When is ok to tell a lie? Clearly, there may well be some cases, such as hiding Anne Frank.

May we sometimes lie about our infidelity, if e.g. we think it could lead to a jealous murder? What about just to spare jealousy in general?

What about selfish reasons, like avoiding financial repercussions?

When is lying permissible?

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    Maybe useful The Definition of Lying and Deception. Commented Aug 30, 2023 at 7:59
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    @forlevel apart from concealing infidelity, there might be someone prying into your affairs which are none of the their business, moreover you suspect they want to interfere with your business. Is telling them a lie to misdirect them better than telling them some partial truth (or keeping silent), from which they might infer more information which you don't want them to know? Even saying "It's none of your business" will raise the importance level of what they are asking, which might not yet have seemed important in their prying. Commented Aug 30, 2023 at 21:28
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    like a little prayer @AgentSmith i do say prayers sometimes (and i cross myself too, same as kaka), but they are more like mini sacrifices haha. i don't have the imagination to tell lies to my advantage, and behave myself, so... too lazy for infidelity lol not worth the "wife" finding out
    – user67521
    Commented Sep 1, 2023 at 2:15
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    Can you define "ok" in "ok to lie"? Commented Sep 1, 2023 at 2:29
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    morally permissible @JaniMiettinen
    – user67521
    Commented Sep 1, 2023 at 2:29

6 Answers 6


Suppose that we are prima facie obligated to believe the testimony of others to some extent, or that by our own assertions, we are, via our assertoric/epistemic attitudes' alethological norms, trying to impose an obligation to believe what we say, on others. As if:

  1. Jones tells Smith, "I am the alligator that brought sin into the world." Then he either expects Smith to believe him, or he doesn't expect this.
  2. If he expects Smith to believe him, then he should be able to apply the general duty of credibility to Smith, i.e. to suppose that Smith is obligated to believe him.
  3. But is Smith obligated to believe him? Moreover, if Smith can tell that Jones is actually the marmoset that thrice denied Jesus Christ, Smith might have a counterobligation to disbelieve Jones.
  4. Or suppose that by giving testimony of some sort, Jones is trying to grant Smith a local permission to believe something that is, however, false. More generally, if Jones were justified in lying, then Smith would be justified in believing Jones: it would be good for Smith to so believe. If Smith isn't really justified in believing Jones, though, is he even merely permitted to believe?

There seems to be something about the default expectations allowable in communication on the one hand, and something about the deontic instability of lying on the other, that at least makes lying and similar acts uniformly problematic. This is not equivalent to a declaration that absolutely all deception everywhere and forever is completely and utterly unjustifiable. For example, if someone sincerely believes in act-utilitarianism and understands the theory enough to nontrivially apply it in their actual life, it would not do to say that such a person is committing an eternal sin if they lie to save a life (or whatever rightly balances the scales of value and disvalue, on their picture of the moral world).

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    "uniformly problematic" agreed, and your assertions as to how make some sense.
    – user67521
    Commented Sep 1, 2023 at 5:52
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    @forlove1 the whole scheme of "are we justified in expecting people to believe the lies they're told" was something I thought of long ago, with a clearer principle, and I wish I could remember the whole meta-argument, it was better than my presentation here :p Commented Sep 1, 2023 at 16:44
  • i lose again haha
    – user67521
    Commented Sep 1, 2023 at 17:12

Some people have a naive belief that all lies are bad, but that is simplistic, and is not a useful policy in the real, functional, engaging world of interpersonal relationships.

There is a huge difference between different kinds of lies. There could be a lot of example scenarios of the different types of lie, but at the extremes, there are

  • Lies to deceive someone with the intention of causing them harm, and malicious untrue gossip.

  • Lies intended to protect vulnerable people from things they don't really understand, when telling the truth might only cause confusion. Perhaps you'll give a better truth later, once they've understood what you first tell them.

Here is an example to support my assertion that "one must never lie" is simplistic.

Your child is at Uni and steals something, and a police investigation ensues. They are not a bad person and it was out of character – a mistake. Your child confides in you and needs advice, but the police arrive and ask you what you know about it.

If convicted the penalty won't be great, but the record will ruin their career prospects, and the indirect punishment will be out of proportion to the crime. Telling the truth will also break the trust they had in you when they confided, and you know that your child will learn from this mistake.

So do you lie to protect your child, and advise them to quietly return the thing?

Or do you tell the truth to protect the world from your child?

The real world is a complex place, and there are continual tests of our integrity, with competing reasons. A moral compass helps us to make the right decision in these cases, but taking the stance "I must never tell a lie" can be just as a damaging as telling lies.

