A good post -- with which I strongly disagree -- by Ed Feser on the natural law. Feser defends the traditionalist Catholic Thomistic view of natural law (in modern understandable terms). A couple of points need to be brought out.
1) Simply calling something "unnatural" (or abnormal) to try to score points against it -- whether it be homosexual acts, pedophilia or interracial marriage or whatever -- is on its face meaningless because there are many dictionary definitions of those terms and most (perhaps all) have absolutely nothing to do with the propriety of the actions or conditions involved. For instance, being left-handed or having an IQ over 150 is "abnormal" according to a commonly accepted understanding of that term. (For instance: "I'm getting an abnormally high number of hits on my website today.") And anything man made, clothes even, or anything that doesn't naturally exist in nature, is "unnatural" according to a commonly understood usage of the term "natural." (For instance: "Those plants were genetically engineered. That's unnatural.")
2) Therefore if we are to use the term "natural" or "unnatural" to mean something in a morally significant or "ought" sense, then it must be attached to a specific, coherent, complete and defensible general *theory* of "natural ends" whereby we can examine all sorts of things -- activities and even traits -- and see how they fit within the rubric of the theory. Otherwise calling something "unnatural" or "abnormal" is an empty rhetorical flourish that has no more meaning than statements such as "left-handedness is abnormal" or "clothes are unnatural." And Feser does a credible job making his case, even though I like most people (even most conservative Christians as I will argue) reject it as self-evidently ridiculous and even harmful as applied to everyday reality.
The most interesting part of Feser's long post (of course) is where he applies this theory to sex:
Since it’s the natural law theory example that critics of the theory always get the most worked up over, let’s look at sex. One way to understand the traditional natural law view of the matter is this. If you consider the sexual drives that human beings have, then it is blindingly obvious that if those drives have any natural purpose at all – if they were, say, designed with a certain end in view – then that purpose is to get people to use their sexual organs. And if you consider the sexual organs themselves, then it is also blindingly obvious that if they were designed with any purpose in mind, then that purpose is procreation. More specifically, the purpose of a penis – again, if you assume that it was indeed designed with a purpose in mind – is quite obviously to deposit semen into a vagina (and also, of course, to urinate). That’s what it’s for, if indeed it is for anything, and whether or not it can be used for other purposes. You can use a corkscrew for all sorts of things – cleaning your fingernails, say – and you might for some reason even have a compulsion to use it only to clean your fingernails. The fact remains that what a corkscrew is for is opening bottles. And the purpose of sexual organs, if they have one, isn’t any more mysterious than that of corkscrews.
We can note further that given the way human beings are constructed – no built-in plugs or sheathes, no ejaculatory on/off switch etc. – it is very difficult to use a penis in a way that accords with its apparent natural purpose (i.e. depositing semen into a vagina) without also having children, and lots of them. The Pill just doesn’t grow on trees, nor is a supply naturally issued with every penis or vagina at birth. So, it follows that if sexual drives and organs were designed for a certain purpose, then that purpose was pretty clearly not just occasional procreation, but fairly steady procreation. Whoever designed them clearly wanted people to have lots of sexual intercourse, and to have it precisely so that they’d have lots of children.
It must also be emphasized that, contrary to another common misunderstanding, “unnatural” in the context of the view I’m describing does not mean “using something other than for its natural purpose.” It means “using it in a manner contrary to its natural purpose.” To borrow an example from Michael Levin, there is nothing unnatural about merely tapping out a little song on your teeth, even if that’s not what teeth are for. But there is something unnatural about painting little pictures on your teeth and then refusing ever to eat again lest the pictures be rubbed off, or pulling them out so as to make a necklace out of them. The former sort of act does not frustrate the natural end of teeth, but the latter acts do. And part of the idea in the traditional natural law understanding of the sexual act is that ejaculating into a Kleenex, or a condom, or into any bodily orifice other than a vagina, doesn’t just involve using an organ other than for its natural purpose (which is not necessarily “unnatural”) but that it uses it in a manner contrary to its natural purpose. For the “aim” or point of arousal and ejaculation, if they have an aim or point at all, is to get semen into a vagina, and the acts just described frustrate that aim.
