Law is a discipline and profession concerned with practices, sets of rules and customs that are recognized as binding by the community and enforced through a controlling authority. These rules form a framework to ensure a peaceful society and, if broken, sanctions can be imposed. There are many different views about what constitutes law and these vary considerably across societies, though some broad themes are often present. These include societal viewpoints on rationality, justice and order. The practice of law itself can also provide an important source of ideas about the nature of the law, for example, John Austin’s utilitarian view that “law consists of commands backed by force or the threat of sanction from a sovereign, to which people have a habit of obedience”.

This article deals with the principle aspects of law, not laws in general or specific legal fields such as criminal, tort or administrative law. For these see relevant articles for a more detailed discussion.

The main functions of law are establishing standards, maintaining order, resolving disputes and protecting liberties and rights. The latter is perhaps the most important of all and is reflected in the constitutions of most nation-states, which often feature rights encoded into them that are protected by the law. The political landscape differs greatly from country to country, however, and unstable or authoritarian regimes may fail to fulfil the principal function of law.

Some countries, such as the United States, use a common law system in which the laws are derived from judicial decisions in particular cases. In contrast, other nations have civil law systems in which the laws are explicitly written down and compiled into codes.

The broader field of law includes many sub-fields, such as employment and labour law (which includes collective bargaining and the right to strike) and family law. Business law involves the regulation of commerce and finance, while biolaw concerns issues at the intersection of law and the life sciences.

The defining feature of law, as articulated by James Madison in one of the Federalist Papers, is that it is a system of rules established to ensure that no single individual or group can gain excessive power over the lives of others. This is achieved by the separation of powers between the legislative, executive and judicial branches of government. This framework, known as the separation of powers, is an essential element in any functioning democracy. It is why, as a country becomes more centralized in its governance, it must be vigilant to protect against excessive governmental power and prevent abuses of that power. This is, in the end, the only way that a country can guarantee its citizens a fundamental level of protection. Without this, a democracy is no more than an autocracy run by a dictator or despot. For this reason, democracies must always be vigilant in defending their own system of law and their own democracy. It is a process that must be constantly tested against the challenges of the real world.