Article II. On the Obligation of a Vow

I Say. The obligation of a vow is always light in light matter; but in grave matter it is light or grave according to the intention of the one vowing. The reason is that a vow is, as it were, a certain private law which someone imposes upon himself. - Cf. St. Alphonsus, nn. 211 and 213; and de Legibus, n. 143.

Question 1. Can someone be bound by another's vow?

Response. Negatively, at least by reason of the vow; because a vow does not oblige, by reason of itself, except the one emitting it (Can. 1310, § 1), and therefore no one can promise the thing or action of another. - Hence vows of parents devoting children to some Religion, or imposing upon them an obligation, for example, of fasting on certain days, etc., cannot bind them. Yet the parents are bound to this, that as much as is in them, with the liberty of the children preserved, they opportunely move them to embrace that which they had vowed for them, and much more that they not stand in the way if the children wish to embrace it. - § 2. The obligation of a real vow passes to heirs, likewise the obligation of a mixed vow for the part by which it is real (Can. 1310); and from obedience at least, which transfers the obligation to the genus of the virtue with a view to which it is induced, subjects are held, both those who now live and those who in the future will become members of the community, to fulfill vows emitted in their name by a civil magistrate, with the Bishop assenting, or by religious superiors. - Cf. St. Alphonsus, nn. 213 and 216. - Baller., note (a), p. 320.

Question 2. What delay is to be judged grave in fulfilling a vow which indeed obliges gravely, but which has not been fixed to a determinate time?

Response. If the vow is for the perpetual service of God, say, of entering Religion, of serving the infirm through one's whole life, etc., it seems probable that its fulfillment can be deferred for two or three years without grave fault, especially if there is a just cause, and the age of the one vowing is not advanced. But if the vow has been emitted for a temporary service of God, as would be a vow of so many fasts, pilgrimages, etc., then, excluding the case in which by the delay the danger is induced of never fulfilling the vow, it seems probable that any delay whatever does not reach mortal sin. Cf. Baller., note (a), p. 321.

You Will Resolve. 1st. Real vows are to be discharged from one's own property; but he who cannot discharge them from his own property is not held to beg from another so that he can satisfy them. Nevertheless he satisfies if another, whether asked or spontaneously, wishes to discharge for him, although he himself could satisfy; because what the other gives, with the consent or ratification of the one vowing being added, becomes his own. Except if the matter of the real vow has been determined; for then that very thing in particular must be given out. - Cf. St. Alphonsus, n. 217.

2nd. A vow indeterminate as to cessation of time, for example, concerning a daily rosary, or a fast to be made every Saturday, obliges perpetually, unless something else is gathered from the circumstances. In doubt whether the vow is temporary or perpetual, or for a month or year, the minimum is to be held. Cf. St. Alphonsus, n. 221.

3rd. He who has vowed to hear Mass for a month or year is more probably not held on feasts to hear two Masses, unless he has explicitly vowed this; because the end of the vow is that on individual days he should gather the fruit of the sacrifice. Likewise he is not held to fast on Sunday who has vowed to fast for a month, a year, or his whole life, unless he has expressly obliged himself to this; because he is judged to vow fasting according to the custom of the Church. - Cf. St. Alphonsus, n. 224.

4th. He who has vowed a fast on the vigil of some Saint, if this falls on a Sunday, can fulfill the vow on Saturday, according to the custom of the Church. - Cf. St. Alphonsus, ibid.