Law is a set of rules that are enforced by an authority. The word comes from the Old Norse lag, which means “laying an order.” The purpose of law is to keep everyone in line and prevent conflict, such as over property. For example, when two people claim the same piece of land, the courts can decide which one is the true owner. Law also protects personal rights and provides for punishment for crimes like murder or theft.
Law is based on a variety of sources. For example, civil law systems use concepts, categories and rules derived from Roman law with some influence from canon law, but are supplemented by local custom and culture. These types of laws cover about 60% of the world. Other laws are based on natural principles, like the principle that property must be fairly valued. The rest of the world uses common law systems.
There are a number of different theories about the nature of law. For example, Bentham’s utilitarian theory of law is that it is a series of commands backed by the threat of sanctions from a sovereign to whom people have a habit of obedience. Jean-Jacques Rousseau, on the other hand, argued that law is a reflection of innate morality.
Roscoe Pound developed a third theory about the nature of law. He believed that law exists to satisfy social wants. His concept of the rule of law was that all citizens, even highly placed officials, are considered equal under publicly disclosed legal codes and processes.