Chapter — Wouters, Manual of Moral Theology
Chapter II. On the Requisites for a Vow
I. Requisites on the part of the one vowing. There are required a will to bind oneself, sufficient knowledge of the thing promised or of the object of the vow, and perfect liberty.
- A will to bind oneself, at least implicit; for this belongs to the essence of a vow. When the aforesaid will is lacking, there is a mere proposal (St. Thomas, In IV Sent., dist. 38, q. 1, a. 1, sol. 1, ad 2; St. Alphonsus, III, 201).
Corollary I. One who is ignorant of the obligation of a vow vows invalidly, because he lacks the will to bind himself; for the will is not borne toward what is unknown. Except one who wills to vow as others are accustomed to do, even if he merely is ignorant that an obligation arises; for he has an implicit will to bind himself (St. Alphonsus, cited place).
Corollary II. One who wills to vow, but positively excludes the obligation, does not vow; for although the obligation itself is the effect of a vow, nevertheless he who positively excludes the obligation does not have the mind, not even implicitly, of binding himself (St. Alphonsus, cited place).
- Sufficient knowledge of the thing promised or of the object of the vow; namely, distinct knowledge is not required, but vague knowledge suffices; yet this, if distinct knowledge is lacking, is required per se. I said:
a) Distinct knowledge is not required, but vague knowledge suffices. The reason is that vague knowledge suffices for the one vowing to consent to the object, that is, to those things by which the object is constituted. Hence, for example, a vow of chastity is valid when the one vowing knows that by this vow carnal pleasures are renounced, although he is ignorant of precisely what these pleasures consist in; likewise even if he is ignorant of the "mysteries of life," as they are called.
b) Vague knowledge, if distinct knowledge is lacking, is required per se; for, when this too is lacking, the one vowing does not consent to the object, since it is in no way known. It is said per se, because even vague knowledge does not seem to be required if the one vowing expressly intends to vow what others vow; for then he implicitly consents to the object. Hence one who, for example, in vowing chastity, expressly intends to vow what is vowed by others seems to vow validly, even if he is ignorant, for example, that by a vow of chastity carnal pleasures are renounced. But a defect even of vague knowledge seems almost hypothetical.
Corollary I. Error obstructs validity if it concerns the substantial elements of the thing promised, that is, whether its substance,1 or the final cause,2 or a circumstance which notably changes the substance.3 The reason is that, while error concerning substantial elements remains, consent to the substance is lacking. That a circumstance which notably changes the thing also must be referred to the substantial elements follows from the fact that in this case, according to common estimation, there is a substance or thing morally diverse (St. Alphonsus, III, 198).
Corollary II. Error does not obstruct validity if it concerns either circumstances of lesser moment,4 or the impulsive cause.5 The reason is that consent to the substance of the thing promised is not lacking. And this holds even if the error gave occasion to the vow;6 for the question is not what someone would have done, but what he did. But the fact that, once the error was removed, he would not have consented, does not prevent the fact that he consented (St. Alphonsus, III, 198).
Corollary III. Religious vows, no less than other vows, are void because of error concerning substantial elements, because the reason given above, being drawn from the nature of the thing, must hold here too. Nevertheless, in practice, the said vows will scarcely be void except because of error concerning the very substance of the vows, because, when that error is lacking, error generally will not be such as to constitute a morally diverse object.
- Perfect liberty, that is, such as is required for sinning gravely; for only an act fully human or fully deliberated suffices for undertaking an obligation (St. Alphonsus, III, 196). Hence vows are invalid when made before the age of discretion, or by one semi-insane, semi-drunk, semi-asleep, or arising from fear which so disturbs the use of reason that full deliberation is impeded. But vows emitted in fervor of devotion are valid, and generally also those which are emitted from sudden passion or levity of mind, because sufficient deliberation generally is present.
Fear which does not impede full deliberation influences a vow in this way:
a) The following do not obstruct validity: 1. grave fear (a fortiori light fear) struck from within, that is, by a cause that is not free; hence a vow emitted in danger of shipwreck is valid; 2. grave fear (a fortiori light fear) justly struck. The reason is that in each case, on the one hand, full deliberation is supposed, and on the other hand no injury has been done to the one vowing, so that no reason exists why the vow would be invalid; 3. grave fear (a fortiori light fear) unjustly struck, but not for extorting a vow, does not obstruct validity; hence a vow emitted so that God may rescue you from the hands of robbers is valid. The reason is that, in relation to the vow, no injury is inflicted on you (St. Alphonsus, III, 197).
b) At least by canon law, grave fear struck from without, unjustly, and for extorting a vow, obstructs validity (can. 1307, § 2). It is disputed whether such fear also by natural law impedes the validity of a vow. Some affirm, and they extend this also to light fear, because God does not accept a vow of this kind, lest He give force to unjust compulsion. Others deny, because, in their opinion, a sufficiently solid reason cannot be alleged why God would not accept a fully deliberated act (cf. St. Alphonsus, cited place).
