Since the fourth century, the Roman Catholic Church has been developing regulations that have had some influence on secular (non-church-related) legal procedures. These regulations are called canons and are codified in the Code of Canon Law (in Latin, Codex juris canonici).
Canon law has its origins in ancient church writings, decisions made by the general councils of local bishops, and rulings issued by the pope. An Italian law teacher, Gratian, organized these ideas in the mid-twelfth century. He sorted the collection into religious law, penal law, sacramental law, and other categories. Along with a set of decisions by the pope called Decretals of Gregory IX, Gratian's work formed the main body of canon law for nearly eight hundred years. In 1917, Pope Benedict XV recodified (revised) the canons. Pope John Paul II reissued the Code of Canon Law in 1983-authorizing increased participation of laity in the church, recognizing the needs of disabled people, and making other changes. A related text, the Code of Canons of the Eastern Churches, was reissued by the Holy See (the seat of papal government) in 1990.
In the middle Ages, canon law was used in ecclesiastical (church) courts to decide many types of cases that in modern times are decided by civil courts, including criminal offenses. Crimes that were tried by the church included adultery, blasphemy, slander, heresy (opposition to official religious views), money lending, and gambling. -Of-faith cases concerning contracts, as well as inheritance and marriage-related cases.
Criminal trial procedures in medieval church courts were the source of some features that found their way into common law. Although witnesses were considered the best source of proof of a crime under canon law, suspected offenders could also be tried because of public fame (suspicion in the community that they had committed a crime). An inquest made up of twelve men-a forerunner of royal courts' grand juries-said under oath whether public suspicion existed. If none did, then a judge had no authority to proceed. After establishing public fame, the court's next step was canonical purgation, in which the accused person swore an oath that she or he was innocent. Proof of innocence was accomplished by compurgation, in which several oath helpers would swear that they believed the oath was true. People who objected to the purgation of an accused person had the chance to prove their accusation of guilt.
The use of canon law in governmental decisions is not well documented. In the early fifteenth century, commissions of the English Parliament made use of canonical procedures and canon law experts to decide issues involving laws of war, diplomacy, and other questions. For example, Parliament's justification for deposing King Richard II seems to have been based on papal bulls (decrees).
In modern times, the creation, interpretation, and use of the canons closely resemble those of secular law. The Episcopal Conference of Local Bishops and the National Conference of Catholic Bishops are voting bodies that set policy for the church. When policy has been codified, it is used by judges in Catholic tribunals in determining whether certain practices or requests are acceptable according to the canons. (Catholic tribunals make up the Church's own court system, which interprets canonical policy to resolve questions of church practice.) Case law (previous