The Conditions Required for an Oath

246. The conditions of a valid oath are two: a. the intention of swearing; b. an oath-formula.

That on the part of the one swearing there are besides required for a valid oath the same conditions which are required for a vow, namely perfect deliberation and perfect liberty, is gathered from the same reason in each case. But on the part of the matter in a promissory oath it is required that it be possible, good or licit, and better than the opposite, as was said above concerning vow.

1. The intention of swearing is required, either formal or at least virtual: for an oath by its nature is an act of the will, namely a petition; but without the intention of petitioning there is no true petition.

a. The value of an oath in conscience depends upon the intention of the one swearing, so that he truly swears who has the mind of swearing, even if the formula which he uses is less suitable; and he certainly does not swear who does not have the mind of swearing, whatever the words or signs may be which he uses. In doubt concerning the intention of swearing, the value of the oath must be judged from the sense which the words used have from common acceptance; therefore if the words from common use are oath-words, he must be judged truly to have sworn; if from common use they are not oath-words, he is presumed not to have sworn; but if the words are ambiguous, likewise no oath is had.

b. He has virtual intention who uses oath-words in their customary sense, even if he does not expressly think of invoking divine testimony. Therefore if one uttering oath-words, whether from ignorance or from inconsideration, does not even implicitly advert to an oath, he makes no oath.

2. An oath-formula is required, by which God is invoked in testimony. For although an internal oath conceived by the mind alone, absolutely speaking, is a true oath,¹ nevertheless, because an oath from its proper end is used for the sake of others, it must be manifested to them by an external sign.

¹ Suarez, l. 1, c. 1, n. 4.

247. Some oath-formulas are certainly oath-formulas; some are ambiguous; some certainly are not oath-formulas.

a. Formulas of explicit oath are: let God be witness to me; I swear by God, by Christ, by the truth of God; may God destroy me, if, etc.; even simply the word I swear suffices, if the intention of swearing is established. Nevertheless, when the intention of swearing has not been premised, he does not make an oath who uses these words: I swear that it is so, because he does not invoke the testimony of God. For although I swear signifies: I invoke God as witness, yet those who use this word alone, unless they have been warned about oath, do not attend to its full sense. God lives, that it is so, is an oath: for the life of God is added in testimony of truth.

b. Formulas of implicit oath are: I swear by the Blessed Virgin, by the cross, by the holy Gospels, by the altar, by the sacraments, by the Catholic faith, by the Church, by the saints, by the temple, by my soul, by heaven, etc.; for he who swears thus is judged to invoke the author or lord of these. In practice, however, those who frequently use these words: bei Gott, bei meiner Seele, etc., do not think of God; therefore from defect of intention these formulas often do not contain oaths.

c. Ambiguous formulas are: by my oath (auf meinen Eid); by my conscience; by my faith; God lives; God is truth; God knows; I speak before God, etc. These and words of this kind are true oaths if the intention of swearing accedes, or if they are required in the judicial forum as oath-words; but if the intention of swearing is not established, they are judged to be uttered only enunciatively, for procuring greater belief, not invocatively for invoking divine testimony. Wherefore if in common conversation the formulas are used: ich schwore dir einen Eid, dass ich das tun werde; bei meinem Eide tue ich das, most intend by these words not seriously to swear, but to affirm more gravely.

d. Oath-formulas are not: truly; certainly; in truth; it is as certain as it is certain that I exist, that I am here, that the sun shines, etc.; nor: may I die, may my ears be cut off, may the devil destroy me, if this is not true: for these and things of this sort contain a certain exaggerated confirmation of truth, not an oath, because invocation of divine testimony is lacking. Wherefore if what is affirmed by these formulas is false, only a venial lie is committed. Nevertheless, if the formula contains a penalty to be inflicted by God: may I be struck by lightning, if it is not true, it can more easily be held to be an oath-formula.

e. If an assertion or promise is exacted from priests and furnished through their consecration: bei meiner priesterlichen Ehre und Treue, there is not question of a true oath, but of a firmer and more secure affirmation of truth, according as it befits a priest to affirm or promise. The same must be said of the formula which princes are accustomed to use: bei meiner fuerstlichen Ehre und Treue.

f. Formulas by which the truth of an assertion is compared with the truths of faith: It is as true as God exists - as Christ is in the venerable sacrament - as the Gospel is true; I am as innocent as the Blessed Virgin, etc., seem to some to contain an oath with blasphemy. Nevertheless they certainly contain neither an oath, because no one is invoked as witness, nor blasphemy, provided that what is affirmed is true, because the one uttering intends to signify only a likeness between the certitude of his assertion and the certitude of revealed truth, not equality. Therefore he who uses formulas of this kind sins venially by vain invocation of the divine name, provided the thing is true; but if the asserted thing is false, he commits blasphemy objectively, because he contemptuously compares his lying speech with divine speech or existence.

248. The conditions of a licit oath from Jer. 4:2 are three: "Thou shalt swear: the Lord liveth, in truth and in justice and in judgment"; for if one of these conditions is lacking, the oath lacks the reverence owed to God.

1. The truth of an oath requires that a lie be excluded from the oath; therefore in an assertory oath it requires that that which is asserted be so, or at least be believed to be so, as it is asserted; but in a promissory oath, that the one swearing have the will of afterward fulfilling what he promises.

a. It is not lawful to swear with only probable knowledge of the matter, but certain knowledge of the thing which is sworn is required; however, that moral certitude suffices which is had when no prudent and reasonable doubt militates against the thing. If one must swear concerning the deed of another, which is known from the report of a man worthy of faith, outside judgment indeed it is lawful to swear, because morally certain knowledge of the thing is had; but in judgment it is not lawful to swear unless the fact is known by one's own experience: for an oath in judgment, unless something else is expressly said, is understood of one's own knowledge.

b. Therefore he who swears with doubt concerning the truth sins gravely, because he wills that God testify to it, whether it is true or false. - And he who in judgment swears to a thing indeed true and certainly known, of which nevertheless he does not have experimental knowledge, commits perjury. - He who makes a promissory oath without the mind of executing the thing promised, likewise he who doubts whether he will do what he swears, and finally he who judges the thing promised to be morally impossible for himself, swears falsely.

c. Whether it is licit to swear with mental restriction. alpha. To swear with purely mental restriction is perjury; beta. to swear with broadly mental restriction before those who have the right of knowing the whole truth is mortal; gamma. to swear without a just cause, with broadly mental restriction before those who do not have this right, is venial; delta. but from a just cause it is licit: for since the assertion is true, God is not invoked in testimony of falsehood. Nevertheless, a greater cause is required for making restriction with an oath than if it is made without an oath.¹

2. Justice in an assertory oath consists in this, that the one swearing can licitly communicate with others the thing which he asserts; but in a promissory oath it consists in this, that the thing promised is licit and honorable.

Thus he swears against justice (by an assertory oath) who without a just cause reveals another's hidden crime with an oath; likewise he who with an oath boasts about a duel committed. He swears against justice (by a promissory oath) who obligates himself by oath to telling a lie, to committing a duel, to inflicting damage upon another.

3. Judgment or discretion in an oath requires two things: first, that a just cause of swearing be present; then, that the oath itself be furnished with that external and internal reverence which befits the divine majesty. But any cause of necessity or of great usefulness is judged just.

¹ Cf. St. Alphonsus, l. 3, n. 151.

307. Two things are required for an oath, namely: 1. The intention of swearing, at least virtual; because without such intention a formal oath cannot exist ¹. 2. An oath-formula, either explicitly by God, or implicitly by creatures; because, since God is invoked as witness, it is necessary that this be expressed in the oath. - St. Alphonsus, n. 134.

¹ Intention of swearing contributes so much to the validity of an oath that, if this mind is present, a person truly swears (for the internal forum), although the words may be less suited to express the invocation of God, and therefore among others (as also in an oath by a merely internal act) he does not in reality swear; and contrariwise, when that intention is lacking, there is no oath, even if the words are juratory, whether that intention is lacking because of the deceit of one fictitiously swearing, or because of the ignorance of one not knowing what the act of swearing means. Laymann (lib. 4, tr. 3, c. 1, n. 3); Suarez (De Religione, tr. 5, lib. 1, c. 11, n. 2); Croix (lib. 3, p. 1, n. 258).

308. Resolves. 1. A fictitious promissory oath, or a merely external one, is not valid, because of a defect of will or intention. But one swearing thus sins; yet more probably, speaking per se, only venially, because it is nothing but a lie with a vain usurpation of the Name of God ². - St. Alphonsus, Homo apostolicus, n. 17. Often, however, this is mortal by reason of common or particular harm.

² You have on this matter proposition 25, proscribed by Innocent XI: "With cause it is lawful to swear without the mind of swearing, whether the matter is light or grave." Besides, St. Alphonsus, both in the cited place and lib. 3, n. 172, certainly teaches with the common opinion that one sins venially; but he limits this, if one swearing fictitiously thus otherwise has the mind of fulfilling the things promised; for otherwise, he says that one sins mortally. See the reasons in Sanchez (Decal., lib. 3, c. 6, n. 8-10).

2. More probably, an oath made with the mind indeed of swearing, but not of obliging oneself from religion, is not valid, because this is nugatory. But an oath made with the mind of swearing indeed, but not of obliging oneself from justice or from fidelity, is valid.

3. It is an oath to say: "I swear by God, by the Saints, the temple, the cross, the altar, the Gospel, the Catholic Faith, the Church, heaven, earth." Likewise to say: "I call God to witness... May God be witness to me... I invoke God as witness." It is otherwise if someone swears by creatures in which the divine goodness or power does not shine forth in a special way, for example by the beard, etc. - St. Alphonsus, n. 134, 138.

4. 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 ³... by my faith... by my conscience... may I die... or may the devil destroy me," unless it is so intended ⁴. Indeed, according to St. Alphonsus, it is not even an oath to say: "I swear," or "I swear that it is so," unless a question about furnishing an oath has preceded. - St. Alphonsus, ibid., and many others.

³ The same is to be said of a priest interposing his priestly faith or holy consecration (c. Si quis presbyter, 4, caus. 2, quaest. 5), or of kings or princes, etc., who in place of an oath pledge on the faith, or by the faith, of a king, prince, soldier, etc.

⁴ On these things St. Alphonsus says (lib. 3, n. 143): "The words, 'May I be killed if this is not so,' and similar words, although they are true oaths if they are said by way of execration... besides, commonly they contain nothing except a certain pledge or obligation to punishment." Therefore the rule which the author sets forth first must be applied, namely that the words, and also usage, circumstances, and the intention of the speaker be inspected. But the invocation of God, and thus execration, is more easily understood where the matter concerns events which, according to the common sense of men, are judged to be disposed and directed by the special providence of God.

** To the other formulas St. Alphonsus (l.c.) also adds this one: "So may God favor me"; and he alleges the Salamancans, tr. 17, c. 2, n. 27. But the Salamancans do not have it thus, but thus: "May God favor me better"; which is very different.

309. A threefold condition is required for the lawfulness of an oath, according to that saying of Jeremiah 4. 2: "You shall swear: The Lord lives, in truth, and in judgment, and in justice."

I. Therefore truth is required, that is, conformity of the assertion with the intention and cognition of the one swearing. Therefore it excludes every lie, but not every error. In an assertory oath, truth regards the existence of the fact; in a promissory oath, the existence of the intention ⁵.

⁵ In a promissory oath an assertory oath is also included; for a person both calls God as witness that he now has the intention or will of doing what he promises, and, by employing the same God somehow as surety of the promise, assumes from the virtue of religion the obligation of fulfilling the promise. Nevertheless someone could swear only concerning his present purpose or intention, for example: "I swear that I now have the will of going to Rome next month"; and certainly someone could afterward break such a purpose without perjury. Laymann (lib. 4, tr. 3, c. 4, n. 4).

II. Judgment, that is, that it be done with discretion, prudence, consideration, and reverence, and not without necessity or grave cause.

III. Justice, that is, that the oath be concerning a just, lawful, and honorable matter: thus he would swear against justice who by oath obligated himself to inflict damage unjustly upon his neighbor, or to do anything else prohibited. - St. Alphonsus, n. 144 ⁶.

⁶ Many doctors require justice not only in a promissory oath, but also in an assertory oath, yet with this distinction: that in a promissory oath they seem to consider the defect of justice with regard to the thing sworn, but in an assertory oath with regard to the act itself of swearing.

