Mortal/venial sins

Growing up protestant I wasn’t really exposed to the difference in committing sin. I’m curious are only certain sins mortal or can any sin be mortal under certain conditions? Are some sins always venial no matter what?

There are three conditions which must be met for sin to be mortal. Some sins are not grave matter.

From the Catechism:

1857 For a sin to be mortal, three conditions must together be met: "Mortal sin is sin whose object is** grave matter** and which is also committed with full knowledge and deliberate consent."131

To be a mortal sin, it has to be grave and serious matter. You also have to know that it is serious and still freely do it. So no, not any sin can be mortal under the right circumstances. Some sins – for example, losing patience with a spouse – will always be venial.

Does that help a little?

Grave leaves the door wide open to interpretation however… What if the spouse is verbally abusing the other spouse. That is surely a very grave matter my friend.


My point was just some things are always venial because the matter is not serious. Maybe losing patience with a spouse wasn’t the best example. (Although, verbal abuse is a separate action from getting annoyed, so I think it still works.) But you get my drift.

I still don’t agree. Consistently committing venial sins will always lead to mortal sins. If your constantly getting frustrating with your spouse that will lead to verbal abuse, and then to physcal abuse. We have a respectful disagreement, however my views are consistent with the church’s teachings my friend.


I don’t think we are actually disagreeing. :slight_smile: I think we are talking about two different things.

The OP asked if a venial sin can ever in certain circumstances be a mortal sin. The answer is no. You need grave matter for a sin to be mortal. Yes, consistently commiting venial sins can lead to commiting a mortal sin. But that’s different than saying a venial sin can be a mortal sin in certain circumstances. Which is the question the OP had.

Getting frustrated can lead to all those other things you mentioned, which ARE mortal sins. But getting frustrated is not in itself a mortal sin and never can be. That’s all I’m talking about.

When a circumstance suffices to change the object, it can render the same material action grave which was venial under other circumstances, or not sinful at all.

Example: Drinking a little too much, period, vs. drinking the same amount while driving.

Another example: Smoking a cigar, vs. smoking a cigar while pumping gas.

Another: Flipping someone the bird on the highway, vs. doing it at a papal audience to His Holiness.

Etc. You get the idea.

Some sins are “generically venial,” meaning that they absolutely require some special circumstance or intention to make them mortal, like idle words.

Most sins are generically mortal, but due to certain kinds of imperfections in their execution they are not mortal in the instance of commission. Anger, for example.

I would not say that is “surely a very grave matter”.

Depends on what is meant by those terms…

But that would carry us off the purpose of the thread.

No I would not say that.

Mortal sins a others have noted involve grave matter, full knowledge and complete consent.

Even if it is grave matter - if the knowledge or the deliberate consent is lacking - it would be a venial sin that is committed (or no sin).

You can also commit a mortal sin if what you do would not be a sin under normal circumstances. Basically if you purposely intend to commit a mortal sin but are wrong about a fact that would make it not mortal it is still mortal. Quoting from the Baltimore Catechism:

Suppose during Lent a person should mistake Friday for Thursday and should eat meat—that person would not commit a real sin, because it is not a sin to eat meat on an ordinary Thursday. He would commit what we call a material sin; that is, his action would be a sin if he really knew what he was doing. On the other hand, if the person, thinking it was Friday when it was really Thursday, ate meat, knowing it to be forbidden, that person would commit a mortal sin, because he intended to do so. Therefore, if what we do is not known to be a sin while we do it, it is no sin for us and cannot become a sin afterwards. But as soon as we know or learn that what we did was wrong, it would be a sin if we did the same thing again. In the same way, everything we do thinking it to be wrong or sinful is wrong and sinful for us, though it may not be wrong for those who know better.

Hi wkj_123,

Great question! Thanks for asking. There’s a lot of confusion on this topic. The basic method for determining a mortal sin is (as other users have stated) the sin must meet the following criteria:

*]Grave matter (It’s something serious)
*]Full knowledge (You knew it would be a mortal sin if you did it)
*]Full consent (You willingly did it anyway)

The part that trips people up the most is the first condition. When do you know something is serious? The good news is you don’t have to guess - the CCC spells it out for you. Take gambling for an example:

2413 Games of chance (card games, etc.) or wagers are not in themselves contrary to justice. They become morally unacceptable when they deprive someone of what is necessary to provide for his needs and those of others. The passion for gambling risks becoming an enslavement. Unfair wagers and cheating at games constitute grave matter, unless the damage inflicted is so slight that the one who suffers it cannot reasonably consider it significant.


I underlined the part that’s grave matter. So it’s not a sin to gamble, as long as you’re gambling to the point where you’re not depriving yourself or others of needs. It becomes mortal if you deliberately cheat or have an unfair wager, unless it’s insignificant.

Hopefully that helps you understand how to discern the difference between a mortal and a venial sin. If you find yourself still struggling, seek counsel from a priest for further help.

God bless!

How else would one explain the process of analysis in the Summa: “Whether x is a mortal sin?” The answer is basically always, “Yes, but…”

Yes there are sins that are grave matter that also admit of parvity of matter. Sure.

There are some sins that are often “light matter” (like anger) which could also involved grave matter (anger seriously going against justice or charity…for example out of anger deliberately desiring to murder somone…seriously harm them…).

St. Thomas asked questions - in that form - that was the form of the time. The scholastic way.



The commission of an intrinsically evil act is always at least a venial sin. The repeated commission of unrepented venial sins may lead to mortal sin.

It may be helpful to separate the notions of “evil” and “sinful” regarding human acts. We can speak objectively about the evilness of an act but not the sinfulness of an act. The latter always has subjective criteria which only God and the actor can know as other posters have already noted.

no not really.

It can be no sin at all due to say complete invincible ignorance.

It objectively of remains evil…but there can be a lack of culpability on the part of a person.

Yes, really. Unintentional ignorance operates to mitigate or eliminate the culpability of mortal sins. Full culpability in the transgression of the principles of the moral law is not relieved and, at a minimum, is venial transgression.

CCC# 1860 Unintentional ignorance can diminish or even remove the imputability of a grave offense. But no one is deemed to be ignorant of the principles of the moral law, which are written in the conscience of every man. … (Emphasis mine).

CCC#1862 One commits venial sin when, in a less serious matter, he does not observe the standard prescribed by the moral law, or when he disobeys the moral law in a grave matter, but without full knowledge or without complete consent.

I understand where your concluding that - it is not though correct.

It* can be that not even a venial sin* is committed.

The second part of 1860 is not meaning that a person cannot be completely invincibly ignorant about this matter or that matter. So that It is meaning that they will not be ignorant of the principles natural moral law (though as elsewhere it is noted too that such is necessarily not preceived clearly or even immediately 1960). Persons can be invincibly ignorant even to the point where imputability is not there at all.

And CCC 1862 there is not meaning that there will be necessarily a venial sin. It is discussing what venial sin is.

A person can be completely invincibly ignorant - indeed they may be convinced wrongly that what they do is good.

Yes… Like if a child is taught that going to Mass is not obligatory, to what degree could he be responsible later on when he doesn’t go? Possibly none.

But this sort of thing is rarer than many would like to think… I recall a passage from Romans…

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