I despise illogical argument, and I love my wife. But just as much, I love my culture, that sum of received practice, belief, and wisdom I have come to share, or to believe I share, with those around me.
If gay marriage threatens your marriage, you haven't got much of a marriage.
That little line, destined to become a liberal talking point, encapsulates at least two logical fallacies.
First, no one I'm aware of is arguing that their own marriage will be harmed by allowing people who are unqualified to marry to do so. Straw man arguments are often appealing to those already convinced, but merely draw ire from those who disagree.
Second, it exhibits the Fallacy of Division, in which the parts of a thing are conflated with the whole. It is not the case that two unqualified individuals marrying harms my marriage in any appreciable way, nor do they even harm marriage itself. But in the aggregate, the change to the structure of the institution is profound.
And it is the institution I wish to protect. For our nation, and indeed Western civilization, derives considerable benefit from it. Children are best reared when their parents are there. Women are protected from the misuse of their youth by a lifelong commitment. Most importantly, marriage is an ideal, and ideals are what policy should encourage. That the ideal is becoming less common is not the fault of marriage, but those who have blindly or with malice sown the seeds of its deterioration.
The unspoken premise in all of this, of course, is the old argument over whether homosexuality is acquired or innate. The human mind is a glorious thing, able to convince its owner of all sorts of things that are not so. Those owners are often unwilling to admit that they have been convinced of an untruth.
But it has thus far not been shown that homosexuality is genetic in origin. That seems strikingly odd, since all sorts of personality traits such as alcoholism or even the tendency to like one's job have been shown to have genetic origin. So innately biological a phenomenon ought to have some genetic component, but despite great effort, no such cause has been found.
Were homosexuality found to be genetic, I would be beating the civil rights drum for non-discrimination while thanking God for making me as I am. But thus far, it seems only a choice.
Now, were some church (or some social club calling itself a church) to begin handing out marriage certificates to gay couples, I really wouldn't care. It's cultural folly, but that's the price of freedom.
For my government to do it, on the other hand, is a different story. Because government handing out marriage certificates places a stamp of approval on the gay union, and that, for a variety of cultural and religious reasons, I do not share. Taking what ought to remain a private liberty and giving it the imprimatur of government puts my approval on the choice of another, and that is a choice of which I would never approve. Why I do not approve is not the issue; that I do not is.
Even if government approval does not imply my own, that will be quickly demanded. For if something is legal, it must be moral, right?
If the issue is your liberty, you have it; if it is my approval, you do not.
And indeed, the burden of proof is on those who wish to further change marriage to show that their alteration would not harm it, or at least, to show that the harm they would do is somehow offset by the benefits of the new policy. As GK Chesterton wrote:
There exists in such a case a certain institution or law; let us say for the sake of simplicity, a fence or gate erected across a road. The more modern type of reformer goes gaily up to it and says, "I don't see the use of this; let us clear it away." To which the more intelligent type of reformer will do well to answer: "If you don't see the use of it, I certainly won't let you clear it away. Go away and think. Then, when you can come back and tell me that you do see the use of it, I may allow you to destroy it." This paradox rests on the most elementary common sense. The gate or fence did not grow there. It was not set up by somnambulists who built it in their sleep. It is highly improbable that it was put there by escaped lunatics who were for some reason loose in the street. Some person had some reason for thinking it would be a good thing for somebody. And until we know what the reason was, we really cannot judge whether the reason was reasonable. It is extremely probable that we have overlooked some whole aspect of the question, if something set up by human beings like ourselves seems to be entirely meaningless and mysterious. There are reformers who get over this difficulty by assuming that all their fathers were fools; but if that be so, we can only say that folly appears to be a hereditary disease. But the truth is that nobody has any business to destroy a social institution until he has really seen it as an historical institution.
Libertarian philosophy is oblivious to institutions and traditions, an area of weakness that leaves it incapable of being used in governing. Liberal philosophy, on the other hand, is openly hostile to institutions and tradition.
So it is unsurprising when liberals, so intent on protecting the commons from pollution, cannot see the damage they do to our cultural institutions, and on being shown, do not care.