And here the Salamancans (tr. 17, c. 2, n. 45-47), whom St. Alphonsus follows (lib. 3, n. 146), having posed the question whether a defect of justice is a grave sin even in an assertory oath, introduce Soto with Toledo, Ledesma, and Aragon as affirming, and oppose to them Suarez with Sanchez, Tamburini, and others; and they confess that they follow these, except in the case of grave detraction confirmed by oath. But this disagreement among the doctors is plainly imaginary. For Soto (De Iust. et Iur., lib. 8, q. 1, art. 3), Aragon (In 2.2, q. 89, art. 3), and de Ledesma (Sum. hisp., tom. 2, tr. 11, c. 2, dub. 4) say that he sins who, revealing hidden crimes, confirms them by oath; but they do not say whether he sins gravely or lightly. Toledo (lib. 4, c. 21, n. 8) holds that the sin is grave or light according to the nature of the matter; and indeed these authors observe that every sin can be absent, if a just cause is present, for example of revealing a hidden crime to a judge with an oath. But Suarez (De Religione, tr. 5, lib. 3, c. 12, n. 7-8), with Sanchez and others, whose opinion St. Alphonsus calls more probable, judges that the fault is generally light, because the thing sworn is supposed true, and only judgment is lacking in the swearing. Nevertheless he excepts an oath added to the narration of a true crime for the purpose of procuring greater credibility for it, because in that way the oath is assumed as a means to iniquity.

** Here the VV. deny that the disagreement of the doctors, of which the Salamancans speak, and after them St. Alphonsus, is imaginary; and therefore through eighteen columns (pp. 260-269) they wish to prove that disagreement actually existed among the doctors. But perhaps the VV. themselves do not sufficiently beware of the rock upon which the Salamancans rather often strike, because they consider too little whether the authors whom they present as dissenting dispute about the same matter and under the same respect, or rather about a diverse matter or under a diverse respect; whence it happens (as was noted at this place in another edition) that they wrongly feign battles of the doctors, and then enter into battle now against these, now against those. Whether this has happened in the present case must now be seen briefly.

According to the Salamancans, the disagreement of the doctors resides in this: that some condemn the defect of justice in an assertory oath as a grave fault, others as a light fault. Now let this be set aside for the moment: that even those authors whom the VV. allege (p. 267), namely Navarrus, Bonacina, Concina, Collet, Potestas, and Voit, would prove this disagreement to be imaginary, since they generally hold that the sin is grave or light (as Bonacina says) according to the gravity or lightness of the matter. But let these be omitted, since, as the VV. also observe (ibid.), they do not sufficiently determine the state of the question.

Marcus Struggl has the question better determined (tr. 5, q. 3, art. 1, n. 9), where he asks what sort of sin an oath from defect of justice is. And he responds: "An assertory oath concerning an unjust thing, if the assertion is just, is not a sin; because the unjust thing is only the material and extrinsic object of the oath... Thus, therefore, a witness can swear in court that Peter committed homicide... But if the assertion itself is gravely unjust, then the oath also, as its confirmation, is gravely unjust; but if it is lightly unjust, then the oath also is a lightly unjust confirmation. Hence he who discloses another's hidden crime, and gravely defames him, and confirms by oath the crime committed, sins mortally by swearing; but he who discloses another's light crime, and confirms the committed crime by oath, sins venially by swearing."

No less clearly Peter Catalani says (Th. Mor., part 2, q. 9, c. 4, n. 6): "It must be said secondly that the defect of justice in an assertory oath is grave or light, not from the grave or light thing asserted, but from the grave or light mode of asserting, namely from the evil mind, greater or lesser, by which God is brought in as witness of the thing asserted... so that, because of your evil end, it may be rendered safer and firmer. Therefore if the end for which you use an assertory oath as a means is mortal, the oath will be mortal; but if it is venial, the oath will be venial. Thus Sanchez, Suarez, Castropalaus. Hence if you gravely detract from your neighbor, and confirm the detraction by oath for the end of gravely harming him, you would commit a grave sin beyond the detraction from defect of justice in the oath; for you would assume the oath as a means to confirming grave iniquity. But if you detract lightly from your neighbor, etc."

Here indeed one begins to ask: What is the reason that Suarez and Sanchez are here alleged for this doctrine, when the Salamancans say that these stand for light fault against Soto, Ledesma, and Toledo, as though these stand for grave fault? But further, what, I ask, does Toledo say on this matter? Behold (Sum., lib. 4, c. 21, n. 8): "Concerning justice, observe that it is not enough to swear what is true, for the oath to be lawful, but one must swear with justice; that is, a man ought not to swear that truth which it is a sin to reveal. For if someone were to reveal another's hidden crime, defaming him, he would sin, although he spoke the truth, because he acts against justice; and if he swore this truth, he would sin again. But this oath is mortal when the injustice upon which one swears is mortal; it is venial when the injustice is venial." Thus far Toledo. Do these things differ even in the least from what, according to Catalani as witness, Sanchez and Suarez teach?

And what does Soto say? You may see it with your own eyes. After he has related (De Iust. et Iur., lib. 8, q. 1, art. 3) the opinion of Cajetan, as though justice were not the companion of an assertory oath, he adds: "But perhaps more rightly it is judged that justice also properly belongs to an assertory oath. For justice properly regards not only the thing sworn, but also the cause of swearing, as St. Thomas says in the solution to the second... Hence if I, asserting under oath crimes of a citizen wholly hidden, denounce them, certainly the oath is unjust... But if, required by law and custom, I reveal those things, my oath becomes just." Here the VV. subsume (p. 262) that Soto must surely be understood of mortal sin. - Resp. This will be admitted when they have shown that whatever is unjust, according to the mind of Soto, is a mortal sin of its whole genus.

From Ledesma the VV. (p. 263) report these words: "But if justice is taken in the other sense, it always accompanies a lawful assertory oath; since if the cause which moves one to swear is not just, the assertory oath will be iniquitous." Do the VV. wish even Ledesma to hold as grave sin whatever is not just? Therefore let them not conclude that the Salamancans rightly attributed that doctrine to Ledesma. For it was vigilantly said in the Note above that Soto, Ledesma, and Aragon said that one sins in the case; but whether gravely or lightly, that they do not say; nor did the aim either of Soto or of Ledesma require this further.

But that Catalani rightly attributes this common doctrine to Sanchez is clear from these words (Decal., lib. 3, c. 4, n. 33): "More clearly Soto, Aragon, Peter de Ledesma, and Toledo say that for the honorableness of an assertory oath justice as companion is required, and that this is attended not only on the part of the thing sworn, but also on the part of the cause of swearing, and therefore an oath is unjust whenever by it a neighbor's crime is unjustly uncovered. And Soto and Ledesma add that this oath is no less unjust than when an unjust thing to be done is promised by oath. And Toledo says that this sin is mortal when the sworn assertion is mortal, and venial when it is venial." Sanchez adds that he admits these things, and that they are also held by Sayrus and Suarez.

The things said up to this point can and indeed ought to seem sufficiently clear, and at the same time sufficient to persuade that the disagreement of authors in this question is imaginary. Nevertheless it is worthwhile also to hint whence the occasion arose for the confusion which this question presents among the Salamancans.

Namely, there were those who extended more broadly the justice which is the companion of an oath. Hence that saying of Tamburini (Decal., lib. 3, c. 1, §4, n. 5): "Justice consists in this: that what is sworn is sworn honorably and without sin... for here justice is not taken strictly for the virtue of rendering to each his own, but broadly according to that saying: 'It is fitting for me to fulfill all justice.'"

But Sanchez explains this thus (l.c.): "According to the opinion of some, whenever someone by an assertory oath affirms a matter in the assertion of which mortal fault is committed, then by asserting it there is, besides that mortal fault of the assertion, another mortal fault of the oath from defect of justice. And if a venial fault is committed in the assertion, there is another venial fault by reason of the oath, as we have said happens in a promissory oath." He then gives examples in this way (ibid.): "For example, if someone without just cause discloses the hidden grave infamy of a neighbor, or says a mortal contumely to him, asserting this by oath; or by oath relates his own mortal crime with boastfulness or delight over it; beyond the mortal sin of detraction, contumely, boastfulness, or delight, that oath is mortal from defect of justice." He alleges St. Thomas (2. 2, q. 89, a. 3 ad 2), Cajetan (ibid.), and Valentia (2. 2, disp. 6, q. 7, punct. 3), who nevertheless merely say that the justice of an oath regards the cause of swearing, and the example touched on by Valentia is referred to justice strictly so called.

But whatever may be the case about this, it is certain that Suarez also considered the justice which is companion of an oath in that broad sense of which we have spoken. For diverse circumstances or hypotheses he thus gives diverse judgment concerning the guilt of the assertion. "Although," he says (De Iuram., lib. 3, c. 12, n. 7), "the narration is about a mortal sin, often it is not itself a sin, at least not mortal, because it is not done with complacency in it, nor with injury to a third party, nor with scandal; indeed if that narration has an honorable cause or necessity, there can be no sin; but if it is done lightly, of itself it will only be a venial sin. Therefore to confirm it by oath will either be no sin, if it is done for a good end with usefulness or necessity, or it will only be a venial fault." But as regards injury to a third party, which he supposed to be absent in this text, he does not hesitate at all to affirm that grave fault is added through an added oath. "An exception must be made," he says (ibid., n. 8), "... unless the malice itself of the wicked narration is increased by oath, as, for example, if someone defames his neighbor against justice by narrating hidden truth, and adds an oath so that the infamy may become more probable. For then the malice against religion and the irreverence toward God seem to be gravely increased, so that under this title it is necessary to explain that circumstance in confession; because the Name of God is assumed as an instrument for doing grave injury to a neighbor, which contains grave injury to God."

But in giving diverse judgment according to the diversity of hypothesis, Sanchez and Tamburini certainly followed Suarez, and therefore, in the narration of some grave sin confirmed by oath, they teach with Suarez that a light fault can intervene. Yet that does not prevent each from agreeing altogether with the same authors with regard to the question commonly proposed by authors, of which we spoke above. And indeed, concerning Sanchez we saw this above. But as regards Tamburini, it is clear from these words of his (l.c.): "Therefore he who, for example, defamed someone with an oath... would commit an oath lacking justice, to be opened specially to the confessor besides the infamy... because to take the testimony of God as a means for acting wickedly is... irreverence against God... What if the wicked action of detraction is only venial? I respond that the oath will be venially rash."

Therefore let us conclude what is manifestly clear from these premises: When the subject of the question is the same, as we have seen regarding justice of an oath taken strictly, Suarez and Sanchez and Tamburini, etc., agree exactly with Soto and Ledesma and Toledo, etc. Therefore the disagreement and battle which the Salamancans fashioned among them is imaginary. But when Suarez and Sanchez and Tamburini, etc., take the justice which is companion of an oath in a broad sense, while Soto and Ledesma and Toledo, etc., take the justice which is companion of an oath only in a strict sense, there can be no battle among them, because the subject of the question is diverse. Again, therefore, it is clear that the disagreement vaunted among them by the Salamancans is plainly imaginary.

310. Questions. Q. 1. What is a sufficient cause for swearing?

Resp. Any honorable cause of some weight, for example peace to be confirmed in families, greater security in contracts, etc. - St. Alphonsus, Homo apostolicus, n. 14.

Q. 2. Whether it is lawful to swear with probability of truth?

Resp. It is denied, because God cannot be invoked except as testimony of a certain thing; nevertheless a certain moral certitude suffices. - St. Alphonsus, Homo apostolicus, ibid. ⁷.

⁷ St. Alphonsus (lib. 3, n. 148): "Some moral certitude suffices, or a certain probability which reaches to a certain moral certitude..." Indeed Sanchez with Valentia, Suarez, and the Salamancans, with the common opinion, say more expressly that in an oath, whether assertory or promissory, probability of the asserted truth or of the fulfillment of the promised thing to be carried out suffices; provided, it is to be understood, that there is not a probable reason to the contrary.

Q. 3. Whether it is lawful to swear with a mental restriction?

Resp. It is denied, if it is purely mental ⁸; but otherwise, if it is broadly mental, from a just cause ⁹. See what is to be said on the eighth precept, n. 442 and following.

⁸ To this, according to the common opinion, pertain propositions 26 and 27 from those condemned by Innocent XI. Indeed St. Alphonsus recalls also proposition 28 to mental restriction strictly and purely taken, which reads thus: "He who by means of recommendation or gift has been promoted to a magistracy or public office can, with mental restriction, furnish the oath which is customarily required by command of the king, without regard to the intention of the one exacting it, because he is not bound to confess a hidden crime."

