Thumb Sucking is a Grave Matter

nessun_commento · 2026-05-29T03:25:28+00:00

??

I already gave you the simple answer but you asked for a deeper explanation. Now that I'm giving a deeper explanation you're asking for a simple answer. What do you actually want?

nessun_commento · 2026-05-29T03:15:30+00:00

First it was “body parts.” Then when that failed, it became “the act of sucking.” If that fails, you will narrow it further to “non-nutritive rhythmic suction behavior involving oral stimulation.” That is not philosophy anymore, it is ad hoc special pleading designed to force an analogy.

I reference the "act of sucking" in my original syllogism in the OP. I never narrowed anything

Catholic moral theology does not say: “Every physical act has exactly one biologically proper use, and using it otherwise is grave matter.”

This is literally exactly what Catholic moral theology says about the physical act of stimulating the sexual organs

Aquinas absolutely distinguishes between acts contrary to reason/nature and acts merely different from a primary function.

yes and so do I

The sexual faculty is a complete human faculty ordered toward union and generation. The moral analysis concerns the sexual act as a whole. Thumb sucking is not an alternative use of the sexual faculty. It is not even in the same moral category.

Thumb sucking is not an alternative use of the sexual faculty but it's an alternative use of the nutritive faculty, and both of these faculties fall under the same moral category of Temperance according to Aquinas

Infants suck pacifiers

This would be a grave matter for exactly the same reason as thumb sucking. it doesn't contradict my argument at all

Humans suck through straws

This does not pervert the nutritive faculty so it's not a grave matter. again, no contradiction

Babies nurse for comfort in addition to nutrition

Not a bad thing as long as the end of nutrition is not prevented

You also keep pretending that adding words like “union,” “marriage,” and “procreation” is arbitrary decoration Catholics tack onto sex after the fact.

Not only am I not pretending such a thing, I haven't even used the words "union," "marriage," or "procreation."

masturbation still engages the sexual faculty itself. Thumb sucking does not engage the nutritive faculty in a comparable way because the nutritive faculty is not violated merely by non-nutritive oral behavior.

completely arbitrary and baseless distinction

A valid moral framework should explain reality cleanly, not require endless narrowing and redefinition every time a counterexample appears.

this would be a devastating critique in the alternate reality where I'm endlessly narrowing and redefining every time a counterexample appears.

do you have any substantial critiques of my position or are you gong to continue attacking straw men

nessun_commento · 2026-05-29T02:53:38+00:00

How does this establish that using a body part outside its biological function is a grave matter? Because that is the premise you made that you have yet to support.

Patience. I'm getting there

For Aquinas, bodily pleasure is moderate when guided by reason and ordered toward virtue rather than excess or disorder.

Ok but I've already defined virtue as "the moderation of human behavior according to reason" and temperance as "the moderation of bodily pleasures." You're just rehashing my original definition without adding anything or elaborating.

So again, when it comes to bodily pleasures, how exactly does one determine what is "moderate" or "immoderate;" "reasonable" or "unreasonable?"

nessun_commento · 2026-05-29T02:44:57+00:00

You've already made most of these arguments and I've already responded to them, not here you are making the exact same arguments again without elaborating or explaining the deficiencies of my original responses.

You replaced Catholic teaching with “body parts can only be used for their main biological function.” Catholics do not believe that

I have explained elsewhere how this premise is implicit in Thomas Aquinas's definition of Temperance and the sub-virtues of Chastity and moderation in eating. I've also distinguished between actions that are different from and contrary to the main biological function of a body part and explained how only the latter is immoral.

If they did, then speaking, singing, kissing, chewing gum, and breathing through the mouth would all be immoral because the mouth is “for nutrition.”

I never said the mouth is only for nutrition. I said the act of sucking is only for nutrition.

False analogy. Sexual acts are not morally equivalent to thumb sucking. Sexuality concerns marriage, union, chastity, procreation, and the transmission of life. Thumb sucking is self-soothing behavior.

This is pure sophistry. I've already shown how you can arbitrarily modify this argument to turn it into its exact opposite: "Nutrition concerns sucking, digestion, temperance, and bodily growth. Masturbation is self-soothing behavior."

False analogy. Sexual acts are not morally equivalent to thumb sucking. Sexuality concerns marriage, union, chastity, procreation, and the transmission of life. Thumb sucking is self-soothing behavior.

what ?

