject of debate. The term can also refer to the field of jurisprudence, and to lawyers, judges and other professionals who work in this area.
The purpose of the legal system is to ensure that all individuals are treated equally, and that their rights are respected. The legal system must be transparent and fair, so that all participants are aware of the procedures by which decisions are made. It must be accessible to all citizens, and it must provide competent and impartial representatives and neutrals who reflect the makeup of the communities they serve. The legal system must protect privacy, property, and freedom from discrimination, while providing equal opportunities for all, regardless of racial or ethnic background, social class, religion, or gender.
A central principle of the legal system is that only those who have been harmed may sue for damages or other remedies. To bring a lawsuit, a party must show that its legal right has been violated, and that a specific action by the defendant directly caused harm or injury to it. Those who have been harmed may sue either a private party, or the government, depending on whether the alleged violation was committed by a state, city, or federal agency, or by a political entity such as a county, state legislature, or congressional district. In the United States, cases are typically heard by a circuit court of appeals, or the Supreme Court, although the latter hears very few cases each year.
To become a law, a legislative act must be passed by the House of Representatives and Senate, and approved by the president. Once a law is signed, it becomes known as a statute. The citation, or numbering, of a statute will usually include its year of passage and the name of the president who signed it. For example, a statute will be cited P.L. 107-101, meaning that it was passed during the 107th Congress and signed by the president on 101st day of that same Congress.
Laws are derived by the legal system from an abstract concept that is essentially immutable, such as equality or natural justice. Alternatively, they can be rooted in specific human activities and shaped by the values and needs of society as a whole. A common example is the use of the word idiopathic to describe an illness or condition, such as DISH (Diffuse Idiopathic Skeletal Hyperostosis). In the case of DISH, this description is based on medical research and the opinions of doctors and other health care professionals, and has been adopted into law. In general, legal scholars have tended to favor laws that are grounded in external goals such as efficient allocation of resources or moral justice, over those that are merely based on abstract concepts.