But others judge (see Viva on proposition 28 of Innocent XI, n. 1 and III) that here the case of restriction even not purely mental is included. For the doctors commonly agree that cases of this sort occur, in which one must abstain even from a restriction that is not purely mental; which Cardinal Lugo also indicates thus (De Fid., disp. 4, n. 67): "In certain cases there is without doubt an obligation of abstaining from equivocations, and of using words in that sense in which they are received by the hearers. 1. When from that error the hearers would fall into some grave inconvenience; and then the obligation will be from the virtue of faith or religion, when the error which they would conceive would be against faith; just as when it would be against justice or chastity or other virtues, the use of amphibology would indirectly be against these virtues. 2. When by reason of office we are bound to instruct someone and to teach truths, lest he err; and all the more, if we are bound to this after accepting payment or stipend. 3. When we celebrate onerous and mutual contracts; for we ought from justice to utter words according to the mind of the contracting party, lest we deceive him. 4. When we are commanded to respond to a judge or prelate legitimately interrogating; for we ought to respond in the sense of the one interrogating, or certainly in the sense in which he ought to interrogate."

And to this last case pertains both the example proposed in the cited proposition 28 and many others, for example if someone to be promoted to sacred orders is interrogated concerning birth, irregularities, censures, or if someone wishing to contract marriage is interrogated about impediments. For it is not lawful for these to use equivocation; but they must sincerely confess the things about which they are interrogated. Nor does it stand in the way that it seems harsh (as is objected in the cited proposition 28) to compel someone to the confession of his own crime. For, as Viva (cited place) observes, here confession of the crime is not required for vengeance, to which confession the accused is not bound unless he has been convicted by proofs; indeed, neither is it required absolutely that someone manifest his crime or defect, but only that he withdraw from his request; namely, that offices or sacred order or marriage may not be conferred upon the unworthy to the detriment of the commonwealth.

⁹ On this matter St. Alphonsus says (lib. 3, n. 151): "It is certain and common among all, that from a just cause it is lawful to use equivocation... and to confirm it by oath."

But what the just cause may be, he soon explains thus (ibid.): "A just cause can be any honorable end for preserving goods useful to spirit or body." And again (ibid.): "An absolutely grave cause is not required, but any reasonable cause suffices, for example to free oneself from the importunate and unjust interrogation of another." Indeed, as he adds with the common opinion of the doctors, n. 170, when there is a just cause of necessity or utility, one can use amphibologies in an oath, even if he spontaneously offers himself to swear.

Finally he adds (ibid.) that, according to the more probable opinion, it is venial if someone does this without cause. "The reason," he says, "is that in an oath of this sort truth and justice are already present, and only judgment or discretion is lacking, the deficiency of which is only venial." But for more examples of equivocations, which at times are useful for practice, see the same St. Alphonsus, n. 155 to 167.

Q. 4. Whether it is lawful to furnish an oath in disturbances of the commonwealth?

Resp. This depends very often on circumstances. Weigh what justice or the common good demands, and what the obligations of the required oath are, whether positive or negative ¹⁰. - But especially it is expedient to consult ecclesiastical superiors, to whom it belongs to define what is to be done according to various circumstances.

¹⁰ You would call negative, for example, the obligation which in certain modern codes of law, atheistic by their own character, is imposed, that subjects not impede certain crimes against God and good morals, whose free faculty for each person the atheistic law commands to be preserved.

311. Q. 5. What sort of sin is it to swear without truth, judgment, and justice?

Resp. To the first. It is mortal; because to bring God as testimony of falsehood is to will to destroy His truthfulness. It is also clear from proposition 24 condemned by Innocent XI.

Resp. To the second. It is venial per se, that is, with the danger of perjury set aside; because it is only a vain usurpation of the Name of God. - Thus nearly all, even the stricter authors.

Resp. To the third. Certainly it is mortal, if the matter is grave, as is clear. But more probably otherwise, if the matter is light; because from this grave injury does not seem to redound to God, since He is invoked not as surety of sin, but as witness of the purpose. - Suarez, Collet, Antoine (with whom St. Alphonsus also agrees) ¹¹, against others.

¹¹ It is said less exactly that St. Alphonsus agrees with this opinion, since he has these words (lib. 3, n. 146): "But the opposite opinion pleases me more, which Elbel holds... with March., Turr., etc.; because it seems not light but grave irreverence to invoke God as witness and surety of sin, even if light." Suarez (De Religione, tr. 5, lib. 3, c. 19, n. 3) follows the other opinion as common, giving the reason that God is merely invoked as witness of the truth, namely of the present purpose, no differently than in an assertory oath God is brought as witness concerning a past thing that is most wicked. But this reason will perhaps seem less to cohere with the notion of a promissory oath, which is commonly handed down, and also admitted by Suarez (ibid., lib. 1, c. 8, n. 2, 3), namely that besides confirmation of present truth it includes an obligation from the virtue of religion that a man make true that which he swore, according to his possibility (which are the words of St. Thomas, 2. 2, q. 89, art. 7 ad 1), by which indeed God is brought in as surety of the promise to be fulfilled, as we said above (note to n. 309) with Laymann.

Among prohibited oaths are numbered those which are customarily emitted in secret societies, whether of the Carbonari or of the Freemasons (Francs-Maçons). For an oath cannot in any way be held lawful which its authors do not wish to be manifested even to the Church.

603. PRINCIPLE. For a valid oath there are required: the intention of swearing and a swear-formula. These two are essential; nevertheless the first parts are held by intention, so that, although God is invoked as witness only internally, an oath is present.

I. The INTENTION OF SWEARING is required, at least virtual; because without such an intention an oath, as an invocation of God, is not a human act (III, 134).

Hence: 1. If the mind of swearing is lacking, whether from inadvertence, as in him who does not know or does not notice that the words which he uses are sworn words, or who does not intend to usurp them as sworn words but only wishes to affirm more expressly the things which he says; or from malice, as in him who swears fictitiously, by positively excluding the intention of invoking God as witness, there is no oath. 2. The same must more probably be said concerning a promissory oath, if the mind of obliging oneself from oath, or from religion, is lacking; because it is contradictory to will to promise by swearing and to be unwilling to contract an obligation of religion. 3. If only the mind of fulfilling the promise is lacking, the oath is valid, since the intention of truly swearing is present; but perjury is committed, on account of defect of truth, as will be said n. 606. Cf. St. Alph., III, 172.

II. A SWEAR-FORMULA is required, by which it is expressly or tacitly manifested that God is invoked as witness. Otherwise how could God be employed in a sensible way as witness before others? (III, 134).

Moreover: 1. The invocation is EXPRESS whenever God or his attributes are brought into the midst for making faith. Of this sort are the following formulas: I attest God, I call God to witness; let God be witness to me; I swear by God, by Christ, by the truth of God, by the faith of God, by his mercy, justice; may God destroy me, if, etc. (III, 140-143).

2. The invocation of God is TACIT when it is done through nobler creatures, insofar as divine perfections shine forth in them, for example: I swear by the Blessed Virgin, by the Saints, by heaven, etc.; likewise when signs alone are employed, for example hands are raised, the Gospel is touched, if from a preceding determination those signs are held as a swear-formula (III, 135-138). Indeed, this determination being presupposed, the contact of hands alone suffices, which officials of the State, priests, or even those who are enrolled in the sect of Mennonites, use in some regions, so that they assert the truth of the matter before a judge.

604. Hence it is inferred: a) If the divine persons or perfections, or the aforesaid creatures, are simply remembered for the sake of affirming and merely by way of narration or similitude, formulas of this sort are not reputed sworn formulas, unless something else is established or argued from the circumstances. Thus he is not considered to swear who says: "I speak before God, the angels, the blessed; God knows; God knows all things; God sees my conscience; hold me as innocent of this evil as the angels of God; it is as true as God exists; God lives before whom I stand, etc." (III, 134-138).

b) Execratory formulas, as for example, "may I be killed if this is not so," are commonly not considered a true oath, unless God is expressly named, for example: May God destroy me, if I lie. Otherwise they contain only a certain sponsoring or obligation of penalty (III, 143; l. El. qq. ref., n. 19).

c) Of itself, the invocation of one's own conscience, faith, life, body, one's own affairs, or a common creature does not suffice for an oath: for example, "I swear from conscience, by conscience, by my faith, probity, by priestly honor, military honor, by my head, by honor, by house, by children, etc." But otherwise, if one swears by the faith of Christ or the Catholic faith (III, 134-135). Nevertheless a promise made by invoking priestly honor is altogether serious and obliges.

d) Similarly, he does not swear who says: "I swear that it is so; I swear that I am going to do this"; unless from the previous declaration of the one swearing or of the one asking, the intention of furnishing a true oath is manifest (III, 136).

e) A lay oath, as they call it, is not an oath, since invocation of God is lacking (Ami du Cl., 1908, p. 870).

PRACTICAL RULES. 1. In the INTERNAL forum, the matter is to be judged from intention. He who has the mind of swearing truly swears, whatever words or signs he uses. Indeed he truly swears, even if he uses words which do not import an oath, if he believes it to be an oath. In doubt concerning the intention of the one swearing, one is accustomed to judge according to the common acceptance of the words which he used (III, 134; Lehmkuhl, I, 554).

2. In the EXTERNAL forum, one must stand by the formula which the one swearing usurped. For, although perhaps the oath is null before God because of defect of intention, nevertheless, in the external forum he is judged to have sworn who usurped such a word or such a sign which either of itself or because of circumstances attests a true oath.

Note. Concerning the oath in the declaration of revenues, see n. 967.

444. B. Conditions required for a lawful oath.

For a lawful oath three conditions are required, already enumerated above, which are customarily called the companions of an oath,⁵³⁸ and which are already indicated by Jeremiah: "Thou shalt swear: The Lord liveth, in truth and in judgment and in justice."⁵³⁹ If even one of these conditions is absent, an oath lacks due reverence toward God and consequently is unlawful.

1. The truth of an oath does not signify the objective truth of the assertion made, but the veracity of the speaker, who does not speak contrary to his mind, or who does not tell a moral lie. This truth, therefore, presupposes a firm will to speak the truth (in an assertory oath) or to fulfill what is promised (in a promissory oath). Truth is the principal companion of an oath; if it is absent, there is the very grave sin of perjury, concerning which the discourse will return below in n. 456ff. But it is required not only that the one swearing avoid every moral lie, but also that he have moral certainty concerning the things asserted. Hence it is not lawful to swear either with doubtful truth or with merely probable truth. Likewise, it is never lawful to swear with a purely mental restriction. Thus holds the most common opinion, which is corroborated by the condemnation of propositions 26 and 28 pronounced by Innocent XI.⁵⁴⁰ But to swear with a broadly mental restriction is not lawful except for a grave cause; namely, in the case in which no other means is at hand to defend oneself or others against an unjust aggression, an unjust manner of questioning, or another grave evil. Thus a confessor who is unjustly compelled to give sworn testimony concerning things which he learned under the seal of confession can, and indeed must, swear with a mental restriction.

It is asked how great a sin it is to swear without sufficient cause with a broadly mental restriction. Many authors teach that such an oath is a mortal sin, since it is a grave irreverence against God to employ the invocation of His name to deceive others. St. Alphonsus⁵⁴¹ admits this doctrine concerning an oath in a trial or in contracts, but thinks it more probable that it is only a light sin if someone without sufficient reason employs a broadly mental restriction in other private oaths, because truth is not absent in such an oath, since the words pronounced can easily be understood in a right sense; nor is justice absent, because the questioner has no right, as is supposed, to a simple answer without restriction. Therefore only the third companion of an oath, namely judgment or discretion, is violated, and its violation is only a light sin. Although these things are true, nevertheless in practice this case seems scarcely possible. For it has already been prohibited that anyone swear without necessity or a grave reason. Therefore it is prohibited much more severely that anyone swear without necessity with a mental restriction.

⁵³⁸ Eidesgefährten [companions of an oath].

⁵³⁹ Jer. 4:2. Cf. also S. theol. 2, 2, q. 89, a. 3.

⁵⁴⁰ Cf. what was said above in n. 171 concerning mental restriction.

⁵⁴¹ St. Alphonsus, Theol. mor. l. 3, n. 151.

