But if we just accept this shift [valuing lifelong commitment over serial relationships], we’re giving up on one of the great ideas of Western civilization: the celebration of lifelong heterosexual monogamy as a unique and indispensable estate. That ideal is still worth honoring, and still worth striving to preserve.I can't think of a single thing that gay marriage would take away from my marriage. I can't even imagine a context in which gay marriage would lead me take a different or lesser view of my marriage than the one I presently hold. If anything, the "serial monogamy" Douthat decries diminish marriage by making divorce and remarriage seem easy and acceptable, as if changing a spouse is no different from updating your wardrobe.
When Douthat offers the conclusory statement that gay and heterosexual marriage are "similar in emotional commitment, but distinct both in their challenges and their potential fruit". I would like to see Douthat develop and explain that idea (or any idea, instead of his usual waffling), but I suspect that as soon as he tries to substantiate his argument it collapses. (To the extent that he speaks of "lifelong heterosexual monogamy at its best" as offering "a microcosm of civilization, and an organic connection between human generations", he's presenting far more of a mystical than a logical argument, and he's holding up the exception as the rule.) There are enough states and countries that now permit gay marriage that Douthat should be able to substantiate his opinions with real world examples. But the real world seems to reflect my side of the debate.