nojoum wrote:

Adding to the case of sterile couples, we can go to homosexuals. First, Dr. Feser does not show that homosexuality is a grave sin as it is viewed in Catholicism. Moreover, suppose that homosexuals adopt enough number of children. Therefore what is wrong for them to marry each other and have sex because they fulfilled the nature's end of having sex-which is suitable reproduction- by adoption  ( just like the couples who have enough children or can’t we say that or just like the sterile couples who have sex )? or at least can't we say that they commit much less sin if they adopt children?

Can I add a quick qualification here - the issue is not so much with homosexuality or contraception being irrational, that conclusion is inescapable if one excepts the teleology of organs dictating morality premise (although one might try to argue the genitals as centres of orgasmic stimulation serve another function in the case of homosexuality), but how one gets from irrational to gravely immoral, a jump which is usually made by appealing to issues of the 'Common Good'.
 

DanielCC wrote:

Can I add a quick qualification here - the issue is not so much with homosexuality or contraception being irrational, that conclusion is inescapable if one excepts the teleology of organs dictating morality premise (although one might try to argue the genitals as centres of orgasmic stimulation serve another function in the case of homosexuality), but how one gets from irrational to gravely immoral, a jump which is usually made by appealing to issues of the 'Common Good'.
 

Thank you for your response. I think actually the problem is the teleology of the sexual organs. Using contraception or being homosexual is not like cutting your arms for no reason; especially if you consider a family which has already enough number of children. In such family, what is wrong with parents having protected sex for unitive purposes only?

nojoum wrote:

Dr. Feser mentions that according to perverted faculty argument there is nothing with wrong with sterile couples having sex because the sterile couple are not actively frustrating the nature's end. However, this seems to be problematic. If it is impossible for the couple to conceive a child, what intention other than unity they have for having sex? Therefore, the couples are intending to have sex for unitive purpose not the procreation which seems to be morally wrong. Moreover, we can add that, it is in fact the fault with their reproductive organ that is acting as a contraceptive and they are using sex merely for unitive purposes which seems to be against the perverted faculty argument (one might say that they are not actively frustrating the nature's end but this objection does not seem convincing to me, because I do not see any difference between sterile couples and normal couples who have protected sex).

As I understand it​, what is important according to Thomistic law is not primarily the intentions of the couple (except perhaps in the case where someone who can have children has married someone infertile because they are infertile), but the ends of the organs or faculties involved. The couple are using their sexual organs according to the natural ends of those organs. It is not the couple's fault this does not result in procreation, and there is no perversion of the faculties involved. Procreation is one end of our sexual organs, but we cannot procreate in some other way and then use our sexual organs against their nature. As I mentioned above, there seems to be a holistic quality to natural law thinking.

I think Dr. Feser discusses such cases. If I recall, as the rotting limb has completely ceased to fulfill its purpose, and may kill the patient, I think he argues it is permissable to cut it off. Maybe someone has his exact words?

It does seem to me like there is a difference here. The limb cannot function whereas the sexual faculties in question (for some reason it is always about them - what would moderns have to discuss if homosexuals didn't exist!) clearly can.

It is still the case, I believe, that the functions of, say, a leg are subordinate to the life of the organism in its entirety. A rotten limb will presumably kill you if not removed. The natural law perspective, though it emphasises the importance of the ends of our faculties, still ultimately subordinates these to the overall end of the human being. There does seems a difference here between the example of homosexual acts or contraceptives, as the same sort of threat to the overall organism cannot be shown - our sexual organs are still functioning and the jettisoning of their ends would be premature.