I. On the requisites for the essence of an oath. - 366. - Two things are required for an oath, namely: 1° The intention of swearing, at least virtual; because without such intention there cannot exist a formal oath. 2° An oath-formula, either by God explicitly, or implicitly by creatures, or an oath-sign; because, since God is invoked as witness, it is necessary that this be expressed in the oath.⁴

367. You will resolve. - 1° A fictitious promissory oath, or one merely external, is not valid, because of defect of will or intention. Yet he who thus swears sins; but more probably, speaking of itself, only venially, because it is nothing but a lie with vain usurpation of the name of God.⁵ - Nevertheless it is mortal in contracts, or before a judge (because of grave deception against justice), or if the one swearing fictitiously does not have the mind of fulfilling the promises.⁶

2° An oath made with the mind indeed of swearing, but not of obligating oneself from religion, more probably is not valid, because this is nugatory. But an oath made with the mind indeed of swearing, but not of obligating oneself from justice or from fidelity, is valid.

3° It is an oath to say: I swear by God, by the Saints, 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. Otherwise, if someone swore by creatures in which the divine goodness or power does not shine forth, for example by a beard, etc.¹

4° 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 an honest man (upon my word and honor), by my faith,... by my conscience,... by priestly faith,... may I die, or may the devil destroy me, unless it be so.... Except when these last two are uttered by way of execration, and not rather, as is customary, by way of pledge. Indeed it is not even an oath to say: I swear or I swear that it is so, unless a question about giving an oath has preceded. - St. Alphonsus,² and many others.

II. On the requisites for the liceity of an oath.

368. • A threefold condition is required for the liceity of an oath according to that saying of Jeremiah:¹ Thou shalt swear: The Lord liveth, in truth, and in judgment, and in justice.

I. Therefore Truth is required, that is: conformity of the assertion with intention and not with the fact. For an oath excludes only lying, not every error. In an assertory oath truth regards the existence of the fact; in a promissory oath the existence of the intention.

II. Judgment, that is, that it be done with discretion, prudence, consideration, and reverence, and not without necessity or a just cause.

III. Justice, that is, that the oath be about a just, licit, and honorable thing. Thus he would swear against justice who by oath would obligate himself to inflict damage unjustly on his neighbor, or to furnish something else prohibited.

369. Questions. - Quaer. 1° What is a sufficient cause for swearing?

Resp. Any honorable cause of some weight, for example peace to be confirmed in families, greater security in contracts, etc.¹

Quaer. 2° Is it licit to swear with probability of truth?

Resp. Negatively, because God cannot be invoked except in testimony of a certain thing; nevertheless a certain moral certainty, or sole probability, suffices.²

Quaer. 3° Is it licit to swear with mental restriction?

Resp. Negatively, if it is purely mental; but otherwise, if it is broadly mental, and a just cause is present, which nevertheless ought to be greater than that which is required for an unsworn restriction, and greater in proportion as the words furnish greater occasion of erring.⁴ See what is to be said n. 513-515.

Quaer. 4° Is it licit to swear, touching and kissing Protestant Bibles, when they have been presented to us by magistrates?

Resp. Negatively, of itself, as is plain; hence one about to swear is accustomed to bring Catholic Bibles or a prayerbook in which some part of Sacred Scripture is contained. For the rest, solemn affirmation among us suffices. I said: Negatively, of itself, because ignorance often excuses. Collect. p. 630 n. 1180.

Quaer. 5° Is it licit to give an oath in public disturbances of the commonwealth?

Resp. This generally depends on the circumstances. Weigh what justice or the common good postulates, and what the obligations required by the oath are, whether positive or negative. - But especially it is expedient to consult ecclesiastical Superiors, to whom it belongs to define what, according to the various circumstances, is to be done.

370. • Quaer. 6° What kind of sin is it to swear without truth, judgment, and justice?

Resp. to the first. It is mortal, because to bring God forward in testimony of falsity is to will to destroy His veracity. It is established also from Proposition 24 condemned by Innocent XI (see p. XV). L. IV. 147.

Resp. to the second. It is venial of itself, that is, with the danger of perjury excluded;⁵ because it is only vain usurpation of the name of God. - Thus almost all, even the stricter authors.

Resp. to the third. An assertory oath must be distinguished from a promissory one. In the former, for instance if someone boasts with an oath about some sin, more probably there is only a venial sin against religion, because it is not done to confirm complacency in sin, but only to make others more certain about it, which is only a certain venial levity of soul. Except, however, an oath for confirming detraction; for it is employed as a means for making another's infamy more certain. In the latter oath it is certainly mortal, if there is question of a grave matter, as is plain; if of a light matter, St. Alphonsus¹ is more pleased by the opinion which affirms that even in this case one sins mortally, because it seems to be a grave irreverence to invoke God as witness and surety of sin, even light sin.

You will resolve. - 1° Among prohibited oaths are listed those which are customarily emitted in secret societies, and by which members obligate themselves to obey those things which perhaps will be ordered by certain superiors, or to keep secrecy even against legitimate power.² See n. 1721. 1°. d).

Yet there are certain societies of workers in which an oath is emitted, or is judged to be emitted, with a restriction, that it is licit to reveal its object to the Ordinary or to a priest; and these, indeed, if the oath contains nothing else which is opposed to justice, and the society is not illicit from elsewhere, are not to be disturbed. See n. 1721. 1).

2° The oath of preserving the Constitution of the United States is to be understood in the popular sense, which, namely, is received among all; for each person is not judged to embrace with judgment of mind whatever is contained in it, nor does the Constitution obligate to this.³ Nor is a law to be called evil, but good, which permits a lesser evil that it may prevent a greater one. Moulart, L'Eglise et L'Etat.

3° The oath of foreigners seeking the right of citizenship here is licit, even for him who shall have given an oath of fidelity to the prince from whom he departed. For that oath of fidelity was exacted for confirming the natural obligation of citizens, rather than for inducing a new one, and therefore it must be explained according to the nature of that obligation, by which no one, unless a public and grave cause presses, is bound to remain in his fatherland, and which he satisfies who obeys the prince while he dwells in his domain. But as regards the oath which is given here by foreigners seeking the right of citizenship, and by which every foreign prince is abjured, and consequently also that one from whom someone departed, it is understood of that natural obligation being abjured which, by departing from his domain, has already ceased; and therefore it cannot be called illicit.

4° He who, while war is raging among some nations, brings goods under a neutral flag and documents either fictitious or purposely made into a neutral port, so that thence they may be carried to one or the other of the nations which wage war between themselves, is sometimes compelled to swear that the documents are true. Such an oath cannot be given in the case. (o) p. 473.

S. Th. II-II, q. 89, a. 1, 4, 6.

742. Oath (serment; eed) is said from right, because it was introduced for right or law, among all nations, so that what is said under invocation of divine testimony may be held as true; therefore to swear (eed doen of zweren) is to appeal to God as witness of some matter, or, as St. Thomas says, a. 1, "to assume God as witness." Whence oath is defined: Invocation of divine testimony, or with the Code (can. 1316): "the invocation of the divine Name as witness of truth."

Therefore the end of an oath is the confirmation of truth. Confirmation in the sciences is made through reason, which proceeds from evident things to conclusions; there witnesses and oath are not employed: for one would seem ridiculous if, in the disputation of some science, he wished to prove what was proposed by an oath. But the particular and contingent facts of men cannot be confirmed through reason (from intrinsic causes), and therefore they are accustomed to be confirmed through witnesses. Human testimony, however, is not always sufficient for confirming these things, on account of defect of veracity or knowledge, and therefore it was necessary to have recourse to divine testimony, because God can neither lie nor be ignorant of anything (a. 1).

But one swearing does not ask that God here and now testify to the truth of the statement by an actual sign (for that would commonly be tempting God), but when and how it pleases Him, at least in the future judgment (a. 2, ad 3), or that He punish most gravely one swearing falsely (a. 1, ad 3). And yet the invocation serves to produce faith immediately among men, because someone is not easily judged to be of such impiety and boldness that he would make God a witness of falsehood and subject himself to divine vengeance.

743. An oath is an invocation; therefore it is an act of reason: an interior speech, which nevertheless presupposes an act of the will, namely, at least the implicit intention of swearing and of calling God as witness.

Hence an oath is not:

a) An invocation pronounced indeliberately by him who does not know what an oath is, or by him who is ignorant of the sense of the words or does not advert sufficiently: an unconscious oath.

b) Nor an invocation pronounced merely materially in circumstances which exclude every intention of invocation, for example, if it is made in school or in a theater for the sake of teaching or representing, or by way of interjection as in common speech, by God (for example, par Dieu, c'est vrai): a narrated oath.

c) Nor a deliberate but merely external invocation without intention: a fictitious oath, for example, by him who does not admit the existence of God.

For a human act does not operate beyond the intention of the agent. But an oath must be a human act, not only insofar as it is speech, but also insofar as it is an invocation of God as witness: for invocation can be made for a diverse end. Therefore, in order that it be made for a witness, the intention of uttering words and expressing an invocation of divine testimony does not suffice, but the will of invoking God as witness is required. A fictitious oath is an irreligious lie, of itself venial, sometimes mortal because of grave public or private harm, as in judgments and contracts.¹

¹ Hence condemned by Innocent XI is proposition 25: "With cause it is licit to swear without the mind of swearing, whether the matter is light or grave."

A merely internal oath, although it is valid before God, as if someone invokes Him internally as witness that he wishes firmly to avoid sin, nevertheless does not obtain its effect of confirming assertions and promises before men, whence it is incomplete; likewise if someone, intending to swear, uses a formula wholly unfit for this. Therefore, in order that an oath be complete, it must be expressed by some oath formula; and therefore on the part of the mode by which the invocation is expressed, it is divided into verbal, real, and mixed, according as it is expressed either by words or by signs (the raising of fingers, the touching of a scepter, cross, or gospels), or by both.

744. An oath is the invocation of testimony or an appeal as witness of truth.

Hence a) it is not the invocation of the merciful and omnipotent God by way of prayer and supplication for obtaining some good, favor, or help, even, for example, for showing truth or conciliating faith for ourselves; but it is the invocation of the infinitely true God for obtaining testimony for confirmation, by which, insofar as it is in us, we constitute Him witness, that is, we cite Him and consent that He be witness, if He wills.

b) Nor is it the invocation of Sacred Scripture to confirm doctrine: for it is one thing to use testimony already given, another to invoke the testimony of God as to be exhibited (a. 1, ad 1).

c) Nor is it a simple assertion of divine omniscience, as in the expressions: I speak before God; God hears me; He knows that I speak the truth; God is witness; God will testify in His own time; God is truth; the Lord lives; the Lord sees my conscience, etc.; unless they are pronounced not only narratively and enunciatively, but invocatively, as the Apostle, Gal. I, 20: Behold before God, that I do not lie...

d) Nor is it a simple comparison of the asserted truth with an evident truth, for example, it is as true as God exists, as the sun shines, as I sit here (as in Dutch waarachtig Gods), or with a truth of faith, for example, it is true as the Gospel, after the likeness of faith, as infallible as the Church: in which case nevertheless ordinarily some irreverence toward God or sacred things will not be lacking.

e) Nor is it a simple vehement affirmation as in the expressions: in truth, by my faith (that is, human faith), in conscience, by my conscience, by the conscience of my soul (for example, ma foi, ma parole d'honneur; op mijn woord).

f) Nor is it a simple wager or obligation of a penalty, for example, if it is false, I pledge my head; I wish to be a thief; let me be a heretic; let my ears be taken off; let me be killed, hanged, die; let the devil take me; ... by damnation, come here, etc.; unless God is invoked as witness of truth and at the same time avenger of falsehood.

On the part of the testimony which is sought, an oath is merely contestatory or directly invocatory (getuigeniseed) if God is invoked only as witness for manifesting truth; or indirectly, namely, execratory or imprecatory (vervloekings- of verwenschingseed) if He is also invoked as avenger for punishing falsehood. This often happens if He is expressly named, for example, if I lie, may God punish me, destroy me, damn me..., or if the evil is commonly regarded as proceeding specially from divine providence, for example, if I lie, may lightning from heaven strike me, may I descend into hell (a. 1, ad 3).

745. An oath is the invocation of divine testimony or of the divine name. Hence he does not swear 1. who does not say whom he invokes, for example, I swear that it is so, unless from the circumstances it is clear that he intends God, for example, if the demand for an oath preceded; nor 2. he who invokes false gods; nor 3. he who appeals to men as witnesses; or 4. even to the saints, stopping at their testimony: for this is nothing but an act of dulia.

