In his classic text ''After Virtue,'' the philosopher Alisdair MacIntyre lamented, not so much the immorality that runs rampant in our contemporary society, but something more fundamental and in the long run more dangerous; namely, that we are no longer even capable of having a real argument about moral matters. The assumptions that once undergirded any coherent conversation about ethics, he said, are no longer taken for granted or universally shared. The result is that, in regard to questions of what is right and wrong, we simply talk past one another, or more often, scream at each other.

I thought of MacIntyre's observation when I read a recent article on the Supreme Court's consideration of the much-vexed issue of gay marriage. It was reported that, in the wake of the oral arguments, Justice Elena Kagan remarked, "Whenever someone expresses moral disapproval in a legal context, the red flag of discrimination goes up for me." Notice that the Justice did not say that discrimination is the result of a bad moral argument, but simply that any appeal to morality is, ipso facto, tantamount to discrimination. Or to state it in MacIntyre's terms, since even attempting to make a moral argument is an exercise in futility, doing so can only be construed as an act of aggression. I will leave to the side the radical inconsistency involved in saying that one has an ethical objection (discrimination!) to the making of an ethical objection, but I would indeed like to draw attention to a very dangerous implication of this incoherent position. If argument is indeed a non-starter, the only recourse we have in the adjudication of our disputes is violence, either direct or indirect. This is precisely why a number of Christian leaders and theorists, especially in the West, have been expressing a deep concern about this manner of thinking. Any preacher or writer who ventures to make a moral argument against gay marriage is automatically condemned as a purveyor of "hate speech" or excoriated as a bigot, and in extreme cases, he can be subject to legal sanction. This visceral, violent reaction is a consequence of the breakdown of the rational framework for moral discourse that MacIntyre so lamented.

A telltale sign of this collapse is our preoccupation, even obsession, with poll numbers in regard to this question. We are incessantly told that ever-increasing numbers of Americans--especially among the young--approve of gay marriage or are open to gay relationships. This is undoubtedly of great interest sociologically or politically, but in itself, it has nothing to do with the question of right or wrong. Lots of people can approve of something that is in fact morally repugnant, and a tiny minority can support something that is in fact morally splendid. For example, if polls were taken in 1945 concerning the rectitude of dropping atomic bombs on Japan in order to bring the war to a rapid conclusion, I am quite sure that overwhelming majorities would have approved. And if a poll had been taken in, say, 1825, concerning the legitimacy of slavery, I would bet that only a small minority of Americans would have come out for eliminating the practice. But finally, in either case, so what? Finally, an argument has to be made. In the absence of this, the citation of poll numbers in regard to a moral issue is nothing but a form of bullying: we've got you outnumbered.

Still another indication of the breakdown in moral argumentation is the sentimentalizing of the gay marriage issue. Over roughly the past twenty-five years, armies of gay people have come out of the closet, and this is indeed welcome. Repression, deception, and morbid self-reproach are never good things. The result of this coming out is that millions have recognized their brothers, sisters, aunts, cousins, uncles, and dear friends as gay. The homosexual person is no longer, accordingly, some strange and shadowy "other," but someone I know to be a decent human being. This development, too, is nothing but positive. The man or woman with a homosexual orientation must always be loved and treated, in all circumstances, with the respect due to a child of God. Nevertheless, it does not follow that everything a decent person does or wants is necessarily decent. Without a convincing argument, we cannot simply say that whatever a generally kind and loving person chooses to do is, by the very nature of the thing, right. This is why I am never impressed when a politician says that he is now in favor of gay marriage, because he has discovered that his son, whom he deeply loves, is gay. Please don't misunderstand me: I am sincerely delighted whenever a father loves and cherishes his gay son. However, that love in itself does not constitute an argument.

The attentive reader will have noticed that I have not proffered such an argument in the course of this article. That will have to be matter for another day. What I have tried to do is clear away some of the fog that obfuscates this issue, in the hopes that we might eventually see, with some clarity and objectivity, what the Catholic Church teaches in regard to sexuality in general and the question of gay marriage in particular.

Father Robert Barron is the founder of the global ministry, Word on Fire, and is the Rector/President of Mundelein Seminary near Chicago.