Sloth as a mortal sin?


Deep apologies for asking this again,

When would sloth become a mortal sin? In St. Thomas Aquinas’s Summa Theologica, he says it becomes mortal when we have sorrow to do something for God, aka sorrow for the Divine good. Does this mean laziness in striving after virtues? Or the scorning at having to say a prayer even though one isn’t obliged to?


Laziness is not necessarily sloth.

There can be yes venial sin in laziness …even in working on virtues.


Spiritual sloth has to do with* refusing* the joy that comes from God…being repelled by his Goodness.

(remember such involves the will.…all sorts of emotions could happen to a person without any will being involved…no sin involved).

(and of course for a mortal sin one needs grave matter, full knowledge and complete consent).


Refusing the joy as in indulging in worldly goods for happiness?



Well one could yes turn from God - reject him and turn towards worldly goods as if they are God.

That would yes be mortal…

But not sure I would call that sloth…though perhaps that can be involved.

Again spiritual sloth has to do with refusing the joy that comes from God…being repelled by his Goodness.

So I suppose one could be repelled by the Goodness of God and turn away from him to other gods…

(again not just some feeling that happens to someone without consent of the will…)


See this ask an apologist question:

If you have this idea of a mortal sin being committed for not praying as much as possible, then that’ll lead to scruples. Notice how ambiguous it is to simply not strive after being virtuous. Stick to an examination of conscience like this one:

It outlines what is a mortal and venial sin, so you probably won’t have to confess anything not listed there. It’s actually only a mortal sin of sloth (about prayers) when one neglected praying for as long as a month, and a venial sin for not praying every day. However, as I noticed, a lack of prayer throughout the day can easily lead to committing even a mortal sin in the course of one’s activities.

Try to not read things that are ambiguous, since a lack of joy for God can range from not praying 24/7 to giving up one’s religion

God bless


No I would not suggest that one for anyone who does not have a good formation already and thus can sort it out and not being prone to scruples.

For it is dated and thus can* lead *one to scruples in some cases.


Yeah, you’re right about it not being helpful for a scrupulous person, my bad.

I guess finding what’s a venial and mortal sin should just be from your confessor if one’s scrupulous.

But it’s helpful for anyone (except for a scrupulous person) who might just want to clear up and know the differences between a venial and mortal sin in a certain case; and not for a scrupulous person to examine their conscience with–which would take them hours to do so.

Thank you


Yes a regular confessor is key for those who do struggle with such.


No …again it is dated and it can thus be misleading (and thus wrong now).


That’s not exactly what Thomas says. He does say this:

"Therefore sloth is a mortal sin in respect of its genus. But it must be observed with regard to all sins that are mortal in respect of their genus, that they are not mortal, save when they attain to their perfection. Because the consummation of sin is in the consent of reason: for we are speaking now of human sins consisting in human acts, the principle of which is the reason. Wherefore if the sin be a mere beginning of sin in the sensuality alone, without attaining to the consent of reason, it is a venial sin on account of the imperfection of the act. "

He’s referring to sloth as grave matter in the first sentence. He goes on to say, as with any other sin involving grave matters, it does not rise to mortal sin unless they, "attain to their perfection ". This is an action of reason not just a simple case of weakness of flesh.

“So too, the movement of sloth is sometimes in the sensuality alone, by reason of the opposition of the flesh to the spirit, and then it is a venial sin; whereas sometimes it reaches to the reason, which consents in the dislike, horror and detestation of the Divine good, on account of the flesh utterly prevailing over the spirit. On this case it is evident that sloth is a mortal sin.”

So, here ^ Thomas uses some pretty strong language to highlight when sloth becomes a mortal sin, as opposed to venial.


In proverbs, it says the slothful man
will not roast his prey(so that he can
eat it!!) We must LEARN to prepare
for our own SPIRITUAL food and not
be SPOON-FED all the time, grow
up, in other words


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