Yet a) if a creature is invoked insofar as it belongs and is referred to its Author, and represents His supreme truth and majesty, the Creator who shines forth in creatures is implicitly and mediately invoked, for example, if someone swears by heaven, by the holy faith, by the cross, by the Gospels, by the sacraments, by the temple, by the saints, by relics, or by other nobler creatures which commonly are regarded insofar as they have a special relation to God; but by baser creatures no one is judged to swear, nor would that be licit because of irreverence.

Similarly b) if someone obliges himself or something pertaining to himself to a penalty and offers it to God as avenger of falsehood, there is an execratory oath in which God is implicitly invoked as witness and avenger, for example, I swear by my head, by my son, by my salvation... Such an oath is the expression by my soul (II Cor. I, 23), unless nevertheless, as often happens, the faithful do not advert to the special relation of the soul to God.

On the part of Him by whom one swears, an oath is explicit or immediate, or implicit or mediate (a. 6).

746. Famous is the division of oath into assertory and promissory, which is taken on the part of the object or matter, according as an oath turns upon the assertion or affirmation of the one swearing concerning the present, for example, I think it is so, I am incapable of paying, or concerning the past, for example, I did this, or upon an action or omission to be executed by the one swearing in the future. In the first case it is assertory (bevestigende of bloote eed), in the other promissory (belovende of verbindende eed).

In a promissory oath 1. God is invoked to testify to the present intention of the one swearing to do what he proposes; whence it includes an assertion concerning the present and adds a purpose concerning the future, and therefore when we distinguish an assertory oath from a promissory one, we understand it as merely assertory. 2. Nevertheless God is not invoked as witness of the future execution, for testimony is not given about a thing not yet done;² nevertheless 3. God is as it were the patron,³ who gives special authority and force to the promise and urges its execution by a special obligation of religion: for just as men promise or enter betrothals before a king, judge, or other man of great authority, who lends authority to the contract, so that they understand that they would do injury to him if they do not fulfill the promises, so also they promise with God invoked; but if they do not fulfill, they inflict injury upon Him. Whence by such an oath God is invoked that He may confirm the present sincere will and bind it lest it be changed in the future.

² Although future things are present before God, nevertheless by oath there is not asked from God testimony concerning a future thing as it is present to Him, but as it is in the word of the one promising. But in this way testimony does not fall upon the word except insofar as it is capable of truth when it is spoken; therefore with respect to a future deed God is not invoked as witness. Suarez, De Religione, l. I, c. 9, n. 25.

³ Others say surety, but "this word... we cannot take in the strict sense, in which he is called a surety who answers for another so as to take upon himself the burden of paying the promise in defect of another." Dignant, De Virtute religionis, n. 221.

A promissory oath is a) strictly promissory or accessory when the action which is sworn is truly promised, whether to God by vow (a sworn vow), or to man (a sworn deed), or to both (a sworn vow in favor of a third party); or b) broadly promissory or standing of itself when the action is not promised but only proposed, whether for another's honor or favor (an oath confirmatory of a purpose or a sworn purpose), or for penalty or vengeance (a comminatory oath; bedreigingseed).

747. An oath is an act of religion. For nothing is confirmed except by something which is more certain and more excellent; therefore he who invokes divine testimony to confirm what he says, by this very fact professes God to be more excellent, as one whose truth is indefectible and whose knowledge is universal, and thus he exhibits reverence to God. But to reverence God belongs to religion; therefore. Cf. Deut. VI, 13; Ps. LXII, 12; Hebr. VI, 13-16.

All oaths in the account of oath are of the same species, because since the account of oath consists essentially in the invocation of God, all the differences brought forward above, or diverse modes of invocation, are related materially and per accidens to God's testification, and consequently do not change its essence and species.⁴ - Nevertheless other species can accede, for example, of fidelity, justice, dulia, and if the oath is sinful, of blasphemy, injustice, scandal, etc.

⁴ Nor is a promissory oath distinguished in species because one thing is to invoke God as witness of present truth, and another as patron of future execution. For in an oath the testimony of God and His authority are not invoked distinctly and separately, but God is invoked as testifying to the present intention and consequently He urges the future execution, because the matter concerns a future thing promised; which returns to a material difference. Dignant, o. c., n. 246.

748. Practical observations. - 1. In doubt concerning the intention of the one swearing, judgment is to be made from the circumstances, for example, whether the demand for an oath preceded, whether the one swearing is accustomed to swear, etc., but especially from the words employed: if the formula from its proper sense and common usage is oath-like, and was pronounced advertently, an oath is presumed; if it is doubtfully oath-like, it is not presumed but must be proved; but if it is ambiguous and the intention is not established, an oath is not judged to be present.

2. By the prescription of the Church, "an oath which the canons require or admit cannot validly be furnished through a proxy" (can. 1316, § 2).

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.

I. From Chapter II of this Dissertation it has been demonstrated against the heretics that an oath is an honorable act, and lawful, indeed an act of virtue — namely, of religion, or of latria — provided it is attended by the necessary conditions. In this chapter we undertake to explain these conditions, which ought to accompany an oath. But, before we examine each singly, it must be noted, from St. Thomas, that an oath is not absolutely to be sought after, and frequently employed. For, among those goods which are to be sought only when necessity presses, one may reckon that which is medicine — a good thing, given the illness which it meets. Thus an oath has been instituted to provide for weakness — namely, of the incredulous man. "Just as medicine (says the Angelic Doctor, q. 89, art. 5, ad 3) is useful for health, but the more virtuous it is, the greater harm it induces, if not duly taken — so too an oath is indeed useful for confirmation by divine testimony; yet the more it is to be venerated, the more dangerous it is, unless duly employed."

II. Now, in order for an oath to be opportunely employed, three conditions must accompany it, as Jeremiah 4 has it: "Thou shalt swear: As the Lord liveth, in truth, and in judgment, and in justice." St. Thomas assigns the reason why these three conditions are required (loc. cit., art. 3, in the body): "An oath is not good, except for one who uses it well. For a good use of an oath, two things are required. The first is that one swear not lightly, but from a necessary cause, and discreetly, as regards that which is confirmed by the oath — namely, that it be neither false, nor anything unlawful; and as regards this, judgment is required. The second is required on the part of the swearer's discretion. First, one swears truly by an oath who confirms that which is true; but an oath lacking judgment is called rash. Second, one swears rightly by an oath who confirms by it what is lawful. As regards this, truth is required, whereby it is true, and not a lie; and justice, by which one confirms what is lawful."

From this angelic teaching, the sense of the aforesaid conditions plainly shines forth.

III. In every oath, then, truth is first necessary, in confirmation of which divine testimony is invoked. This truth, or certainty of the truth, can be considered both on the part of the thing sworn, and on the part of the swearer. On the part of the thing sworn, it is required that the thing sworn be true according to common understanding and custom. Thus one who swears that a student frequented the schools swears truly, even if he was sometimes absent — since this is commonly understood in this sense. Certainty on the part of the swearer consists in this: that a man confirm, by oath, a matter such as he holds, or believes, in his mind to be true. If he knows the matter to be certain, he cannot swear it as doubtful; and if he judges it to be doubtful, he cannot swear it as certain. In a promissory oath, a twofold truth is implied: one, of the intention now had of fulfilling what he promises; the other, future, or of the deed, in the execution of what is promised. But of this twofold truth, more below.

Second, justice is required for an oath: that truth is necessary for an oath which excludes from the matter to be confirmed anything unjust, or any dishonorable thing — that is, an unlawful, culpable saying or deed, whether contrary to justice, or to any other virtue. He is said to swear falsely who confirms, by oath, present or future matter, contrary to what he presently has in mind. He is said to swear unjustly and wickedly who is opposed to justice. The former is opposed to truth by oath; the latter, to justice.

Third, judgment is necessary, which is not taken for the exercise of justice, but for prudent consideration; and it consists in this: that a man, before he swears, maturely and seriously weigh the utility and necessity of swearing. For, just as prudence is the guide, or rule, of all the virtues, especially insofar as it directs the oath, this third condition is supremely necessary, so that the oath may be lawful, and an act of virtue.

The first two conditions, however, are required so that it may not be a sin. Under this "judgment," in a certain way, are contained all the other conditions. As to truth and justice, this is clear: for, just as this judgment prescribes that one ought to swear, having regard to the utility and necessity of the matters, so too it forbids swearing to something false, or vicious. Other conditions too — chiefly theological faith, whereby one believes that God knows all things, and devotion, whereby, on the part of the swearer, the reverence owed to God is shown — are, St. Thomas openly teaches, comprehended under "judgment" (loc. cit., art. 5, ad 2): "Devotion, and faith, and all such things as are required for the due manner of swearing, are understood as included in judgment."

St. Augustine speaks excellently of this "judgment" (Sermon 28, on the words of the Apostle, ch. 9): "As far as it depends on me, I do not wish to swear; but, when I see that I am not believed, and that it is not expedient that he does not believe, who does not believe him to whom I am a witness — this reason having been weighed, and this consideration balanced, I swear, compelled by great necessity, as it seems to me, saying, with great fear, in the presence of God, or, as Christ knows in my soul, or such things."

IV. The Angelic Doctor not only explains the three common conditions which ought to accompany any oath whatsoever, but furthermore pursues the occasions in which an oath is free of fault, indeed possesses the merit of virtue. He assigns six such cases. First, when an oath is a conclusion of peace. Second, the necessity of preserving one's own reputation. Third, as a pledge of fidelity to be maintained. Fourth, for rendering obedience to a superior. Fifth, when the necessity presses of securing a promised thing. Sixth, so that the truth, which it greatly matters be believed, may be rendered credible. Here are the words of the holy Doctor, in his Epistle to the Hebrews, ch. 6: "The causes, however, in which it is lawful to swear, are these. First, for the confirmation of peace, as Laban swore (Genesis 30). Second, for the preservation of one's reputation. Third, for keeping fidelity, as vassals swear to their lords. Fourth, for fulfilling obedience, if something honorable is commanded by a superior. Fifth, for effecting security. Sixth, for attesting truth." Thus swore the Apostle (Romans 1): "God is my witness."

I. As has been said, truth is the chief of the conditions necessary for a lawful oath. It is not, however, necessary that this truth always be so in fact; but it suffices that the swearer, in good faith, believe the matter about which he swears to be true in his own mind. For it can happen that a matter is false, although it does not really stand thus, in the mind of the swearer; that is, metaphysical truth is not required, but moral truth. Wherefore truth is not taken so much from the object itself, or the matter sworn, as from the swearer himself — namely, that you swear the matter to be true, when, with sincere mind, you think it to be true, so that you swear without perjuring yourself. And, on the contrary, it can happen that you swear a false matter, and perjure yourself, because you think it to be false. So that I may resolve more clearly all the difficulties that can occur in the use of an assertory oath, I will present the following little questions with their responses.

II. Question I. Does one who swears falsely in the lightest matter sin mortally? Response: The Summa Angelica reports Godfrey teaching, in the chapter "Quod autem," that perjury in the lightest matter is a venial sin; which opinion Angles reckons probable, in these words (s.v. Perjurium): "It might, however, be said that a jesting lie is not, properly, a lie; and therefore he could hold that it is not properly perjury. But the safer opinion, according to the judgment of theologians, is otherwise." Antonio da Ignazio, in the Prolegomenon of Moral Theology of the Jesuits, ch. 1, and Henrique a Santo Ignazio, adjudge this same opinion, along with Bauny, in his Summa, p. 65, 15th edition, where he teaches it. And what Bauny says — as Godfrey's opinion, that one does not sin mortally, since it is not so great an irreverence as this — is proposition 24 among those condemned by Innocent XI, in these words: "To call God to witness to a light lie is not so great an irreverence as to warrant that one should be unwilling, or unable, to condemn a man for it." Domenico Viva, in his Theological Balance, interprets Bauny as admitting the smallness of matter only in a promissory oath. Let it be so. For I willingly interpret Catholic writers, as far as I can, in a sound sense along with the others. What I deny is that the proposition condemned by Innocent XI was, in its very words, conceived entirely in the sense of an assertory oath, not a promissory one. That the reason for the proscribed proposition does not hold, Fr. Viva himself testifies. Whatever the case may be, it is evident that the matter stands thus — since the malice of perjury does not derive its gravity from the lie, whether light or grave, whether jesting or pernicious, but from the irreverence, and supreme injury, which is done to God, whenever such matter of invocation, or the calling of God to witness of falsehood, occurs, whether it be the gravest, or the lightest.

