Law is a set of rules created and enforced through social or governmental institutions to regulate behavior. It can be based on religious precepts, such as Jewish Halakha or Islamic Sharia, and it can also include Christian canon law, which survives in some church communities. Law can be based on human elaboration, such as Roman legal codes, or it may be unwritten and based on custom and precedent. The precise definition of law is a matter of ongoing debate.
Law serves many purposes in a society, including keeping the peace and maintaining the status quo; protecting minorities against majorities; providing for social justice; and encouraging orderly social change. Law can be imposed by the state through legislation, decrees and regulations; or it may be made through a system of case-based adjudication, which is typical in common law jurisdictions. In a legal system, laws are enforceable by courts and tribunals that can be empowered by the legislative or executive branch to uphold a specific law, to deviate from it, or to ignore it altogether.
The laws that a nation or a people observe can cover almost any area of human activity, but they are generally grouped into broad categories. Commercial law, for example, covers complex contract and property law. Banking law includes regulation of the amount of capital banks must hold and rules about best practice for investment, to protect against economic crises, such as the Wall Street Crash of 1929. The law of a corporation is based on the separation of ownership and control, which gives companies separate legal personality. Tax law includes government regulation of value added and corporate taxes.
In addition to its societal functions, the law has an important metaphysical aspect. It defines what is right and wrong, as opposed to empirical or natural sciences (such as a law of gravity) or even social science (such as a law of supply and demand). This makes law more complex than other disciplines from a methodological viewpoint.
A fundamental principle of law is that all individuals and entities, whether public or private, must be held accountable by laws that are publicly promulgated, equally enforced and independently adjudicated. This principle requires adherence to internationally accepted norms and standards, including the supremacy of the law, equality before the law, accountability to the law, and fairness in its application. It also demands that the processes through which law is adopted, administered, adjudicated and enforced are transparent, accessible and participatory. Law is the basis of democracy and the pillars of social justice. It shapes politics, economics and history, and serves as the mediator between the different parts of a society. In this sense, the concept of law is as old as human civilization. It is, however, only in modern times that the development of law has begun to accelerate rapidly. It has been influenced by a number of cultural and technological changes. The most significant influences have been the Enlightenment, industrialization and globalization.