Law is a system of rules and principles that regulates human behavior. The rules are enforced by a government, or another entity with authority to do so. The laws are derived from a variety of sources, including legislation and judicial decisions. The law influences politics, economics, history, and society in many ways, as it governs the way people behave. It is also a mediator of relationships between people.
A common law system like the United States, for instance, bases its laws on judicial decisions based on a case-by-case basis. This means that the decisions of higher courts bind lower courts, which makes it easier for judges to reach similar conclusions in future cases. A common law system can be contrasted with a civil law system, which relies on laws that explicitly specify how judges should rule in particular situations.
Some people have criticized the idea of law as nothing more than power backed by threats and coercion. They point out that laws can be amended or repealed at any time by those with the authority to do so, and that citizens often have options for dealing with a government they feel is not responsive to their needs. In addition to allowing citizens to vote out government officials, many democratic systems allow citizens to protest the actions of their governments and even bring civil lawsuits against them, for example, over environmental or economic concerns.
Other scholars have come up with different law definitions, with some of the most important focusing on the purpose and function of laws. Roscoe Pound, for example, believed that laws serve a number of purposes, including providing order and maintaining social stability. He created a legal technique, which is referred to as “law acting,” that seeks to satisfy social wants through law.
John Austin provided a more formal definition of law, saying that it is an aggregate set of rules established by the sovereign as its will in relation to men as political subjects. He believed that the law consists of a collection of rules that is not exhaustive but that includes laws relating to such topics as crime, property, family, and marriage.
The law may be categorized into several subfields, such as criminal law, administrative law, civil rights, and tort law. Contract law, for example, covers agreements that involve the exchange of goods and services, while property law encompasses one’s rights toward tangible assets such as land or buildings, as well as intangible assets such as shares of stock. Family law encompasses the rights of married and single individuals, as well as their children.
Other fields that are considered to be part of the law include aviation, railroad, and shipping laws; bankruptcy law; sex, gender, and disability law; international law; business law; and biolaw, which focuses on the intersection between law and the life sciences. Each of these areas includes specialized branches. For more information, see articles on those branches.