Law is a system of rules that governs the conduct of a society and is enforced by a controlling authority through penalties. It is distinguished from other types of rules in that it has a normative character, telling people how they should behave or not. It is also a subject of study; the branch of knowledge that studies laws is called jurisprudence. The principal purposes of law are establishing standards, maintaining order, resolving disputes and protecting liberties and rights.
Legal systems vary widely, with the law shaping politics, economics and history in a wide variety of ways. The general distinction is between civil law jurisdictions (which tend to be more centralized) and common law societies, in which the laws are largely derived from judge-made precedent. However, even within these general categories there are variations.
In some countries, including the United States, law is based on a constitutional system of government with separation of powers and an independent judiciary. In others, such as Japan, law is largely governed by statutes or codes with very little judicial influence. The law can also be influenced by religion, culture or custom.
There are many different areas of the law, ranging from property and criminal law to family and labour law. Each of these fields has a number of sub-fields, each of which can be divided further into sub-topics. For example, intellectual property law covers the ownership of ideas and works of art, while commercial law is concerned with contracts. Labour law is the study of the tripartite industrial relationship between worker, employer and trade union, involving issues such as employment rights and the right to strike. Criminal law is the study of crimes and the punishment for those crimes.
Despite these variations, there are certain similarities between the broad categories of the law. For example, the legal profession has adopted a scientific approach to its work. This is reflected in terms such as the use of the term ‘evidence’ to describe what can be presented to the court to prove a case. There are also certain conventions that are used to denote the status of a lawyer. For example, the title Esquire is used to indicate a barrister of greater dignity and the degree Doctor of Law is used to denote a person who has obtained a PhD in law.
The law has its roots in ancient traditions and continues to evolve in response to social change. In addition, the law is dependent on the shape of the physical world and its limitations. It cannot dictate behaviours that are impossible or force people to do things that they do not have the capability to achieve. This makes the law uniquely complex from a methodological point of view. Unlike empirical sciences such as biology or physics, it is not possible to test the content of law through experimentation. It is therefore not a ‘law of nature’ or a ‘law of human action’ in the sense that it can be compared to other laws such as the law of gravity or the law of supply and demand.