D. 39 - Perjury and oaths

Division of the text

Having considered lying, here the Master considers perjury.

And it is divided into two parts:

in the first he considers perjury;

in the second he considers oaths, at but if it is asked whether it is evil to swear, we say that it is sometimes evil, sometimes not. (Sent. III, 39.4(153).1.)

As regards the first he does two things:

first, he defines perjury;

second, he brings forward a certain question about that definition, at here it is asked whether there can be perjury where there is no lie. (Sent. III, 39.2(151).1.)

As regards the latter, he does three things.

First, he states the opinion on behalf of one side of the question;

Second, he states the opinion on behalf of the other side, at it pleases some to hold that there is no perjury where there is no lie; (Sent. III, 39.2(151).2.)

third, he determines the truth, at but the better view. (Sent. III, 39.3(152).1.)

As regards the last, he does two things:

first, he determines the truth;

second, he proposes two questions about that determination.

The first of these is at but when one swears what is true, believing it to be false, the question arises of where the perjury is in that case; (Sent. III, 39.3(152).3.)

the second is at here an objection is made. (Sent. III, 39.3(152).4.)

But if it is asked whether it is evil to swear, we say that it is sometimes evil, sometimes not. (Sent. III, 39.4(153).1.) Here he considers taking an oath:

first, he considers it on the side of the one swearing the oath;

second, on the side of the one requiring the oath, at it is also asked whether he sins, who compels another to swear. (Sent. III, 39.12(161).1.)

As regards the first he does three things.

First, he asks whether it is licit to swear;

second, he considers the form of the oath, at it is also asked whether it is lawful to swear by creatures; (Sent. III, 39.5(154).1.)

third, he considers its obligation, at it remains now to see whether every oath is to be fulfilled. (Sent. III, 39.9(158).1.)

As regards the second, he does two things.

First he considers the appropriate form of an oath;

second, he asks whether it is licit to make an oath that has an inappropriate form, at after these matters, it is asked whether one ought to rely on the promise of one who has sworn by demons or idols. (Sent. III, 39.8(157).1.)

As regards the first, he does two things:

first, he touches on the form of an oath that occurs in giving testimony;

second, that which occurs in making a curse, at there is also 'a very grave kind of oath, which is done in the form of a curse.' (Sent. III, 39.7(156).3, quoting Augustine, Enarrationes in Psalmos, Ps 6, para. 3 (CCSL 38; PL 36:99).)

As regards the first, he does two things:

first, he lays out the form of an oath;

second, he explains it, at here it is asked what it means to say: 'I swear by God.' (Sent. III, 39.7(156).1.)

As regards the first, he does two things:

first, he lays out the form of an oath with respect to diverse things;

second, he compares oaths in reference to diverse deeds, at if it is asked who is more bound, whether one who swears by God, or one who does so by the Gospel or by creatures, we say: the one who swears by God. (Sent. III, 39.6(155).1.)

It remains now to see whether every oath is to be fulfilled. (Sent. III, 39.9(158).1.) Here he considers the obligation of an oath, and regarding this he does three things.

First, he shows in what case an oath binds one;

second, whether one is guilty of perjury from [violating] a non-binding oath, at but it is usual to ask whether one who changes is to be called a perjurer; (Sent. III, 39.10(159).1.)

and the third is about the artfulness of the words with which one swears, at it is also to be known that. (Sent. III, 39.11(160).1.)

It is also asked whether he sins, who compels another to swear. (Sent. III, 39.12(161).1.) Here he does two things:

first, he asks whether it is licit to require an oath;

second, at what time they should convene for taking oaths, at the holy synod proclaimed that . . . (Sent. III, 39.12(161).2, quoting Ivo of Chartres, Decretum, bk. 12, ch. 33, 69, 70; Panormia, bk. 8, ch. 120 (PL 161:768, 797, 1334).)

Question 1

Perjury and oaths

Here five things are asked:

first, what is an oath;

second, whether swearing an oath is licit;

third, the obligation of an oath;

fourth, what perjury is;

fifth, whether every perjury—that is, abuse of an oath—is a mortal sin.

Article 1

Whether to swear an oath is the same as to invoke God as a witness

To the first we proceed thus. (Parallel: ST II-II.89.1.) It appears that swearing an oath is not the same as invoking God as a witness.

Obj. 1: For sometimes, as is said in the text, (Sent. III, 39.7(156).3.) it is licit to swear by created things. But in such a case it appears that divine testimony is not being invoked, but rather the testimony of a created thing. Therefore to swear an oath is not to invoke God as a witness.

Obj. 2: Further, the Apostle says in Hebrews 6:13 that men swear an oath through one greater than themselves; nor is this understood to be only as regards God, but even as regards men who are above us. For Joseph swore an oath by the salvation of Pharaoh. (See Gen 42:15.) Therefore swearing an oath is not the same as invoking God as a witness.

