Law shapes politics, economics, history and society in numerous ways and serves as a mediator of relations between people. Its precise nature is the subject of enduring debate, but philosophers have generally agreed that the concept must include both formal and substantive aspects. It must also include both a public and private dimension and encompass rights and duties, both individual and collective.
The word “law” has evolved over time to encompass a wide variety of conventions and rules. Its Greek root, nomos, referred to the prevailing custom in a given context, and its meaning was broadened by Plato (428-427 bce) to include a proclaimed directive establishing a standard for human behavior.
Today, a law may be any set of rules adopted by a community to regulate conduct or settle disputes. It can be a written statute or a collection of court decisions that have binding force. In “civil law” jurisdictions, laws are codified by a legislature or central body, while in “common law” systems judges’ decisions are recognized as law along with statutes and regulations. This is called the doctrine of stare decisis, which assures that subsequent cases will reach similar conclusions.
The sense of stability and certainty that a law conveys is its fundamental purpose, although the specific way in which a law functions varies from one country to another. In all nations, the legal system is shaped by a complex relationship between politics and law. Each year there are revolts against the legitimacy of existing political-legal authority; calls for greater democratic rule and more rights for citizens are a constant feature of political life.