With the legal status of same-sex marriage in California thrown into limbo yet again following a federal judge’s ruling against Proposition 8, the moral arguments for and against differing conceptions of marriage rage on. In the case of Prop 8, some commentators have realized that many of the moral arguments once used to defend same-sex marriage bans are no longer defensible in an ethically diverse society.

Ross Douthat’s recent column in The New York Times was a case in point. One by one, Douthat concedes that many of the traditional arguments against gay marriage are no longer persuasive.

Is marriage defined as the union of one man and one woman really a deep-seated cultural norm around the world? No, asserts Douthat, arguing that polygamy has been pervasive throughout human history.

Is heterosexual monogamy the universal, natural way to form families and raise children, making same-sex relationships “unnatural?” Douthat argues that it’s difficult to sustain that argument when the contemplation of having children is not a prerequisite to marriage, and when so many marriages end in divorce.

The data is startling, even after a generation of no-fault divorce. The overall divorce rate is often stated as 50 percent, or 1 in 2. But this conceals the fact that the rate actually goes up for subsequent marriage, from 41 percent for first marriages to 60 percent for second marriage to 73 percent for third marriages. Serial monogamy may involve the triumph of hope over experience, as the old joke goes, but clearly the statistics are stark – and often result in what Douthat calls a form of “postmodern polygamy.”

So, purely as matter of equity, why not allow homosexual marriage as an exception to the monogamous heterosexual norm, just like divorce? Judged by values like faithfulness and integrity, a same-sex couple’s lifelong commitment is better than the successive monogamy found in heterosexual relationships.

Seeking to recast the debate, Douthat is ready with a subtle if not necessarily game-changing answer: What if lifelong heterosexual monogamy was defended not as a universally applicable expression of natural law, but as a particular, highly worthy ideal of Western civilization? The elements of this ideal date back to Jewish and Christian conceptions of the created order, and are supplemented by powerful notions of romantic love and generational continuity.

No matter how the current American Kulturkampf over marriage plays out, the legal consequences remain important for many people and their families. Marriages sanctioned by law (as well as domestic partnerships) involve certain rights and responsibilities. Regardless of the side one takes in the debate, practical realities set in when issues like divorce and separation, alimony and support, and child custody and visitation, must be resolved.