Obj. 3: Furthermore, it is not the same thing to be a judge and to be a witness. But in an oath made with a curse, God appears to be invoked as judge, as when we say, “if I have done this, then so may it happen to me”; Job uses this manner of speaking in Job 31. Therefore not every swearing of an oath occurs by the invocation of divine witness.

Obj. 4: Furthermore, receiving testimony from God and receiving it from man are only materially different. But one who invokes a man as a witness is not said to swear by the man. Therefore also he who invokes God as a witness is not said to swear by God.

Obj. 5: Furthermore, the text says, in Augustine’s words, that to swear is to render to God his right. (Sent. III, 39.7(156).1, quoting Augustine, Sermones ad populum, serm. 180: De verbis Apostolorum, ch. 6, n. 7 (CCSL 41B:669; PL 38:975).) But whoever speaks the truth, even if he invokes no witness, renders to God the right of truth. Therefore the invocation of divine testimony is not required for an oath.

On the contrary, Augustine says: what does 'God is my witness' mean, if not I swear by God? (Sent. III, 39.7(156).1, quoting Augustine, Sermones ad populum, serm. 180: De verbis Apostolorum, ch. 6, n. 7 (CCSL 41B:669; PL 38:975).) But this is the most common form of swearing an oath. Therefore an oath is an invocation of divine testimony.

Further, everything that is taken up to confirm something in some way gives testimony to it. But in an oath the divine truth is brought in to confirm our words. Therefore to swear an oath is to invoke God as a witness.

Furthermore, controversies are not usually brought to a conclusion unless by means of witnesses. But an oath ends every controversy, as the Apostle says in Hebrews 6:13. Therefore it appears that an oath is an invocation of divine testimony.

I answer that an oath properly speaking is made to confirm things that are doubtful for the listener, but about which the speaker either has certitude or says he has certitude, and about such dubious things that are doubtful from their nature, like contingent deeds, which cannot be confirmed through reason. For it seems ridiculous to offer an oath in other things.

Therefore certitude about these dubious things can arise only from someone whose knowledge is not deficient, and whose truthfulness is infallible. Now, this is found only in God. And therefore only his testimony is efficacious for confirming this sort of thing. But his testimony is either taken up to confirm what has already been presented—and this is not to swear an oath, but more to offer a proof by authority—or it is invoked for the sake of what is to be presented—and this is swearing an oath, properly speaking.

And therefore some swearing of an oath occurs when the divine testimony is invoked simply speaking, as when one says, “with God as my witness.” But some swearing of an oath occurs when his witness is invoked with reverence, which testimony makes one credible, whether one swears on God himself—as when one says, “by God,” or “as the Lord lives”—or on one of his chief effects, as when one swears “by heaven,” or “by the Gospel,” or “by the saints.” But sometimes the very manner of his witness is specified, as when one says, “if it is not so, may such and such happen to me.”

Reply Obj. 1: When someone swears by a created thing, he is also invoking the same God. But this can happen in two ways: in one way, through some created thing wherein the divine magnificence is manifested, which latter is brought in as a witness; in another way, an effect of the divine testimony is said to be sought in that created thing, as when one says, “by my head,” or “by my salvation.”

Reply Obj. 2: Joseph swearing by the salvation of Pharaoh could have been an oath in either of the stated ways, or as though pledging the salvation of Pharaoh to God, to whom he was bound, or as venerating the divine magnificence in Pharaoh’s power, and bringing that in as a witness.

Reply Obj. 3: By this very fact that God is being made the judge, God who takes vengeance on a lie, one testifies to the truth or falsity of the speaker.

Reply Obj. 4: Just as the veneration given to the highest majesty has a special mode and name beyond other venerations shown to whomever else, for it is called “latria,” so too the invocation of an infallible witness to a truth has a special notion and name for giving testimony, beyond that of other witnesses. And therefore, to invoke a man as witness is not to swear an oath the way that invoking God as a witness is, just as likewise to serve a man is not to offer him latria, as in serving God. Yet it is licit to swear an oath by a created thing, but not to offer the created thing latria; for the divine testimony consists in manifestation, and divine things are manifested to us through created things. But latria is shown him insofar as he is highest in his very self, and therefore it is not shown him in any created thing.

Reply Obj. 5: Someone is properly said to render God the right of the truth he has spoken when he traces his statement back to him as to the first origin of every truth; and this does not occur in a simple assertion. Therefore one should say that an oath given through a created thing is in a certain way licit, and in a certain way illicit. For if someone swears an oath by a created thing as though it were the first origin of truth, the oath is illicit, and pertains to idolatry. But if someone swears an oath by a created thing as that in which the first truth shines forth, then the oath is licit.

Article 2

Whether swearing an oath is among things that are desirable in themselves

Quaestiuncula 1

To the second we proceed as follows. (Parallels: ST II-II.89.5; Super Matth. 5.) It seems that swearing an oath is among the things that should be desired in themselves.

