Article Third. On the Promissory Oath

249. Definition. 1. A promissory oath is an act by which someone, under invocation of the divine name, obligates himself to doing or omitting something.

a. Therefore two things are confirmed in a promissory oath: alpha. the truth of the present assertion, that is, that the one swearing actually has the will of doing the work promised; and beta. the truth of the future execution, that is, that he will actually do the work promised; and for each truth he invokes God, and indeed as witness of the former and as surety of the latter. Insofar as a promissory oath regards the present will of doing the work promised, it is assertory; but insofar as it regards future fulfillment, it is exclusively promissory, and under this respect it is considered here.

b. In a promissory oath God is not introduced as witness of future execution: for testimony is borne only concerning past or present truth. For confirming a promise as to future execution, a surety is customarily introduced; but God cannot properly be called a surety: for He Himself does not assume the burden of fulfilling in the default of the one promising. Therefore suretyship with respect to God only signifies that God, by His authority, gives greater firmness to the promise made before Him, insofar as the one promising through the oath takes upon himself the obligation of fulfilling from reverence toward God, and therefore from the virtue of religion, what he promises.¹

2. A twofold promissory oath is distinguished, simple and confirmatory, according as the thing to which someone obligates himself to do or omit is a mere resolution or a promise made to another.

If the first obtains, there is had a sworn resolution: I swear that I shall fast; if the other obtains, the promissory oath either confirms a promise made to God, and is a sworn vow: I swear that I shall observe the fast promised to God; or it confirms a promise made to a man and accepted by him, and is a sworn pact: I swear that I shall fulfill the betrothal contracted; or finally it confirms each, namely the promise made to God and to man, and is a vow sworn with a pact.

¹ Cf. Suarez, l. 3, c. 16, n. 10 ff.

250. Principles. 1. A promissory oath induces an obligation of religion of keeping the things promised: for the one swearing is held, from reverence toward God, whom by swearing he invoked as surety, to keep the promise.

a. Therefore he who violates a simple promissory oath commits one sin against religion; he who violates a sworn vow sins in two ways against religion, namely against fidelity through violation of the vow and against reverence owed to God through violation of the oath; he who violates a sworn pact commits two sins, one against fidelity or justice, the other against religion.

b. The obligation of the oath, which accedes to and is superadded to a promise made to a man and obligating from justice, is altogether personal; accordingly, it affects only the one swearing and does not pass to his heirs.

c. Theologians ask whether the obligation of a vow or of an oath is greater. The question must be understood in such a way that the comparison is made between vow and oath insofar as it is promissory, not insofar as it is assertory. Now to the question so proposed it seems it must be answered that the obligation of a vow is greater than that of an oath. For a vow obligates from fidelity toward God; but a promissory oath, insofar as it is an oath, properly obligates not from fidelity but from reverence owed to God: for by an oath nothing is promised to God, but He Himself is invoked that by His authority He may give special firmness to the resolution or promise made to another. Wherefore transgression of a promissory oath is not a sin of infidelity, but a sin against reverence owed to God.¹

2. A promissory oath, whether the promise was made to God or to man, obligates under grave or under light obligation according as the thing promised is grave or light: for since the obligation of an oath is less than the obligation of a vow, and a vow in light matter obligates only under light obligation, an oath also in light matter obligates only under light obligation.

Therefore an oath not fulfilled is a grave or light sin according to the nature of the matter. Therefore he who does not fulfill a light thing which he promised by oath, or a small part of a grave thing, sins venially. There are indeed some who say that a promissory oath always obligates under grave obligation, because in a promissory oath God is adduced as witness of future execution; but in this oath God is adduced only as witness of the contracted obligation, so that this cannot be violated from the intention of the one swearing without irreverence inflicted upon God. But this irreverence is grave or light according to the nature of the matter.

