As homosexual acts are unnatural, are all sins unnatural?

Yes, though "natural" has to be understood correctly.

[37602] Iª-IIae q. 94 a. 3 ad 2
Ad secundum dicendum quod natura hominis potest dici vel illa quae est propria homini, et secundum hoc, omnia peccata, inquantum sunt contra rationem, sunt etiam contra naturam, ut patet per Damascenum, in II libro. Vel illa quae est communis homini et aliis animalibus, et secundum hoc, quaedam specialia peccata dicūntur esse contra naturam; sicut contra commixtionem maris et feminae, quae est naturalis omnibus animalibus, est concubitus masculorum, quod specialiter dicitur vitium contra naturam.

Human nature can be said of those things which are proper to man, and, in this way, all sins, inasmuch as they are against reason, are also against nature, as is clear in the 2nd book of Damascene. Or it can be said of those things which are common to man and animals, and, in this way, certain specific sins are said to be against nature; just as sexual intercourse between men, which is specifically called the vice against nature, is against the mingling of man and woman, which is natural to all animals

What’s your definition of “unnatural” that allows you to confidently assert that “homosexual acts are unnatural”, jack3?

For example, do you think it is “unnatural” for a woman to enjoy receiving a sensuous massage, consensually, from another woman? Is there a point at which such a massage changes from being “natural” to being “unnatural”, and if so, by what definition of “unnatural”?

Acts which are ordered towards their good and proper end are natural. Acts that which are not ordered towards their good and proper end are unnatural.

Homosexual intercourse is not ordered towards the natural end of what male ejaculation is intended; the fertilization of the female ovum. Therefore, it is unnatural.

I'm skipping a lot of detail because frankly I know its a total waste of time to explain all the premises. Suffice to say even pagan Aristotle reasoned that homosexual sex is unacceptable, so its not just a religious thing.

You will need to do some serious reading on what things and their proper ends. What things are designed for if you will. If you make it so malleable as to making things a matter of interpretation and pleasure, you will come up with all sorts of problems......religious or not. And it's not a hard line where everything is equally wrong if you will (like using a fork designed for specific purpose for something else). Some things are more grave than others.

Can you give a source, please?

IIRC Edward Feser's "The Last Superstition".

I've loaned it out, but will confirm as soon as I can get it back.

Dominic - I purposely skipped all of this (e.g., "what things are designed for") as we're getting into some deep territory doing so (i.e., milk before meat so to speak).

It should be noted that while sodomy is called the unnatural vice, all sexual sins that inherently exclude procreation are called unnatural. This would include masturbation, bestiality, contraception, and imperfect sodomy (such as oral or anal sex between a man and woman)

Again, all sins are against nature, but there violate even the order that arises from those inclinations we share with beasts.

Homosexual acts are especially singled out, e.g as one of the four sins that cry out for vengeance, not because they are the most unnatural (beastiality beats it there) but because such behavior as was seen in the ancient world, e.g pederasty, was an exemplification of moral decadence, something fallen into as a result of sin

As it says in Romans

For the wrath of God is revealed from heaven against all ungodliness and injustice of those men that detain the truth of God in injustice: [19] Because that which is known of God is manifest in them. For God hath manifested it unto them. [20] For the invisible things of him, from the creation of the world, are clearly seen, being understood by the things that are made; his eternal power also, and divinity: so that they are inexcusable.

[21] Because that, when they knew God, they have not glorified him as God, or given thanks; but became vain in their thoughts, and their foolish heart was darkened. [22] For professing themselves to be wise, they became fools. [23] And they changed the glory of the incorruptible God into the likeness of the image of a corruptible man, and of birds, and of fourfooted beasts, and of creeping things. [24] Wherefore God gave them up to the desires of their heart, unto uncleanness, to dishonour their own bodies among themselves. [25] Who changed the truth of God into a lie; and worshipped and served the creature rather than the Creator, who is blessed for ever. Amen.