Obj. 1: For as it says in the text, to swear is to render God his right. (Sent. III, 39.7(156).1, quoting Augustine, Sermones ad populum, serm. 180: De verbis Apostolorum, ch. 6 (CCSL 41B:669; PL 38:975).) But this is a most honorable thing, and should be desired. Therefore so is an oath.

Obj. 2: Furthermore, the text says, based on Augustine’s words, (Sent. III, 39.5(154).1-2, quoting in fact Jerome, Commentarii in euangelium Matthaei, bk. 1, v. 34 (CCSL 77; PL 29:546).) that whoever swears by something venerates it. But one should desire to show veneration to God, and should do so often. Therefore an oath is like this.

Obj. 3: Furthermore, every act wherein we are conformed to God is good in itself. But to swear an oath is like this, for Psalm 110:4 says, the Lord has sworn and will not change his mind. Therefore swearing an oath is good in itself.

On the contrary, the desire for, or delight in something good in itself is not forbidden. But, as Augustine says, (Augustine, Expositio epistulae ad Galatas, on 1:20, para. 9 (CSEL 84:63; PL 35:2110); De Mendacio, ch. 15, n. 28 (CSEL 41:448; PL 40:507); see Sent. III, 39.4(153).3.) we are forbidden to swear an oath out of desire of, or delight in oath-swearing. Therefore to swear an oath is not good in itself.

Furthermore, frequent attention to anything good in itself is advantageous. But frequently swearing oaths is forbidden in Sirach 23:9: do not accustom your mouth to oaths. Therefore to swear an oath is not a good thing.

Quaestiuncula 2

Obj. 1: Moreover, it appears that it is also not licit. (Parallels: ST II-II.89.2; De decem praeceptis, a. 2; Super Matth. 5; Super Rom. 1, lect. 5; Super Heb. 6, lect. 4.) For everything forbidden is illicit. But swearing an oath is forbidden in Matthew 5:34: but I say to you, Do not swear at all; and in James 5:12, but above all, my brethren, do not swear. Therefore swearing an oath is illicit.

Obj. 2: Furthermore, willing something is forbidden only if it is the willing of a sin. But wanting to swear an oath is forbidden when it is said, “do not wish to swear an oath,” as the saints and masters say. Therefore swearing an oath is illicit.

Obj. 3: Furthermore, in drawing lots, and trials by fire and water, or by a duel, the divine witness is looked for. And on account of this, these things are forbidden, since in them it seems like God is being put to the test. But an oath is an invocation of the divine witness, as was said. Therefore swearing an oath is illicit.

On the contrary, the Apostle swore an oath in many passages, as is clear in Romans 1:9: for God is my witness, and so on.

Furthermore, no act that falls on its appropriate matter is illicit, as long as there arise no corrupting circumstance. But to swear an oath by God is an act that falls on its proper matter. Therefore, since no corrupting circumstance is indicated in this, it appears to be licit.

Quaestiuncula 3

Obj. 1: Moreover, it appears that the three “attendants” listed in the text (Sent. III, 39.2(151).1, quoting Jerome, In Hieremiam prophetam libri VI, bk. 1, on 4:2 (CCSL 74:51; PL 24:706).)—that is, truth, justice, and judgment—are not required for an oath to be licit. (Parallels: ST II-II.89.3; 98.1.ad 1; De decem praeceptis, a. 2; Super Matth. 5.) For where there is no truth, there is no justice, since the truth is a part of justice. But a part should not be divided against its whole. Therefore truth should not be counted alongside justice.

Obj. 2: Furthermore, a judgment appears to be nothing other than an execution of justice. Thus, it is superfluous to add judgment when justice is already included.

Obj. 3: Furthermore, swearing that occurs without these attendants is perjury, as is said in the text. (Sent. III, 39.2(151).1.) Therefore if judgment is an attendant of swearing an oath, it will never be licit to swear an oath outside of a judgment—which is false.

Obj. 4: Furthermore, many other things are required for swearing an oath besides these three—such as the appropriate form of swearing, the appropriately established time, namely, that one coming to swear an oath should fast, and many other such things. Therefore it appears that not only these three are the attendants of swearing an oath.

Obj. 5: Furthermore, these three things are required in all our deeds. Therefore they should not be asserted to be the attendants of swearing an oath any more than the attendants of our other actions.

Response to Quaestiuncula 1

I answer that, just as in a confirmation made through arguments there are two elements—namely, the middle [term] that causes the proof, and that which is proved—so too in a confirmation made by oath there is the human statement as the thing to be proved, and the divine witness as the proving middle. Now, in the syllogistic art the middle should be taken from the same genus [as the conclusion], so in necessary matters necessary things are taken as middles, and in contingent matters, contingent middles.

However, the least firmness belongs to the truth of human speech, both because error easily befalls reason, and because a language is prone to defect. And therefore on certain occasions it is fitting, if there is a pressing need, to take up the divine truth, which is altogether infallible, to confirm our statements. And therefore swearing an oath should not be counted among things that should be desired through themselves, but rather as among things that occur on account of a necessity, the way useful goods, like cutting a wound, or such, are desired.

