Canon law

Canon law refers to the rules and regulations created by church leadership to govern a Christian organization or church and its members. This body of internal ecclesiastical law applies to the Catholic Church (including both the Latin Church and Eastern Catholic Churches), the Eastern Orthodox and Oriental Orthodox churches, and the national churches within the Anglican Communion. How these laws are made, interpreted, and sometimes adjudicated differs significantly among these four groups. In each tradition, a canon originally meant a rule adopted by a church council, and these early canons formed the basis of canon law.

The word "canon" comes from the Greek *kanon* (κανών), which means a straight rod or rule, and is related to the Hebrew *kaneh* (קָנֶה) and Arabic *qaanoon* (قانون), all sharing the root meaning of "reed." By the fourth century, the First Council of Nicaea (325) used the term for the church’s disciplinary measures, distinguishing them from state laws, which were called *leges* in Latin.

The Apostolic Canons are an ancient collection of ecclesiastical decrees—eighty-five in the Eastern Church and fifty in the Western Church—concerning early Christian church government and discipline. They are part of the Apostolic Constitutions, which are included among the Ante-Nicene Fathers.

In the Catholic Church, canon law is the system of laws and legal principles created and enforced by its hierarchical authorities to regulate the church’s external organization and government, as well as to direct the activities of Catholics toward the church’s mission. It was the first modern Western legal system and remains the oldest continuously functioning legal system in the West. In the Latin Church, positive ecclesiastical laws derive formal authority from the supreme legislator (the Pope) for universal laws, or from a lesser legislator for particular laws, and are based directly or indirectly on immutable divine or natural law. The subject matter of these canons covers not only doctrine and morality but the full range of human experience, extending beyond revealed truth.

The Catholic Church also includes five main rites of churches in full union with the Holy See and the Latin Church: the Alexandrian Rite (Coptic Catholic, Eritrean Catholic, and Ethiopian Catholic Churches); the West Syriac Rite (Maronite, Syriac Catholic, and Syro-Malankara Catholic Churches); the Armenian Rite (Armenian Catholic Church); the Byzantine Rite (including numerous churches such as the Albanian Greek Catholic, Belarusian Greek Catholic, Bulgarian Greek Catholic, Greek Catholic Church of Croatia and Serbia, Greek Byzantine Catholic, Hungarian Greek Catholic, Italo-Albanian Catholic, Macedonian Greek Catholic, Melkite Greek Catholic, Romanian Greek Catholic, Russian Greek Catholic, Ruthenian Greek Catholic, Slovak Greek Catholic, and Ukrainian Greek Catholic Churches); and the East Syriac Rite (Chaldean Catholic and Syro-Malabar Churches). All these groups are in full communion with the Pope and are subject to the Code of Canons of the Eastern Churches.

The history of Latin canon law is divided into four periods: the *jus antiquum*, *jus novum*, *jus novissimum*, and the Code of Canon Law. In relation to the Code, history is split into the *jus vetus* (all law before the Code) and the *jus novum* (the law of the Code). The canon law of the Eastern Catholic Churches, which developed different disciplines and practices, underwent its own codification, resulting in the Code of Canons of the Eastern Churches, promulgated in 1990 by Pope John Paul II.

Catholic canon law is a fully developed legal system with courts, lawyers, judges, a legal code, principles of interpretation, and coercive penalties, though it lacks civilly-binding force in most secular jurisdictions. A historical example of conflict between secular and canon law occurred in the English legal system and its derivatives, such as in the United States. Criminals could claim the benefit of clergy, allowing them—if in holy orders or fraudulently claiming to be—to be tried by ecclesiastical courts, which were generally more lenient. Under the Tudors, the scope of this benefit was steadily reduced by Henry VII, Henry VIII, and Elizabeth I, and the papacy disputed secular authority over priests’ criminal offenses. The benefit of clergy was systematically removed from English legal systems over the next 200 years, though it still occurred in South Carolina in 1855. In English law, this mechanism, by then a legal fiction used for first offenders, was abolished by the Criminal Law Act 1827. Academic degrees in Catholic canon law include the J.C.B. (Juris Canonici Baccalaureatus, Bachelor of Canon Law).