Law is a system of rules that are created and enforced through social or governmental institutions to regulate behavior. It serves many purposes, including establishing standards, maintaining order, resolving disputes, and protecting liberties and rights. Its precise definition is a matter of longstanding debate.
Law may be imposed by the state through legislatures, producing statutes, decrees or regulations; by the executive, producing administrative codes, ordinances and executive orders; or by judges, producing case law. Private individuals may also create legally binding contracts. The formation of laws may be influenced by constitutions, either written or tacit, and the rights encoded therein. The laws themselves can include criminal or civil, but they may also include private rights such as contract law, property law, and civil procedure.
The philosophical study of Law encompasses a wide variety of subjects, such as the nature of authority, the relation between morality and law, the justification of political rule, and the underlying concepts of knowledge and truth. Philosophical speculation about the nature of law often depends upon, and sometimes contributes to, answers to fundamental questions such as these.
Ultimately, however, the nature of Law is a practical rather than theoretical question. There are several reasons for this. First, laws are a necessary means of governing human behaviour, yet the shape and limitations of the physical world mean that they cannot impose precepts which are unattainable or force people to do things beyond their abilities.
Second, the primary function of laws is to ensure that members of a community adhere to the will of the state. This is the reason why the judicial system embraces the ideal of objectivity, with the hope that every judge will follow the same criteria in reaching their decisions. Unfortunately, this is often not the case.
A further difficulty is that, although philosophers have a great deal of scope for speculation about the nature of law, it is essentially impossible to test any theory of the nature of Law through empirical investigation. This is because, unless some sort of universal system of laws can be discovered, it is difficult to determine which theories are correct.
As a result, any philosophical speculation about the nature of Law will be inevitably parochial in a broad sense, since it is usually carried out with a particular type of legal system and legal culture in mind. This is an important point to bear in mind when reading or discussing legal philosophy. There are exceptions, of course, but they tend to be relatively rare.