Law is a system of rules created and enforced by social or governmental institutions to regulate behavior. It has several distinct features which distinguish it from other disciplines such as empirical science (as a law of gravity) or even social science (as a law of supply and demand in economics). Law has a normative, prescriptive nature and is based on the power of a controlling authority to punish those who violate its rules. This power to discipline is unique in modern societies which have a large number of state agencies and bureaucracies with significant authority over the daily lives of many citizens, including the police, military and civil servants. This power poses special problems for accountability that earlier writers such as Locke and Montesquieu were not prepared to anticipate.
The principal functions of law are establishing standards, maintaining order, resolving disputes and protecting liberties and rights. Different nations have different systems of law to achieve these goals. For example, the law of a dictatorial nation may keep the peace and maintain the status quo but is not likely to promote social justice or protect minorities against majorities. In contrast, the laws of a democratic nation may serve all of these purposes more effectively.
In some countries, such as the United States, judges use a common law system in which judicial decisions are considered as “law” on an equal footing with statutes adopted by the legislative process and regulations issued by the executive branch. In contrast, other countries have a civil law system in which judges follow written codes to guide their decisions. The doctrine of precedent, also called stare decisis, applies in both common and civil law systems. Decisions of higher courts typically bind lower courts and future cases with similar facts and issues, unless overturned by later decisions.
Other areas of law include criminal law, which relates to crimes such as murder and rape; contract law, which outlines the terms and conditions that must be included in contracts; and property law, which describes people’s rights and duties toward tangible and intangible possessions. Laws dealing with the exploitation of animals, the environment and public utilities (such as water, electricity and gas) are also part of the field of law.
Other topics in law include administrative law, which deals with the way government agencies conduct business and the rules that govern their activities; labour law, which studies the tripartite industrial relationship between worker, employer and trade union; and evidence law, which defines what kinds of materials are admissible to support a case. In addition, there is tort law, which relates to damages paid for harm caused to an individual or group of individuals, and constitutional law, which outlines the foundations of a country’s political structure.