Law Definition


Law, body of official rules and regulations, generally found in constitutions, legislation, judicial opinions, and the like, that is used to govern a society and to control the behaviour of its members. The nature and functions of law have varied throughout history. In modern societies, some authorized body such as a legislature or a court makes the law. It is backed by the coercive power of the state, which enforces the law by means of appropriate penalties or remedies.

Formal legal rules and actions are usually distinguished from other means of social control and guides for behaviour such as mores, morality, public opinion, and custom or tradition. Of course, a lawmaker may respond to public opinion or other pressures, and a formal law may prohibit what is morally unacceptable.

Law serves a variety of functions. Laws against crimes, for example, help to maintain a peaceful, orderly, relatively stable society. Courts contribute to social stability by resolving disputes in a civilized fashion. Property and contract laws facilitate business activities and private planning. Laws limiting the powers of government help to provide some degree of freedom that would not otherwise be possible. Law has also been used as a mechanism for social change; for instance, at various times laws have been passed to inhibit social discrimination and to improve the quality of individual life in matters of health, education, and welfare.

Some experts believe that the popular view of law overemphasizes its formal, coercive aspects. They point out that if a custom or norm is assured of judicial backing, it is, for practical purposes, law. On the other hand, a statute that is neither obeyed nor enforced is an empty law. Social attitudes towards the formal law are a significant part of the law in process. The role of law in China and Japan, for example, is somewhat different from its role in Western nations. Respect for the processes of law is low, at least outside matters of business and industry, and tradition looms much larger in everyday life. Resort to legal resolution of a dispute is truly a last resort, with conciliation being the mechanism that is preferred for social control.

Law is not completely a matter of human enactment; it also includes natural law. The best-known version of this view, that God’s law is supreme, has had considerable influence in many Western societies. The civil rights movement, for example, was at least partially inspired by the belief in natural law. Such a belief seems implicit in the view that law should serve to promote human dignity, as for instance by the enforcement of equal rights for all. Muslim societies also embrace a version of natural law, which is closely linked to the religion of Islam.


Law develops as society evolves. Historically, the simplest societies were tribal. The members of the tribe were bonded together initially by kinship and worship of the same gods. Even in the absence of courts and legislature there was law—a blend of custom, morality, religion, and magic. The visible authority was the ruler, or chief; the ultimate authorities were believed to be the gods whose will was revealed in the forces of nature and in the revelations of the tribal head or the priests. Wrongs against the tribe, such as sacrilege or breach of tribal custom, were met with group sanctions including ridicule and hostility, and, the tribe members thought, with the wrath of the gods. The gods were appeased in ritualistic ceremonies ending perhaps in sacrifice or expulsion of the wrongdoer. Wrongs against individuals, such as murder, theft, adultery, or failure to repay a debt, were avenged by the family of the victim, often in actions against the family of the wrongdoer. Revenge of this kind was based on tribal custom, a major component of early law.

Tribal society gradually evolved into territorial confederations. Governmental structures emerged, and modern law began to take shape. The most significant historical example is Roman law, which influenced most of the legal systems of the world. In the 8th century bc the law of Rome was still largely a blend of custom and interpretation by magistrates of the will of the gods. The magistrates later lost their legitimacy because of gross discrimination against the lower (plebeian) class. The threat of revolution led to one of the most significant developments in the history of law: the Twelve Tables of Rome, which were engraved on bronze tablets in the 5th century bc. They were largely a declaration of existing customs concerning such matters as property, payment of debts, and appropriate compensation or other remedies for damage to people. The Twelve Tables serve as a historical basis for the widespread modern belief that fairness in law demands that it be in written form. These tables and their Roman successors, including the Justinian Code, led to civil law codes that provide the main source of law in much of modern Europe, South America, and elsewhere.

The common law systems of England, and later of the United States, developed in a different manner. Before the Norman Conquest (1066), England was a loose confederation of societies, the laws of which were largely tribal and local. The Anglo-Norman rulers created a system of centralized courts that operated under a single set of laws that superseded the rules laid down by earlier societies. This legal system, known as the common law of England, began with common customs, but over time it involved the courts in lawmaking that was responsive to changes in society.

Modern legislatures and administrative agencies produce a much greater quantity of formal law, but the judiciary remains very important because of the continued vitality of the common law approach even in matters of constitutional and statutory interpretations. Increasingly in civil law countries, the subtleties of judicial interpretation and the weight of judicial precedents are recognized as involving the courts in significant aspects of lawmaking.


