In a five minute audio excerpt from the book Lying by Sam Harris he argues lying is bad. If I have done something bad, and I don't want my friend to know it, isn't is equally bad to lie about it as hiding it or saying "I prefer not to answer".

For example: a woman has been sleeping with another man than her husband, and they have promised each other not to do so. Surely the husband would want to know (arguably even have the right to know) but if not asked about it she hides the truth.

The question arises: is this hiding equally immoral to answering "no" if the man did ask the question? What are some common theories about this?

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    Are you asking generally if "omission is a lie" or "omission, as seen by Sam Harris, is a lie"? Aug 11, 2016 at 13:43
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    I asked a very similar question years ago, but I'm not sure if it's close enough to be a duplicate.
    – commando
    Aug 11, 2016 at 15:22
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    Sissela Bok has whole books on both Lying and Secrets (by those one-word names) so this discussion about what is and is not lying, and what does and does not constitute a reason for lying through silence, as opposed to 'open secrecy', could go on for quite some time. I just wanted to throw that in because he explicitly mentioned saying "I prefer not to answer.'
    – user9166
    Aug 11, 2016 at 16:29
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    I have edited your question to not ask 'is it immoral' but 'what do philosophers say about this', so that it is objectively answerable within our guidelines. I hope that's okay with you. You can read more about our policies on the tour, the help center and on How to Ask.
    – user2953
    Aug 19, 2016 at 8:28

3 Answers 3


On the subject of the morality of lying and secrets, I really like the utilitarian approach, that one must search for the greatest happiness for the greatest amount of people.

In your example, telling the husband about the affair could... nah. It most likely will go against that goal. At least on the short term.

The wife has two choices: Keeping the secret and bearing the guilt, but keeping her husband happy and content, or telling him, which will diminish his happiness and might or might not ease her conscience. It might cause a breakup with everybody being miserable.

That would suggest that keeping the secret is the moral choice. But...

A relationship works best if both are happy in it. She isn't, so keeping the secret might just delay the inevitable. The husband might forgive her, and the relationship could end up stronger than before. Or the breakup, that at first made everyone miserable, allows both to find partners that are better suited, which ends up causing the greatest amount of happiness for not only two, but four people. The chances for that are marginal though.

As you see, both lying and being truthful can lead to good or bad.

I don't think it is immoral to keep secrets. I think it is not even immoral to lie, unless it is done with intent to harm. And, I don't think that telling the truth is by default morally right.

But what do all the bad endings have in common? Weakness.

The reason we lie is that we are weak. Either the liar or the belied is not able to handle the truth, or we just don't trust people to deal with the truth in a manner that aims for the greatest benefit of all involved. This weakness is the cause of lies, and the nature of the evil that we falsely deem to be within the act of lying itself.

If the Bible speaks of the Father of Lies, that is how I as atheist would picture him: Our weakness, our distrust, and our lack of benevolence in the face of uncomfortable truths.

  • First, I like that you took some angles on the example I provided. Second, you said "I don't think it is immoral to keep secrets. I think it is not even immoral to lie, unless it is done with intent to harm." Can you argue why? Third, I do see that weakness can be one explanation of why we lie—but surely there are other explanatory variables too, don't you think?
    – jacob
    Aug 28, 2016 at 20:08
  • @jacob I did argue why, utilitarian method. The argument is that both truth and lies can do both good or bad. Showing that was the reason for going through the outcomes of the example. It's a question of judging the tool vs judging the deed. I might expand my answer if and when I find the time, so things become more clear. As for other causes... mind giving me an example of explanatory variables other than personal weakness on either side preventing honesty, and not rooted in personal weakness, existing or assumed?
    – Estharon
    Aug 29, 2016 at 15:18

It is not positively making a false statement, but it reveals a mind in hiding - one knowing it has crossed an agreed upon boundary but not capable of admitting the guilt to the other person in the equation. It can be seen as bad as lying because from a psychological point of view, in not telling the truth straight away you are in the same position of avoiding responsibility of breaking an agreed upon rule by choice.

I actually did the above, owned up to it the next day by my own volition and me and the missus haven't had an issue about it since, nor did we really have one when talking about it! Nor do my female friends think that with truth, the actual breaking of the rule is much of an issue.

Both are 'not truth'. But silence is also 'not lying'.

This is more of a 'if a mistake has been made, not learning from it is a bigger mistake' kinda thing for me.


George Orwell said it best: "Omission is the most powerful form of lie".

While the act of omission doesn't necessarily pertain to the act of lying they do occasionally intersect. In the field of Rhetoric these types of lies are referred to as "lies of omission". And technically speaking they are logical fallacies.

You can read more about it on the RationalWiki: http://rationalwiki.org/wiki/Lying_by_omission

  • Lying is not a logical fallacy, because one may think logically on the basis of a lie. It even isn’t an argumentative fallacy, since one cannot prove whether the other person yet believed in what he/she obviously lied, even if he/she is mentally ill. The whole thing defies any classification. One may only counteract this by stating and proving the truth. However, the unveiled lie will then be a continual argumentum ad hominem against the liar. So, what I say here is also an argumentum ad “hominem” against your “rationalwiki” link.
    – user26880
    Jun 13, 2017 at 15:26

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