For whoever invokes God, tacitly testifies that God can be deceived, or can deceive — and thus takes away from God his infallible truth. Therefore every perjury is a mortal sin. Indeed, the Angelic Doctor adds (II-II, q. 98, art. 3), where he establishes that every perjury is a mortal sin — he adds, I say, in his reply to the second objection, that perjury in a light matter is, in one respect, a graver sin than in a grave matter, and therefore, on the part of its own genus, a mortal one. He who perjures himself in jest does not avoid the divine irreverence, but in some respect increases it; and therefore is not excused from mortal sin. Only the defect of consideration, and of deliberation, or advertence, could excuse from mortal fault; but in such a case there would not be perjury — since the very reason for swearing requires deliberation, in the manner to be explained below. Here are the Angelic Doctor's own words: "He who swears falsely from a slip of the tongue, if indeed he adverts that he is swearing, and that what he swears is false, is not excused from mortal sin, any more than from contempt of God. If, however, he does not advert to this, he does not seem to have the intention of swearing; and therefore he is excused from the crime of perjury." Thus all authors teach, after Innocent XI condemned the aforesaid proposition.

III. Question II. Does one who swears a doubtful matter as certain, or, on the contrary, a certain matter as doubtful, sin mortally? Response: All the Doctors respond affirmatively. For one who swears a doubtful matter as certain, or a certain matter as doubtful, really lies: therefore he commits perjury, which is a mortal sin. You ought, then, to affirm or deny a matter in that manner in which you, all things prudently weighed, judge it to be. If the matter is doubtful to you, you ought only to declare it while doubting; if certain, you ought to declare it not doubtingly, but assertively.

IV. Question III. Does one who swears something by hyperbole, which, as it sounds, is not true, sin mortally? Response: Sánchez (Bk. III, on the Decalogue, ch. 4, n. 5), Tamburini (Bk. III, on the Decalogue, ch. 2, §1, n. 4), Leander (tract. 1, disp. 7, q. 7), Bonacina (disp. 4, q. 1, punct. 3, n. 6) respond negatively — since to say something false by a hyperbolic and figurative locution is not a lie, nor a sin. For this opinion they praise St. Augustine, and St. Thomas, who explains this in II-II, q. 111, art. 1. He recounts several sayings of Sacred Scripture which are explained by a figurative signification. In this manner is explained that saying of David (1 Kings 1): "Saul and Jonathan... were swifter than eagles, stronger than lions." That very many expressions of Sacred Scripture are explained by figurative and hyperbolic speech is well established. But that men who are neither Prophets nor Patriarchs, as those commonly were who are established from Scripture to have spoken figuratively, can confirm their hyperbolic assertions by oath, does not seem to me proven at all. For this reason, oaths of this kind, which Tamburini presses in the place cited — namely, "I swear that Peter possesses infinite riches," "that you are loved by me infinitely," "that your rivals are innumerable," etc. — since in the first place it is certain that such oaths are for the most part incautious, and consequently lack judgment, and are therefore illicit; moreover, an oath is granted by strictest right, and by way of medicine — therefore it is to be employed only when a grave illness, or necessity, presses.

V. Question IV. Is it lawful to swear something which you judge only probably to be true? Response: This little question is proposed by La Croix (Bk. III, part 1, ch. 70, n. 267). He responds in these words: "Sánchez (Bk. III, ch. 4, q. 2, dub. 3, n. 77) affirms this — since you swear this which you judge to be true; therefore you do not perjure yourself. Castropalao, part 5, n. 2, and others, in Diana, part 4, tract. 4, n. 10, extend this to swearing even in judgment. Some hold that one can lawfully swear a matter which he has heard from a notable and trustworthy man to be true. That which is probable, according to some, in Diana, is licit to swear even in judgment." Leander (tract. 1, disp. 8, near the end, p. 48), recalling to examination the kind of probability necessary for an oath, reports Tamburini as requiring a probability that induces moral certainty. But, reckoning this too rigid, he adds this: "But certainly any probability makes for moral certainty, as we have often said, with the common view." Whence... , as Palao well says, it will suffice, if he prudently judges, "according to a probable reason, that it is so." If you wish to know the principles of this doctrine, you must recall to memory the principles of probability, which Leander employs in their fullest amplitude. For he says that any probability whatsoever produces moral certainty, and that therefore any probable opinion whatsoever is a rule of honest action, and this is contained in that proposition condemned by Alexander VII, which stands in order 3: "Generally, whenever we act with either intrinsic or extrinsic probability, however slight, provided we do not depart from the bounds of probability, we always act prudently." This assertion, so indefinite, and generally set forth, Leander asserts of any probability whatsoever — whether grave, or slight — generating moral certainty, which anyone can prudently follow, as a rule of his own conscience, and this even in swearing. The Church has expressly condemned this. By a stronger right, then, that which Leander adds is to be execrated, namely, that anyone can swear a matter to be true which he judges only probable. Do not theologians commonly teach that God is called by oath to witness the truth? But, according to Leander, and those whom he cites, Sánchez, Diana, Castropalao, we will be able to invoke him as witness of probability! How can we swear that something is true which is not true, but only probable to us? For "true" is opposed to "false," and "probable" is opposed not to "false," but to "improbable." Since, then, contrary probable reasons occur most frequently concerning the same matter, anyone will be able, by oath, to affirm the same matter, and also, by oath, to deny it. According to the Probabilists, one can, from probable opinions, follow whichever one prefers, and now embrace, now reject, the same one. Or at least one will be able to select whichever part is to be affirmed or denied by oath, whichever has seemed more opportune, and more accommodated to his own affairs. All of which not only betrays laxity, but even strikes horror. If Leander, with the authors he adduces, had said that one can swear a matter which he knows to be probable, as probable, it would somehow seem tolerable. But, since they assert that one can swear as true what we merely judge probable, and moreover that any probability whatsoever can induce moral certainty, we can in no way admit this. Wherefore we reject Leander's opinion as false.

The opinion, however, which Fr. La Croix reports from Sánchez and others, we reject as improbable — since what we know only by probable conjecture, as Sánchez himself says, we cannot affirm as true, but as probable. For the common opinion of theologians is that the matter of an oath is truth, considered not absolutely, and as it is in reality, but in the manner in which it is perceived by the intellect. Therefore, if the swearer knows the matter as probable, he cannot swear it as true; and if he does not know it as true, he cannot swear it as merely probable. What they further add — that for an oath to be given in judgment, moral certainty is required, but that in other private oaths probable certainty suffices — this, as I judge, is a mere fabrication. For the reasoning is the same for a private, as for a public, oath: for the same is the formal reason which is attributed to each species — namely, the invocation of divine testimony in confirmation of truth. The same certainty, therefore, is necessary for both oaths, whether in judgment, or outside judgment. One who knows a matter as probable cannot swear it as true, but as probable, and conversely. It is indeed true that, according to the decrees of the laws, in judgment, testimonies are not admitted except of those things of which the witness has evidence, that is, unless he is a witness from having seen with his own eyes; and consequently a knowledge of the truth wholly evident is necessary. For the rest, whatever positive law may prescribe, in every oath, whether public or private, moral certainty is necessary — which we shall explain in the following little question.

When, however, someone confirms by oath a probable knowledge which he has of some matter, the matter of the oath is not the probability, or the doubt itself, but the truth of the probability and of the doubt: for, when I swear that I either opine, or doubt about some matter, I swear the truth — because it is really true that I have such an opinion, or doubt, or suspicion.

VI. Question V. What certainty is required, in order for someone to be able to swear licitly? Response: For a clearer, and fuller, understanding of the preceding question, I have proposed to settle this little question. There is one certainty which is evident, and metaphysical; another, experimental; another, moral; another, probable, which admits various degrees. Very many recent theologians and Casuists teach that a knowledge which is verisimilar, or probable, concerning some matter, suffices for someone to be able to swear. Thus teach, besides those cited in the preceding number, the theologians of Salamanca (tract. 17, ch. 2, punct. 3, §1), who praise Candido, Lessius, Azor, and others. This opinion does not at all convince me, and, according to the adversaries' own principles, seems to me false. For, if they themselves teach that a probable opinion produces moral certainty, and that we can choose, between two opinions on the same matter, whichever we reckon more opportune for ourselves — it certainly follows that we too will be able, by oath, to confirm or deny the same matter, according as time and our own reasons shall demand. How false, and erroneous, this is, no one fails to see.

VII. Rejecting, then, this opinion, we say, first, that indeed a mathematical, and altogether evident, certainty is not always required in an oath — since this cannot be had in very many cases; but we assert that a moral certainty is necessary, which excludes every prudent doubt. This moral certainty, however, is in no way induced by conjectures, and merely probable and verisimilar reasons — since the adversaries themselves flee to reflex principles, so that these merely probable reasons may not remove this doubt. But most weighty foundations, and reasons, are necessary, which render us certain concerning the matter about which we must swear. This opinion of ours is clearly drawn from the Catechism of the Council of Trent, Part III, on the second commandment of the Decalogue, §2: "The first thing, then, that is required in an oath is truth — namely, that what is asserted be true, and that the one who swears judge it so to be, not rashly, nor led by any light conjecture, but by the most certain arguments." This same thing is taught by Cardinal Bellarmine (Bk. I, on the Sacraments in general, ch. 16): "Even though one has a probable reason for believing, he nonetheless does not have certainty; for it can happen that he thinks he believes, and yet does not really believe. But certainty is required for testifying, that is, in the name of God; nor does a probable opinion suffice, as is clear in the similar case of an oath."

To witness truly, and to swear well, is not lawful, except for one who can know what he swears. No one swears well unless he can say, 'I have sworn... and I will keep it, to judge the justice of thy testimonies' — that is, unless he has certainty. For nor does a probable opinion suffice, just as a probable opinion does not suffice for testifying by oath; but only in a matter of which we are most certain. This opinion can be confirmed by what St. Ambrose writes (on Psalm 118, sermon 14, n. 14): "The voice of one walking in light." To say, "I swore," is a testimony of knowledge... Let it not be permitted, then, to swear except concerning matters of which we are most certain. Let no one swear who does not know what he swears... To swear, then, is a judgment of knowledge and of conscience... Let light go before you, if you intend to swear — that is, let the knowledge of the truth go before you, so that the bond of the oath may not harm you.

VIII. It is true, however, that the adversaries too admit that moral certainty is necessary; but in this they fail, that they teach that this moral certainty can be had by merely verisimilar conjectures, and merely probable reasons. For even granting that a probable opinion produces so much certainty as suffices as a rule of honest action, it does not, for that reason, follow rightly that it produces so much certainty as suffices for swearing that to be true which we opine to be only probable. For a greater certainty is required for an oath than for any moral opinion whatsoever. For this latter, mere true probability suffices to be a rule of honest action. But when someone swears something as true, it is not enough that it be probable; it is required that it appear true to the swearer — not through merely probable reasons, but through most weighty principles, or arguments, and certain ones. When this certainty is lacking, and only conjectures and probable reasons appear, then the swearer ought to affirm, or deny, a matter as probable, not as true.

IX. Question VI. What certainty is required for an oath to be tendered in judgment? Response: In the forum, certain knowledge is necessary... ; testimonies from hearsay are not admitted there, since witnesses there must have evidence from sight. More recent theologians commonly teach, the theologians of Salamanca, Sporer, La Croix, and many others whom they cite, that a witness worthy of credence suffices for swearing outside judgment; not so in judgment. When someone swears concerning another's deed, they say, experimental knowledge is necessary, such as is had by sight; but that a single credible witness suffices outside judgment, not so in judgment.

But it seems to me that it must be said that, whether in judgment or outside judgment, no one can swear a matter as true which he has heard only from a single witness, even a trustworthy one; but he must swear it in the manner in which he knows it — namely, either because he has had it established by his own eyes, or because he has received it by report from others. Although a trustworthy witness may be a foundation for me to believe prudently what he relates, this faith, or credulity, cannot be of such authority to me that, relying on it, I could absolutely swear that what I have heard is true; but I can only swear that I have heard it. Why can we not swear before a judge, absolutely, that what we have heard from a single witness is true? For no other reason, surely, than that a single human witness does not induce certainty sufficient for an oath. And although in judgment the discussion concerns the harm of one's neighbor, nonetheless such a great certainty is demanded in judgment, not so much to avoid the harm of anyone, as so that every occasion of perjury may be removed. This is the peculiar thing that occurs to be said concerning judicial oaths — namely, that judges, in pronouncing sentence, ought to exact such oaths as are established by the testimony of the eyes concerning that which is affirmed — namely, oaths of experimental, as it is called, certainty.