In broad terms, substantive law defines the rights and duties of people; procedural law defines and deals with procedures for enforcing those rights and duties. Substantive law determines a wide variety of matters—for example, what is required to form a contract, what the difference is between larceny and robbery, when one is entitled to compensation for an injury, and so on. The rules of procedure and jurisdiction determine the court or administrative agency that may handle a claim or dispute; the form of the trial, hearing, or appeal; the time limits involved; and so on. Related rules also cover the kinds of evidence that may be presented. Such rules are more limiting in trial courts than in administrative agencies. The fine points of procedural law are considerable, but they are generally thought to be indispensable to whatever efficiency and fairness law may have.


Public law concerns the relationships both within a government and between governments and individuals. Because the Roman codes were almost entirely limited to the private area, public law is usually not codified, that is, arranged systematically into a set code. In civil law countries, separate administrative courts adjudicate claims and disputes between the various branches of government and citizens, and many lawyers specialize in public law. In France, Germany, and Italy, still other courts handle constitutional issues.

Public law is not quite so clearly demarcated in the United Kingdom. Under the common law approach the same courts handle public and private litigation. Because the United Kingdom has no written constitution, basic principles pertaining to government powers and limits and to fundamental individual rights are found in acts of Parliament, judicial opinions, and tradition. The High Court has the power to declare an act of Parliament to be in breach of the Human Rights Act 1998.

Laws concerning taxation and the regulation of business are in the public area, as is criminal law, which involves the exercise of governmental power by way of enforcement and punishment. Historically, criminal law in the United Kingdom included crimes defined by the courts. The public law nature of the area is further emphasized by other constitutional protections such as the presumption of innocence, protection against self-incrimination, and the rule against double jeopardy (whereby a defendant cannot be tried twice for the same crime—although retrials are now permissible in the UK for the most serious offences). Criminal law not only promotes security and order but also reinforces moral norms. Debate has been continuous regarding the legitimacy of government intervention in areas where moral attitudes are in significant conflict, such as in matters of sexual practices, pornography, birth control, and euthanasia.

An important area of public law concerns the welfare of children: the courts have wide powers to intervene in family life to protect minors.


Private law involves the various relationships that people have with one another and the rules that determine their legal rights and duties among themselves. The area is concerned with rules and principles pertaining to private ownership and use of property, contracts between individuals, family relationships, and redress by way of compensation for harm inflicted on one person by another. Historically, government involvement was usually minimal. Private law has also operated to provide general guidelines and security in private arrangements and interactions in ways that are complementary to morality and custom but that are not necessarily enforceable in a court of law, such as noncontractual promises and agreements within an association of private individuals.

The relative significance of purely private law has decreased in modern times. Public law dominates in government-controlled societies; democratic societies increasingly have a mix of public and private law. The private sphere includes individuals and a vast array of groups, associations, organizations, and special legal entities such as corporations and limited companies. They compete with one another and with government for control of resources, wealth, power, and the communication of ideas and values. Special fields of law, such as labour law, facilitate and control this competition. Much of such law is in the commercial and corporate areas. The formerly purely private law of property and contracts, for example, is now overlaid with legislation, regulations, and judicial decisions reflecting the competition. The public law of taxation has significant impact on the whole private sphere. Courts have increasingly regarded resolution of seemingly private disputes as vehicles for response to changing social conditions and values—especially in the United States. Thus, manufacturers have experienced an expansion of liability for physical injuries caused by defects in their products. The mechanism of insurance allows manufacturers to spread such costs across the general consuming public.


The legal process that concerns relations among nations is called international law. Belief and experience in some form of international law dates from at least the days of the Roman Empire. Such law differs greatly from national legal systems. No court has the authority or power to give judgments backed by coercive sanctions. Even in its most modern developments, international law is almost wholly based on custom. The precedents on which it rests are the acts of independent governments in their relations with one another, including treaties and conventions. Behind many of its rules is only a moral sanction: the public opinion of the civilized world. When treaties or conventions are involved, however, machinery to enforce them exists—either an arbitration or conciliation procedure or the submission of the dispute to a regional or international court.

A discernible body of rules and principles is observed or at least acknowledged in international relations. These rules concern such matters as territorial titles and boundaries, use of the high seas, limits on war, telecommunication, diplomatic and consular exchange, and use of air space. The major sources of international law on these matters are multilateral treaties, international custom, and such general principles as are recognized by civilized nations.

The United Nations is one of the primary mechanisms that articulate and create international law. The General Assembly and other agencies of the UN bring a combination of diplomacy, negotiation, and propaganda to bear on world affairs in ways that produce effective international treaties and affect world opinion. Certain courts also have indirect impact, including the International Court of Justice and the International War Crimes Tribunal. Domestic courts in various nations at times also engage in the articulation of international law.