Gary Gutting is a Notre Dame philosophy professor who thinks that what counts about arguments is whether they “work.” And so his complaint against natural-law arguments for Catholic teachings about sex is that they “no longer work (if they ever did)”. His New York Times “Opinionator” post of March 12th (“Unraveling the Church Ban on Gay Sex”) names us as two people who are “still” exponents of such arguments. For us what counts about an argument is whether it is sound, i.e., whether its premises are true and its logic valid. If a line of thought about the morality of sex is reasonable today, it was reasonable in the time of Jesus or Plato or Abraham or as far back as we find men and women and their children. Whether arguments “work” persuasively in one era but not another is philosophically irrelevant, as any philosopher should take for granted.

Gutting seems to think none of the positions of Judeo-Christian civilization on sex ethics are true, though he mentions only a few acts or practices that his own principles would leave immune from moral objection, carefully stopping short of calling attention to others such as polygamy, polyamory, prostitution, adultery, promiscuity, incest, bestiality and the man-boy sex that Plato’s friends and associates admired (but Plato himself condemned, like his teacher Socrates as Plato depicts him). This is not surprising, since his whole article never mentions, even by implication, the idea that grounds and unifies the whole set of sex-morality teachings, not only for Catholicism but also for Socrates, Plato, Aristotle and other great thinkers.

The idea is not “heterosexual union,” nor “shared acts directed towards reproduction,” nor any of the other concepts Gutting refers to and associates with “nature.” Instead, it’s the idea—the intrinsic human value—of marriage.

Even apart from any question of its legal status, marriage is a natural form of human association, with its own basic structure and value. It is the sort of loving union inherently oriented to family life; it is the sort of living bond that by its nature would be fulfilled—extended and enriched—by the bearing and rearing of children. Children by their nature need such familial, parental nurture, support, and guidance; by their coming to be, they make possible the continuance and flourishing of the wider society whose aid and social capital made feasible the wellbeing of their parents and other forebears.

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Of course, people sometimes band together in other arrangements with a view to child-rearing, and other forms of association can realize other types of (non-erotic) love. But only a man and woman together can commit to a loving union of the kind inherently oriented to family life and appropriate to being the mother and the father of their children. What this procreative-parental commitment and union require is an especially deep and far-reaching bond: the man and woman’s making the most extensive and permanent of human mutual commitments to sharing of life and earthly destiny, centered upon a permanently exclusive sexual relationship. The shaping end of procreation-and-nurturing thus unifies and explains all the features of marriage as “traditionally” understood: permanent exclusivity, sexual consummation, family life, and a radical union of the persons (in body as well as mind, in the wide-range pursuits of domestic life) that is uniquely extensive across time (“until death us do part”) and at each time (exclusive).

Because marriage is in these ways (i) an especially complete loving union (ii) of the sort oriented to procreation, it is uniquely embodied in sex acts with the same dual nature: acts that are (i) chosen as a seal of their complete (permanently exclusive) marital love-and-commitment (ii) and of the sort apt to make them (where circumstance allows) parents, the mother and father of their children. Only coital acts—chosen with a will to permanently exclusive marital love—can actualize, express, and allow the husband and wife to more fully experience their marriage—the multi-level (physical, emotional, rational-dispositional) sharing of life whose foundation and matrix is the biological unity made uniquely possible by sexual-reproductive complementarity. That explains why historically in our law (and in philosophical accounts of the intelligibility of the pertinent legal norms) only acts of spouses that fulfill the behavioral conditions of procreation have validly consummated marriage—and they do that whether or not the non-behavioral conditions of procreation happen to obtain. In short, only such sex acts are marital.