It is false, then, what more recent theologians commonly assert — that, outside judgment, one can absolutely swear something to be true which he knows only through probable reasons and conjectures; but, whether in judgment or outside it, you are able to swear what you know: and what you know only by hearsay, you ought to swear by hearsay; and what is established to you by sight, you ought to swear is established to you by sight. The reason for this is that, whether in judgment or outside it, the formal reason of the oath is the same — namely, the invocation of divine testimony; and the same reverence is owed to God everywhere and always. This, however, is the distinction between judicial and private oaths: that a judge decides nothing, unless witnesses swear a matter established by sight; private men, however, more often give credence to, and deliberate much upon, oaths concerning things heard (especially where the harm of a third party is not at issue). Wherefore, if you swear to me that you heard from a most trustworthy man, subject to no exception, that some deed occurred, I, as a private man, would give it full credence; and, insofar as such knowledge concerned my affairs or business, I would use it as a rule for many of my deliberations; but, as a judge, I would have no faith in you, nor would I decree anything relying on such an oath.

X. Question VII. What diligence is required in inquiring into the truth necessary for an oath? Response: The theologians of Salamanca (loc. cit., n. 4) answer in these words: "Equal diligence is not required in every matter to scrutinize the truth of the thing sworn; but, according to the condition of the greater or lesser weight of the thing, greater or lesser diligence is to be employed. For in matters of greater weight, greater care is to be employed than in matters of lesser moment."

This rule seems to me false. Since it is not the nature of the thing sworn, but the supreme gravity and dignity of the oath itself, that ought to be the norm of the diligence necessary in the inquiry of the truth before one swears. Is not assertory perjury, even in the lightest matter, a mortal sin? Why? Because the gravity of perjury is derived not from the matter sworn, but from the injury done to divine truth. Therefore, since an oath, by its own nature, with no regard to the matter sworn, is, among all peoples, a matter of the highest moment, the utmost diligence for the inquiry of truth ought to precede it. Only, then, can it be said that greater or lesser diligence is to be employed with respect to the truth itself, insofar as the matter which is sworn is more or less accessible and open to view, not with respect to the matter sworn. When, however, the matter sworn is grave in weight, since it concerns the reputation, or fortune, of one's neighbor, greater diligence and deliberation is required, not by force of the oath, or of the virtue of religion, but by force of another virtue, of justice, or of charity — since, if you swear falsely against your neighbor in a grave matter, besides perjury you commit the sin of injustice. And it is in this sense that it is said that, when the matter sworn is of great weight, grave diligence is also required on this ground, so that, besides perjury, the sin against justice may be avoided. All this seems certain to me, and cannot be denied even by more recent authors, though they assert the contrary in ambiguous words.

XI. Question VIII. Does one who is notably negligent in inquiring the truth of the matter he swears sin mortally, even though it happens that the matter he swears is true? Response: Sánchez (Bk. III, on the Decalogue, ch. 4, n. 10), Leander (tract. 1, disp. 7, q. 1), and, in them, Scotus, Cajetan, Richard, Sotus, Navarrus, and commonly all Doctors teach that this person sins mortally — since he exposes himself to the danger of perjury, and omits the necessary diligence in a matter of grave weight.

But, so that all that has been said in the preceding little questions may be more validly confirmed, and especially that rule in which we said that probable knowledge, which can suffice for governing other human acts, by no means suffices for the making of an oath, it is worth bringing forward St. Thomas's teaching. The holy Doctor, then, has this (II-II, q. 89, art. 3, ad 3): "There is great danger in an oath, both on account of the greatness of God, whose testimony is invoked, and also on account of the fickleness of the human tongue, whose words are confirmed by the oath. And therefore such things (namely, truth, judgment, justice) are more required for an oath than for other human acts."

XII. Question IX. Can it be lawful — as the Scholastics call it — to swear that one saw a fellow student attend classes for the time required by the university for completing his course, if it suffices that they have commonly seen him frequent the schools? Response: Tamburini (Bk. III, ch. 2, §1, n. 8) relates this case from Hurtado, in Diana, Part V, tract. 8, resol. 10. A student, wishing to prove attendance, for which he needs two witnesses, can employ two friends who did not see him present at the lectures, but who are sufficiently persuaded that he was present; but they cannot swear that they saw it. Tamburini approves this decision, to which I in no way can accede. For this resolution is quite involved, and entangled. Why can they not swear that they saw him, but can absolutely swear that he frequented the schools? Because they are sufficiently persuaded that he was present at the lectures. Why so? No ground of that persuasion is adduced. Wherefore it seems to be implied that these two student friends did not at all see him, and yet can freely and absolutely swear that they saw him attend classes, or that the student himself testifies to it, or that they themselves, kindly and out of a certain inclination toward their student friend, have been persuaded that he really did frequent the schools. But no one fails to see that these foundations are by no means sufficient for making the oath that the student attended lectures — for, in order for the aforesaid friends to be able to swear this in good faith, it is necessary either that they themselves saw him, or that they have as witnesses persons worthy of credence who affirm this. What authors commonly teach afterward — that, for this oath to be given without fault, it is not necessary that the swearers should have seen the student go to school every single day — is true, since such knowledge cannot be had by due diligence. It will suffice, then, for them to know that the student commonly attended the lectures; for this is what universities require, and no more — although, so that the oath may be pronounced with due religion, the swearers ought to confirm by oath a common, not a daily, presence in the schools. Extremes are nonetheless to be avoided. When an oath is made according to the mind of the one questioning, truth, judgment, and justice accompanying it in good faith, one must beware of excessive anxiety, and superstition, lest, while you strive to avoid one extreme, you fall into the other.

XIII. Question X. Is it lawful to persuade someone to swear a truth of which he himself is ignorant? Response: It is certain among all that this is not lawful — since one who swears without certain knowledge sins mortally; therefore one who induces him to swear in this manner, without certain knowledge, similarly sins. For the clarity of this matter, this case is usually proposed. Peter, a merchant, to prove that Paul owes him a hundred gold pieces, which he really does owe, but which Paul otherwise denies owing, induces Anthony to swear the truth of this debt — namely, that Paul owes Peter a hundred gold pieces — although it is false that Anthony has this knowledge. Anthony swears. His oath, then, is certainly perjury. He is not, however, bound to restitution, since the debt of a hundred gold pieces is supposed to be true. And although Peter the merchant produces reasons which seem to him... seem true, you cannot for that reason swear in judgment that you know it; nor even outside judgment; but you can only swear that you have heard from Peter that this sum of money is owed him by Paul.

I. It has been explained above what truth, justice, and judgment are necessary for any oath whatsoever. In the present chapter, however, we chiefly undertake to discuss whether, just as the defect of truth in an assertory oath is always a mortal sin, so too the defect of justice and of judgment, in the same oath, constitutes a mortal sin. And, to resolve certain difficulties concerning this, we propose the following questions.

II. Question I. Is the defect of justice in an assertory oath a mortal sin? Response: Before I answer directly, I note that someone can swear an unjust matter in two ways. First, when someone relates a wicked matter as true, for a just cause — for instance, when, for a good end, he confirms by oath a sin committed by himself, or by another. In this manner, one would honestly, and justly, swear an unjust and wicked matter. Second, when someone manifests a wicked matter for a wicked end — for example, if someone were to reveal the hidden crime of a neighbor, whose reputation would be gravely injured by such a revelation. In this way, one would swear an unjust matter in an unjust manner, and would use the oath as an instrument for confirming a wicked manifestation. In the first case, he would confirm the truth of an iniquity committed, urgent just cause pressing; in the second, he would confirm the wicked manifestation of a crime, impelled by malice alone.

III. To the question, the theologians of Salamanca respond (tract. 17, ch. 2, punct. 2, §1, n. 34), teaching, from Suárez, Sánchez, Palao, Tamburini, and Leander, that the defect of justice in an assertory oath is not a mortal, but a venial sin — unless the oath is taken up as an instrument of iniquity, in which case the sin would be mortal. They adduce an example. You reveal the true, but hidden, crime of your neighbor, from which his reputation suffers grave harm. Then, so as to render your defamation more certain, you confirm it by oath. Then, surely, you sin mortally — not only with the sin of defamation, but also with a sin against justice, an accompanying oath. If, however, you disclose your own sin out of boastfulness and deliberate delight, and at the same time confirm by oath that you committed that sin, you indeed sin mortally with the sin of complacency, but you do not sin mortally against the justice necessary to an oath, but only venially. Thus the theologians of Salamanca distinguish, with the authors they cite.

The opinion of Sotus (Bk. VIII, on justice and law, art. 3, concl. 2), of the second matter, however, of Toledo (Bk. IV, ch. 22, n. 10 and 11), of Ledesma (Vol. II, Summa, tract. 11, ch. 3, dub. 4), of Aragón (II-II, q. 89, art. 10) seems more probable to me — namely, that the defect of justice in an assertory oath is a mortal sin, when the swearer's assertion is such that it constitutes a mortal sin; but if the assertion is only venial, the crime of the oath will likewise be venial. The reason seems manifest: because a most grave injury is done to God, when his authority is employed to confirm an assertion gravely wicked. And, to use the adversaries' own example, I do not see a disparate reason why they should say that one who confirms by oath a mortal complacency in his own sin does not sin mortally against the oath; while one who, by oath, makes another's infamy more certain, sins gravely against that same justice. Since, although, on the part of the sworn matter, it is a graver crime to defame one's neighbor than to delight in one's own iniquity already committed; nonetheless, on the part of the manner of swearing, as it is called, as often as God is brought forward as witness of a grave iniquity, a grave injury is done him.

Nor is the adversaries' response of any weight — namely, that, justice being lacking, the end of the oath still stands, which is the confirmation of truth; which standing, God is not called to witness of a lie, but of an iniquity. Since we too concede that the chief end of an oath is the confirmation of truth, or that truth is the foremost of the conditions necessary for a licit oath; and therefore we say that the defect of truth, even in the lightest matter, always induces a mortal sin; but the defect of the other two conditions, in a light matter, is only a venial sin. But from this it can in no way be inferred that the defect of justice, in a grave matter, is not a mortal sin. We conclude, then, that, whenever a swearer uses divine testimony for a bad end, or with a culpable and depraved mind, whether to strengthen a wicked manifestation, or of his own, or of another's mortal sin, he commits a double sin: one against the virtue to which the matter related is opposed; the other against the justice of the oath.

IV. Question II. Is the defect of judgment in an assertory oath a mortal sin? Response: We have spoken above of the judgment required for an assertory oath. This condition of judgment requires a reasonable cause for swearing: for whenever the reason, or cause, of swearing is lacking, the oath lacks judgment, as has been said. We have also produced, above, ch. 8, n. 4, six causes of this necessity from St. Thomas. Now we add that necessity, or the cause of this truth, or confirmation, is then present, when these two things concur. The first is that the truth cannot be proven by another way, except by the oath. The other is that it redounds either to the public, or the private, utility. The precise degree of this necessity cannot be prescribed, but it must be left to the judgment of a prudent man, when it really occurs, or is present. This is the general rule: that, without some moral utility, the necessity of swearing is never present.

V. So that we may answer the proposed question distinctly, however, a distinction must be admitted. If the matter which is to be sworn is manifestly true, and there is just, or licit, necessity of swearing, then, absolutely speaking, the defect of judgment in the inquiry of truth is only a venial fault. If, however, the defect of judgment is in this — that the oath is made without necessity — then a distinction must be made: if the negligence is light, the fault will be light; if the negligence is grave, it will be a mortal sin. The response is clear from what has been said above.

