Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior,[1] with its precise definition a matter of longstanding debate.[2][3][4] It has been variously described as a science[5][6] and as the art of justice.[7][8][9] State-enforced laws can be made by a group legislature or by a single legislator, resulting in statutes; by the executive through decrees and regulations; or established by judges through precedent, usually in common law jurisdictions. Private individuals may create legally binding contracts, including arbitration agreements that adopt alternative ways of resolving disputes to standard court litigation. The creation of laws themselves may be influenced by a constitution, written or tacit, and the rights encoded therein. The law shapes politics, economics, history and society in various ways and also serves as a mediator of relations between people.
Legal systems vary between jurisdictions, with their differences analysed in comparative law. In civil law jurisdictions, a legislature or other central body codifies and consolidates the law. In common law systems, judges may make binding case law through precedent,[10] although on occasion this may be overturned by a higher court or the legislature.[11] Historically, religious law has influenced secular matters and is, as of the 21st century, still in use in some religious communities.[12][13][14] Sharia law based on Islamic principles is used as the primary legal system in several countries, including Iran and Saudi Arabia.[15][16]
The scope of law can be divided into two domains: public law concerns government and society, including constitutional law, administrative law, and criminal law; while private law deals with legal disputes between parties in areas such as contracts, property, torts, delicts and commercial law.[17] This distinction is stronger in civil law countries, particularly those with a separate system of administrative courts;[18][19] by contrast, the public-private law divide is less pronounced in common law jurisdictions.[20][21]
Law provides a source of scholarly inquiry into legal history,[22] philosophy,[23] economic analysis[24] and sociology.[25] Law also raises important and complex issues concerning equality, fairness, and justice.[26][27]
The word law, attested in Old English as lagu, comes from the Old Norse word lǫg. The singular form lag meant 'something laid or fixed' while its plural meant 'law'.[28]
But what, after all, is a law? [...] When I say that the object of laws is always general, I mean that law considers subjects en masse and actions in the abstract, and never a particular person or action. [...] On this view, we at once see that it can no longer be asked whose business it is to make laws, since they are acts of the general will; nor whether the prince is above the law, since he is a member of the State; nor whether the law can be unjust, since no one is unjust to himself; nor how we can be both free and subject to the laws, since they are but registers of our wills.
Jean-Jacques Rousseau, The Social Contract, II, 6.[29]
The philosophy of law is commonly known as jurisprudence. Normative jurisprudence asks "what should law be?", while analytic jurisprudence asks "what is law?"
There have been several attempts to produce "a universally acceptable definition of law". In 1972, Baron Hampstead suggested that no such definition could be produced.[30] McCoubrey and White said that the question "what is law?" has no simple answer.[31] Glanville Williams said that the meaning of the word "law" depends on the context in which that word is used. He said that, for example, "early customary law" and "municipal law" were contexts where the word "law" had two different and irreconcilable meanings.[32] Thurman Arnold said that it is obvious that it is impossible to define the word "law" and that it is also equally obvious that the struggle to define that word should not ever be abandoned.[33] It is possible to take the view that there is no need to define the word "law" (e.g. "let's forget about generalities and get down to cases").[34]
One definition is that law is a system of rules and guidelines which are enforced through social institutions to govern behaviour.[1] In The Concept of Law, H. L. A. Hart argued that law is a "system of rules";[35] John Austin said law was "the command of a sovereign, backed by the threat of a sanction";[36] Ronald Dworkin describes law as an "interpretive concept" to achieve justice in his text titled Law's Empire;[37] and Joseph Raz argues law is an "authority" to mediate people's interests.[38] Oliver Wendell Holmes defined law as "the prophecies of what the courts will do in fact, and nothing more pretentious."[39] In his Treatise on Law, Thomas Aquinas argues that law is a rational ordering of things, which concern the common good, that is promulgated by whoever is charged with the care of the community.[40] This definition has both positivist and naturalist elements.[41]
Definitions of law often raise the question of the extent to which law incorporates morality.[42] John Austin's utilitarian answer was that law is "commands, backed by threat of sanctions, from a sovereign, to whom people have a habit of obedience".[36] Natural lawyers, on the other hand, such as Jean-Jacques Rousseau, argue that law reflects essentially moral and unchangeable laws of nature. The concept of "natural law" emerged in ancient Greek philosophy concurrently and in connection with the notion of justice, and re-entered the mainstream of Western culture through the writings of Thomas Aquinas, notably his Treatise on Law.
Hugo Grotius, the founder of a purely rationalistic system of natural law, argued that law arises from both a social impulse—as Aristotle had indicated—and reason.[43] Immanuel Kant believed a moral imperative requires laws "be chosen as though they should hold as universal laws of nature".[44] Jeremy Bentham and his student Austin, following David Hume, believed that this conflated the "is" and what "ought to be" problem. Bentham and Austin argued for law's positivism; that real law is entirely separate from "morality".[45] Kant was also criticised by Friedrich Nietzsche, who rejected the principle of equality, and believed that law emanates from the will to power, and cannot be labeled as "moral" or "immoral".[46][47][48]
In 1934, the Austrian philosopher Hans Kelsen continued the positivist tradition in his book the Pure Theory of Law.[49] Kelsen believed that although law is separate from morality, it is endowed with "normativity", meaning we ought to obey it. While laws are positive "is" statements (e.g. the fine for reversing on a highway is €500); law tells us what we "should" do. Thus, each legal system can be hypothesised to have a 'basic norm' (‹See Tfd›German: Grundnorm) instructing us to obey. Kelsen's major opponent, Carl Schmitt, rejected both positivism and the idea of the rule of law because he did not accept the primacy of abstract normative principles over concrete political positions and decisions.[50] Therefore, Schmitt advocated a jurisprudence of the exception (state of emergency), which denied that legal norms could encompass all of the political experience.[51]
Later in the 20th century, H. L. A. Hart attacked Austin for his simplifications and Kelsen for his fictions in The Concept of Law.[52] Hart argued law is a system of rules, divided into primary (rules of conduct) and secondary ones (rules addressed to officials to administer primary rules). Secondary rules are further divided into rules of adjudication (to resolve legal disputes), rules of change (allowing laws to be varied) and the rule of recognition (allowing laws to be identified as valid). Two of Hart's students continued the debate: In his book Law's Empire, Ronald Dworkin attacked Hart and the positivists for their refusal to treat law as a moral issue. Dworkin argues that law is an "interpretive concept"[37] that requires judges to find the best fitting and most just solution to a legal dispute, given their Anglo-American constitutional traditions. Joseph Raz, on the other hand, defended the positivist outlook and criticised Hart's "soft social thesis" approach in The Authority of Law.[38] Raz argues that law is authority, identifiable purely through social sources and without reference to moral reasoning. In his view, any categorisation of rules beyond their role as authoritative instruments in mediation are best left to sociology, rather than jurisprudence.[53]
The history of law links closely to the development of civilization. Ancient Egyptian law, dating a