Reply Obj. 1: Supposing that one should swear the oath, it is just that it be sworn by God, since in him is recognized the original power of every true word. Yet it is not necessary that swearing an oath, simply speaking, is just and good through itself.

Reply Obj. 2: The divine veneration consists in the very oath as the assumed middle, but the its application to the matter, wherein defect easily occurs, is not altogether fitting.

Reply Obj. 3: In a divine oath the middle is taken from the same genus, since just as God is unchangeable, so too there can be no falsity in his own statement. And on account of this, his oath is through itself a good thing. Nor is this like our oaths.

Response to Quaestiuncula 2

To the second question, it should be said that something can be unbecoming in two ways: either through itself, or from what follows from it. Now, what is unbecoming from itself in no way can be licit, however pressing the need; this is clear in debauchery and in other things that are evil by their genus. However, what is unbecoming on account of a danger that follows it requires two things for it to occur in a fitting way: the one is sufficient caution for avoiding that danger, and the other is a useful consequence. This is clear in the cutting of a wound, for if heath is produced by it, and such caution is applied such that other members are not harmed, then it occurs fittingly.

Now, an oath appears to have a certain unfittingness, as was said, on account of our human words’ ability to fail—to which the unchangeable truth is being applied. However, if human words were so defective that they would always fail, then every oath would be unbecoming of itself, and by no necessity would it be licit to swear an oath. But because human words do not always fail, but sometimes the bear the truth, therefore if diligent caution is applied so that the defect might be avoided, it is licit to swear an oath on account of some pressing necessity.

Reply Obj. 1: Swearing an oath is not wholly forbidden, either by Christ or by his Apostle. Rather, an easiness about swearing an oath is forbidden, on account of its danger—that is, so that someone would not swear for just any reason whatsoever, nor would he enjoy oaths as things good in themselves.

Reply Obj. 2: Absolute willing is for things good in themselves, but willing something good only on account of some imminent necessity is not absolute willing, but conditional willing. Therefore both wills for things that are evil in themselves are forbidden, neither will is forbidden for things that are good in themselves; but when willing things that are good because of some necessity, the first will is forbidden but the second is not. And in this way the will for swearing an oath is forbidden.

Reply Obj. 3: In these deeds, where we look for a divine judgment and witness, a man attaches to God, as it were, the terminus and mode of rendering witness, and this is why it is a testing of God. But in swearing an oath it does not occur so, and therefore it is not alike.

Response to Quaestiuncula 3

To the third question, it should be said that three elements are required for an oath to be sworn rightly. One is on the side of the very thing about which one is swearing; and in this way truthfulness, whereby the statement is adequate to the truth, is required—or else the statement would not be worthy of confirmation. Another is required on the side of the cause for the sake of which one is swearing; and in this way justice is required—or else the appropriate necessity would not be present. And the third thing is required on the side of the one swearing it; and in this way it is required that the oath be sworn with discernment—or else the appropriate caution would not be used; and this is the judgment.

Reply Obj. 1: “Truth” here is not being taken as the part of justice, but as speech’s adequateness to reality.

Reply Obj. 2: “Judgment” here is not being taken as of one person in his relation to someone else, which is the execution of justice, but as of one in his relation to his very self, in that he discerns what he should do, and what can occur.

Reply Obj. 3: And through this, the solution to the third objection is clear.

Reply Obj. 4: A judgment, which is the discernment of the one swearing the oath, includes the appropriate form, outcome, time, and all things that come up for consideration on the part of the one swearing it.

Reply Obj. 5: On account of the danger that hangs over swearing an oath, these attendants are brought to bear especially to an oath, before our other acts.

Article 3

Whether an incautious oath is binding

Quaestiuncula 1

To the third we proceed thus. (Parallels: ST II-II.89.7; Quodl. III, q. 5, a. 2 and 4; V, q. 13, a. 2; XII, q. 14, a. 2.) It appears that an incautious oath is binding.

Obj. 1: For an oath is called “incautious” if it tends toward an evil outcome, or something less good. But such was the oath that Joshua made to the Gibeonites, (See Joshua 9.) which was against God’s command wherein he commanded they make no covenant with the nations; and yet he kept that oath, considering himself bound. Therefore an incautious oath is binding.

Obj. 2: Furthermore, may it never be that someone swear an oath never to enter religious life; such oath is considered to be incautious. And yet it appears that it is binding, since one is able not to enter religious life without there being a sin, and if he did enter it, he would incur perjury. Now, everyone is bound to giving up that good that cannot occur without one sinning. Therefore an incautious oath appears binding.

Obj. 3: Furthermore, if someone were to swear an oath that he never accept being put over others, this oath is likewise thought to be incautious, in that it might impede the common benefit. And yet, it appears that one is bound to keeping this, since even if he had not sworn it, it is praiseworthy for someone to flee such elevation. Therefore an incautious oath is binding.

