Article I: On Lying Itself

S. Th. II-II, q. 110.

857. A lie (mensonge; leugen) is directly opposed to truth by defect and therefore is speech against the mind. It is called:

1. Speech, and indeed external speech, which can be made by any external sign whatever, whether by word, writing, gesture, or deed; hence on the part of the act a lie is divided into a lie strictly so called, which is made by words or equivalent signs, and simulation, which is made by deeds, of which hypocrisy is a species, which chiefly is the simulation of holiness.

2. Against the mind, namely, that which proceeds from the intention of enunciating what is false; hence if someone enunciates what is false, erroneously thinking it to be true, falsity is not present except materially, nor is there a lie; in other words, he errs but does not lie. On the contrary, if someone enunciates what is true, erroneously thinking it to be false, he does not err but lies, because falsity is present formally, and accordingly a lie.

In this intention there is implicitly included the intention of deceiving, because the proper effect of a false enunciation is that another be deceived; but that someone explicitly intends to establish falsity in the opinion of another does not pertain to the species or essence of a lie, but to a certain perfection of it (a. 1).

858. Principle I. Every lie is a sin. - It is proved:

1. From the Scriptures (Ecclus. VII, 14; Prov. XIII, 5 and Col. III, 9; John VIII, 44; I John II, 21).

2. From the authority of St. Augustine and St. Thomas.

3. By reason, because a) it is essentially evil, as an act which falls upon undue matter. Namely, it is repugnant to the end of speech and of the faculty of speaking, which were established by the author of nature so that man might manifest his thoughts to man: for since voices by their nature are signs of concepts, it is unnatural and undue that someone signify by voice that which he does not have in his mind; from which disorder follows b) another, that a lie of itself by its nature induces the deception of the neighbor, and accordingly, once universal suspicion has arisen, brings harm to trust and security in social life and to the public good (a. 3).

859. A threefold lie: officious, jocose, pernicious. - On the part of the end (motive) or effect and fault, a lie is distinguished as officious, jocose, and pernicious, according as it is made for the sake of one's own or another's utility, of delight, or of inflicting special harm: the first is lighter than the second, and the second than the third; but the gravest of all is a lie which harms God in the matter of religion (a. 2 and 4).

An officious and jocose lie is venial from its genus, and is not mortal except accidentally, for example by reason of scandal, for a deception of small moment does not overthrow social life, but inconveniences it: for from deception of the neighbor about something of small moment concerning which it does not matter whether it be known, the neighbor is not harmed; but a pernicious lie is mortal from its genus on account of the evil joined to it, whether on the part of the matter, if it is made in doctrine of religion or of good morals or of some science, or in a contract, or on the part of the end, if it is said to the injury of God or to the notable detriment of the neighbor.

860. Principle II. Although it is never licit to lie, "nevertheless it is sometimes licit prudently to hide the truth under some dissimulation" (q. 110, a. 3, ad 4). - This is customarily done in a twofold way:

1. By amphibology or equivocation (dubbelzinnige uitdrukking), which is a speech having of itself a twofold sense: one, ordinarily more obvious and common, which the speaker foresees is to be perceived by the hearer; the other, less common, yet perceptible by the hearer from the circumstances, which the speaker intends to express, for example, I say no, I will, Peter is at home, this book belongs to Peter, etc.

2. By restriction (voorbehoud), which is a limitation made in the mind of some absolute affirmation or negation, or an act of the mind by which someone restricts or turns words in his mind to a sense other than the natural and obvious one. It is twofold: a) purely mental, when the limitation cannot appear externally, but the whole sense lies hidden in the mind and the truth can in no way be perceived, as if someone says that he has seen Rome, understanding in a picture, I did not break the vow, understanding in the previous year, I did not take your thing, thinking with the left hand, I did not do this, namely, that which I am now thinking, etc.; b) broadly mental or real, when the limitation can be gathered from the circumstances of things, persons, places, and received common usage, for example, if a priest or physician says: I know nothing about these things, understanding, which I can reveal; then by reason of the circumstances the speech is now made equivocal, and rather there is restriction of the utterance than of the mind. Now then:

I. It is never licit to use a purely mental restriction, because it is simply a lie, for the words neither of themselves nor from the adjoining circumstances in any way outwardly manifest the internal concept of the mind. This is clear from the condemnation of propositions 26 and 27 by Innocent XI.¹

¹ "If anyone, either alone or before others, whether interrogated, or of his own accord, whether for the sake of recreation, or for any other end whatever, swears that he did not do something which in reality he did, understanding within himself something else which he did not do, or another way from that in which he did it, or any other true addition whatever, he does not really lie nor is he perjured." - "A just cause for using these amphibologies is present whenever it is necessary or useful for safeguarding bodily health, honor, family goods, or for any other act of virtue, so that the hiding of truth is then judged expedient and studious."

