From Carson Holloway at the Witherspoon Institute:
What would the triumph of same-sex marriage mean for American civilization? Americans disagree on this question. Liberals think of it merely as an incremental step toward justice understood as equality. For them, homosexuals have been unjustly excluded from marriage, and now they no longer will be. Nothing more momentous is involved.Conservatives, on the other hand, think of same-sex marriage not as an extension of marriage but as a radical redefinition of it. To tamper with the very definition of a fundamental social institution like marriage, they warn, is to invite all manner of threatening consequences.
The conservatives are closer to the truth than the liberals on this question, but their foreboding does not go far enough. To embrace same-sex marriage is to plunge headlong into the abyss of nihilism. It is to step into a realm in which there are no longer any solid or reliable public standards of judgment as to what is right and wrong, just and unjust. It goes without saying, I hope, that this is not what the defenders of same-sex marriage intend. It is nevertheless the end toward which their position tends.
We cannot embrace same-sex marriage and live in continuity with our past as a civilization. To embrace it is to deny that tradition, revelation, reason, and nature have any authority over us. We can make society whatever we want it to be. What will it be? No one can say for sure.
I do not expect that these reflections will mean much to many contemporary liberals. They seem exhilarated at the prospect of total liberation from the past. They think such liberation is itself a form of progress, and they are not ready to consider that it might in fact be a form of decay. Perhaps these arguments will, however, prompt second thoughts in those conservatives who regard the fight over same-sex marriage as a pointless distraction, who think conservatism should drop its opposition to the redefinition of marriage and get about the important business of defending free-market capitalism. Such conservatives should understand that the kind of audacity that can insist on redefining marriage is not likely to bow down with reverence before such concepts as property, contracts, and economic liberty.