On the contrary, as Bernard says, (Bernard, Liber de praecepto et dispensatione, vol. 3, para. 5, p. 257 (PL 182:863).) what was instituted for charity does not militate against charity. But swearing an oath has been instituted for charity. Therefore, since by an incautious oath charity is assaulted—since it concerns doing some evil or omitting some good—it appears that such an oath is not binding.

Furthermore, nothing attains it proper power except when it has been perfected, as is said in the Physics 7. (Aristotle, Physics 7.3, 246b28; Aquinas, In Physic., bk. 7, lect. 6, n. 2.) But the power of an oath is in its binding. Therefore, since an oath is perfected by the three attendants, it appears that an oath that occurs without the three attendants is not binding. But in every incautious oath either justice is lacking, if what is sworn is illicit, or judgment is, if some good is impeded by it. Therefore an incautious oath is not binding.

Quaestiuncula 2

Obj. 1: Moreover, it appears that a coerced oath is not binding. For no one can be bound to some specific thing if he does not bind himself. But one is said to do only what he does willingly. Therefore, since a coerced oath excludes the will of the one swearing it, it appears that such an oath is not binding.

Obj. 2: Furthermore, the bond of marriage is greater than that of an oath, since if someone swore an oath that he would never marry, and later became married, he is held to preserving his marriage. But the coercion of a contract impedes marriage. Therefore it also impedes the binding of an oath.

Obj. 3: Furthermore, an oath binds only in the necessity of avoiding sin. But coercion excludes the guilt of sin; this is why Lucy said, if you try to violate me, against my will, my chastity will be doubled in my crown. (source) Therefore also it takes away the binding of an oath.

On the contrary, there is the authority of Augustine, (Recorded in Gratianus, Decretem, causa 22, q. 4, canon 22 (PL 187:1147).) who, based on the advice of blessed Ambrose, answers someone coerced to swearing to take someone as a wife, that the marriage is binding. Therefore it appears that a coerced oath is binding.

Furthermore, an oath that is not lacking any of its attendants is binding. But coercion does not take away any of the attendants of an oath. Therefore it does not take away the binding of the oath.

Quaestiuncula 3

Obj. 1: Moreover, it appears that an oath does not bind according to the intention of the receiver. For no one ought to be bound to something unknown. But the intention of the one receiving the oath is unknown to me. Therefore my oath does not bind me according to his intention.

Obj. 2: Furthermore, an oath is shown to confirm the speech of the one swearing it. But the swearer’s intention is closer to his own speech than is someone else’s intention. Therefore it binds more according to the intention of the swearer than that of the receiver.

Obj. 3: Furthermore, the swearer’s will, which binds him, is required for the binding of the oath. But if the intention of binding himself according to the recipient’s intention is absent, the will of binding is not present here. Therefore an oath will not be binding according to the intention of the recipient.

On the contrary, an oath is established so that, by it, the recipient can trust the statements of the one who is swearing it. But this could be only if the oath should be received according to his own understanding. Therefore an oath binds according to the intention of the recipient.

Furthermore, one should not defend anyone’s fraud and deception. But this would occur if someone deceptively swearing an oath were to bind himself only according to his own intention. Therefore one is bound according to the intention of the recipient.

Response to Quaestiuncula 1

I answer that an oath is of two sorts: one assertive, and the other promissory. A promissory oath is about what is expected the one swearing the oath will do in the future, whether by himself or through another. An assertive oath is one is made to confirm a truth, whether present or past, if we too were not present for it. Therefore in an assertive oath there is only one binding, that by which someone is bound to sin if truthfulness is absent from his oath. However, in a promissory oath there are two bindings: one by which someone is bound to doing what he promised to do by the oath, and another by which he is bound to sin if he does not do it.

Therefore, seeing these things, note that, just as not every assertion is worthy of being confirmed by an oath, so too neither is every promise, but only one that contains some benefit. Whence, if a promise confirmed by oath is about something that impedes one’s salvation, whether it be contrary to one’s salvation or to the perfect path to salvation, from this very fact the oath becomes improper, as an act falling on an improper matter. This is why it binds with the second binding, which is to sin, nor does there remain in it a power of binding with the first binding, toward doing it. For the first binding is to avoid the second binding, so an oath that necessarily binds one to sin, by that very fact is emptied from the other binding.

Reply Obj. 1: Joshua’s oath was not about something that would be illicit in itself, but about something done that was illicit because it was forbidden. Whence in this it was enough to uphold the intention of the one forbidding it. And therefore, as Ambrose says in On Duties, (Ambrose, De officiis, bk. 3, ch. 10, para. 69 (CCSL 15:179; PL 16:165).) he punished them with something better than death, namely, with the subjection to the divine ministry, so that there would be a more merciful sentence; and thereby they were in a way killed by their servility, which is a meaning of “death” according to laws.