Moral reasoning is “of a natural law kind,” whether in St. Paul or Aquinas—or in Plato, Aristotle, Musonius Rufus, and others untouched by Jewish or Christian thought—not because it tries to read premises or conclusions off biological or sociological facts. It doesn’t. Instead, it considers what are the basic forms of human flourishing: conditions or activities that are good for us in themselves: friendship, knowledge, life and health, and the like. The identification of these of course takes into account biological and other cause-and-effect facts. But it is focused not on those but on the intrinsic goodness of the various elements of human fulfillment. We can then reason to the moral goodness and badness of types of choice and act by considering which choices are consistent with love and respect for ourselves and all others in regard to each of these basic dimensions of fulfillment. A choice consistent with love and respect for all the goods in all persons is morally upright; one that isn’t, is immoral.

That determination of consistency must take into account the fundamental circumstances of all our choices and acts. The basic goods for which we can act are many and various, so we cannot realize them all at once. But they all remain always goods, and each in its own irreplaceable way. So in pursuing some, we ought not to choose to denigrate or damage any of the others. And as they are goods for all people, we ought not to let our choosing be deflected by prejudice, wayward passion, and the like.

Now one of the basic human goods, as each of the thinkers mentioned above—and not just the Catholics or other Christians—understood, is marriage. So sex ethics unfolds by considering the conditions under which choices to engage in sex acts are consistent with the good of marriage. A few sentences in a short essay such as this one are not enough to show the good sense of this unfolding by defending and deploying its premises in ordered sequence to their conclusions. But one key to understanding it all is to grasp that—aside from obvious forms of injustice and harm-doing involving sex, especially the various forms of rape and some aspects of incest—every conclusion about wrong kinds of sex act is of the form: this kind of choice is wrong because it is unreasonable because it is against the good of marriage that is intrinsic to human fulfillment (of mother, father, their children, and their society). All forms of morally bad sex are against human nature because contrary to integral human fulfillment and therefore against reason.

The fact that from a limited perspective they may, as Gutting writes, be experienced or conceptualized as contributing to “meaning, growth and fulfillment” does not show that they truly are—that is, that they can be integrated with human fulfillment considered in a more rationally adequate way. Plato himself exposed the fallacy of thinking otherwise, at the very founding of Professor Gutting’s academic discipline. What satisfies desire or induces pleasure, however good or bad it is in its full reality, will likely be experienced, at least initially, as promising meaning, fulfillment, and even personal growth—the elements of Gutting’s truncated and superficial replacement of natural law theory.

The point of philosophical reflection is to evaluate prospective choices from a critical-rational standpoint in order to assess their compatibility with human fulfilment traced to its ultimate principles in the basic human goods, and considered holistically or integrally. Indeed, the contrary thought, applied to sex—as in Gutting’s post—would make it impossible to justify general moral exclusions of promiscuity, or anonymous sex, each of which can satisfy desire, and in each of which some people report finding meaning or personal satisfaction. (Thus, John Updike extensively expounded in novels and life the “sacrament of [serial] adultery,” and Andrew Sullivan the “spiritual value” of anonymous sex—i.e. intimate relations among strangers who do not even share their names with each other. Can Gutting find grounds consistent with his rejection of our views for denying what Updike, Sullivan, and many others claim? We don’t think so, though he is, of course, welcome to try.)

So Gutting’s arguments to show that homosexual sex acts can be morally right are all beside the point. He has invented a weird straw-man “natural-law” “selfish pleasure” argument against same-sex sex acts, and knocked it down. But it is not an argument either of us has ever endorsed. The natural-law argument against such acts is essentially the same as against any other kind of non-marital sex—from masturbation to fornication to adultery to bestiality. (The last is more degrading than the others, of course, in expressing an equality between persons and beasts; these kinds of act aren’t alike in every morally significant respect and degree—the point is just that there is one morally disqualifying feature they all share.) If popular speech singles out some of these acts—masturbation, same-sex sex acts, or indeed acts with beasts—as “unnatural,” it is because they are especially visibly not of the marital kind, involving behavior visibly not of the procreative sort. But the truly morally significant thing about all non-marital sex acts is that, in diverse forms, they involve disrespect for the basic good of marriage.

