Quest. V. Is it always a sin to speak falsely or disagreeably to the matter, when I know it to be false? that is, Is it always a sin to speak contrary to my judgment or mind? Answ. Yes: for God hath forbidden it, and that upon great and weighty reasons, as you shall hear anon.
Quest. VI. Is it a sin when I speak not a known untruth, nor contrary to my opinion, nor with a purpose to deceive? Answ. Yes: it is oft a sin when there is none of this. For if it be your duty to know what you say, and to deliberate before you speak, and your duty to be acquainted with the truth or falsehood which you are ignorant of, and your duty to take heed that you deceive not another negligently, and yet you neglect all these duties, and by a culpable ignorance and negligence deceive both yourselves and others, then this is a sin, as well as if you knowingly deceived them.
Quest. VII. But though it be a sin, it remaineth doubtful whether it be a lie. Answ. This is but lis de nomine, a controversy about the name and not the thing. As long as we are agreed that it is a sin against God, and to be avoided, whether you call it a lie, or by another name, is no great matter. But I think it is to be called a lie: though I know that most definers follow Cicero, and say that a lie is a falsehood spoken with a purpose to deceive; yet I think, that where the will is culpably neglective of not deceiving, an untruth so negligently uttered deserveth the name of a lie.
Quest. VIII. Must my words, to free them from falsehood, be always true in the proper, literal sense? Answ. No. Augustine's determination in this case is clear truth, Quod figurate dicitur non est mendacium, (i. e. eo nomine). To speak ironically, metonymically, metaphorically, &c. is not therefore to lie. For the truth of words lying in that aptitude to express the thing and mind, which is suited to the intellect of the hearers, they are true words that thus express them, whether properly or figuratively; but if the words be used figuratively, contrary to the hearers, and the common sense of them, with a purpose to deceive, then they are a lie, notwithstanding you pretend a figure to verify them.
Quest. IX. Must my words be used by me in the common sense, or in the hearer's sense? Answ. No doubt but so far as you intend to inform the hearer, you are to speak to him in his own sense. If he have a peculiar sense of some word, differing from the common sense, and this be known to you, you must speak in his peculiar sense. But if it be in a case that you are bound to conceal from him, the question is much harder. Some think it an untruth and sinful to speak to him in words which you know he will use to his own deceit. Others think that you are not bound to fit yourselves to his infirmity, and speak in his dialect contrary to common sense; and that it is not your fault that he misunderstandeth you, though you foresee it, where it will not profit him to understand you, nor yourselves are obliged to make him understand you, but the contrary: the next will open this.
Quest. X. Is it lawful by speech to deceive another, yea, and to intend it, supposing it be by truth? Answ. It is not a sin in all cases, to contribute towards another man's error or mistake.[499] For, 1. There are many cases in which it is no sin in him to mistake, nor any hurt to him: therefore to contribute to that which is neither sin nor hurt, is of itself no sin: yea, there are some cases in which an error (though not as such) may be a duty; as, to think charitably and well of a hypocrite, as long as he seemeth to be sincere. Here if by charitable reports I contribute to his mistake, it seemeth to be but my duty. For as he is bound to believe, so I am bound to report the best while it is probable. 2. There are many cases in which a man's ignorance or mistake may be his very great benefit; his life or estate may lie upon it; and I may know that if he understood such or such a thing, he would make use of it to his ruin. 3. There are many cases in which a man's innocent error is necessary to the safety of others, or of the commonwealth. 4. It is lawful in such cases to deceive such men by actions; as an enemy by military stratagems, or a traitor by signs which he will mistake. And words of truth which we foreknow he will mistake, not by our fault, but by his own, do seem to be less questionable than actions which have a proper tendency to deceive. 5. God himself hath written and spoken those words which he foreknew that wicked men would mistake and deceive themselves by; and he hath done those works, and giveth those mercies, which he knoweth they will turn to a snare against themselves. And his dominion or prerogative cannot here be pleaded to excuse it, if it were unholy. And in this sense (as to permitting and occasioning) it is said, Ezek. xiv. 9, "And if the prophet be deceived, I the Lord have deceived that prophet." Yet must we not think with Plato, that it is lawful to lie to an enemy to deceive him. For, 1. All deceit that is against charity or justice is sinful. 2. And all deceit that is performed by a lie. As Augustine saith, There are some lies which are spoken for another's safety or commodity, not in malice, but in benignity, as the midwives to Pharaoh.—These lies are not commended in themselves, but in the deceit (or charity) of them. They that thus lie will deserve (that is, be in the way) to be at last delivered from all lying. There is also a lying in jest, which deceiveth not; because he that is spoken to, knoweth it to be spoken in jest. And these two sorts are not faultless; but the fault is not great. A perfect man must not lie to save his life.—But it is lawful to silence the truth, though not speak falsely. In Psal. and in Enchirid. he saith, Mihi non absurdum, &c. It seemeth not absurd to me that every lie is a sin; but it is a great matter or difference, with what mind and in what matters a man lieth. Some think a physician may lie to entice his patient to take a medicine to save his life: he may lawfully deceive him by hiding a medicine, and by true speeches and dark, which he thinketh will be misunderstood; but not by falsehood.
