Law is the set of rules that social or governmental institutions create and enforce to regulate behavior. Its precise definition is a longstanding source of debate and it has been variously described as a science, an art, or a system of justice. Law serves many purposes, but four of the most important are establishing standards, maintaining order, resolving disputes, and protecting liberties and rights.
Different approaches to defining law offer different insights into its nature and role in society. For example, Hans Kelsen’s pure theory of law states that it is a ‘normative science’ and defines the meaning of a law as ‘rules to abide by’. Roscoe Pound’s law definition is more complex: it states that it is a tool of social control.
There are a wide variety of fields within the legal system that reflect its underlying purpose and structure: contracts and agreements; property; torts; and criminal and administrative law. Contract law, for example, deals with the exchange of goods and services or other items of value; property law covers one’s rights to tangible property (such as buildings, land, and automobiles) and intangible property (such as intellectual property like patents); tort laws cover injury to people’s persons and their possessions; and criminal laws punish those who commit offences against the state.
Another important issue in defining law is deciding what is the proper input to a legal interpretation, and what is the proper output. Some, such as intentionalists, give primacy to the intentions of lawmakers (the legislature in the case of statutory law and the framers or ratifiers of constitutional law). Others argue that the proper input is something other than the linguistic meaning of a provision, such as its genuine normative impact or the best justification for its enactment.