Reply Obj. 2: By the very fact that someone binds himself to not enter religious life, he commits perjury. For although it is licit not to enter religious life, still it is not licit to place a barrier before the Holy Spirit. And therefore, to guard against the crime of perjury, which he cannot avoid then, one must not lay aside entrance to the religious life.

Reply Obj. 3: Although sometimes fleeing being put over others can come from a good [will], nonetheless to resist it stubbornly is always evil. This is clear in Gregory’s Gloss on Jeremiah 1, (Gregory the Great, Regulae pastoralis, bk. 1, pt. 1, ch. 7 (PL 77:20).) who proves this by the example of Jeremiah and Moses, who—although they first refused the office of being placed over others—in the end humbly obeyed. Whence an oath of this sort is thought to be incautious, since in and of itself it is prejudicial to divine providence, and it excludes obedience to one’s superiors, to whom one is bound to obey in this matter.

Response to Quaestiuncula 2

To the second question, it should be said that the coercion in an assertive oath cannot be sufficient [to force one to swear it], since nothing can sufficiently coerce a man to sin mortally—which latter happens if one asserts something false with an oath. Whence such an oath, to whatever degree coerced, does bind one to sin.

However, in a promissory oath, note that the coercion can be sufficiently coercive as regards what was promised. For to avoid a greater danger someone can promise something that is a loss to himself, which can occur without sin. And then such coercion, if what can occur in a resolute man is sufficient, takes away the binding of the oath in the forum of contention, since the action due to the binding of that oath does not belong to him who exerted the power [of coercing the oath]. But in the forum of conscience it is binding, since a man ought to subject himself more to a temporal loss than to breaking faith. Nevertheless, this [kind of oath] holds a remedy for demanding repayment from another in a court judgment; if the latter swears that he will not pay, the former can denounce him to the judge, who from his office ought force a seizure for the sake of restitution. However, if he swore he would not denounce him, he has sworn against fraternal correction, and is not bound to uphold this.

Reply Obj. 1: In this case, coercion cannot cause violence absolutely, but only a mixed violence, since it is still necessary that the one who swears the oath move his members to speak, and do so by his own will. Now, such violence, as the Philosopher says in the Ethics 3, (Aristotle, Nicomachean Ethics 3.1, 1110a9‒18.) although it is simply speaking involuntary, still is voluntary in the here and now; for he wishes to be subject to a lesser loss to avoid a greater evil.

Reply Obj. 2: Coercion removes the bond of marriage because the latter requires not only consent, but even free consent. But this does not occur in the binding of an oath.

Reply Obj. 3: Lucy is speaking of violence simply speaking, wherein the one suffering it contributes nothing to the one doing it. However, such violence cannot be present in this case.

Response to Quaestiuncula 3

To the third question, it should be said that a promissory oath, as was said, binds one with the necessity of avoiding fault. Whence it binds one to doing everything wherein no fault is incurred when it is done. Therefore one should make a distinction about the one who swears the oath, for he swears it either simply speaking or deceptively. If he swears the oath deceptively, a fault can follow from two sides: that is, from the breaking of the oath, and from the deception. Therefore, although from the very notion of an oath, as an oath, it does not bind one to keep it unless according to one’s own intention, still from the need of the oath, insofar as it was deceptive, one is bound to keeping it in such a way that another is not harmed by the deception. And this happens when he fulfills the oath according to the intention of the one who receives it.

However, if he swears the oath simply speaking, without any deception, then he is bound by it in the forum of conscience only according to his own intention. But in the forum of contention, where that intention is not known, he is bound according to how the words are customarily taken.

Reply Obj. 1–3: And through this, the replies to the objections are clear.

Article 4

Whether perjury is a lie confirmed by an oath

To the fourth we proceed thus. (Parallel text: ST II-II.98.1.) It appears that perjury is not a lie confirmed by an oath.

Obj. 1: For every lie is a false signification of speech, as was said in the previous distinction. But perjury can occur without any false signification of speech, since, as is said in the text, (Sent. III, 39.3(152).3.) he who swears to something true that he thinks is false commits perjury. Therefore not every perjury is a lie confirmed by an oath.

Obj. 2: Furthermore, perjury sometimes occurs in oaths that are about future contingencies. But there is no determinate truth or falsity in future contingencies, as the Philosopher shows. (Aristotle, On Interpretation 9, 17a25; Aquinas, Expositio Peryermeneias, lect. 9, n. 3.) Thus perjury can occur without any false signification of speech, and without a lie.

Obj. 3: Furthermore, it is said in the text (Sent. III, 39.3(152).1.) that one who swears to something false that he believes is true commits perjury. But such a one is not lying. Therefore perjury can occur without lying.