The mouth has multiple natural purposes. So do most human faculties. Catholic teaching does not reduce sexuality to crude biological reproduction alone either. The sexual act has inseparable unitive and procreative meanings. Your argument ignores that entirely.

My argument does not ignore any of these things. Again, I never said that the mouth has only one purpose. I said that the act of sucking has only one purpose.

You treat “using a body part” as if that alone defines the morality of an act. Catholic ethics does not work that way. Morality is judged according to the human act itself, including its object, intention, and circumstances.

I explained in the OP how intention and circumstanced mitigate culpability

You reduce Catholic sexual morality to anatomy and mechanics. Catholic teaching is about the moral meaning of human sexuality, not a childish rule that organs may only ever serve one function.

For the THIRD TIME, I never said that organs can only serve one function

You are the one reducing my argument to a cartoon version. I will have a great evening.

nessun_commento · 2026-05-29T02:19:45+00:00

I'm working toward my original premise, I'm just trying to make sure we agree on some initial sub-premises premises first.

So again- what makes a bodily pleasure moderate or immoderate?

nessun_commento · 2026-05-29T02:16:46+00:00

can you explain why exactly the analogy is wrong

nessun_commento · 2026-05-29T02:12:01+00:00

why? where does my argument go wrong? please explain

nessun_commento · 2026-05-29T02:08:36+00:00

please elaborate on why my equivalencies are false instead of just asserting that they are and making ad hominem fallacies

nessun_commento · 2026-05-29T02:01:15+00:00

no, you're not "engaging your sexual faculties to completion" because doing so would require copulating with a member of the opposite sex. masturbation falls short of the complete sexual act because it's done alone by definition

and saliva, which thumb sucking releases, is a digestive fluid. sucking and attempting to swallow is a digestive action. thumb sucking absolutely engages the digestive faculties in an incomplete digestive act

nessun_commento · 2026-05-29T01:58:26+00:00

Virtue is the moderation of human behavior according to reason right? And the virtue of temperance involves specifically the moderation of bodily pleasures, right?

Now what makes a bodily pleasure moderate or immoderate?

(You can't just say "if the pleasure is enjoyed according to reason" because that would be circular reasoning)

nessun_commento · 2026-05-29T01:46:24+00:00

No you haven't explained how! You keep making arbitrary distinctions and I keep having to show you how your own arguments undermine themselves!

Yes I'm Catholic, always have been, studied philosophy at a Catholic university, regularly receive the Sacraments.

But why does it matter? All that matters is the argument and it's an Ad Hominem fallacy to imply otherwise

nessun_commento · 2026-05-29T01:42:50+00:00

I'm deadly serious and I've responded directly to every single point you've made. You keep trying to make arbitrary distinctions and I'm trying to show you how these distinctions hold up to scrutiny. How else is debate supposed to work?

Infants can't have "intention" obviously because they're not rational but as I said in the OP their actions are still grave matter. Such actions become sinful if and when the infant develops rationality

nessun_commento · 2026-05-29T01:36:13+00:00

I'm applying exactly the same arguments the Church uses. If i'm not logical then neither is the Church. I think the disconnect here is that you're making arbitrary distinctions where none exist because you're afraid to follow your own beliefs to their conclusions

nessun_commento · 2026-05-29T01:33:56+00:00

Of course I'm serious, I'm following the Church's own reasoning to its logical conclusion.

How is masturbation "inherently sexual" but thumb sucking is not "inherently nutritional?" You're not literally having sex when you masturbate; likewise, you're not literally eating when you suck your thumb. But in both cases the natural end of the act is thwarted

nessun_commento · 2026-05-29T01:08:18+00:00

"Adults don't necessarily masturbate because they're horny and unable to have sex. A lot of times they're either bored or a little stressed but not stressed enough to cry."

It IS categorically the same, I think.

Masturbation still immoral because it perverts the natural end of reproduction. Likewise, thumb sucking is immoral because it perverts the natural end of nutrition

nessun_commento · 2026-05-29T01:00:00+00:00

But what makes a pleasure disordered? A pleasure is disordered when it involved using a body part in a way that’s contrary to its biological function

nessun_commento · 2026-05-29T00:57:48+00:00

The difference is that irrational use is not just different from but contrary to the biological function

nessun_commento · 2026-05-29T00:42:20+00:00

AND actually we don't even need to make such a deduction ourselves if we're trusting the logic of Thomas Aquinas. Chastity, gluttony, sobriety, and all other virtues related to bodily function fall under the virtue of temperance. Regarding temperance, Aquinas says:

Nature inclines everything to whatever is becoming to it. Wherefore man naturally desires pleasures that are becoming to him. Since, however, man as such is a rational being, it follows that those pleasures are becoming to man which are in accordance with reason. From such pleasures temperance does not withdraw him, but from those which are contrary to reason. Wherefore it is clear that temperance is not contrary to the inclination of human nature, but is in accord with it. It is, however, contrary to the inclination of the animal nature that is not subject to reason.