There are several ways to see this disrespect. Here, in these next four paragraphs, is one. Adequately respecting any basic good requires, among other things, not setting one’s will directly against any conditions essential and internal to that good. Now if a husband and wife do not reserve sex to their marriage, then even their sex acts with each other can’t really actualize and embody their marital bond: for these acts can’t express a truly exclusive commitment, which marriage inherently is. The husband and wife’s firm will to reserve sex for each other is, then, an essential condition of any sex they have with each other being marital sex. Even just a husband’s conditional willingness to engage in sex with someone else—e.g., “if the circumstances ever ensured that my wife wouldn’t find out…”—disables the marital quality of his sex acts with his wife, whether or not he ever actually cheats; and likewise for a wife.

Similarly, if people are willing to perform a sex act that fails to embody permanent commitment, or a bond that is procreative in type (whether or not it is, or can in the circumstances be, procreative in effect), they disable themselves from willing in such a way that their sexual congress can actualize and express the good of marriage, which is inherently permanent and procreative in type. Even mere approval of anyone’s non-marital sexual conduct implies a conditional willingness to engage in such acts oneself—namely, if one were in relevantly similar circumstances. That is, such approval implies willingness to choose sex under a description (e.g., “simply pleasing to all three of us,” or “simply expressive of affection,” or “simply conducive to my psycho-somatic health”) other than: marital.

Any such willingness vitiates an essential condition internal to any realization of the good of marriage and damages that aspect of ourselves—our human nature—that makes us, to quote Aristotle, conjugal beings. (Aristotle is famous for teaching that the human being is by nature a political animal; what is less often recalled is his teaching that human beings are even more fundamentally conjugal than political.) So it involves a failure to respect that basic human good; so it involves immorality, whether or not one is married or plans to be.

And because this particular basic good is so central to the common good, failures to respect it—forms of willing or willingness at odds with it—are also failures of due respect for the good of one’s whole society. This is not a merely abstract or “merely moral” matter: Such contra-marital attitudes easily spread and cause tremendous and quite visible social harm, as the carnage of the Sexual Revolution makes clear—harm measured in broken hearts and homes, fatherless children, and broader related injustices.

Plato, Aristotle, Paul, and everyone in the tradition understood that everyone unwillingly experiences some disordered tendencies towards some non-marital acts, and that some experience disordered tendencies exclusively to non-marital acts. They also understood that many who choose to engage in same-sex sexual relations do not have such an exclusive tendency. Their moral arguments are valid for both and all kinds of persons, though harder for some to live up to than for others.

Catholic sex ethics is “still” as fully reasonable today as it was when St Paul expounded it—and identified prostitution and same-sex sex acts as obviously or visibly far out of line with it—as the sort of thing that people would lose their sound judgment about if and only if they or their society were blind to or careless about the omnipresent, invisible reality of divine causation ex nihilo, divine providence, and the possibility of a divinely willed human destiny beyond death. The natural law understanding of human fulfillment is inherently intelligible without adverting to that “theistic” framework. But when reason closes itself off against the real framework as a true whole—in thought decapitating it—other distortions of understanding and judgment will ensue, especially in reason’s practical domain, where desire and satisfaction provide every incentive to rationalization of misjudgment.

The Archbishop of San Francisco wasn’t depending on natural law philosophizing when he said (what Gutting takes his cue from) that homosexual acts are against nature. He was just repeating Paul’s letter to the Romans, where the connections between reason, conscience, natural law, divine existence, and the divine revealed will and promise for human wellbeing are laid out as building blocks of the Catholic faith. But the concordance of this revealed faith with the best philosophy untouched by Hebrew sources, as a higher synthesis of the insights of Plato and Aristotle and many others, is just a sign of its perennial validity. Another equally telling sign is its good fruit—the good fruit of its exclusions and its condemnations of certain kinds of choice. These include the protection of children’s rights to have a father and a mother exclusively and devotedly theirs, in fruitful families within a civil society that can fulfill the elementary conditions of sustainability: large numbers of marriages generously welcoming children who are nurtured in dignity and supported in respect for (and willingness to adopt in their turn) this fulfilling, generous, but demanding form of life.