II. It is licit to use real restriction and amphibology, provided that a just cause is present for hiding the truth, and another honest means is lacking, and deception of the neighbor is not intended.

It is proved: a) by the example of Christ. "But of that day no one knoweth... nor the Son," understanding: so as to manifest it (Mk. XIII, 32; Mt. XXIV, 36; cf. John XI, 11; VII, 8);

b) by reason: on the one hand, it is not a lie, because the words which are uttered, taken together with the circumstances of the speaker, the hearer, etc., which according to common estimation co-signify, signify the true sense which the speaker has in mind, although not clearly and distinctly; on the other hand, deception of the neighbor is not necessarily intended: for that speech has a twofold effect, one good, the hiding of truth which the speaker intends, the other evil, the deception of the neighbor which he only permits from a just cause. Hence the neighbor is not directly and necessarily deceived, but his deception is only permitted, which for a just cause is licit. For we are not bound to speak according to the mind of others if a just cause is present. But if this were not licit, there would not exist a way of licitly keeping secrets, which would be pernicious to human commerce, no less than lying, says St. Alphonsus, l. III, n. 152.²

² Real restriction is not something new, although the name is new. In ancient times it was known, although not so expressly; even by St. Thomas, as is clear from what he has concerning various sayings by Christ, and concerning the sacramental seal.

We said: from a just cause; for such utterances ordinarily are not licit, otherwise social life itself, which is founded upon mutual trust and mutual manifestation of truth, would totter. A just cause is an honorable end for preserving goods useful to the spirit or body; and this cause is required to be proportionate, that is, greater 1) the more the words furnish occasion of erring; 2) the graver the matter of error is; 3) the more numerous and greater are those to be deceived. A greater cause, for example, is required that someone use them publicly, or not interrogated, or asked by authority, than that he use them privately, or interrogated, especially if not by authority. But for swearing with real restriction or amphibology a greater and grave cause is required, out of reverence for the name of God.

861. Principle III. It is not always licit to hide the truth. - It is not licit to use any restriction or equivocation when some other special precept of faith, charity, justice, etc., demands the open confession of truth; in which case one who nevertheless used it would sin in two ways, both against truth and against the other virtue: a) when the precept of externally confessing the faith presses; b) when by reason of office we are bound to instruct someone and teach him true things lest he err, especially if for a price or stipend; c) when a judge legitimately interrogates, having the right of knowing the truth (to this right of knowing some truth there corresponds in another the obligation of confessing it, and in such a way that the truth be known by the hearer), or a superior concerning those things which pertain to the governance of subjects, or a confessor concerning those things which he must know in order rightly to judge the penitent; d) in onerous and mutual contracts, on account of a similar motive: for justice requires that no injury be brought upon another.

One who uses amphibology without sufficient cause violates the affirmative precept of truth, by which, on account of the good of society, we are obliged not to hide the truth without cause, or at least not to furnish occasion for the deception of the neighbor: for if this were always done and without reason, no one could any longer believe another without suspicion of ambiguity, which would tend to the manifest detriment of society. Yet such a person does not make a lie, because the utterance in some signification is conformed to the internal judgment of the speaker, provided that it remains equivocal when all the circumstances are considered. Hence if he confirms it by oath, he makes an unjust assertory oath, which of itself is venial; yet it can be mortal, if another virtue is gravely injured, for example commutative or legal justice, as in contracts and judgments.

But one who uses restriction without sufficient cause, besides this, makes a lie, because if sufficient cause is lacking, the circumstances do not sufficiently indicate the restriction added in judgment by the mind; hence one who in this case confirms it by oath makes perjury strictly so called.

862. Remarks. - 1. Let proposition 28 be noted among those condemned by Innocent XI,³ by which we know that all restrictions are illicit when an oath is required on account of the public good, whether by the Republic or by the Church, lest the unworthy be promoted, for example, in those to be promoted to sacred order (concerning birth, censures, irregularity), in those wishing to contract marriage (concerning a diriment impediment), in conditions for teaching in schools for an academic degree, etc.

