On the Problem of Mental Reservation

Should we lie when the Nazi stands at the door and asks us his infamous evil question? Traditional proposals about how to solve this problem by means of what is called “mental reservation” tend to be unsatisfying, because they are based on technicalities. It is intuitively apparent to most people that an ethical problem should not be reduced to a technical one, and so it seems both implausible and distasteful to suggest that while a lie is immoral even in dire circumstances, a technical evasion (such as “There are no stupid Jews in my house”) is fine. Why should the moral life depend on technicalities? Do they not leave our essential meaning and intention just the same as it was before? Why should a “transgression of genera” (in this case, from the ethical to the technical) be allowed to stand here any more than it is allowed to stand in any other theoretical discussion?

The deeper underlying reason why this problem seems vexing is because we tend not to think with much nuance about what lying is, about how it is related to deception, or about what it means to be a “cause” of deception. Such tendencies are exacerbated by the deeply ingrained positivism of our intellectual culture. This positivism induces us to pay insufficient attention to what things mean; instead, one tries to think merely about “facts,” as if that alone could satisfy our quest for the truth. The question about lying and mental reservation must, at its more serious level, be a question not only about the factual, but about what it means to be or not be truthful. No amount of mere factual logic-chopping about when or how much we can get away with is likely to further our grasp of that.

For example, everyone is aware of the commonplace idea that a lie is a deception, and that to deceive is to cause another to believe what is untrue; but frequently the answers to the question as to whether one can ever use mental reservation just assume that the proper gauge of whether one has “caused” deception is purely and simply what the listener is apt to infer from what is said. So by this account, if the listener is deceived, then one has lied; if not, not. This amounts to a purely factual reduction of the real question; the pursuit of real meaning has already been lost. This reduction, moreover, places the entire burden of “telling the truth” on the speaker, and removes it from the listener. Then it naturally seems strange to say that lying is always wrong. Perhaps that is why even some traditional Christian scholars have wondered how lying can always be wrong. But all of this rests on implausible assumptions to begin with.

So we must go back to the beginning, and consider not just facts but meaning. What does it mean to lie? To lie means to misrepresent the truth, deliberately, in such a way as to be a cause of deception. But to be a “cause” can be understood in a proper or a loose sense, and so can “to misrepresent.” Still further, we should ask ourselves whether “causing deception” is a proper effect of lying, or whether it constitutes the lie itself; for these are not the same.

In discussing lies, Aquinas proposes that the real virtue in question here is the virtue of truthfulness. Truthfulness derives not only from our obligations to others, but from our more fundamental obligation to the truth itself. Hence a lie is understood by Aquinas to be an evil not most immediately because we have an obligation to another person, but more immediately because it is our nature to orient ourselves towards the truth. This orientation toward the truth is so fundamental that there is no more fundamental principle which could justify its occasional suspension. That is why it is traditionally held that a lie is not only an evil, but an “intrinsic” evil, which cannot be compromised.

The deception of another person, then, is not what immediately constitutes a lie; yet it is a natural consequence, and of course it is also generally the goal of the person who lies. But to see more clearly how deception is a consequence, we must think about causality. For it is apparent that by lying we do make ourselves a source of deception for others. Yet there are several ways in which we might be a source. Often a source is a cause, and in the proper sense, to be a cause (speaking here of what is traditionally called an “efficient cause”) means to give being to something — or, in an opposite kind of scenario, to deprive something of being.

This is different from being merely an occasion. If an intemperate man is induced to fly into a rage whenever he sees someone for whom he has an irrational hatred, it is not the person he sees who is, properly speaking, the cause of his rage; it is rather the intemperate man’s own vicious habit that is much more properly the cause. The person he sees is more an occasion than a cause. The person who is seen does not “make” the intemperate man fly into a rage, as much as the intemperate man makes himself do so.

To “deceive” someone can thus be seen to be correspondingly ambiguous. For just like an intemperate man, someone who is apt to be deceived on account of his own untruthful dispositions may actually be thus deceived on the occasion of something someone else says, even if what is said happens to be true. Bill, on account of a narcissistic disposition, thinks that whenever Mary takes a walk without him, she is deliberately slighting him. And so he asks her one day whether she just took a walk without him, to which she answers, “Yes, I did.” Perhaps she knows perfectly well what he will infer, and that he will be thus deceived. But she is not a liar. Her speech is an occasion of his deception, but not a cause except in a very loose sense. His own habitual narcissism is the true cause.

It is commonly understood that we don’t necessarily lie if we don’t tell the whole truth, or if we tell as much of it as is appropriate in circumstances. If, in answer to a customer’s question about “whether he has any oranges,” a shopkeeper says, “No,” he isn’t lying if he doesn’t mention the ones in his lunchbox. It is obviously natural to consider circumstances when determining what one ought to say or not say, precisely so as to represent as much of the truth as it is appropriate to represent. The truth of the answer is thus conformed to the truth of the circumstances. Everyone understands that mental reservations of this sort are perfectly reasonable.

