Law is a set of social norms enforced by governmental institutions that regulate behavior. It is the source of much scholarly inquiry in the fields of legal history, philosophy and economic analysis, and raises important questions concerning equality, fairness and justice.
The precise definition of law has been a subject of longstanding debate. It has also been viewed as both a science and an art. A system of laws may consist of a constitution, statutes and court decisions. It may also encompass custom and policies endorsed by a government or society: e.g., property law or criminal law. Law may be derived from divine sources or human creation. Its content is often highly subjective and subject to interpretation, while its enforcement is usually objective.
A basic element of any law is that it imposes some restriction or prohibition on a human action: a law prohibits treason and murder, while a customary or ethical rule may forbid lying. A judicial decision may create a legal precedent, binding future courts to follow the same ruling.
Law may be based on religious precepts, as in Jewish Halakha and Islamic Sharia, or it may rely on human elaboration, such as precedent, Qiyas (reasoning by analogy) and Ijma (consensus). In some systems, all of these sources contribute to the legal system, while in others the law is developed primarily through legislative statutes and administrative regulations.
Some systems, such as the United States, combine a primarily legislative system with a civil law system that addresses non-criminal claims like divorce, breach of contract and torts. In general, laws are most effective when they are clearly expressed, enforceable and accessible to citizens. They also need to be consistent with international human rights standards and national constitutional requirements, including separation of powers, participation in decision-making, legal certainty and avoidance of arbitrariness.
Observer-centric definitions of law, such as Holmes’s, are not without problems. One problem is that they deprive law of its objectivity, which is a requirement for scientific discovery and verification. A further problem is that they can only predict the intersection of an individual’s own narrative of reality and a shared external reality shaped by other peoples’ narratives.
The modern concept of law is complex and difficult to define. A common view is that the law is an enumeration of rights and duties established by the state or society and enforceable through the judicial or executive branch of government. The modern concept of the rule of law is a more demanding one, requiring measures to ensure supremacy of the law, equal treatment under the law, accountability to the law and independent adjudication, separation of powers, participation in the lawmaking process, legal certainty and transparency. This requires measures to ensure adherence to international human rights standards and national constitutional requirements, such as participation in decision-making, legal certainty, transparency, independence from undue influence and avoidance of arbitrariness.