Law is the set of rules that govern a particular society or community. The study of law is known as jurisprudence, and legal practice is the profession which interprets and applies these rules. Law is a social creation and is subject to change as societies evolve, and new problems arise which require new laws or new interpretations of old ones.
The chief purposes of law are establishing standards, maintaining order, resolving disputes and protecting liberties and rights. Disputes are inevitable in any well-ordered society, but a legal system can help people settle them by peacefully turning to the courts to decide their claims. Law can also protect the interests of individuals, families and businesses by regulating their conduct and ensuring that public servants, including police and government workers, follow strict codes of behaviour.
In the modern world, law is usually governed by statutes and regulations made through a legislative process. The law may be supplemented by the rules of procedure and evidence. The rules of procedure are the procedures by which a court must operate, and the rules of evidence are the material that can be used to build a case.
There are many different kinds of legal system, from the rudimentary of Aristotle’s Athens to the more advanced common-law systems found throughout the Anglophone world. In these, specially trained lawyers argue cases for their clients in the courts and other forums. Judges play a quasi-legislative role in fashioning legal rules through decisions which are binding on lower courts and future judges. This process is called stare decisis.
Legal systems differ from country to country, and the nature of political power is an important determinant of whether law will serve its principal functions. The most stable and liberal nations tend to have the highest levels of respect for individual rights, but there are still many countries in the world with unstable or authoritarian governments, and each year there are protests against existing political-legal authority.
The most important determinant of the status and quality of a nation’s laws is its ability to make and enforce laws, and to respond to new social challenges. This requires a degree of independence from vested interest and the capacity to create a political environment where law-making is based on rational argument rather than on the exercise of raw power. The ability of a national legislature to pass and enforce laws also depends on the quality of its judicial branch, which must be independent from the executive and legislative branches. This is the fundamental premise of the separation of powers.