Law is a system of rules that are created and enforced by social or governmental institutions to regulate behavior. Its precise definition is a matter of longstanding debate. In broad terms it encompasses the rules and procedures that govern a society’s dealings with crime, business agreements, social relationships and other matters of public interest. The term may also be applied to the profession of law, which involves the study and practice of law, and the people who work in it.
Legal systems vary widely in their scope and complexity, from the simple statutory codes of many common law countries to the multi-volume treatises of civil and criminal procedure found in the law books of many major jurisdictions. There are, however, certain basic concepts which all systems share. These include the principle that laws should be publicly promulgated and equally enforced, that people are equal before the law and that it is the role of the courts to interpret the law and not to make it.
The law is a human invention. As such, it can be influenced and defined by many different factors, including religion, culture, philosophy, economics, and politics. It can also be shaped and extended by the actions of individuals, societies and the government itself.
The earliest legal principles were devised by philosophers such as Thomas Aquinas and Sir William Blackstone. Aquinas distinguished between natural, divine and human law. The later English common law largely followed Blackstone’s distinction, though with differences of terminology. Other important early concepts were the law of trusts, which separated ownership from control in business ventures, and the law of property, whose basic elements are the right to own and use tangible things (real estate) and the right to receive compensation for a loss or damage to personal possessions. The modern law of corporations began with the Joint Stock Companies Act 1856, and commercial law is now a complex field involving agency law, insurance law, bills of exchange, insolvency law, sales law and other areas which derive from the medieval Lex Mercatoria.
The law is based on the assumption that there are certain fundamental precepts of humankind which are inviolable, and that these must form the basis of a fair society. In the past this view of law was often reflected in religious law, such as Jewish Halakha and Islamic Sharia, although these are not necessarily law-like, since they cannot be amended by judges or governments, and must be interpreted through interpretation (Qiyas) and consensus and precedent (Ijma). Similarly Christian canon law continues to play an important part in some church communities.