But then the question arises as to whether mental reservation in the interesting cases — the ones where one hopes, in fact, that the listener will be deceived — is the same thing. To hope for deception, and then to allow it to come about, seems tantamount to causing it — or so one surmises. But if we understand what has just been said about what a cause is properly speaking, we can see that to be a cause in the strict sense is not reducible to what one hopes for. It is perfectly possible that one may hope for something, and then make oneself an occasion for what one hopes for. In such a case the hoping just by itself will not turn the occasion into a cause.

To see this more clearly, it will help to say still more what the underlying root of the obligation to avoid lying really is. As already noted, this is not a technical question; it is an ethical question, which is to say that it is about what we, as human persons, are ordered to. It involves what our speech is ordered to as well, but we must remember that speech is but a tool (albeit a natural one). If speech has a natural order to the truth, that is because we persons have a prior and more fundamental order thereto. Our prior order to truth involves the duty to seek it, to distinguish it from what is false, and to live by it, even when others are not immediately involved.

That the virtue of truthfulness bears first on persons, and only consequently on speech or other tools with which we are naturally endowed, involves two consequences. The first is that the virtue of truthfulness does have a social aspect, because we are social beings. The obligation to truthfulness is not just something I owe to myself; in some measure I owe it to others as well. It can only be for that reason that deception of others is recognizable as a moral evil, since by deceiving others we interfere with the duty to truthfulness that they share with us. But at the same time this duty to truthfulness cannot be taken over by one person on behalf of all others in such a way that those others cease to bear any responsibility for themselves. Truthfulness is quite manifestly a shared responsibility, but as with most things that are shared, there may well be moments when one person fulfills his duty to another without, for all that, the other fulfilling his own duty to himself.

The second consequence of truthfulness being an obligation upon persons before it is an obligation bearing on the use of instruments such as speech is that it can, in fact, bear upon far more than speech; for it bears upon anything by which a person may express the truth. It will be appropriate to illustrate what I mean here by an example taken from the question raised at the beginning. The Nazi shows up at the door wearing an impressive uniform, accompanied by others of like bearing, and carrying guns or other instruments associated with the enforcement of justice. He and his accomplices shout orders with what appears to be grave and urgent authority. How often, in discussions of this old conundrum, is it observed that the picture here described is profoundly false, right from the start?

I do not, of course, mean that bare existence itself can somehow be false; but still it is deeply important to see that much of what we surround ourselves with in our lives is significant, and that it is quite possible for this signification to substantially violate our obligation to truthfulness. The façade of justice depicted here, for example, is in a very real sense a lie. And hence the question of what one ought to do in such circumstances is far more than a mere “factual” or technical question. It is a question about how to sustain what remains of truthfulness in a situation that is already deeply impregnated with lies involving both self-deception and an endeavor to deceive others. Nor is the question that the Nazi himself poses to the terrified home dweller a mere “factual” question. The Nazi’s question is already a lie, insofar as it is set forth as a representation of what is just.

By seeing these things, we may now also see that there is simply not a legitimate argument to make that the person who hears the Nazi’s question is obliged to take it in just the way it is posed — for as just noted, the question itself is a lie. For the listener to take the Nazi’s question in the way that the Nazi proposes to understand it would therefore in fact already be to participate in a lie. What then is the listener to do? Is he obliged to explicitly point out that the Nazi is engaged in lies and deceit, or reveal that that is what he thinks? The virtue of truthfulness cannot extend that far. We cannot be obliged to say everything that is true, any more than the shopkeeper described earlier is obliged to do so. We are especially — and on some level rather obviously — not obliged to do so when grave evils may ensue therefrom.

Hence, as it turns out, there is in most cases a fairly obvious solution to the conundrum which is posed about what to say in response to the Nazi’s interrogation. “Do you have any Jews in your house?” Answer: “No.” We can now begin to see that according to the true order of justice, there is no difference between this situation and the situation of the shopkeeper who is asked if he has any oranges; in both cases the answer “no” is perfectly appropriate to the truth of circumstances, as expressing just as much truth as deserves to be expressed according to justice. If the Nazi is deceived by such an answer, it is perfectly correct to say that he deceives himself. He is no different from the narcissist who flies into a rage on account of his own habitual self-deception, suffering an evil of which he himself is the primary and truest cause.

There appear to be many instances in Scripture of this sort of deception. Our Lord refers to the destruction of the temple which is to be rebuilt in three days. He does not scruple to warn His listeners that He does not mean what they assume He means, though predictably they end up being more deceived than they were before. Indeed, even Scripture itself becomes at times an occasion of deception: “that seeing they may not see, and hearing they may not hear.” These are perfectly real examples of mental reservation. But now we can understand this notion of “mental reservation” in a way which includes no hint of casuistic or “technical” tactics for avoiding the obligation to be truthful. What we find here is indeed just the opposite: namely, the natural way to be truthful in a larger context where life itself is understood to be ordered to Truth.

Dr. Sean Collins About Dr. Sean Collins

Dr. Sean Collins graduated from Thomas Aquinas College in 1979, and received a Ph.D. from Université Laval in 1987. After teaching at St. John’s College in Santa Fe for several years, he returned to his alma mater in 1994, and has taught there since then. Dr. Collins and his wife Catherine are proud parents of eight children.


  1. Mental reservation to cover for clerical child abusers is always morally wrong.