1 For example, someone vows a thing of his own which he judges to be glass, when it is a gem.
2 Someone vows a Mass for the health of his father, when he is dead.
3 Someone vows a pilgrimage which he judges to be three leagues, when it is six leagues.
4 Someone vows a pilgrimage which he judges to be three leagues; but it is three and a half leagues.
5 Someone vows alms to be given to poor Peter, whom he judges to be religious, when he is irreligious.
6 Suppose that in the cases set forth under 4 and 5, had the error been absent, he would not have vowed the pilgrimage or the alms.
II. Requisites on the part of the thing promised. The thing promised must be possible, morally good, and better than its contradictory.
Let it be possible, and indeed physically and morally. For there can be no obligation to physically impossible things; but an obligation of morally impossible things, since it would tend to detriment, is not accepted by God. If the thing promised is partly possible, partly impossible, the vow is valid for the possible part, if the matter both is divisible by its nature, and by the intention of the one vowing has been promised dividedly. If in the matter of a vow one thing is principal and another accessory, the vow is valid as to the possible principal thing, although the accessory is impossible; but not the converse (St. Alphonsus, III, 202).
Let it be morally good, because God is offended by an evil thing and is not worshiped by an indifferent thing; hence a promise of things of this kind is not accepted by God. An indifferent thing indeed can be done in an honorable manner; but the thing, not the manner, is supposed to be vowed. Otherwise one must speak if an act indifferent in itself becomes good because of a circumstance; in that case, as clothed with that circumstance, it can be vowed.
Let it be better than its contradictory; and this either in itself, or with the circumstances considered, because a promise of abstaining from a thing by which God is worshiped more is not accepted by Him.
Corollary I. A vow of not sinning at all, whether perpetually or for a notable time, is null. For that is impossible without a special privilege of God.1 But a vow of avoiding all mortal sins is valid; likewise a vow of employing special care to avoid all sins; likewise - but only in a person of solid virtue - a vow of avoiding either all fully deliberated venial sins, or a certain species of venial sins not so difficult to avoid, for example a vow of not stealing. Otherwise one must speak concerning a certain species of venial sins which scarcely can be avoided, as are, for example, idle thoughts (St. Alphonsus, III, 203). A vow of always doing what is held to be more perfect is valid in a person of very great virtue, insofar as it is understood of fully deliberated acts.
Corollary II. A vow of not marrying, or of chastity, is generally valid. I said generally, because it is disputed whether it is valid if it is pronounced in the world by one for whom, because of peculiar frailty, a peculiar danger of incontinence is imminent. Some deny, because marriage seems better, all things considered. More commonly it is affirmed, because, since other means of preserving continence are available, celibacy is better and remains so. A vow of a thing prescribed, since it is morally good, is valid, and effects that a transgression is also opposed to religion (St. Alphonsus, III, 213). A vow emitted against the precept of a superior is valid if the superior only forbade vowing; in that case the act of vowing is evil, but the object which is vowed is good, as is supposed. Otherwise one must speak if a thing forbidden by the superior is vowed.
A vow made concerning a good work, but for an evil end:
a) It is valid if only the act of vowing is elicited for an evil end, for example if someone publicly vows alms in order to gain vainglory (St. Alphonsus, III, n. 206).
b) It is not valid if a good work is vowed as to be directed to an evil end alone, or from a mere affection for an evil thing, for example alms to be given for vain glory alone, or only for seducing someone to sin. The reason is that the thing promised, as it is intended - that is, as a means of attaining an evil end - is evil. If a good work is vowed as also to be directed to a good end, the vow is valid, and the thing promised seems to have to be performed for the good end alone, because the thing promised, as it is intended, is also good (St. Alphonsus, cited place).
A vow made concerning a good work, but for an indifferent end (for example if someone vows fasting in order to save expenses): such a vow is not valid if a good work is vowed as to be directed to an indifferent end alone; if a good work is vowed as also to be directed to a good end, the vow seems to be valid, as was said concerning a good work to be directed to an evil end and to a good end.
A vow emitted from affection for a good thing, even if joined with an evil cause or condition, seems to be valid, because the thing promised, as it is intended - that is, as a means of obtaining a good or licit thing - is good; for example if you vow alms so that you may not be caught in a crime (St. Alphonsus, III, 206).
Corollary III. A vow of marrying is not valid per se, because the opposite is better; it is valid per accidens: 1. if someone is otherwise bound to marriage; 2. one who, because of a particular danger of incontinence, emitted the said vow, more probably is bound by the vow, but only conditionally, namely unless he wishes to use other means; 3. likewise, per se, a vow of marrying a poor girl is valid if one is going to marry someone (St. Alphonsus, III, 207, 209; VI, 75). Likewise, a vow of passing to a laxer Religion is invalid. Likewise, a vow not to vow is invalid, because to vow is better; nevertheless a vow of not vowing without the counsel of the confessor is valid. He who has emitted this vow and nevertheless, without consulting the confessor, vows, acts validly but illicitly; besides, in that case, more probably he would also vow invalidly if the one vowing had intended from the beginning that vows emitted without the counsel of the confessor would be null, and without attending to this intention emitted a vow (St. Alphonsus, III, 210).