Article — Merkelbach, Summa Theologiae Moralis
Article VII: On Custom
St. Thomas, I-II, q. 97, a. 3.
404. Custom, considered as a fact, properly is use or manner, that is, frequent repetition of the same acts, a frequent mode of acting, and the inclination arising from this to act similarly. But in the present matter, in juridical speech, it designates right introduced by the use or manners of the people. It is usually defined: legal right introduced by the long-standing manners of the community with some consent of the legislator.
Another custom is according to law (inhesive or declarative), which interprets a law previously enacted; another against law, which abrogates a law or derogates from it; another beside law, which introduces a new law, as is that which is now strengthened by can. 135.
- Hence special promulgation is not required. Hence the nature of the thing is not changed when custom is reported in a written document, unless the writing itself is formally promulgated.
The conditions required for custom are:
a) On the part of the acts, that they be 1) frequent, that is, often repeated; 2) long-standing, that is, exercised for a long time; 3) uniform or constant and therefore not interrupted, whether on the part of the people or on the part of a superior contradicting; 4) public and notorious, otherwise it would not be the custom of society as such; 5) deliberate or freely placed, and not placed from force or fear or error, by which the consent of the community is impeded; 6) practiced not by a few particular persons, but by the greater part of the community, or of the part for which a law can be made (can. 26), for example, of a diocese, class of faithful, religious order, or its province, but not of a parish or religious house.
b) On the part of the matter, that the custom be reasonable (can. 27), at least negatively, and therefore that the conditions necessary for law be present.
c) On the part of the subjects, the intention of obligating themselves (or of de-obligating themselves, or of understanding and fulfilling the obligation in such a mode, or of extending or limiting the obligation to this), which can be manifested by word or deed of the superior or subjects, by practice, by the common judgment of experts, etc.: thus customs from gratitude or devotion, for example, of hearing three Masses on the Nativity of the Lord, of signing oneself with blessed water, of saying "The Angel of the Lord...," are not obligatory.
d) On the part of the legislator, consent (can. 25), whether special, express or tacit, which is gathered from action or omission, or general or presumed, given to every legitimate custom, or of approving any customs whatever adorned with certain conditions.
405. What the Law establishes concerning custom. - According to the new Law:
Nevertheless custom differs from prescription:
a) the latter is the mode by which private persons acquire a right; the former induces an effect for the community;
b) for prescribing, good faith is required by which someone is ignorant that the thing is not his; for custom it is not always required that those introducing it be ignorant that the law exists;
c) for prescription the consent of him against whom prescription is made is not required; for custom the consent of the legislator is required;
d) for prescription and custom a different continuous time is required: for prescription thirty years ordinarily suffice, or another lesser time determined by law; for custom, a time of forty years.
- Nevertheless, unless it makes express mention of them, a law does not revoke a centenary or immemorial custom, just as neither does a general law revoke particular customs (can. 30).
Hence, by promulgation of the new Code, centenary and immemorial customs were not removed, unless they are expressly reprobated there (can. 5).
406. In what way custom obtains the force of law. - Custom, furnished with the due conditions, just as it can make laws, so also can abrogate them and derogate from them. This happens in two ways:
a) By way of connivance or special personal consent, with the superior personally knowing and consenting either expressly or tacitly, that is, not contradicting when he conveniently can and ought to contradict: for he is not judged to consent if the custom is unreasonable, for example, one which is contrary to divine right, offers an occasion of sinning, is harmful to the common good, dangerous to faith, pernicious to ecclesiastical discipline, divine worship, the liberty of the Church, or is expressly reprobated in law as an abuse or corruption (can. 27, § 2), such as a custom contrary to the preceptive rubrics of the Mass (can. 818), unless it is so called because of circumstances now changed. This of itself does not require time but has force as soon as it is clear that consent is present: thus a law which was never received by use ceases to obligate after a few acts tolerated by the superior.
b) By way of prescription, or by consent not special but general, not personal but legal or juridical (which is contained in a law which ratifies all legitimate customs), with the superior even ignorant of the custom and giving presumed consent: this requires that it be reasonable and that it have been continued for a long time, and not interrupted; otherwise it does not sufficiently appear that the law is not accommodated to the manners of the subjects, nor could the legislator be presumed to consent. How much time is required must be determined by the judgment of the prudent.
But now it is universally established in law that no custom can derogate from ecclesiastical law unless it has legitimately prescribed through forty continuous and complete years; but against a law which contains a clause prohibiting future customs, only a centenary or immemorial custom can prescribe (can. 27, § 1).
Wherefore it has seemed to some that a custom tacitly approved by way of connivance no longer has force unless it has also endured without interruption for forty years (or one hundred). But they do not demonstrate this efficaciously.
407. In what way custom against law can be introduced. - To understand how a custom against law can be introduced, even without sin, let St. Thomas be heard, q. 97, a. 3, ad 2: "Human laws fail in some cases. Hence it is possible sometimes to act beside the law, namely, in a case in which the law fails (epikeia), and nevertheless the act will not be evil; and when such cases are multiplied on account of some change of men, then it is manifested through custom that the law is no longer useful; just as it would also be manifested if a contrary law were promulgated by word. But if there still remains the same reason on account of which the first law was useful, custom does not conquer law, but law conquers custom; unless perhaps the law seems useless for this reason alone, that it is not possible according to the custom of the country, which was one of the conditions of law. For it is difficult to remove the custom of a multitude."
From this last point it is already understood that it is not necessary that every custom against law be introduced by acting legitimately and without sin; as moderns are accustomed to note with St. Alphonsus, Theologia Moralis, book I, n. 107: "Custom against law does not require good faith, but can also be introduced by sinning. For custom has a threefold state. In the beginning those introducing it against law all sin (unless they are excused by some reason). In progress, those using it, already introduced by their elders, do not sin (in good faith), but can be punished by the prince. But in the end they neither sin nor can they be punished when using it, already prescribed."
408. Custom can do everything which the legislator can do, for example, abrogate obligation in conscience as to fault and not as to penalty, or vice versa; likewise abrogate invalidating laws; indeed even laws which are borne with the clause: notwithstanding any custom whatever to the contrary, because this regards customs already existing, but does not impede future ones. But it cannot change the law against the legislator when he wills that it not be changed by custom, as if he contradicts this; whence if the law was enacted with the clause: notwithstanding any custom whatever, even future, the law does not presume consent unless the custom is centenary or immemorial (can. 27).
409. Custom ceases 1) from within, if it has become unreasonable;
- from without, by contrary custom legitimately prescribed;
- likewise by a law which suppresses it. Nevertheless:
a) Special laws of places, as particular customs, statutes, and privileges, because although they are reasonable, they can easily be unknown to the universal legislator, are not judged abrogated by a contrary universal law, even if it is borne with the clause: notwithstanding custom; unless the law indicates this specially and expressly, for example, by saying: notwithstanding nothing, or notwithstanding any contrary custom whatever (can. 30); nevertheless they are removed by a law enacted by the particular legislator of the place.