Law is the set of rules that a particular community or nation recognizes as regulating the actions of its members and that are enforced by a central authority. Its scope is vast, encompassing everything from criminal, tax and social security laws to international and family law. Law is also the subject of significant and sometimes controversial scholarly inquiry, involving subjects as diverse as legal history and philosophy, economic analysis and sociology.
There are four main functions of law: setting standards, maintaining order, resolving disputes, and protecting liberties and rights. The primary means of achieving these ends is by the rule of law, or the idea that the courts should interpret and apply the law consistently in the same way to all parties involved in a case. The judicial branch of government thus possesses an unmatched power to shape the course of human events, but the exercise of this great power comes with serious constraints.
The first of these constraints is that there are no means of empirical verification of any statement of law, unlike statements of fact (such as the force of gravity between two objects) or precepts of a normative nature (such as ethical principles). Law is a human invention, and therefore its content can never be completely known. Consequently, the legitimacy of law is always subject to doubt.
A second constraint is the need for courts to decide cases based on evidence that is presented to a fact finder, such as a judge or jury. This necessitates a fair and impartial trial.
In addition, there is a need for law to be a dynamic and evolving tool of society. The changing needs of the public and the rapid development of technology can often require legal changes. These changes can be achieved through a legislative process, or through the judicial system by interpreting existing laws and creating new ones.
Some of the most important areas of law include property law, which establishes people’s rights and duties toward tangible possessions; contract law, which governs agreements to exchange goods or services; and administrative law, which is the legal framework for public administration. Other important areas of law are family and employment law, immigration and nationality law, and civil rights law. The latter concerns the rights of citizens and non-citizens to work in a country, obtain citizenship, and marry or divorce within that jurisdiction. The laws governing these matters are largely determined by the constitution of each nation-state. They can also be influenced by regional or global traditions of law, such as the civil code of Egypt or Roman law, and by the customary practices of some communities. Law also plays a role in international relations. This is covered in articles such as treaty; international law; and world politics.