³ "One who by means of recommendation or a gift has been promoted to a magistracy or public office will be able, with mental restriction, to furnish the oath which by mandate of the king is customarily required from such persons, no regard being had to the intention of the one requiring it; because he is not bound to confess a hidden crime."

2. We note that Catholics commonly admit broadly mental restriction as a necessary means of hiding the truth. Nor is it to be admitted what certain moderns have said for this end: that false-speaking is licit, or a psychological lie which harms no one but benefits the speaker or another, distinguishing it from a moral lie, which denies truth when it ought to be affirmed, and thus perverting the definition of a lie.⁴ Although practically in most cases broadly mental restriction and false-speaking return to the same thing as to the matter, nevertheless the doctrine must be held which says that every lie and false-speaking is illicit, both because it more easily excludes abuse, and because every false-speaking is against the essence of speech, and because broadly mental restriction, as being speech true in itself, can also be confirmed by oath, which is sometimes necessary. But false-speaking, even if it were said to be licit, cannot be confirmed by oath, because it is falsity.

⁴ Thus not only Grotius and Pufendorf, Protestants, but also certain Catholics, such as Bolgeni, Il possesso, c. 48; Dubois, Une théorie du mensonge; and the author of the little work: Étude sur la malice intrinsèque du mensonge par un professeur de théologie. Against these especially Waffelaert, Dissertation morale sur la malice du mensonge; and Vermeersch, in the periodical Gregorianum, I, wrote very well.

3. The comparison cannot be admitted which some, such as Fr. Vermeersch, institute between homicide licit from just defense on account of a good effect, and false speech or a restriction which is not sufficiently indicated by the circumstances, licit from just defense of a secret which otherwise could not be defended. For homicide is not always and essentially evil, because it is not against the essence of things but only against their natural condition, and therefore it is not always an illicit means but only the homicide of an innocent person; on the contrary, lying is essentially and always evil against the very essence of speech (in the same way as lust against nature, because it is against the very essential order of the generative organs); and therefore it is always illicit even for just defense, because evil things, even the least, are not to be done for the sake of good things.

4. It must be noted that penitents sometimes affirm that they had to lie in order to keep a secret. Then the confessor would try in vain to explain to the simpler the distinction between a lie and broadly mental restriction, which in the case is licit. Therefore, having asked what utterance they had used, let him simply tell them that such things are not lies, but licit responses which can be given on account of necessity, and whose sense in those circumstances does not deceive an upright and prudent man (for example, in a merchant).

863. Corollary. - False testimony is of itself a grave sin, as being a pernicious lie. It is directly prohibited by the eighth precept of the decalogue (Ex. XX, 16), and is hateful to God (Prov. VI, 16, 19) and very harmful to the neighbor (Prov. XXV, 18).

It has a threefold deformity: a) against legal justice, because it does not obey the command of a judge or superior legitimately interrogating, and for that reason it is apt to harm the good of the community; b) against commutative justice, if besides it causes unjust harm to the neighbor; c) against religion, if, as is customary, it is done under oath, because then it is perjury strictly so called. From this last head it is always a mortal sin, even in a slight matter; from the first and the other it is mortal from its genus. Hence in law it is said (Decr. l. V, tit. 20, c. 1): "A false-speaking witness is liable to three persons: first to God, whose presence he contemns; then to the judge, whom he deceives by lying; lastly to the innocent person, whom he harms by false testimony."

From these things it is understood that this is accidentally venial: a) from some inadvertence or insufficient deliberation; b) also from lightness of matter, if it is not done under oath and brings only slight harm.

A false witness is bound:

1. to revoke the testimony, and indeed if he said it only materially or from error, he is bound when revocation is useful to another and does not bring grave harm to himself; but if he said it formally and knowingly, he is bound, when revocation is useful to another, even with equal or greater inconvenience to himself, therefore even with danger of life if he has thrown an innocent person into the same danger, for in equal harm favor is rather to be shown to the innocent;

2. to restitution of the harm already following, he is bound; and indeed if he knowingly said false testimony and thus effectively brought harm upon another, he is bound simply. But when in good faith he gave false testimony, he is bound to restore if afterward he did not revoke it, although he could conveniently have done so and reparation would have been useful to another: for then he indirectly wills to be an efficacious cause.