Thou Shalt not Lie?

I am seeking a clarification on the matter telling a lie…

Several times I have run across threads that ask questions or pose queries on this matter. As Children we are taught that it is a “sin” to lie.
Yet in the ten commandments, I see no such blanket prohibition. In both Exodus and Leviticus, the commandment is against, “bearing false witness against your neighbor”.

Are there other commands that cover other instances of speaking something that is not factually true?

Thanks for any help.


The ten commandments is part of the foundation of the moral law, but it is not the entire moral law. There are many sins, some grave, some venial, not mentioned in the ten commandments.

CCC 1753 “A good intention (for example, that of helping one’s neighbor) does not make behavior that is intrinsically disordered, such as lying and calumny, good or just. the end does not justify the means.”

The Church teaches that lying is intrinsically evil, and is not justified by a good intention. Notice that not only calumny (a lie that is a false accusation, as mentioned in the ten commandments), but also any lying, is intrinsically evil.

Neither can circumstances change an intrinsically evil act into a moral act:

1754 “Circumstances of themselves cannot change the moral quality of acts themselves; they can make neither good nor right an action that is in itself evil.”

So lying is always immoral; it is always at least a venial sin.

A little devil’s advocate here…If somebody has an ugly baby, should you tell them so?

If asked, “do these jeans make me look fat?” Should you truthfully answer, no, because it’s really not the jeans fault?

In reality to lie is wrong, always. Not alway easy, or even kind, to be truthful, but truth is always the best path to follow.

Many God Bless and Keep You.


Numbers 23:19 says, “God is not man, that he should lie, or a son of man, that he should repent. Has he said, and will he not do it? Or has he spoken, and will he not fulfil it?” (RSV) I would say that if God doesn’t lie, then we shouldn’t either.

I regard to True Believer’s comments, while I wouldn’t tell someone with an ugly baby that their baby was ugly, I would look for something positive and truthful to say (nice hair, beautiful eye(s), whatever). As for the “no win” questions (Do these jeans make me look fat?), I’ve found after 24 years of marriage that the best answer is “Sweetheart, you look perfect to me, no matter what you wear!” It’s honest, truthful, and won’t offend anybody that I’m aware of.

You’ll also want to make sure that the person has a right to the truth.

nazi/hiding jews scenario?

that, or a poker game.

Interesting comment. And just how does one do that in every case?

A man walks up ans asks the time, do I question him why he want to know just in case he might be planning to rob a bank at a specific time?

Silly example I know, but still…


It is a sin to tell a friend that you are baking a cake for church when you are realy baking if for their suprise birthday party…
It is a sin to tell a child about Santa Claus, the Easter Bunny or the Tooth Fairy…
It is a sin to lie to protect innocents you are hiding from a regime that wants to kill them.

In any of the cases above, I wonder if my confessor would tell me that I had sinned…

Thanks to all for the answers. It appears that biblically at least there is not really a blanket prohibition on stating something that is not factually true.
The prohibition is against “bearing false witness against your neighbor.”
Thus the requirement under the Law is that it be a falsehood (lie) against someone (neighbor)

The Church, in the catachism referenced by Ron Conte above, lumps all untruths (lies) together regardless of who is involved or the intent or the circumstances. Yet the catechism also says, this in defining what consitutes a lie.
2483 Lying is the most direct offense against the truth. To lie is to speak or act against the truth in order to lead someone into error. By injuring man’s relation to truth and to his neighbor, a lie offends against the fundamental relation of man and of his word to the Lord.
Is this (to lead into error) the intent of our actions when we speak of certain mythical holiday characters, or when we distract our neighbor to preserve the surprise of the upcoming party?

I’m not trying to be difficult here, but I/we have seen any number of scrupulous types here at CAF who stumble over these types of issues. I a trying to understand more fully so that I/we might be prepared to offer the best possible advice.


In John 8:44, Jesus calls the devil: “father of lies”. But if lying were not always wrong, this would not be a fitting saying.

{6:16} Six things there are that the Lord hates, and the seventh, his soul detests:
{6:17} haughty eyes, a lying tongue, hands that shed innocent blood,
{6:18} a heart that devises the most wicked thoughts, feet running swiftly unto evil,
{6:19} a deceitful witness bringing forth lies, and he who sows discord among brothers.

If lying were sometimes moral, it would not be hated by the Lord, nor would it be listed with these other sins.

{12:22} Lying lips are an abomination to the Lord. But whoever acts faithfully pleases him.

If lying were sometimes moral, it would not be called an abomination to God.

{13:5} The just shall detest a lying word. But the impious confound and will be confounded.

If lying were only immoral sometimes, those who are just would not detest lying.

{4:2} Slander, and lying, and killing, and theft, and adultery have overflowed, and bloodshed has brought more bloodshed.