The QUESTION concerns the requirements of the Divine natural law for the lawful manner of swearing. The constant sentiment of the Theologians is that three things are required, as it were companions, from Jeremiah 4, Thou shalt swear: The Lord liveth in truth, and in Judgment, and in justice. So St. Jerome expounds it, and it is cited caus. 22. quaest. 2. et cap. ultimo 22. quaest. 4. St. Thomas has this 2. 2. quaest. 89. art. 3. St. Bonaventure in 3. dist. 39. quaest. 1. et in dub. lit. where he observes that an Oath is compared to three things, namely to the one swearing, from whom it proceeds: to the thing, or matter of the oath, about which one swears: and to the cause for which, or through which one swears. In the one who swears (he says) judgment is required, that is, discretion, and a certain prudence necessary for every one swearing. These three things are required, says Valencia. The first is, that what we affirm with an oath cannot be sufficiently proved without the oath; for then it would be an abuse of the oath; for the institution of swearing ought to be referred to contingent and hidden facts alone, which need the proof of Divine testimony, before whose eyes all things are naked and open. The second is, that some pious cause for swearing be present. The third is, that the one about to swear diligently foresee whether what he is about to swear be true or false. But the second condition seems to be reduced to justice by St. Bonaventure. Yet I do not think it so, as I shall say below.

IN order, however, to the thing about which one swears, truth is required, at least according to the reasonable judgment of the one swearing. Yet Truth is required differently in an Assertory oath and in a Promissory one; for in a Promissory oath a twofold truth is required; one consists in the concordance of the promissory word and the interior intention of doing in its own time what is promised: the other truth is the concord also of the effect, or of the thing promised, with the promise, and this is properly the truth of a promissory oath. But the truth in an Assertory oath is the union, that is, the concord of the assertion with the deliberate mind, as I said.

IN order to the cause, through which, or about which one swears, justice is necessary, namely that the act of swearing be just, that is, not against the laws, and be done for a just cause. And indeed in a Promissory oath justice is required not only in the act; namely that it not harm one's neighbor, but also in the matter of the oath; namely that it be a just work, reducible to some virtue, even if indifferent in itself, as I shall say quaest. 13. But in an Assertory oath justice is not required on the part of the matter; for the crime of one's neighbor is often lawfully uncovered by an oath; but justice is required in the act of swearing alone, namely that it harm no one. St. Bonaventure indicates this, when he says that justice is required, that it be done for a just cause, not on account of a just cause, which pertains to the judgment of discretion; and therefore he says prudently also that justice is required in the cause about which, that is, in the matter of the oath, insofar as it formally has the character of the cause of the oath in the Promissory; and in the act, insofar as it is productive of the oath in the Assertory.

From the lack, therefore, of any of these circumstances the oath is rendered unlawful; for if justice is lacking, the one swearing makes God, as far as in him lies, a cooperator of evil, and the Oath is called iniquitous, or unjust. If truth is lacking, God is made either ignorant or wicked; for it is necessary that he who is the witness of falsehood be one or the other, and then the oath is called false, or perjury properly speaking. Finally, if judgment is lacking, irreverence is inflicted upon God, since he is dragged forth in testimony without cause, and the oath is called heedless and rash. See St. Bonaventure, especially sermone 3. in Decalogum.

From these is resolved the first question of St. Bonaventure, namely whether in every perjury there is a lie.

For there can be perjury because it was rashly uttered; yet not a lie, since the one swearing thought from inconsideration that it was true. St. Bonaventure proves this in corpore, from St. Augustine serm. 23. de verbis Apostoli. Therefore from the defect of the judgment of discretion there arises a perjury which is not formally a lie.

FURTHERMORE the defect of an oath can come from injustice, as if someone should swear to commit murder, rape, or another crime with the intention of fulfilling it; it will not be a lie, and yet it will be perjury broadly; It will nevertheless be a lie, if he swears not with the intention of fulfilling the promise. So St. Bonaventure loco cit.; for that is properly perjury which properly opposes the end of the oath, which is to establish truth. Therefore, if only justice is lacking, it will be perjury in the broad mode, as Sanchez notes cap. 8. num. 5.

The REASON, therefore, of a lie stands in the defect of Truth, if the falsehood uttered by voice is intended; but if you intend to say what is true, and say what is false from inconsideration, there will be rashness, as I said; for a lie formally ought to be directly voluntary; nevertheless a falsehood uttered also from rashness is in some way a lie, at least broadly.

From these you have that, taking a lie broadly, in every perjury, as opposed to an assertory oath, there is a lie; but if a lie be taken properly and strictly, it is not found in every promissory oath; nor in every assertory one. See Valencia quaest. 14. puncto 1. Tanner disp. 5. quaest. 8. dub. 1. Fagundez in 2. Praec. lib. 2. cap. 51. Clarum lib. 5.

The Holy Doctor CONCLUDES, therefore, from the testimony of Jeremiah and Jerome cited, that there is properly a lie from the violation of the second condition alone, that is, of Truth, but not from the violation of Judgment, or of Justice;

Of Justice; yet from each of them singly it comes about that one sins against the law of the oath, which requires those three conditions. So also in the opusc. declaratorio terminorum Theol.

I ASSERT first, that if the thing promised is gravely evil and deadly, the oath will be mortal against religion from a defect of justice, against the second precept of the Decalogue, besides the mortal sin of the purpose of fornicating, killing, and the like. So teach D. Bonavent. in 3. dist. 39. quaest. 1. argumento secundo fundamenti, whom they commonly follow, as Sanchez cap. 4. num. 26. Valencia puncto 3. citato, Sanchez lib. 3. cap. 19. a num. 9.; for it is a grave injury to God to invoke Him as a witness to the perpetration of a crime against His law; for it is a great contempt of the Divine majesty, and perjury from a defect of justice, as S. Bonavent. says loco citato, and after him the rest.

It will be mortal, however, EVEN IF the intention of fulfilling is not present, because God is brought in as a witness to a falsehood; yet it will be a single sin: but when the mind of fulfilling is present, it will be twofold, namely, perjury from injustice, and the purpose of sinning. So Navar. summa, cap. 12. num. 13.

I ASSERT second, that one who swears to commit a venial fault, with the intention of fulfilling, sins mortally from a defect of justice, and thus it will be a twofold sin; so Suarez lib. 3. cap. 4. Sanchez num. 33. against Bassaeus 5. num. 3. and others there.

It is PROVED, because therefore one who swears to sin mortally sins deadly, because he makes, as far as in him lies, God a cooperator of that deadly thing; but to make God guilty even of a venial fault is a grave offense contending with the Deity: Therefore.

Sanchez num. 28. OBJECTS, because it is not a grave irreverence to God.

It is ANSWERED from our argument, that it is a grave offense to make God cooperate in a venial fault, for this implies a contradiction with the Deity; nor could God sin venially except by losing the Deity, which is said to be the perfection of infinite goodness. So Valencia judges it probable.

HENCE also, it will be mortal to fulfill, by reason of the oath, a thing venially culpable. The reason is the same, because God is asserted to hold the oath as ratified and just. So Hugo holds, as reported by Angelus V. Iuram. 5. who laughs with Soto lib. 8. de Iustitia, quaest. 1. articulo 7.

I ASSERT third. If anyone swears not to observe some counsel, e.g. to enter religion, it is probably only venial. So Sanchez cap. 4. num. 30. Valencia loco cit. and others. Although others say it is mortal, among whom is Sylvester loco cit. q. 7. whom I wonder asserted that to observe a sworn venial thing is only venial: and to commit a venial sin upon oath is only venial. So V. Iuram. 4. q. 1. For it is worse to swear a venial sin, and to observe it by oath, since these render God, as far as in them lies, a cooperator of evil.

I ASSERT fourth, that to swear an indifferent thing is venial, from a defect of justice, because it is not apt matter for an oath. So commonly, with Sanchez num. 31.

I ASSERT fifth, that a defect of justice exists also in an assertory oath, as if anyone uncovers, and confirms by oath, the sin of someone undeservedly, or boasts of himself concerning some mortal sin. So Sotus lib. 8. de Iustitia, quaest. 1. art. 3. Aragon. 2. 2. quaest. 89. art. 3. Peter Ledesma Tomo 1. summae, Tract. 11. cap. 2. dub. 4. Toletus lib. 4. summae, cap. 20. num. 10. and it seems so to D. Bonavent. in 3. dist. 39. dub. 1. where: He gravely requires justice in every oath, that it be done for a just cause, which D. Thom. also confesses 2. 2. quaest. 89. art. 3. ad 2. and there Cajetan, Valencia puncto 3. col. 5. Suarez lib. 1. de Iurament. cap. 3. num. 6. and lib. 3. cap. 2. num. 5. and cap. 12. num. 7. Sanchez loco citato, num. 33. Yet these two last hold that a defect of justice in an assertory oath is only venial, because it is not opposed to the end of the oath, nor does it make God the witness of a lie, but of a wicked thing, which of itself is not a grave injury. Likewise, because it is accidental to the testification of truth, in which the reason of the oath is situated, to narrate the truth with sinning or without sinning. Therefore they conclude that an oath is mortal only then, when it is assumed as an instrument of that sin, for instance, that the infamy of one's neighbor become more probable, asserted by that assertory oath; because it is a grave injury done to God.

But who does not see that all these things are confirmed by oath, that they may be rendered more certain? For why would anyone swear that he perpetrated that deed, for instance with that woman, that he committed that crime, unless to persuade it? Therefore, since this is the ordinary end of such swearing, they are to be condemned.

But let us grant that it is sworn only so that those crimes are asserted simply by oath, since God is invoked as a witness of a gravely evil thing, will it not be a grave injury to God? For if to bring God in as a witness to a thing to be done against His law is mortal, as Sanchez confesses num. 26. why will it not be mortal to bring God in as a witness to a mortal thing already perpetrated, since a grave offense to God intervenes here also? Nor does Sanchez answer sufficiently, that that oath is accidental to the deed; for against him is, first, that in the promissory oath also it is accidental, for one can swear without the intention of not doing, and yet whether the mind of fulfilling be present or not, the oath will be mortal, as Sanchez teaches num. 34.

Moreover, the assertory oath falls upon a past crime just as the promissory upon the future.

I assert first, that an oath lacking judgment as to the necessary cause of swearing, and reverence, is judged venial. So Valencia 2. 2. disp. 6. quaestio 7. puncto 3. Suarez lib. 3. cap. 12. Sayrus eodem cap. n. 32. Lessius lib. 2. de Iust. cap. 42. dub. 3. num. 17. D. Antonin. 2. part. tit. 10. cap. 7. §. 1. Angel. V. iuram. 3. num. 7. Sylvester 2. quaest. 8. eodem titulo, Navar. sum. cap. 12. Sanchez cap. 4. num. 35. after D. Bonavent. art. 1. q. 3. For it does not seem a grave injury.

I assert second, that if the judgment of due inquiry, gravely omitted, is lacking, it is mortal: So S. Bonavent. loco cit. Sanchez, and Valencia, and the rest, in the places adduced.

It is proved by Valencia loco cit. and Sanchez num. 14. from D. Bonavent. dist. 39. quaest. 1. ad argumenta, and quaest. 3. ad ultimum, because he exposes himself to the danger of bringing God in as a witness to falsehood.

Sanchez notes, however, num. 36. that these are not perjuries in a confession necessarily to be distinguished — whether he lied, or swore in doubt, or intending not to fulfill; for it is enough to say: I swore falsely so many times.

He notes also num. 38. that it is worse to swear what is true by false gods, than mendaciously by the true God, because the former pertains to Idolatry and blasphemy, which is worse than perjury, as D. Thom. testifies prima secundae, quaest. 13. art. 3. ad 2. So holds Sotus lib. 8. de Iust. quaest. 2. art. 3. concl. 1. Covarr. de pactis, p. p. §. 1. num. 10. Suarez cap. 3. num. 6. Sayrus lib. 5. cap. 3. num. 18. Azor tract. 1. lib. 11. c. 12. quaestio 12. Whence D. Augustine epist. 154. and it is reported cap. movet, 22. quaest. 1. signifying the opposite is meant, as Azor well explains loco citat. quaestio 12. when a Christian swears by false gods, while he judges them false with the sole intention of deceiving; for he, if he does not keep faith, indeed deceives, but is not a perjurer: but one who swears falsely is a perjurer, and thus sins gravely. Or as Sotus says, dic, it is graver in the reason of perjury; for to swear falsely by the true God is properly perjury, for a falsehood is said; but by false gods, it is secundum quid, while truth is said, as D. Thom. testifies 1. 2. quaest. 98. art. 1. ad 2. Sanchez has this from D. Bonavent. in 3. dist. 39. dub. list. num. 6. and lib 3. Phar. cap. 3. at the end, where he reports the testimony of D. August. epist. 154. ad Public. Tom. 2. and gives the reason.