Quest. XI. Wherein lieth the proper vice of lying? Is it in deceiving? or in speaking falsely? or in speaking contrary to the thoughts? Answ. It is the aggravation of a lie, that it be an injurious deceit. But the malignity of the sin doth not consist in the mere deceit of another man's intellect: for, as is said, it may be a great benefit to many men to be deceived: a patient's life may be saved by it, when his physician findeth it necessary to his taking a medicine, which without deceit he will not take. And so children and weak-headed people must be used. Now such a charitable deceit, as such, can be no sin. Therefore the common nature of a lie consisteth not, only, in the purpose of deceiving, but in the speaking falsely, contrary to the mind: else it would follow, either that all deceit is sin, or that all lying or false speaking is lawful, where the deceit of another is charitable or lawful: which are neither of them to be granted. Yet it is not every untruth that is a lie. Some schoolmen distinguish between mentiri (as being contra mentem ire) and mendacium dicere; as if to tell a lie were not always to lie, because not contrary to the mind. But then by mendacium they mean no more than falsum.
What a lie is.
How sin is voluntary.
I conclude then, that a lie is the voluntary asserting of a falsehood. And the more it tendeth to the injury of another, the more it is aggravated; but it is one thing to be injurious, and another thing to be a lie. When I name a falsehood, I mean that which is apt to deceive the hearer. So that it is necessary to the being of a lie, that it be deceitful, though the purpose of deceiving be found only in the more explicit sort of lies; for falsum dicitur a fallendo, it were not false, if it were not deceitful, or apt to deceive. For an unapt or figurative expression which hath a right sense as used by the speaker and hearer, is no falsehood. In one language a double negative affirmeth; and in another a double negative is a more vehement kind of denial; and yet neither is to be called by the others an untruth. By asserting, I mean any expression that maketh the falsehood our own, as distinct from an historical narration; for it is not lying to repeat a lie, as only telling what another said. By voluntary, I mean not only that which is done knowingly, upon actual will and deliberate choice, or consent; but also that which is done ex culpa voluntatis, by the fault of the will, and is to be imputed to the will.[500] For it is of great necessity to observe this about every sin, that whereas we truly say, that all sin is voluntary, and no further sin than voluntary; yet by voluntary, here, is not meant only that which is actually willed; but all that the will is guilty of. For it is true that Austin saith, Ream linguam non facit nisi rea mens, The tongue is not made guilty, but by a guilty mind. But then it must be known, that the mind or will is guilty of forbidden omissions as well as actions: and so it is a lie or voluntary untruth, when the mind and will do not restrain the tongue from it when they ought. As, 1. When a man erreth or is ignorant through wilful sloth or negligence, and so speaketh falsely when he thinks it true; this is a culpable falsehood, and so a lie; because he might have avoided it and did not: and this is the case of most false teachers and heretics. So, also, if a man will through passion, custom, or carelessness, let his tongue run before his wits, and speak falsely for want of considering or heeding what he saith, this is a culpable untruth, and a lie, and it is voluntary; because the will should have prevented it and did not; though yet there was no purpose to deceive.