Mortal sin and Grave Matter


I’ve a question that I’m interested in discussing, but since mortal sin is a topic people really jump the gun on, I’d like to set a few ground rules.
This thread is not my attempt to say Mortal sin doesn’t exist. As such 2 things: don’t use this post to explain mortal sin does exist (the existance of mortal sin is taken as a given in this thread) and don’t post here that they don’t exist either because this thread is accepting the existance of mortal and venial sins as a given.
Secondly, attempting to understand when a gravely sinful action my or may not have less than mortal effects on the soul does not mean that a person is attempting to excape from their conscious or from truth. This topic is for understanding and is not in relation to specific circumstances - thus please refrain from assuming any such connections.

Okay, all that said:

Everyone pretty much understands that mortal sin has 3 requirements:
full knowledge
full conscent
grave matter

Including the CCC:
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.”

But somehow there is still a notion that any grave matter sinned over is always a mortal sin. Which can’t make any logical sense if we just explained that mortal sin is grave matter accompanied by these other 2 conditions.

It seems to me that we are using rather poor terms in trying to define sin, causing some ambiguity or double meaning.

Mortal sin definitions seem to cause this problem b/c people use “mortal sin” to define 2 things:

  1. the objective nature of sins which concern grave matter. (I’ve seen something like this called “objective mortal sin”)
  2. the moral result of only those sins which fullfill all three of the above stated conditions.

My argument demands people understand that #1 and #2 are actually different. So, if I have to really lay out the differences in thick I will but please read #1 and #2 again if you don’t see a difference because to give more exhaustive explination would be legnthy and tedious (to read more than write, as I am willing)

The Catholic Church seems to use definition #2:

1859 Mortal sin requires full knowledge and complete consent. It presupposes knowledge of the sinful character of the act, of its opposition to God’s law. It also implies a consent sufficiently deliberate to be a personal choice. Feigned ignorance and hardness of heart do not diminish, but rather increase, the voluntary character of a sin.

This being the chosen definition, why use the same phrase for a second and significatly different definition as well?

This notion of “grave matter = mortal sin” is problematic to reconcile with this line as well:
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. (emphasis added)

My main questions on this are:

When people pick out some sin (murder, suicide, masterbation, etc…) and say it is always objectively mortal sin, is this ever true?
Are they saying that such actions always constitute grave matter and assume that is the same as mortal sin?

Anyway, I’d love comments and thoughtful answers. Much thanks.


Yes, exactly. It is a case of careless, imprecise speech, nothing more.



To tell you the truth, people don’t pick out their sins; it’s actually a moment of weakness.:wink:


I think that part, if not all, of your answer may lie in the fact that the Church determines what acts are sufficiently grave to be considered mortal sin. Making moral determinations on complex subjects is generally beyond the ability of the common man.


The key lies in the word “objectively.” If the matter is grave, then as an objective moral consideration, the sin fits into the "mortal"category. But that speaks only to the first condition, not the other two.

One can say that murder is always objectively a mortal sin. One cannot say that a particular person who commits murder is subjectively guilty of mortal sin, because one does not know the last two conditions.


Your post pretty much sums up the answer. Not much left except that ultimately God judges our souls and only He knows our intention during those objectively grave acts that we may commit. In His infinite mercy He will find anything possible to see that a mortal sin has not been committed but in His infitnite justice He will judge accordingly. This is recognized in the crucifixion where God’s infinite mercy and infinite justice culminated…God Bless:)


Hey Jim, thanks for the response. These type of posts are exactly what confuse me.

“One can say that murder is always objectively a mortal sin.” You say this. Teachccd agrees. Both of you are people that I would normally be inclined to listen to. Many intelligent and faithful Catholics I konw say things nearly identical to this…but this line makes no logical sense to me.

Basically it’s saying that grave matter is mortal sin.

It’s calling mortal sin something that can exist absent of knowledge and intent.

If that were true then viruses killing people, lightning falling from the sky, or water flowing into a person’s lungs (all of which obviously lack knowledge and intent) can somehow be accused of committing objectivly mortal sins when they cause something that could possibly be considered grave matter (like a human’s death).

Of coures everyone will say this is all rediculous…and that’s my point. If we remove an intellect and a conscious, we can’t have sins we can only have grave matters.

Everything that I’ve read suggests that ALL mortal sins REQUIRE grave matter, knowledge, and consent. Making them always subject to circumstances.

Therefore an “objectivly mortal sin” is logically impossible, like a square circle.

Unless someone has an explination of how this could all possibly fit together making sense; it seems that this is what Besty said, " case of careless, imprecise speech".

Mortal sin - is an informed mind and conscience choosing evil with a grave matter.

Grave matter - "is specified by the Ten Commandments, corresponding to the answer of Jesus to the rich young man: “Do not kill, Do not commit adultery, Do not steal, Do not bear false witness, Do not defraud, Honor your father and your mother.” (CCC 1858)

Objective mortal sin - isn’t existant. (generally people mean this action is objectivle grave matter when they say this)


I agree that a sin can be objectively grave but not objectively mortal.