  • the attitude that other people won't understand if you tell the truth comes off as vice ridden (arrogant, unnecessarily self involved, etc.) in many situations.
    – user67521
    Commented Aug 30, 2023 at 23:10
  • @forlove1 there might not be time to explain the truth properly, or it might not be the right moment. One can approach the world with good intentions, but seeing a need to compromise does not mean that one is "vice ridden". By "vulnerable people" I mean children, adults with special needs: those in our care who need to be protected. How is that self-importantly arrogant? Commented Aug 31, 2023 at 10:25
  • hm well i thought you were talking about it not being the right time to tell the truth because you feel like you might not want to
    – user67521
    Commented Aug 31, 2023 at 19:26
  • @forlove1 you made it sound as though anyone who tells a lie must be a habitual liar and up to no good, perhaps even with a fundamentalist religious aspect where telling a lie will damn your soul forever. I get that one should not go around spreading lies, deceit and dishonesty for personal gain (and I don't), but in the real world, there can be situations where it isn't possible to satisfy your moral code. Or if there is a way, you need the wisdom of Solomon, which most of us don't have. Commented Aug 31, 2023 at 19:36
  • i never mentioned habitual lying and idk
    – user67521
    Commented Aug 31, 2023 at 21:09

It depends on what you mean by okay. For me personally, I only think it is appropriate to lie if saying the truth threatens my personal safety.

If not, I don’t think one should lie. Saying the truth ultimately feels better and allows people to like you…for you. Of course, lying certainly has its benefits, but for me, it would eat away at my soul.

Ultimately, there is no right or wrong answer here

  • If God is unreal what reality can soul have?
    – Rushi
    Commented Aug 31, 2023 at 6:19

Concealing infidelity is morally wrong. Lying to conceal any crime or breach of trust is morally wrong, unless the law is unjust and should be abolished.

The moral harm caused by lying is that it strips others of their right to make their own informed decisions, the same as coercing them by force. The victim of your lying is not able to make the same choices they would make if you had not lied to them. You are trapping them in a false world, leaving them only the illusion of choice. For example, if you are lying about infidelity, your partner is staying with you and trying to make the relationship work, when they would likely make a different decision if they were fully informed. It is the same denial of their autonomy that would result from coercing them to stay with you.

Lying is therefore justified in whatever situation coercing someone by force would be justified. If the Nazis are coming to kill Anne Frank, lying to them is justified, because the use of force against the Nazis would be justified. If someone is not mentally capable of making their own decisions, perhaps because they are a child or mentally handicapped, then the use of force might be permissible in some cases to keep them from harming themselves, for example if they are trying to climb up the girders of a fairground ride. In those cases (where the use of force would be permissible) the use of lying would also be permissible.

But if someone is a mentally capable adult, to lie to them is to deny their autonomy, deny their right to make their own free choices. This is a hostile, controlling act. You are acting as their enemy, whether they know it or not.

Even if you think you're lying to "save them" from making what you consider a bad decision, that's not your decision to make, it's theirs. You have no right to deny their autonomy by making that decision for them without their consent. (Especially if "saving them" from a "bad decision" coincidentally benefits you selfishly, as in the case of lying to a partner about infidelity.)


The general view expressed here is far too permissive to represent philosophy. e.g.

Act‐utilitarianism implies that lying is morally permissible when, and only when, there is no alternative course of action open to one that has better consequences than lying. Many critics contend that utilitarianism is too permissive about the morality of lying.

Appealing to some vague notion that lying makes things easier for you (to cheat?) is just abusrd.

Lies often deprive us of liberty, freedom to act. Is such a lie always wrong? Presumably we can lie to children in this manner, without much fuss.

What about competent adults? If a doctor tell us "this won't hurt at all" to get us to take noxious medicine, he is usually thought of as being a poor doctor, at least. There are almost always more skilful ways of proceeding, if we truly are not lying for our own benefit.


Instead of treating truth or lie separately you’d better treat this as a part of dharma or adharma. Always practice dharma.

When no other alternative is possible, adharma might become necessary to protect a great dharma. First part of your question should be justfied from this point of view.

You should always tell the truth; but in some cases you will have to give up this advice.

satyam bruyat priyam bruyat na bruyat satyam apriyam… satyam bruyat priyam bruyat na bruyat satyam apriyam priyam ca nanrutam bruyat esha dharmah sanatanah


Speak the truth, speak pleasantly, Do not speak the truth in an unpleasant manner Even if pleasant, do not speak untruth, This is the path of eternal righteousness.

The consequence of lying is illustrated in the story of Yudhishthira's dog (in the Mahabharata). It indicates the obstacle that can happen in one's spiritual path even through a light lie. And the difficulty of practising the truth can be seen in the story of Harishchandra

Often, the intensity of lying varies according to the situation, your profession, age, relation, etc.

If you are a teacher it is your duty to be a role model for all your students. The same is true in the case of parents and their children. So you should always tell the truth.

But if you are a doctor, sometimes you may have to lie to hide some serious illness to appease the patient and give him confidence when there is no alternative solution. The same is true in the case of a first-aid provider. Even then he never hides the truth from the relatives.

If one can imagine the negative effects, before telling the truth, shocking news is often told starting with a light lie. (Eg: Death of close relatives or friends)


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