3. A promissory oath concerning an impossible, illicit, or useless thing induces no obligation. The reason of the first is that no obligation is given to the impossible; the reason of the second is that likewise no obligation is given to an evil thing; the reason of the third is that a vain or indifferent thing does not yield to the worship of God; therefore we cannot obligate ourselves to it for worshiping God.

a. If the thing afterward ceases to be illicit or useless, the oath does not revive: for: that which by law does not subsist from the beginning is not strengthened by the passage of time.²

b. If the oath is concerning a thing indeed honorable, but less good, it must be distinguished whether the promise was made to God alone, or whether it was made for the benefit of a third party. If the first, the oath does not obligate, because it does not yield to the worship of God that a work indeed good, but impeding a greater good, be done; if the other, it obligates, provided the promise has also been accepted by the other, because the acquired right of the third party must be preserved. Therefore a cleric who swore that he would serve some church is held by the oath, unless he obtains dispensation, even if this impedes entrance into religion.

Whether a promissory oath unjustly extorted obligates. Just as a vow unjustly extorted is not valid, so also an oath unjustly extorted must be said not to be valid: for a promise which is founded upon injury is invalid by the law of nature; moreover, God is not judged to confirm by His authority a promise of this kind unjustly extorted.

¹ Suarez, l. 2, c. 3, n. 7.

² Non firmatur, reg. iuris 18, in 6.

251. On the interpretation of a promissory oath. In the forum of conscience a promissory oath must be interpreted according to the mind of the one swearing: for the obligation which he imposes upon himself by oath depends upon his intention. But if the intention of the one swearing is not established, it must be interpreted according to the following rules:

1. An oath must be interpreted strictly: for odious things are to be restricted; but that an oath is odious is gathered from the grave obligation which it induces and from the danger of violation. Moreover, the one swearing is judged to have willed to obligate himself as little as he could.

2. A promissory oath follows the nature and conditions of the act (resolution, promise, contract) to which it is added: for an oath does not change the nature of the act, but supposes the act and superadds to it an obligation of religion. And indeed, since the act is the principal, but the oath is the accessory, the principle holds: the accessory follows the nature of the principal.¹

a. Therefore alpha. an oath added to an act invalid by the law of nature, for example to a promise extorted by (substantial) deceit, is itself invalid. beta. Since every promise contains this tacit condition, unless it be remitted, the oath also contains the same condition, and accordingly ceases when the promise ceases. gamma. Sworn betrothals can be dissolved by mutual consent just as non-sworn betrothals can.

b. He who swore that he would observe the statutes of some congregation, college, office, etc., is not held to observe these except in that way by which they obligate of themselves. Therefore alpha. he is not held to observe those which have already gone into desuetude and are not observed by the greater part of the community; beta. those which of themselves obligate only under light obligation, or under penalty only, or from mere fittingness, are not to be observed otherwise because of the oath; gamma. by transgressing those which obligate under grave or light sin, he commits besides a grave or light sin against religion.²

c. An oath of keeping a secret does not obligate when the obligation of the secret itself ceases; but violation of a secret obligating in conscience will be a grave or light sin against religion according as the secret itself obligates under grave or light obligation, because the obligation of the oath follows the obligation of the secret.³

d. Oaths of parents to punish children for the most part are not true oaths, because there is not present the intention of swearing, but only of frightening the children. But if they are true oaths (sworn resolutions), they must be put into execution unless their obligation ceases; but this ceases if execution of the resolution becomes irrational, as if the penalty would not correct the child but would only embitter him: for the oath is accessory to the resolution, and when this ceases, the oath also ceases.

3. A promissory oath must be interpreted according to the conditions which are understood in every promise; conditions of this kind are: a. if I shall be able, both physically and morally; b. with the right of the superior preserved, who from a just cause can irritate or dispense in the obligation; c. if the thing shall not have been notably changed: for if it has been notably changed, the intention of the one promising did not refer to it; d. if the other shall have kept faith; e. unless the other yields his right.

According to these rules the oath of not playing is to be interpreted.

a. If the oath is made from zeal for mortification and religious perfection, the one swearing is held to abstain from every game.

b. If the oath of not playing in general is made without the intention of greater perfection, the one swearing is not held to abstain from honorable and licit play: for the end of this oath is judged to be lest time be spent uselessly and money squandered.

c. He does not act against an oath of not playing who assists others playing, observes them, gives money to someone which is to be exposed in play, and helps him by his advice: for he who does these things is not said to play.

¹ Accessorium, reg. iur. 42, in 6.

² St. Alphonsus, n. 181.

³ St. Alphonsus, n. 183.