There is a problem with knowledge as well.

Either we don’t know or we were supposed to know. Someone who didn’t know could break the commandment, and this is labelled as not knowing. However, on the release of the tablets everyone was supposed to know, and that fact was driven home to the Levites on Moses’s return, and secondly by the remaking of the tablets. To make up for human frailties of forgetfulness we have the Church beckoning of the lost people to return(change of Faith). So we know they are to return so that they could be *better informed, one of the fruits of our Faith . *So not returning effects not wanting to be better informed, a sin in itself. More importantly to the point, we are required to temper our conscience by reviewing Scripture and dogma.

So it would seem that after the commandments were delivered there is no excuse by anyone in not knowing the gravity of the acts, and if they didn’t, then that is an indicator of someone who hasn’t been doing his obligation to remain informed. So *not knowing *is another sin that actually compounds the mortal sin and curiously the Church allows this as a dispensation for the grave sin in this case. Unless I’m off base here, I assumed another sin can never be an excuse for another.

Also not knowing the rule automatically classifies certain peoples who will have a dispensation from mortal sin. An atheist with an imperfect conscience could always say he didn’t know and that would be true, whereas a Catholic would be assigned more responsibility thus more accountable.

This I don’t understand. :shrug:



I think part of the difficulty here is in the definition of the actions of which we speak. The other part is the definition of full knowledge.

Some terms have the intention built in. Murder is an intentional killing of an innocent, by definition. If there was no intent, it would be manslaugther or an accident (depending on other factors). If the victim was not inncent, it would be self-defence/justifiable homicide. Likewise, adultery or masturbation always have the intent. You can’t do them by accident.

As to knowledge, we are all assumed to have knowledge of the natural law. It is “written on our souls”. Therefore, all humans are assumed to have full knowledge that murder, adultery etc., are against God’s law.

When you combine these two factors, you can see that adultery or murder must almost always be mortal sins (the exception would be the clinically insane, who do not know right from wrong).

God Bless


It is no different than criminal law. Murder is identified in the criminal code as an objectively grave matter. When it comes to prosecution, degrees of knowledge and intent on the part of the perpetrator may lessen (or aggravate) the guilt.

Killing an innocent person is always an objectively grave act. The criminal code would call it murder. Catholic moral law would call it a mortal sin.

If it is determined that the person who commited the act has defective knowledge of his actions, or less than deliberate intent, the seriousness of the crime is mitigated. That of course, occurs on a case by case basis, just as we judge ourselves in the confessional on a case by case basis.

When you speak of there being no such thing as an objectively mortal sin because of the inability of an outsider to know with precision all three conditions, that’s not quite right. Someone knows if those conditions have been met–the sinner, and God.
We go to confession because we have made that judgment.


That’s an interesting distinction, which is not consistently made in the catechetical tradition. Therefore it is more than acceptable for a Catholic to say, “objectively mortal sin”, meaning a sin which is a mortal in its object. For example, see the Catholic Encyclopedia:

Venial sin may also be found in the superior reason when it deliberately consents to sins that are venial in their nature, or when there is not a full consent in the case of a sin that is mortal considered objectively.


Hey Bilop, I was thinking on these points just after starting the thread and I think you are correct.

A person that “murdered” another but have no act of the will (perhaps they were insane or maybe they were a toddler), didn’t actually commit murder, they commited man slaughter or something of the sort.

Murder’s components:.

  • action of killing another.
  • will of killing that person.

2268 The fifth commandment forbids direct and intentional killing as gravely sinful. The **murderer **and those who cooperate voluntarily in murder commit a sin that cries out to heaven for vengeance.

Similarly, the CCC on masterbation:

2352 By masturbation is to be understood the **deliberate **stimulation of the genital organs in order to derive sexual pleasure.

So, some level of conscent is packed in with the definition of masterbation, though this still doesn’t mean automatic full conscent nor automatic mortal sin. For some bit of conscent is needed just to be a venial sin.

Ejaculation lacking any conscent, like nocturnal emission or spme other way it might happen, are of course fully innocent and neither mortal or venial sin.

But yes Bilop, I agree that many sins have more than just the action built in.


What they mean to say by “objective mortal sin” is that by the object of the act would constitute a mortal sin. An example would be if a man or woman uses contraception, by that “act” one is engaging in a grave act. Now whether or not that person is culpable for that grave act is another question and one that is usually (but not always) known to the person and of course God always knows the heart. Within the sacrament of confession one can possibly further extrapolate whether or not they have commited a mortal sin as a good priest will ask questions that person hasn’t considered.

Again, a mortal sin isn’t just engaging in a sin of grave matter but it is doing so with the full and complete knowledge of it being a grave act before God and doing it anyway. God looks at our hearts and our intent and He knows if we love Him or not, so if we truly love him we will seek Him and learn to suffer through these difficulties. :slight_smile:


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