Many fair-minded people will cheer Judge Vaughn Walker’s decision to overturn California’s Proposition 8 that constitutionally banned gay marriage in the state. Although I disagree with his decision, his written opinion is full of good sense with which I fully agree.

Measures of love, he says, do “not differ depending on whether a couple is same-sex or opposite-sex.” Marriage does confer a certain status and certain “tangible and intangible benefits” on married couples. The definition of marriage in California’s constitutional amendment does deny this status and those benefits to gay couples (though I think that every tangible benefit not available to gay couples can and should be created by legislation in every state).

The judge is partly right: If the purpose of marriage was for the exclusive benefit of couples in love, who wanted to share a life and a household, it would be a clear affront to justice to keep this state benefit from other couples who happen to possess a different kind of sexuality from the majority.

But providing benefits to couples is not the whole purpose of marriage. It’s not even its primary purpose. And that’s what’s wrong with Mr. Walker’s ruling, and the arguments on both sides of Perry vs. Schwarzenegger. They’ve been arguing over marriage’s benefits. Instead, we need to be thinking about marriage’s role in sustaining the existence of the human species. When we do that, we’ll see the fundamental wisdom of the decision of the majority of California voters.

For another view, read "Ultimate battle for gay marriage supporters: their fellow Americans"

Striving for status

Let’s go to what the plaintiffs – the two same-sex couples who sued the state – say they cannot have because California denies same-sex marriage: Messrs. Zarrillo and Katami say that only a California marriage (and not their private relationship or California’s provision for domestic partnership) will give them, in the words of former Supreme Court Justice William Douglas: “a coming together for better or for worse, hopefully enduring, and intimate to the degree of being sacred.”

Ms. Perry wishes to marry Ms. Stier because “I’m a 45-year-old woman. I have been in love with a woman for 10 years and I don’t have a word to tell anybody about that.” “Ms. Stier explained that marrying Perry would make them feel included “in the social fabric.”

The goals of the plaintiffs are noble, and shared by most nice people. And it must be painful to believe that only a harmless change in the legal definition of marriage would give Zarillo, Katami, Stier and Perry what they want. But legal marriage – while a wonderful thing – does not, cannot, and was never intended to provide intimacy, the sacred, or a feeling of inclusion. Those goals can be achieved by same-sex couples just as well as by heterosexual couples, married or not – because of their relationship, not the law.

Marriage is about defending women

Among the many different versions of marriage in human history, very few of them have supplied the high-minded qualities that the plaintiffs feel is their right. The vast majority of marriages in the past, perhaps a majority even now, were dictated by families, clans, holy men or magicians, and enforced on the bride and groom by social pressure, enforced if necessary with brutality and violence.

True, many marriages promote loving intimacy and enduring fidelity, but that’s an outcome of the relationship itself – not the raison d’etre for the institution. In primordial terms, marriage only exists at all – in all of its permutations, pleasant or barbaric – because of the nature of human heterosexuality. As a species, we need to protect female sexuality in order to assure ourselves of a future.

Marriage is a necessary defense of a woman’s sexuality and her human liberty from determined assault by men who would turn her into a slave, a concubine – something less than fully human. Human communities need to give women some additional degree of protection – through law, custom, religious decree, or sacrament – generally some combination of all three, neatly summarized by the plaintiffs, who demanded the sacred and the eternal from the state of California.

Of course, marriage’s power to protect women is far from perfect, but no human institution is. Parents, too, sometimes do awful things to their children.

Unions of men and women are unique

That’s why it has never occurred before to lawmakers (or any human society of which I am aware) to offer marriage to pairs of lovers that happen not to include a woman, or that involve only women and not a man.

Relationships that involve a man and a woman are a matter of public concern in a way that other relationships are not. Of course, single people and gay people can be parents, and their equality with married couples as parents can and should be crafted by legislation.

Walker asserts that Prop 8 is motivated partly by “a belief that same-sex couples are simply not as good as opposite-sex couples,” and concludes that the law’s intention is to enact “a moral view that there is something ‘wrong’ with same-sex couples.”

The fact is very nearly the opposite. Heterosexual relationships need marriage because of inferiority: the physical inferiority of sexual defenders to sexual attackers and the moral inferiority of male sexual attackers

Marriage is not about couples or lovers – it’s about the physical and moral integrity of women. When a woman’s sexuality is involved, human communities must deal with a malign force that an individual woman and her family cannot control or protect.

Modern marriage is only the least worst version of marriage that has emerged from all this – but it is still necessary for women. What protects women, ultimately, is that marriage laws and customs confer upon her independence something extra – dignity, protection, sacredness – that others must respect. And if this quality can be bestowed upon anyone, even those not in intersexual relationships – it reduces, even dissolves its force.

Marriage can't be reduced to esteem

That’s why so many – even the most secular, gay-admiring, civil-rights-conscious among us – feel that something more is going on with the movement to turn marriage into a device to give couples self-esteeem – or, in Walker’s terms, status in society.

For Walker, the state of California has an overriding interest in ensuring that a same-sex couple should feel good about themselves. Walker and others are certainly right to want straight people to have a positive view of homosexuals – I want this, too.

But hard as it is for Walker to believe, most of us who prefer to leave marriage (with all its defects) as it is are not concerned with homosexuality at all.

We are merely voicing a sensible desire to preserve an institution that recognizes and protects the special status of women. If marriage becomes a legislative courtesy available to everyone, like a key to the city, it will be women who will lose.

Sam Schulman is a writer whose work appears in The Weekly Standard, Commentary, The Wall Street Journal, the Spectator (London), and elsewhere. Formerly publishing director of The American, publisher of Wigwag, and assistant professor of English at Boston University, he lives near Charlottesville, Virginia.