Not only slander, but also any type of lying is condemned by Scripture.

If a person does not have a right to a particular truth (e.g. confidential medical information), then you should remain silent. In some circumstances, with a good intention, you might use mental reservation.

But the circumstance that a person does not have a right to a particular truth does not justify lying, which is intrinsically evil.

Intrinsically evil acts are always immoral, regardless of intention or circumstances.

Pope John Paul II: “Consequently, circumstances or intentions can never transform an act intrinsically evil by virtue of its object into an act ‘subjectively’ good or defensible as a choice.” (Veritatis Splendor, n. 81.)

There are three fonts of morality: intention, moral object, circumstances. An intrinsically evil act is any act that has an evil moral object, regardless of the intention for which that act was chosen, and regardless of the circumstances.

For example, euthanasia is intrinsically evil.

Pope John Paul II: “Regardless of intentions and circumstances, euthanasia is always an intrinsically evil act, a violation of God’s law and an offence against the dignity of the human person.”
Letter to the Elderly

Pope John Paul II: “Despite the intentions or circumstances, direct euthanasia is an act which is always and per se intrinsically evil…”

Now lying is not generally a mortal sin, as euthanasia is, but as an intrinsically evil act, lying is still independent of intention or circumstances.

In describing lying as “To lie is to speak or act against the truth in order to lead someone into error” the CCC is not implying that lying for some other motive (purpose, or intention) would be moral or would be not a lie. Rather, the CCC is merely describing the most common intention. There is no statement in the CCC, nor in any other magisterial document of which I am aware that lying is ever moral, nor that lying is not lying when done with a good intention, or in dire circumstances.

So every time that we tell a 4 year old that there is a Santa Claus, we need to confess it as a lie.
Either that, or we must not raise children to believe in Santa, or we must not respect another parent’s belief that their small children believe in Santa…etc.

I appreicate your input Ron but I’m afraid that using a clear cut, life and death example like Euthenasia is hardly a good “blanket” comparison given that we all, or many of us, participate in lies like I mention above, willfully misdirect another in order to surprise them with a party or beautiful gift, and most think nothing sinful in it.


I use my best judgment. I gave examples from the trivial (poker) to the deadly serious (Ann Frank), to show how we make these decisions all the time. If asking for the time doesn’t send up warning flags, why not tell him the time?

So you would inform on Ann Frank and send her to the gas chamber and allow yet another nazi to commit a grave sin, or, alternatively, you’d never win another poker hand, all because “lying” as you broadly define it is intrinsically evil?

Or do you Catholics balance intrinsic evils and choose the lesser of the two? This seems to be the kind of moral relativism you are always railing about.

Or do you read up your own CCC and note that 2488 states that the right to the communication of the truth is not unconditional and that misleading the nazis and bluffing opponents in poker is not lying and not intrinsically evil.

In moral theology, we do not determine whether or not an act is intrinsically evil and therefore always immoral by examining every possible example and individually judging each example to be immoral. Instead, we consider the moral object of the knowingly chosen act. If that moral object is evil, then the act is always immoral.

But in the case of lying, the CCC has made it clear that lying is an intrinsically evil act. So we believe as a matter of faith that all lies are immoral, even if lying with a good intention, or in dire circumstances, might seem to be moral.

So the answer is, “yes I would grass up Ann Frank because sending the nazis away is an intrinsically evil act”? Or did you just miss 2488.

Does your CCC really bar verbal miscues in poker as intrinsically evil?

This is circular reasoning. The OP is really asking what the definition of a lie is. The more literalistic among us would have to accuse Jesus of lying when he told parables. They were not literal truths. They were ‘lies’ that told a different truth for a purpose.

So obviously telling a parable is not lying, since Jesus did not sin.

Stating something with double entendre, so that the hearer may hear what they wish, yet it is not what you mean, is not a lie. Jesus does this when asked at his trial if he was a king. Is he the king or not? He denies it without denying it. This is not a sin.

It is the legalism of defining sin which is sin, if the act is an act of love, which only God can know, since our own hearts are deceitful, then it is not sin.

So the kind of lie which is sin is always sin. The kind of lie which is not sin is never sin.

Bearing false witness is always sin.

I missed reading this post before my previous post.

Mental reservation may be used if telling the truth would cause grave harm.
Or a person can remain silent.

Lying is the direct and deliberate deprivation of truth from an assertion. So silence, mental reservation (misleading someone), telling a fictional joke, telling a parable, or bluffing in poker would not be lies.

Intrinsically evil acts are always immoral. So one cannot choose a lesser intrinsically evil act in order to avoid committing a greater intrinsically evil act. One is required by the moral law to refrain from all intrinsically evil acts.

The CCC does not state that lying is justified in a circumstance when the other person has no right to a particular truth.

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