Obj. 4: Furthermore, Jerome says (Jerome, In Hieremiam prophetam libri VI, bk. 1, on 4:2 (CCSL 74:51; PL 24:706).) that an oath that does not have the three attendants is perjury. But the lack of justice or judgment does not make it a lie, but only a lack of truthfulness. Therefore not every perjury is a lie.

Obj. 5: Furthermore, it appears that perjury is nothing other than swearing a perverse oath. But an oath is perverted not only by a lie, but even by the false form of its swearing, as with one who swears by his idols. Therefore perjury can occur without a lie.

On the contrary, there is the definition of perjury in the text. (Sent. III, 39.1(150).1.)

Furthermore, an oath is the confirmation of one’s truthfulness. But a lie is opposed to truthfulness. Therefore perjury, which is a perversion of one’s oath, is a lie.

Furthermore, to swear an oath is to render to God the right of truthfulness. But whoever swears an oath without lying renders to God the right of truthfulness. Therefore the oath is without a lie, and is not perjury.

I answer that everything is denominated from its completion, and a name that is drawn from a thing’s deficiency denominates properly speaking the deficiency that happens in reference to that thing’s completion. Now, an oath is completed in confirmation of one’s truthfulness, just as a syllogism is completed in the confirmation of its conclusion. Whence, when the conclusion does not follow from the premises, it is said to be “unsyllogistic,” but not when any of the premises is false, as long as the proper form is present. So too “perjury,” which names the deficiency of an oath, signifies the defect that happens in something that should be confirmed by the oath. Now, a deficiency contrary to the confirmation of one’s truthfulness is a lie. And therefore “perjury,” properly speaking, names the defect of a lie in the oath.

Reply Obj. 1: Although the assertion of one who speaks the truth while thinking it is false is not a lie absolutely speaking, it is nonetheless a lie in relation to the one speaking; this is also why he is said to be lying. Whence in a certain way there is also a lie in this perjury.

Reply Obj. 2: The future can have a determinate truth only in its cause, which is determined to that effect. Now, the cause of contingent things done by us is our will, which is indeed determined to its effect through a fixed intention of doing something. And he who swears that he is going to do something signifies that he has such intent. Whence from the very fact that he swears to what he has no fixed intent to do, a lie occurs and he commits perjury.

Reply Obj. 3: An oath should be sworn only about that concerning which someone has certainty. Whence whoever swears something signifies that he is certain about it. Now, there can be no certainty about what is false. Whence he who swears something false that he thinks is true, from the very mode of assertion in a way tells a lie, even though the very thing asserted in itself is not a lie.

Reply Obj. 4: A promissory oath wherein justice and judgment are lacking contains, in a way, a lie as regards what ought to be present. For everyone is obligated to abstain from what is illicit, and not to go against good things and perfections. Whence from the fact that one swears to [doing] something illicit, he remains in a certain way bound to lying.

Reply Obj. 5: Not every perversion of an oath makes it perjury, but only that which occurs in its completion, as was said.

Article 5

Whether every perjury is a mortal sin

Quaestiuncula 1

To the fifth we proceed thus. (Parallel: ST II-II.98.3.) It appears that not every perjury is a mortal sin.

Obj. 1: For just as it is possible to lie as a joke, so it is in perjury. But a jocose lie is not a mortal sin. Therefore neither is perjury.

Obj. 2: Furthermore, sometimes due to a habit of swearing oaths someone swears something false, from a slip of the tongue. And it would be grave to say that such a one would be sinning mortally. Therefore not every perjury is a mortal sin.

Obj. 3: Furthermore, just as swearing something false is forbidden by the second precept of the Decalogue—you shall not take the name of God in vain—so too is swearing without cause. But swearing without cause is not always a mortal sin. Therefore neither is it to swear something that is false, and therefore the same as before.

On the contrary, Augustine in a sermon (Augustine, Sermones ad populum, serm. 180 (CCSL 41Bb:665; PL 38:974); serm. 307 (PL 38:1406).) says that false oath swearing is pernicious. But only a mortal sin can be called pernicious. Therefore perjury is a mortal sin.

Furthermore, everything contrary to a precept of the law is a mortal sin. But perjury is directly contrary to the precept, you shall not take the name of your God in vane. Therefore and so on.

Quaestiuncula 2

Obj. 1: Moreover, it appears that it is not licit to receive or require an oath. (Parallels: ST II-II.98.4; Super Rom. 1, lect. 5.) For a Gloss on Romans 1:9—God is my witness—says, you do not do evil, you who use an oath well so that you might persuade another of something useful; but it is due to an evil, and here supply, that of the one who receives the oath. (Augsutine, De sermone Domini in monte, bk. 1, para. 51 (CCSL 35:1261; PL 35:1256).) Therefore the one who receives the oath sins.

