Article I. On the Conditions of an Oath

I Say 1st. For the essence of an oath two things are required, as is clear from its definition, namely, the intention of swearing, at least virtual, and some formula or sign by which it is sufficiently expressed that God is invoked as witness, either explicitly or implicitly through creatures, unless, however, the oath is directed to God alone. - I said 1st, unless, etc., because when an oath is directed to God alone, it can be wholly completed in the mind of the one swearing by interior words. - I said 2nd, some formula or sign, because an oath uttered among men must be considered both with regard to the law of nature alone and with regard also to positive law; in the first case any external sign suffices, in the other a certain formula of words or a certain rite can be required under pain of nullity. - Cf. St. Alphonsus, n. 134. Hence:

1st. A fictitious or merely external oath is not valid because of defect of intention; nevertheless one swearing thus sins, as is clear from proposition 25 proscribed by Innocent XI, which has itself thus: "With cause it is licit to swear without the intention of swearing, whether the matter is light, or whether it is grave." But according to the more probable opinion, speaking of itself, only a venial sin is then committed, because nothing is uttered except a lie with vain usurpation of the name of God. Yet often this is mortal by reason of common or particular damage. - Cf. St. Alphonsus, Hom. Ap., n. 17.

2nd. It is an oath to say: I swear by God, by the Saints, by the temple, the cross, the altar, the Gospel, the Catholic faith, the Church, heaven, earth. - Likewise to say: I call God to witness. ... Let God be witness to me. ... I invoke God as witness. It is otherwise if someone should swear by creatures in which divine goodness or power does not specially shine forth, for example, by the beard, etc. Cf. St. Alphonsus, nn. 134 and following.

3rd. It is not an oath to say: God knows. ... I speak before God, etc., if these are uttered narratively; but otherwise, if invocatively, which is discerned from the circumstances or the intention of the speaker. Nor is it an oath to say: This is as true as God exists ... as I exist ... as I am in this place ... on the faith of a good man ... by my faith ... by conscience ... may I die ... or may the devil destroy me, if it is not so. Indeed, according to St. Alphonsus, it is not an oath to say: I swear, or I swear that it is so, unless a question about taking an oath has preceded. - Cf. St. Alphonsus, ibid.

I Say 2nd. For the liceity of an oath, however, three conditions are required according to that saying of Jeremiah, iv, 2: "Thou shalt swear: The Lord liveth, in truth, and in judgment, and in justice." - And so there is required, 1st, truth, namely conformity of the assertion with the intention and knowledge of the one swearing, and therefore a lie is excluded, but not error. In an assertory oath truth regards the existence of the fact; in a promissory oath, the existence of the intention. There is required, 2nd, judgment, that is, that it be made with discretion, prudence, and reverence, and not without grave cause, of which sort would be peace to be confirmed in families, or greater security in contracts, etc. There is required, 3rd, justice, that is, that the oath be concerning a thing or promise, proposal, or assertion that is licit and honorable. - Cf. St. Alphonsus, n. 144; and Hom. Ap., n. 14.

§ 2. An oath which the canons require or admit cannot validly be taken through a procurator (Can. 1316).

Question 1. What kind of sin is it to swear without truth, judgment, and justice?

Response to the 1st. It is always mortal even in light matter; because to bring God forward as witness of falsity is to will to destroy his truthfulness. This is also clear from proposition 24 condemned by Innocent XI, which has itself thus: "To call God as witness of a light lie is not so great an irreverence that on account of it he would wish or could condemn a man." Yet this does not prevent someone from being able to swear with moral certainty alone of the truth, or with a restriction that is not purely mental. - Cf. St. Alphonsus, Hom. Ap., nn. 14 and 15.

Response to the 2nd. It is venial of itself, that is, with the danger of perjury excluded, because it is only vain usurpation of the name of God.

Response to the 3rd. Certainly it is mortal in a promissory oath, if it concerns perpetrating a grave sin, because it savors of grave irreverence to invoke God as guarantor of some grave iniquity. Indeed, according to St. Alphonsus it would be mortal also if it concerned committing only a venial sin; but Suarez with others denies this, because then, they say, the irreverence would be light by its nature. - Cf. Suarez, de Relig., tract. 5, lib. 3, chap. 19, n. 3. - Baller., note (a), p. 307.

But in an assertory oath, more probably it is only venial of itself, because the oath of itself falls upon the assertion, not as evil, but as true. Thus he who boasts under oath about fornication committed, although by this boasting he sins lethally, nevertheless by virtue of the oath does not of itself confirm the boasting, but only the truth of the fornication. Except, unless the oath is assumed as an instrument or means of sinning, for example, to confirm detraction. - Cf. St. Alphonsus, n. 146.

Question 2. What must be said concerning an oath of observing the American Constitution?

Response. It is altogether licit, for Kenrick says: "The oath to observe the Constitution, which American citizens emit, must be understood in the popular sense, namely, the one which is received among all; nor is each one judged to embrace with the judgment of his mind whatever things are contained in it, but he promises obedience to magistrates and to laws according to the tenor of the Constitution. The things which are handed down concerning liberty of opinions and of worship, concerning the right of divorce, and concerning whatever other matters, do not necessarily demand the assent of the mind; but one is held to obey, and to help that the laws be entrusted to execution, always with the right and law of God preserved." - Cf. Kenrick, tract. 3, n. 68.

Question 3. Is it licit for foreigners who have emitted an oath of fidelity in their own fatherland to immigrate here, and to bind themselves by a new oath for obtaining civil rights?

Response. Affirmatively, for the obligation of an oath of fidelity is to be understood according to the natural obligation of remaining in one's fatherland, which does not subsist whenever a fair cause of utility is given for acquiring a new fatherland without detriment to the former one. - Cf. Kenrick, tract. 5, n. 19.

Question 4. Is it licit among us to swear by kissing Protestant Bibles?

Response. Negatively, as it seems, because such an act is of itself approbative of that book and besides could give rise to scandal. Nor should you say that it is difficult to act otherwise, for a Catholic version is usually given to the one asking, or he who is about to swear is even permitted to bring it with him.

NOTE. Concerning oaths of preserving a secret, which are accustomed to be made among societies of workers, it will be said where secret societies are treated in the tract on censures.