So there you go. This theory of "natural sex" views procreation as the ultimate teleology behind sex (it's kind of hard to argue with while examining the design and functions of our sexual biology). This theory not only (obviously) views homosexual sex as "unnatural," but also equally heterosexual oral sex (and anal sex too -- practiced by many heterosexuals, but not nearly as widely practiced as oral), all acts of contraception and even masturbation. Therefore a good married Christian couple having contracepted sex is doing something every bit as "unnatural" as what homosexuals do. A teenage male masturbating -- every bit as "unnatural" as homosexuality.
You see what I mean when I write that it's not just me but the overwhelming majority of folks, even most red-state Christian conservatives, will reject this theory as unrealistic and untenable.
But this is important to note: The theory as articulated by Feser and those before him is coherent: You accept the entire thing or reject the entire thing. You cannot, in an intellectually honest and coherent way, (and as I'm sure many would wish to do) attempt to modify it to "fit" your agenda; you cannot, for instance, as I've seen done, attempt to argue that married couples having contracepted sex, or oral sex, or masturbation is "natural" on the one hand, but homosexuality "unnatural" on the other. Nope: Doing so is trying to have your cake and eat it too. When attempting to come forth with a natural teleology of sex in an "ought" sex, all roads lead to procreation. Therefore any act that purposefully frustrates the natural procreative aspect of sex is "unnatural," period.
Protestant Evangelical Francis Beckwith (who appears to question the notion that a married couple having contracepted sex is "unnatural") in the comment section, attempts to have his cake and eat it too:
But let me raise a question concerning the natural purpose of sex organs. Could not someone say that they have two intrinsic purposes--one flesh communion and procreation? Thus, contraception, in fact, enhances the intrinsic purpose of one-flesh communion by allowing married couples to engage in conjugal acts that nurture intimacy and shared devotion. Surely, the procreative function is stymied, but it is stymied for the sake of the organs' other goods. So, perhaps, we can think of justifying contraception--along natural law lines--on the ground of the principle of double-effect: there are both good and bad results, but the good outweighs the bad and the intent of the actors is to will the good.
To which, Max Goss, editor of the site, responds:
Frank, I know you addressed your question to Ed -- and I, too, would like to hear his answer -- but let me take a stab at it (also off the top of my head). I see three problems with your suggestion.
1. It would justify sodomy.
2. It is far from clear that the good of sexual intimacy outweighs the bad of preventing the conception of a child.
3. I'm not sure the intimacy of "one flesh communion" can be made sense of apart from the possibility of procreation.
As I said, I reject the entire theory as applying in an "ought" sense. Yes, the natural biological design for our sexual organs is procreation. But it doesn't follow that it is therefore bad to separate sex from procreation. Pleasure in itself, bonding, forming meaningful romantic relationships absolutely cut-off from reproduction and child-rearing is good for human flourishing.
Feser attempts to justify why infertile couple sex is okay -- fits into this theory. Often it is assumed we are referring to young couples who ought to be fertile but by biological defect aren't (and you know "miracles happen"). But arguably this is not most infertile couples. Most infertile couples are so not by defect but rather by biological design. I am of course referring to sex where one party is a post-menopausal woman. (Is God or "Nature" telling us that women past menopause ought not have sex, that to do so would be "unnatural"?)
Marriages of couples like Bob & Liddy Dole, John & Teresa Kerry, Prince Charles and Camilla Bowles -- these marriages have as little to do with "procreation" or "child rearing" as a homosexual marriage. And no, a "miracle" will not happen in a post-menopausal marriage. There is as little chance, again, not by defect but by natural design, of Bob & Liddy Dole's marriage producing a child as with a homosexual couple.