What is canon law?

The Church’s own law

Every lasting community needs law, and the Church has had law from its earliest centuries. The word canon comes from the Greek for a measuring rod: a canon is a rule. Today most of the Church’s universal law for Latin-rite Catholics is gathered in the Code of Canon Law of 1983, a single volume of 1,752 canons. Eastern Catholics (Ukrainian, Maronite, Chaldean and others) are governed by a sister code, the Code of Canons of the Eastern Churches, promulgated in 1990 c. 1.

Canon law is not civil law. It does not come from Parliament or Congress, it is not enforced by the police, and it is not applied in the civil courts. It binds Catholics as members of the Church, through their own belonging, and its sanctions are spiritual and ecclesial: the loss of an office, a prohibition from a sacrament, in the gravest cases exclusion from the community’s life. Where canon law and civil law touch (the civil effects of a marriage, the ownership of a parish church, the reporting of a crime), the Code generally defers to civil law or asks that it be observed c. 22.

Its purpose is stated in its last canon, which asks that in every decision canonical equity be observed and that the salvation of souls, “which must always be the supreme law in the Church,” be kept before one’s eyes c. 1752. That is the measure of everything else on this page. Law in the Church exists so that people can reach God and one another in good order, with their rights protected and their obligations known.

A short history

For its first thousand years the Church’s law was a scattered body of conciliar decrees, papal letters and local customs. Around 1140 a teacher at Bologna named Gratian gathered them into a single reasoned collection, the Decretum, and canon law became a university discipline alongside Roman law. Later papal collections were added to Gratian’s, and together they formed the Corpus Iuris Canonici, which served the Church until the twentieth century.

By then it had become nearly unmanageable, and Pope Pius X ordered the whole of it reduced to a code. The result, the Pio-Benedictine Code of 1917, had 2,414 canons and came into force in 1918. After the Second Vatican Council, Pope John XXIII called for a new revision so that the law would reflect the Council’s teaching about the Church. Pope John Paul II promulgated the present Code on 25 January 1983; it came into force on the first Sunday of Advent that year. The Eastern Code followed in 1990. The Code is still amended from time to time: Book VI, on penalties, was wholly revised in 2021, and the marriage nullity process was reformed in 2015.

What it governs

The Code has seven books. Reading their titles is the quickest way to see what canon law covers:

• General norms: how laws are made, read, dispensed and revoked; persons, offices, and the power of governance cc. 1–203
• The People of God: the rights and duties of all the faithful, of lay people and of clergy; the pope, bishops, dioceses and parishes; religious orders cc. 204–746
• The teaching office: preaching, catechesis, Catholic schools and universities, the media cc. 747–833
• The sanctifying office: the seven sacraments, including marriage, together with sacred places and times cc. 834–1253
• Temporal goods: Church property, its acquisition, administration and alienation cc. 1254–1310
• Sanctions: what counts as a canonical crime and how penalties are applied cc. 1311–1399
• Processes: tribunals, trials, marriage nullity cases, penal procedure and recourse against decisions cc. 1400–1752

Notice that the penal book is the shortest of the seven. Most canon law is about structure, not punishment.

The kinds of norms

Universal law binds everywhere all those for whom it was issued c. 12. Particular law is made for a territory or a group: a diocese, a country’s bishops acting together, a religious order. It generally binds those who live there c. 13. Custom can acquire the force of law when a community has observed it for a long time with the legislator’s approval, though no custom contrary to divine law can ever do so cc. 23–28.

A dispensation relaxes a merely ecclesiastical law in a particular case, for a just and reasonable cause cc. 85, 90. A bishop can dispense from most disciplinary laws for his own people c. 87. But nobody can dispense from divine law, and nobody can dispense from a law that defines what a thing essentially is: no one can dispense two people from the need to consent to their marriage c. 86. Canonical equity is the habit of applying the law with mercy and attention to the person before you; where the law is silent, a case is decided by similar laws, general principles applied with equity, the practice of the Roman Curia and the common opinion of the learned, except that no penalty may ever be supplied that way c. 19.

Finally, who is bound? Merely ecclesiastical laws bind those who were baptized in the Catholic Church or received into it, who have sufficient use of reason and who have completed their seventh year c. 11. A six-year-old is not obliged to fast. A Lutheran neighbour is not bound by the Catholic form of marriage. Divine law, by contrast, binds everyone.

Who makes it, and who interprets it

The supreme legislator for the whole Church is the pope, and with him an ecumenical council cc. 331, 337. A diocesan bishop legislates for his diocese c. 391; conferences of bishops do so in the limited matters the law assigns them c. 455. A lower authority can never validly make a law contrary to a higher one c. 135 §2.

Laws are read according to the proper meaning of their words in their text and context, and if the meaning is still doubtful, by their purpose, by parallel passages and by the mind of the legislator c. 17. Laws that impose a penalty or restrict a right are read strictly c. 18. Only the legislator, or someone he has authorized (in practice the Dicastery for Legislative Texts), can give an authentic interpretation that binds everyone c. 16. A tribunal’s judgment binds only the parties to the case.

Where a lay Catholic actually meets it

Most Catholics meet canon law without noticing. Your baptism was recorded in a parish register that will follow you for life and be consulted when you marry or are ordained c. 877. The godparents you chose had to meet certain requirements c. 874. When you married in the Church, the preparation, the questions about freedom to marry and the presence of a priest or deacon with two witnesses were all canon law cc. 1063–1072, 1108. If a marriage ends and one spouse asks whether it was valid from the start, a tribunal applies the law of consent and capacity: see marriage nullity explained.

You meet it too when a parish is merged or a church closed cc. 515 §2, 1222, when a pastor is moved, when you ask why a child cannot be baptized yet or why a funeral is arranged a certain way. In each case someone is exercising a power the law gives, under conditions the law sets, and you have rights the law recognizes: see your rights in the Church and the sacraments and the law.

Three common misconceptions

“Canon law is Church teaching.” It is not. Doctrine is taught by the Church’s teaching office; the law refers to that teaching and gives it a workable shape, but it does not settle what the faith is. A canon can be changed by the pope tomorrow; a doctrine cannot. I explain this more fully in canon law and theology.

“Canon law is about punishment.” Of 1,752 canons, 89 deal with penalties, and even those insist that a penalty is a last resort, imposed only when fraternal correction and warning have failed c. 1341. Everyone is presumed innocent until the contrary is proved c. 1321 §1. See canonical crimes explained.

“They are only rules; they are optional.” Also not true. Ecclesiastical law genuinely binds the Catholics it reaches, in conscience and not merely in an external way. What is true is that the law is meant to be applied with equity, and that it is ordered to a purpose beyond itself. A canonist who forgets the last canon has misread all the others.