A system of rules enforced by a government or other authority to control behaviour and ensure that people adhere to a social norm. Law may be enacted by a legislature, creating statutes, or made by the executive branch, with decrees and regulations, or established by judges through precedent (the “doctrine of stare decisis”).

Law also includes laws that are created or approved by man, such as customs and policies, and it includes the moral law that is derived from concepts of natural justice, or from the will of a deity. For example, the ten commandments of the Bible establish ethical guidelines for man in his interactions with one another.

In addition to the laws that are imposed on individuals by the state, there are also laws that are created or approved by the community of a nation. These can be based on common beliefs and traditions, or they can be religious in origin, such as Jewish halakha and Islamic shari’a, or they might reflect the societal values and norms of a group of people, such as Christian canon law.

The laws that a society creates can be either positive or negative in nature. Positive laws are a result of a constitution or a written or tacit agreement of the people. These laws typically govern the actions of a state or nation, and are designed to promote public welfare and protect individual rights. Negative law, on the other hand, imposes restrictions and punishments on individuals, groups or institutions that are considered harmful to society as a whole.

The earliest legal systems were based on law of nature, or natural law, as opposed to the positive laws established by the state. Natural law consists of the principles that are common to all human beings, such as that it is wrong to steal, lie or commit murder. The principle that it is wrong to show favoritism in judgment is also part of the natural law, as is the commandment to treat others as one would like to be treated.

Modern law is based on positive laws, but it can be modified by the courts to reflect changes in social circumstances or new needs. This is done through interpretative and creative jurisprudence. It is also possible to have a mix of civil and common law in the same jurisdiction, with both legislative statutes and judicial decisions that are binding.

The professions that deal with law are called the “lawyering” professions. They include lawyers, barristers and solicitors, who are authorised to practice law under the supervision of a recognised regulating body. Lawyers are required to follow certain professional procedures when representing their clients in court, and they must have a high level of competence and honesty. In some countries, it is a crime for an unlicensed person to practise law. A license is usually obtained by passing a professional examination, and it is normally renewed on a periodic basis. In most countries, the practice of law is subject to a code of conduct and other regulatory bodies.