Sources of law

Sources of law are the origins of laws, the binding rules that enable any state to govern its territory. The terminology was already used in Rome by Cicero as a metaphor referring to the "fountain" ("fons" in Latin) of law. Technically, anything that can create, change, or cancel any right or law is considered a source of law.

The term "source of law" may sometimes refer to the sovereign or to the seat of power from which the law derives its validity.

Legal theory usually classifies them into formal and material sources, although this classification is not always used consistently. Normally, formal sources are connected with what creates the law: statutes, case law, contracts, and so on. In contrast, material sources refer to the places where formal law can be found, such as the official bulletin or gazette where the legislator publishes the country's laws, newspapers, and public deeds. Following the Aristotelian notion of the four causes (material, formal, efficient, and final causes), Riofrio also develops additional potential sources of law. For instance, efficient sources of law would include actions of nature or "of God" that change the law, actions of the intellect that produce legal culture, and actions of the will that approve laws and agreements. On the other hand, several final sources of law exist, such as the purposes of law, the intentions of the parties in a legal transaction, the goals of each policy, and the ends of the constitution.

The perceived authenticity of a source of law may rely on a choice of jurisprudence analysis. Tyrants such as Kim Jong-un may wield De facto power, but critics would say he does not exercise power from a de jure (or legitimate) source. After WWII it was not a valid defence at Nuremberg to say "I was only obeying orders", and the victors hanged Nazis for breaching "universal and eternal standards of right and wrong".

Over decades and centuries, principles of law have been derived from customs. The divine right of kings, natural and legal rights, human rights, civil rights, and common law are early unwritten sources of law. Historical or judicial precedent and case law can modify or even create a source of law. Legislation, rules, and regulations form the tangible source of laws which are codified and enforceable.

In civil law systems, the sources of law include the legal codes, such as the civil code or the criminal code, and custom; in common law systems there are also several sources that combine to form "the law". Civil law systems often absorb ideas from the common law and vice-versa. Scotland, for instance, has a hybrid form of law, as does South Africa, whose law in an amalgam of common law, civil law and tribal law.

A state may comply with international law, it may have a written or federal constitution, or it may have regional legislature, but normally it is the central national legislature that is the ultimate source of law. While a written constitution may seem to be the prime source of law, the state legislature may amend its constitution provided certain rules are followed. International law may take precedence over national law, but international law is mainly made up of conventions and treaties that have been ratified; and anything that can be ratified may be denounced later by the national parliament. Although local authorities may feel that they have a democratic mandate to pass by-laws, the legislative power they wield has been delegated by parliament; and what parliament gives, parliament make later take away.

In England, the archetypal common law country, there is a hierarchy of sources, as follows: