Law is the body of rules and their enforcement that governs a community. These rules can be interpreted, changed, and enforced through a controlling authority, such as a sovereign or a court of justice. The purpose of law is to keep peace, maintain the status quo, preserve individual rights, protect minorities against majorities, promote social justice, and provide for orderly social change. Some legal systems serve these purposes better than others. For example, a government ruled by an authoritarian leader may keep the peace and maintain the status quo; but it will likely oppress minorities and political opponents and fail to promote social justice. Various scholars and philosophers have developed theories of law. Some have emphasized the moral basis of law. Others have focused on the utilitarian nature of laws, or on the concept of natural law. Still others have studied the structure of law, including the role of courts and legislatures in creating and changing laws.

A key aspect of law is its ability to be understood and followed by ordinary people. Law must be clear and publicly available, with rules that are stable over time. It must also ensure that core human, property, and contract rights are protected and that government officials are accountable and subject to the law.

It is also important for people to be able to anticipate the legal consequences of their actions, both good and bad. For this reason, laws must be reasonably predictable, although this is difficult in practice because of the many variables involved in a system of law.

The most fundamental element of law is its power to compel obedience. This power is derived from the fact that laws are commands, backed by the threat of punishment, issued by a sovereign. For this reason, even tyrannical rulers create law and can enforce it. For example, Nazi Germany executed six million Jews during World War II and Saddam Hussein used his state’s power to brutally suppress opposition in Iraq.

A more sophisticated analysis of law incorporates ideas about legitimacy and a just society. For example, the principle of the rule of law states that all individuals, institutions and entities, both public and private, must be considered equal and must be held accountable to legally binding, publicly promulgated, fairly enforced laws and policies that are transparent and fair in application. The principle of the rule of law aims to protect against anarchy and Hobbesian wars of all against all, and to guarantee against official arbitrariness. The concept of the rule of law has evolved and been elaborated upon through numerous theories, such as utilitarianism (as articulated by John Austin) and John Locke’s notion of natural law. The idea of the rule of law is now a fundamental part of modern Western legal philosophy.