[26] For this cause God delivered them up to shameful affections. For their women have changed the natural use into that use which is against nature. [27] And, in like manner, the men also, leaving the natural use of the women, have burned in their lusts one towards another, men with men working that which is filthy, and receiving in themselves the recompense which was due to their error.

Aren't there some cases of homosexuality in animals?

Yes and no.

Homosexuality as we have it now is not the same as sodomy. What I mean is that, historically, sodomy has not been tied to an orientation. E.g the practice of pedastry in ancient Greece was not a matter of a different orientation, but a cultural decadence, and such men would marry wives, etc.

The examples in the animal world are seem to be of two sorts... Domination over other males, or out of control sexual drive (otters, dolphins, etc will rape other species and even carcasses!)

There is no analogue for homosexuality as an orientation.

In anycase, natural law is based on reason apprehending human nature. What Aquinas is driving at is not about animal behavior, but rather the inclinations of human nature that we have insofar as we are animals. Remember, he classes the inclinations that natural law is based on into three groups... What we have in common with all substances, what we have as animals, what we have proper to reason. It is still the case that procreation, education of offspring, etc are different for men than for foxes or birds or fish.


From S.Th. I-II q 94 a. 2 co
Since, however, good has the nature of an end, and evil, the nature of a contrary, hence it is that all those things to which man has a natural inclination, are naturally apprehended by reason as being good, and consequently as objects of pursuit, and their contraries as evil, and objects of avoidance. Wherefore according to the order of natural inclinations, is the order of the precepts of the natural law. Because in man there is first of all an inclination to good in accordance with the nature which he has in common with all substances: inasmuch as every substance seeks the preservation of its own being, according to its nature: and by reason of this inclination, whatever is a means of preserving human life, and of warding off its obstacles, belongs to the natural law. Secondly, there is in man an inclination to things that pertain to him more specially, according to that nature which he has in common with other animals: and in virtue of this inclination, those things are said to belong to the natural law, "which nature has taught to all animals" [Pandect. Just. I, tit. i], such as sexual intercourse, education of offspring and so forth. Thirdly, there is in man an inclination to good, according to the nature of his reason, which nature is proper to him: thus man has a natural inclination to know the truth about God, and to live in society: and in this respect, whatever pertains to this inclination belongs to the natural law; for instance, to shun ignorance, to avoid offending those among whom one has to live, and other such things regarding the above inclination.

By that reasoning, male ejaculation is "unnatural" every time it happens except when a man is having sexual intercourse with the intention of "fertilization of the female ovum". I think that's a very peculiar definition of what's "natural" and what's "unnatural", which I don't think many people could agree with.

Aristotle also reasoned that women are inferior to men:

“The relation of male to female is by nature a relation of superior to inferior and ruler to ruled."

“The female is, as it were, a mutilated male, and the catamenia are semen, only not pure; for there is only one thing they have not in them, the principle of soul.”

However, Aristotle did not believe that women are inferior to all men, he reasoned that women are superior to slaves, including male slaves.

Aristotle also maintained that women have fewer teeth than men.

The act is what we are speaking, not the result. You have created a straw man.

Regardless, how would you define natural and unnatural? I’m speaking using the language of philosophy and as noted by another poster, understanding those definitions is key to understanding all of the truth’s here.

You are making an error in reasoning. Because Aristotle was wrong about some things doesn’t mean he’s wrong about all things.

You are making an error in reasoning, Peteem, in concluding that I made an error in reasoning, when there is absolutely no basis for your conclusion. I did not reason that because Aristotle was wrong about some things, he’s therefore wrong about all things.

What I did was suggest that because Aristotle was wrong in his reasoning about some things, he may also have been wrong when he “reasoned that homosexual sex is unacceptable”.

My sincere apologies.

He didn’t.

Who didn’t? Who is “He”? What didn’t he do?

Aristotle didn’t make an error in reasoning about homosexual activity.