252. On the oath of fidelity. By this name is signified the oath of obedience and fidelity which political authority is accustomed to exact from its subjects, not indeed from all, but from magistrates, soldiers, and primary officials of the kingdom.

a. This oath (supposing a legitimate government) of itself is honorable and licit, unless it is exacted from ecclesiastics, and unless it contains anything which is against the rights of God and the Church: for since subjects are held to obey valid laws of the political power, this oath can be exacted and furnished by subjects.

b. It is clear that an oath of furnishing obedience to laws which are contrary to the rights of God and of the Church is illicit; nevertheless, from a sufficient cause it is lawful to furnish an oath of obedience, even if some laws are contrary to divine laws, under this twofold condition: alpha. that the clause be added: with the laws of God and of the Church preserved; beta. that, for preventing scandal, if there is need, it be declared that the Holy See has permitted the oath with this clause added.¹

It is not necessary that the clause be expressed, or that mention be made of the liceity of the oath, if it is publicly known, for example from the declaration of the prince, that the oath is to be accepted in this sense,² or if, the circumstances being considered, scandal is not to be feared, because, for example, from the quality of the person it is already understood that the oath is not made in another sense.

c. It is not lawful to exact this oath from ecclesiastics, nor can they themselves licitly furnish it, because the oath is repugnant to the personal immunity which they enjoy. Nevertheless, alpha. if custom makes the oath honorable, it can licitly be exacted and furnished. For this reason those who receive an office from the government are accustomed to make the oath of fidelity. beta. It is licitly furnished if a pontifical privilege permits it. For this reason bishops are accustomed to swear before the prince before they undertake governing their church.

d. Those who make this oath obligate themselves only to this, that they will to be subject to the laws and to plot nothing against legitimate authority; and if they are public officials, that they will discharge their office according to the laws, but not that they will to observe individual precepts of law also from religion.

¹ S. Poenitent., 10 Dec. 1860. Cf. Scavini, Theologia moralis^2 (Mediolani: Olivia, 1890), t. IV, p. 431 ff.

² It is established that this was done in Austria. Cf. Archiv f. kath. KR., XXVI, p. 250 ff.

253. On the cessation of a promissory oath. A promissory oath ceases: a. by cessation of the end; b. by condonation made by him in whose favor the oath was made; c. by irritation; d. by dispensation; e. by commutation. Therefore the obligation of an oath ceases in the same ways in which the obligation of a vow ceases, with one exception, condonation, by which an oath can cease, but not a vow.

1. On condonation. a. Just as oaths which are made in favor of another do not induce obligation unless they are accepted by the other, so afterward they can be relaxed by the same, if he renounces the favor furnished to himself.¹

b. Just as ecclesiastical authority, so also civil authority can relax the obligation of an oath made concerning those things which are subject to civil power. For by the very fact that civil authority remits an obligation arising from a right acquired for itself, the obligation arising from the oath is also indirectly extinguished: for the accessory follows the principal.

2. On dispensation. Not only he who has ordinary power, but also he who has merely delegated power of dispensing in vows can dispense also in oaths, whether they are annexed to a vow or are not, unless at the same time there is question of the acquired right of a third party, from which that person is unwilling to yield: for vows and oaths are equated as to dispensation.

a. Although all concede this concerning him who has ordinary power, such as a bishop, nevertheless there are some who with St. Alphonsus (n. 190) deny that he who has only delegated power of dispensing in vows can dispense in oaths. But since St. Alphonsus himself concedes the probability of the affirmative opinion, it is safe in practice, because in the case of speculatively probable power the Church supplies. Indeed, many probably teach that he who has delegated power of dispensing in vows can also dispense in sworn vows, in which the double bond of vow and oath concurs.²

b. He who can dispense in vows can also dispense in oaths which turn upon the matter of reserved vows, unless a vow accedes, because oaths are not reserved. But if a reserved vow has been confirmed by oath, he cannot dispense unless he can dispense in reserved vows.

c. Regular confessors from special privilege (of Gregory XIII and Paul III) can dispense in oaths and commute them, unless they were made in favor of a third party and accepted by him.

¹ Suarez, l. 2, c. 39, n. 1 ff.

² Cf. Suarez, De voto, l. 6, c. 14, n. 6; Genicot, Instit. theol. mor., I, n. 307; Ballerini-Palmieri, II, n. 595 ff.