ARTICLE III: ON THE CESSATION OF A VOW

388. • The obligation of a vow can cease:

I. Because of intrinsic causes, namely: 1° by cessation of the end or motive cause; 2° by substantial change of the matter; and 3° by impossibility, whether physical or moral, as was said above concerning laws, n. 137, III, 138, 165.

It is said: 1° by cessation of the motive cause. Titius, for example, a son of the family, when he was playing, having been caught by his father and vehemently rebuked by him, to turn aside his anger vowed that he would play no more. With the father dead, the obligation of the vow ceases; for the anger of the father to be turned aside was the cause of the vow, not only impulsive, but motive and principal, as appears from the case.

It is said: 2° by substantial change of the matter, and 3° by impossibility, whether physical or moral. - This happens: a) if the matter becomes illicit, or indifferent, or impeditive of a better good; b) if it becomes altogether impossible; c) if the state of the one vowing, relative to the matter of the vow, becomes morally diverse, for example if someone had vowed the building of a church, but afterward his wealth is so diminished that he cannot satisfy his vow without notable detriment of his state. - It is plain that the changes under a) and b) take away force from a vow, which ceases to be about a good, and a better and possible one (n. 378, 382). - As to the changes under c), the common opinion is that in every promise, and therefore also in a vow, the obligation is taken away through a change of matter notable of itself, since the thing becomes diverse from that which was promised; indeed probably, and perhaps even more probably, says St. Alphonsus,¹ a vow ceases if a circumstance supervenes which, if foreseen, one would not have emitted the vow, although it would not induce a change notable of itself. Yet in doubt one must stand for the vow, which possesses.

Except nevertheless: 1) If that inconvenience from the nature of the thing could reasonably have been foreseen. Hence even a simple vow of chastity does not cease through vehement stimuli of the flesh supervening, since there is scarcely anyone who does not sometimes suffer grave temptations in this matter; therefore against those stimuli other remedies must be employed,² or dispensation must be obtained. 2) If the public good demands the firmness of the vow. Hence through changes of this sort solemn vows emitted in religious profession or in the reception of Orders do not cease; nor simple vows which are emitted in religious Congregations, especially if an oath of perseverance is added; for then an onerous contract intervenes. Hence, just as a Congregation cannot dismiss an alumnus because of supervening changes, except those by which he would cease to be for edification, so neither can the alumnus desert the Congregation.³

II. Because of extrinsic causes, namely irritation, dispensation, and commutation, concerning which it remains to speak singly.