What is law?
Main article: Analytical jurisprudence
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.[44] McCoubrey and White said that the question "what is law?" has no simple answer.[45] 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.[46] 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.[47] 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").[48]

One definition is that law is a system of rules and guidelines which are enforced through social institutions to govern behaviour.[2] In The Concept of Law Hart argued law is a "system of rules";[49] Austin said law was "the command of a sovereign, backed by the threat of a sanction";[30] Dworkin describes law as an "interpretive concept" to achieve justice in his text titled Law's Empire;[41] and Raz argues law is an "authority" to mediate people's interests.[42] Holmes said "The prophecies of what the courts will do in fact, and nothing more pretentious, are what I mean by the law."[50] In his Treatise on Law 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.[51] This definition has both positivist and naturalist elements.[52]