Article Second. On Obligatory Custom.

204. Its force of obliging. 1. That custom has the force of introducing law is established by the fact that from the law cited above, reasonable and legitimately prescribed custom has the force of law.

A law introduced through custom is called unwritten law, so that it may be distinguished from written law, which is constituted and promulgated by the express ordinance of the legislator.

2. Custom can impose any law whatever: preceptive, invalidating, indeed even merely penal; for custom can effect what law itself effects; but law can impose any obligation whatever.

It is established that the law obliging all clerics constituted in sacred orders to the recitation of the office, and some diriment impediments of marriage, as the impediment of disparity of cult, were introduced by custom.

205. Required conditions. In order that obligatory custom receive the force of law, the same conditions are required which are required for abrogating law through custom:

a. the consent of the legislator, at least legal consent, without which obligation cannot be imposed;

b. reasonable matter, namely matter which contributes to the common good and therefore can be prescribed by the legislator in an enacted law;

c. a community capable of having a law imposed upon it;

d. acts freely exercised by the community, i.e. neither from fear nor from error or ignorance, but with knowledge that no law exists concerning this matter;

e. acts exercised with the intention of obliging oneself; wherefore those things which are exercised by the faithful from mere devotion, as the triple Angelic Salutation, cannot obtain the force of obligatory custom.

Nevertheless even acts of mere devotion can acquire the force of law through custom, provided the faithful, knowing that there is no obligation of it, have the intention of obliging themselves to that act. This intention must be gathered from the circumstances, e.g. if it is constantly observed even with some inconvenience, if transgressors are punished, if pious men commonly judge so.¹

f. acts legitimately prescribed.

Whether a new law removes contrary customs in force.

Clauses by which contrary customs are reprobated are customarily added to pontifical constitutions; but concerning these clauses it must be noted: a. A universal law removes a contrary universal custom, but it does not remove particular customs unless a clause is added which reprobates a contrary custom in force. b. This clause: notwithstanding any custom whatever removes all customs except immemorial customs,² but it does not impede the origin of a new contrary custom. c. The clause: notwithstanding any custom whatever, even immemorial, removes altogether all contrary customs, but neither does it impede the origin of a new contrary custom. d. The clause added to a law: with any contrary custom whatsoever excluded for the future indeed renders more difficult a custom contrary to the new law, but it does not altogether impede its origin: for this clause itself is a disciplinary law; but it belongs to the nature of a disciplinary law that it admit contrary custom.³

¹ St. Alphonsus l. 1. n. 107. IV.

² An immemorial custom is one of whose beginning there exists no memory. It is not said: one of whose beginning there exists no knowledge; therefore a custom can be immemorial even if its beginnings are quite well known from history, provided its existence transcends the memory of men now living (about one hundred years).

³ Cf. Aichner, Compendium iuris eccles. (Brixinae. Weger. 1900) p. 81 ss.