Law

Law refers to a system of rules that governments or social institutions create and enforce to guide human conduct. Exactly what counts as law has been argued for a long time. People have called it both a science and the art of justice. Law influences politics, economics, history, and society in many ways, and it also acts as a go-between in how people relate to one another.

The word itself comes from Old English *lagu*, which traces back to the Old Norse word *lǫg*. The singular form, *lag*, meant something laid or fixed, while the plural form meant law.

The study of law’s philosophy is known as jurisprudence. One branch, normative jurisprudence, asks what law should be. Another, analytic jurisprudence, asks what law is. Many thinkers have tried to produce a definition everyone can accept, but in 1972 Baron Hampstead suggested that no such definition could be made. McCoubrey and White said the question “what is law?” has no simple answer. Glanville Williams pointed out that the meaning of “law” depends on context—for example, “early customary law” and “municipal law” have two different and irreconcilable meanings. Thurman Arnold noted that it is obviously impossible to define the word, yet equally obvious that the struggle to define it should never be abandoned. Some take the view that no definition is needed at all, preferring to focus on specific cases.

One common definition says law is a system of rules and guidelines enforced by social institutions to govern behavior. H. L. A. Hart argued that law is a system of rules. John Austin said it is the command of a sovereign, backed by the threat of a sanction. Ronald Dworkin described law as an interpretive concept aimed at achieving justice. Joseph Raz argued law is an authority that mediates people’s interests. Oliver Wendell Holmes defined law as prophecies of what courts will actually do, nothing more. Thomas Aquinas, in his *Treatise on Law*, said law is a rational ordering of things concerning the common good, promulgated by whoever is responsible for the community’s care—a definition with both positivist and naturalist elements.

Definitions of law often raise the question of how much morality it includes. John Austin’s utilitarian answer was that law consists of commands from a sovereign, backed by threats of sanctions, which people habitually obey. Natural lawyers like Jean-Jacques Rousseau argued that law reflects essentially moral and unchangeable laws of nature. The idea of natural law appeared in ancient Greek philosophy alongside the notion of justice and re-entered Western culture through Thomas Aquinas. Hugo Grotius, who founded a purely rationalistic system of natural law, said law arises from both a social impulse—as Aristotle noted—and reason. Immanuel Kant believed a moral imperative requires that laws be chosen as though they should hold as universal laws of nature. Jeremy Bentham and his student Austin, following David Hume, thought this confused what *is* with what *ought to be*. They argued for legal positivism, holding that real law is entirely separate from morality. Friedrich Nietzsche criticized Kant, rejecting the principle of equality and arguing that law comes from the will to power and cannot be labeled moral or immoral. In 1934, Hans Kelsen continued the positivist tradition in his *Pure Theory of Law*, believing that while law is separate from morality, it has normativity—meaning we ought to obey it. Laws are positive “is” statements (for example, a fine for reversing on a highway is €500), but they tell us what we should do. Each legal system, Kelsen thought, can be assumed to have a basic norm instructing us to obey. His main opponent, Carl Schmitt, rejected both positivism and the idea of the rule of law, because he did not accept the primacy of abstract norms.

Legal systems vary between jurisdictions, and comparative law studies these differences. In civil law jurisdictions, a legislature or central body codifies and consolidates the law. In common law systems, judges can make binding case law through precedent, though a higher court or the legislature may overturn it. Religious law is used in some religious communities and states and has historically influenced secular law.

The scope of law divides into two domains. Public law concerns government and society, covering constitutional law, administrative law, and criminal law. Private law deals with legal disputes between parties in areas such as contracts, property, torts, delicts, and commercial law. This distinction is stronger in civil law countries, especially those with separate administrative courts; in common law jurisdictions, the public-private divide is less pronounced.

Law provides a source of scholarly inquiry into legal history, philosophy, economic analysis, and sociology. It also raises important and complex issues concerning equality, fairness, and justice.