Law is a set of rules that govern behavior and are enforced by society or government. The precise nature of law is the subject of debate and many books have been written about it. The concept of law is closely linked to that of politics, and the political system in which a nation is governed affects its laws. The principal functions of a legal system are to keep the peace, maintain the status quo, resolve disputes and protect rights and liberties. Different legal systems have different ways of meeting these aims.
The word law can be derived from the Latin noun legis, meaning “a rule or order” and the verb form legitimate, meaning “to be in accordance with or sanctioned by legitimate authority”. Law can be the result of either a collective decision of a group of people, resulting in a constitution; or it can be created by individuals, such as a will or a trust. It can also be a formal agreement between two or more parties, forming contract law.
Law can be divided into two broad categories – procedural law and substantive law. Procedural law concerns the guarantees of specific procedures, like a trial or the right to appeal, while substantive law covers a person’s rights and duties, such as contract and tort law.
Some theories of law focus on the morality of laws, while others are based on utilitarian or economic ideas. Bentham’s utilitarian theory states that a law is “commands, backed by threat of sanctions, from the governing power in an organized jural society, to which members have a natural tendency of obedience”. Jean-Jacques Rousseau’s philosophy of natural law advocates that a law reflects unchanging principles of morality and justice.
The practice of law involves the study and advocacy of a country’s laws. This can be done on behalf of a private client, or as part of a governmental agency, for example, the police force or ministry of justice. Individual lawyers are often called solicitors or barristers. They can be transactional, writing contracts and drafting agreements, or they can go to court and argue cases. Lawyers typically have a specific qualification, passed a rigorous legal exam and studied for a law degree.
Legal systems differ greatly between nations, and even within a country, the areas in which law applies can be wide-ranging. For example, constitutional law deals with the limits of federal power and statutory law is a body of laws established by parliament. The rules governing civil and criminal procedure are common law, with most countries having a system of courts which can review appeals, up to a Supreme Court. Aviation law, for example, covers the rules and regulations governing the operation of aircraft and is usually aligned with international standards laid down by the International Civil Aviation Organisation or ICAO. Social and environmental law are often common law, while laws relating to religion are normally statutory. This article discusses law in general, but for more detailed articles on specific areas of law, see the articles on legal profession, legal education and law and society.