Obj. 2: Furthermore, he who requires an oath from someone either knows he swears to something true, or knows he swears to something false, or does not know whether he swears to something true or false. If he knows he is swearing to something true, he appears to sin, since he makes him swear for no reason. If he knows he is swearing to something false, he is killing him, as is said in the text. (Sent. III, 39.12(161).1.) However, if he does not know either way, Augustine says on Romans 1:9, God is my witness, I do not dare to say this is not a sin, but a human temptation. (Augustine, Sermones ad populum, serm. 180, para. 10 (CCSL 41Bb:679; PL 39:978).) Therefore to require an oath is in every way a sin.

Obj. 3: Furthermore, in Romans 1:32 it is said that those who consent to those doing evil are worthy of death. But one who swears by idols sins mortally, but he who receives the oath from him appears to consent in it. Therefore at least the one receiving such an oath sins.

On the contrary, there is what is written in Genesis 31 about Jacob, who received Laban’s oath, who swore by his own gods. (Possibly Genesis 31:49 or 53, though it is not clear that Laban is not swearing by Jacob’s God.) Nor should it be said that he sinned.

Furthermore, without what is necessary to observe judicial order, an oath does not appear to be a sin. But judicial order could not be observed in many cases without the receiving of an oath. Therefore to receive an oath is not a sin.

Response to Quaestiuncula 1

I answer that oaths are of two sorts. There are some in which someone is aware that he is swearing it, and then if he swears to something false, I believe that he always sins mortally, whether it is a solemn oath or not. This is so chiefly when he is aware that he swears to something false. But there are some oaths in which a man does not attend to the oath, and it is as if he is not aware that he is swearing, but due to a slip of the tongue he stumbles in the oath. And because then he, as it were, unknowingly swears, and the ignorance is not thought to be voluntary, in such a case it appears that he does not swear voluntarily. Whence, if what he swears to is false, whether or not he is aware that it is false, as long as it is not a pernicious lie, I do not say this is a mortal sin, but a venial sin. Yet one should beware of it, because it is extremely close to a mortal sin.

Reply Obj. 1: The account of lying and perjury are unlike, because an oath should be approached only with great caution, as was said, and for the sake of some utility. Whence, if someone perjures himself as a joke, he will not be excused.

Reply Obj. 2: This is clear from things said.

Reply Obj. 3: To swear an oath without cause is not directly, but indirectly, opposed to that precept. Now, to swear to something false is directly opposed to it, since the false cannot be confirmed, so an oath to it is empty. Whence it is not necessary that swearing an oath without cause is always a mortal sin, the way swearing to something false is.

Response to Quaestiuncula 2

To the second question, it should be said that just as swearing an oath is not always evil, but sometimes is licit, when one swears by necessity and with caution, so too receiving or requiring an oath, due to a necessary cause and observing other appropriate circumstances, can occur without sin.

Reply Obj. 1: The evil of fault is not meant there, but rather the evil of penalty, which arises from the ignorance of the one who receives the oath. For if he knew whether what one swears to is true, there would be no point to swearing the oath.

Reply Obj. 2: When someone knows, or believes with probability, that someone will perjure himself, it is not licit to require the oath from him—except perhaps in a courtroom judgment. For in court judgments the oath is presented not only for the sake of the judge, but for others too, so it is not in his power to dispense with an oath that must be presented according to the order of justice. Likewise, if he knows that what [the witness] is about to swear to is something true, he can licitly require the oath, not for himself but for the others who do not know. However, if he is doubtful, the doubt can arise from so great a suspicion that it will occur with sin. And this is why Augustine does not dare to say that it occurs without sin; still, he does not say that it is always a sin.

Reply Obj. 3: He who swears by idols sins as regards the form of the oath, but not as regards his assertion of the truth, or his promise of something that redounds to the common good. And in reference to this, one can consent to it without sin, but not in reference to the first [aspect]. And therefore we can sometimes make use of his oath without sinning.

Exposition of the text

Now let us consider perjury. (Sent. III, 39.1(150).1.) It appears that this treatise should have been placed in the exposition of the second precept. But it should be said that lying is presupposed to understanding perjury. Therefore he necessarily treated perjury after treating lying.

And so he forbade this to the weak. (Sent. III, 39.5(154).2.) This was on account of two dangers: first, so that they might not believe that there is some divine power present in created things; and second, so that they not break faith, not believing themselves to be bound by such an oath.

But the one who swears by the Gospels seems to achieve somewhat more. (Sent. III, 39.6(155).1, quoting Pseudo-Chrysostom, In Matthaeum opus imperfectum, hom. 44 (PG 56:883).) This is possible because in a solemn oath, where a greater deliberation is applied, we use this form in swearing the oath.

The holy synod proclaimed that, except for the making of peace, all the faithful should come fasting to swear oaths. (Sent. III, 39.12(161).2, quoting Ivo of Chartres, Decretum, bk. 12, ch. 33, 69, 70; Panormia, bk. 8, ch. 120 (PL 161:768, 797, 1334).) The reason for this institution was because the highest caution is required for an oath, and such demands sobriety. Yet such cases are excepted wherein delay draws out the danger, such as what one should do to bring about peace.