Article First. On Derogatory Custom.

202. Its derogatory force. 1. That ecclesiastical custom, concerning which alone there is question here, has the force of abrogating law is established from canon law, which expressly attributes this efficacy to custom.¹ And indeed the force of custom and of law is the same; but a later law can abrogate an earlier one; therefore custom also can do this, provided it is clothed with the due conditions.

2. Custom cannot abrogate natural law, because this is immutable, nor positive divine law, because the force of custom is derived from human authority, namely from the consent of the human legislator; but human authority can do nothing against divine law. Rather, custom can abrogate only ecclesiastical law.

Although custom does not have the force of abrogating divine law, it can nevertheless interpret it, i.e. indicate how the law, according to the mind of the legislator, is to be understood and observed. Yet this custom, interpreter of divine law, must be governed by the infallible judgment of the Church, which alone is the authentic interpreter of the institutions and commands of Christ.

3. There is no ecclesiastical law which cannot be abrogated by contrary custom; for the texts of law proving custom are altogether universal.

Therefore legitimate custom can abrogate even:

a. A law expressly prohibiting contrary custom.

Indeed while the same circumstances remain on account of which the custom was prohibited, this custom cannot obtain force, since it would then be unreasonable; but once these circumstances have changed, nothing prevents the contrary custom from receiving the force of law, because it can be reasonable and can be approved through the consent of the legislator.²

b. An invalidating law: for an invalidating law can be abrogated by another law; therefore also by custom, which is of the same authority. Therefore even the invalidating impediments of marriage of human right can be abrogated by legitimate contrary custom.

c. Some existing custom.

Therefore universal custom can abrogate universal custom, and particular custom can abrogate particular custom; but a particular custom can derogate in part from universal custom, namely in that place in which the particular custom has prevailed.

¹ C. Quum tanto (11) fin. De consuetud. (I. 4), whose final words are these: "although the authority of even long-standing custom is not worthless, nevertheless it will not be valid to such an extent that it ought to generate prejudice even against positive law, unless it has been reasonable and legitimately prescribed."

² The doctrine of a few theologians, that against the disciplinary decrees of the Council of Trent no custom is admitted, cannot be demonstrated by sufficient arguments. Cf. Biederlack, Die Gewohnheiten gegen die Disciplinardekrete des Trienter Konzils (Zeitschrift f. kath. Theol. VI (1882) S. 438 ff. Wernz I. n. 194.

203. Conditions which are required in order that custom abrogate law:

1. The consent of the legislator; but legal consent suffices.

a. For law cannot be introduced except by legitimate authority, which indeed cannot be the will of the people exercising the custom, but only the will of the legislator himself.

From this it is clear that the consent of the legislator is the true efficient cause of custom which has legitimate value.

b. In order that custom obtain the force of law, personal consent is not required, but legal consent suffices: for nothing prevents the legislator from establishing by a universal law that custom endowed with due qualities have the force of law; but if the legislator has done this, custom receives the force of law without further consent; and this has been established by the law itself.¹

a. Consent can be personal, by which the superior himself approves the custom, or legal, by which the right or universal law approves it. Personal consent supposes knowledge of the custom; legal consent does not require it. Personal consent is express if the legislator gives permission of introducing the custom, and it is tacit if the legislator, conscious of the custom, does not resist it, although he could easily resist. Wherefore a custom which the legislator merely tolerates with prudent silence cannot obtain the force of law through personal consent.

b. Legal consent is customarily defined as a previous approbation made through a universal will expressed in law, of approving any custom whatsoever clothed with due conditions.

c. If personal consent is had for custom, even only tacit consent, legitimate time for introducing the custom is not required, but the obligation of the law immediately ceases.

2. On the part of the matter, that the custom be reasonable.

In order that it be reasonable, it is not required that it be begun without sin: for those who introduce a custom contrary to law generally sin in the beginning. Nor is it required that it be positively reasonable, i.e. that it be commended by a special reason or that it be better and more perfect than the contrary law, but it suffices that it be negatively reasonable, i.e. that for no reason (neither by natural right nor by divine right) it be reproved, nor offer license and occasion of sinning, nor contain corruption of morals, and therefore in some way contribute to the common good.

3. On the part of the community: a. that the custom be introduced by a community on which a law can be imposed, such as a kingdom, province, city, diocese (but not a parish, family, or private person), a religious order, and probably also a province of a religious order; b. that it be exercised by the greater part of the community: for custom is introduced by the community from the consent of the prince; but only the greater part morally represents the community.

4. On the part of the acts: a. that they be free, i.e. that they proceed neither from fear nor from error or ignorance: for without the consent of the people a law cannot be established through custom; but this consent is lacking if the acts are not free; b. prescribed for the legitimate time: for the law itself requires a certain duration of custom in order that it have legal value: unless it has been legitimately prescribed; c. made with the intention of de-obliging oneself from the law. For this it is not required that the community know the law at least in the beginning and nevertheless not observe it, but it suffices that with the opinion that the law does not exist, it in good faith does not observe it. Wherefore that which the faithful omit from lack of consideration or levity can never obtain the force of legitimate custom.

a. How much time is required for introducing custom is nowhere found defined. In order that obligatory custom obtain the force of law, ten years is required and suffices; but in order that derogatory custom have value, forty years are required, although several of the more recent theologians think that ten years suffices.²

b. Supposing a positive doubt concerning custom, so that on the one side it is truly probable that all things are had which are required for introducing legitimate custom, and in like manner on the other side it is probable that something of those things is lacking which are required for legitimate custom, the following distinction must be made: a. in doubt concerning custom beyond law, the custom does not yet oblige: for it is doubtful whether the custom has obtained the force of law; but a doubtful law does not oblige; b. in doubt concerning custom against law, the law no longer obliges: for by the fact that the contrary custom probably de-obliges from the law, the law itself has become doubtful; but a doubtful law does not oblige.

¹ C. Quum tanto (11) fin. De consuetud. (I. 4).

² Cf. Benedict XIV, De synodo l. 13. c. 5. n. 4. Wernz I. n. 190. IV.