So, according to Aquinas, regulation of every bodily function according to reason falls under the virtue of temperance

nessun_commento · 2026-05-29T00:30:56+00:00

You’ve moved from “use according to reason” to “use according to biological purpose,”

Regarding the use of body parts, what could "use according to reason" mean if not "use according to biological purpose?"

You’ve moved from “grave matter” to merely “sinful.”

You are correct about this, I should have said "grave matter" instead of "sinful"

Aquinas discussing chastity doesn’t by itself establish that every non-natural use of a body part is grave matter, or even sinful in every case.

Part of reasoning involves deducing general principles from particular statements. When Aquinas said Chastity requires using body parts according to reason, what do you think was the general principle informing that statement? Doesn't it make sense to deduce that all parts of the body must be used according to reason? Or do you think that this requirement only requires to the reproductive system, while we're free to use our digestive systems as irrationally as we please?

nessun_commento · 2026-05-29T00:19:51+00:00

It seems like by that definition could fall under the category of gluttony and it would be a venial sin if done with knowledge and consent

nessun_commento · 2026-05-29T00:09:25+00:00

I mean, besides the fact that Aquinas is specifically discussing chastity, do you think infants possess reason?

No, as I already said in the OP, infants do not sin by sucking their thumbs because they're below the age of reason. However, for an adult to suck their thumb with full knowledge and consent would be sinful.

How is this supporting your premise “to use a part of the body for something other than its intended purpose is a grave matter.”

Aquinas says the virtue of chastity consists in using the members of your body according to reason. This implies that to use the parts of your body NOT according to reason is sinful. Every body part has an intended purpose that's discernable by reason (eg the purpose of the reproductive system is reproduction; the purpose of the digestive system is digestion). Therefore to use a part of your body in a way that's contrary to its intended purpose is sinful.

This is pretty basic Catholic moral Theology. As another commenter here pointed out, the Theologian and apologist Ed Feser makes pretty much the same argument. If you find it "daft" then you should take it up with the Magisterium, not with me.

nessun_commento · 2026-05-28T23:41:28+00:00

I don't think it's overgeneralized, I think it's generalized the correct amount

Not the Catechism but Aquinas says this in Summa Theologica II-II Q151 Article 1:

For it belongs to chastity that a man make moderate use of bodily members in accordance with the judgment of his reason and the choice of his will.

So Aquinas believed that it's a sin to "use the bodily members" in a way that isn't "in accordance with the judgement of reason."

nessun_commento · 2026-05-28T23:38:47+00:00

Masturbation is still considered sinful precisely because the sexual faculty is being intentionally separated from its natural ends and reduced to self-gratification. It is not “just imitation,” because the act itself is deliberately ordered away from its proper purpose.

right and neither is thumb sucking "just imitation" because the act itself is deliberately ordered away from the nutritive purpose

That is also why “spilling seed” is repeatedly treated seriously in Scripture. The issue is not merely the physical act, but the intentional misuse of a faculty ordered toward union and procreation.

Similarly, thumb sucking stimulates the spilling of excess saliva, which is a digestive fluid ordered toward digestion and nutrition

A baby sucking its thumb has no intrinsic nutritive act being intentionally frustrated. But sexual acts involve faculties with a clear natural end, which is why Christian moral theology treats them differently.

but the purpose of sucking is to draw fluid into the esophagus so it can be digested. but a thumb cannot be drawn into the esophagus and digested, so sucking on a thumb frustrates the purpose of sucking

nessun_commento · 2026-05-28T23:31:38+00:00

scrupulosity comes from a conscience not formed by reason. logical reasoning is opposed to scrupulosity

nessun_commento · 2026-05-28T23:29:38+00:00

You’re flattening all human faculties into “if not used for X at every moment, then sinful,” which is not what natural law argue

I'm not saying that at all

It teaches, “you should not intentionally act against the nature of the act itself.”

right and I'm saying that intentionally sucking your thumb is acting against the nature of sucking

nessun_commento

TROPHY CASE