Apropos of the debate before the Supreme Court about gay marriage, this article has been making the rounds. It’s part of an attempt to refute the Justice Alito’s actual assertion that marriage has been solely about joining men and women for “millennia,” only to be reconceived in the late-20th century. Not so, sayeth the BBC:

Homosexual acts may be outlawed in Kenya but there is a long tradition among some communities of women marrying each other.

This is hard to fathom in a country where religious leaders condemn gay unions as “un-African” – and those who dare to declare their partnerships openly often receive a hostile public reaction.

But these cases involving women are not regarded in the same light.

If a woman has never had any children, she takes on what is regarded as the male role in a marriage, providing a home for the younger woman, who is then encouraged to take a male sexual partner from her partner’s clan to become pregnant.

Her offspring will be regarded as the fruit of the marriage.

The article goes on to point out ways in which this traditional practice differs from same-sex marriage as we conceive it. For one thing, there is nothing particularly romantic about the partnership. The female “husband” must be post-menopausal, and the assumption of this tribal society (and of the female “husband” interviewed) is that women of such an age no longer experience sexual desire – an assumption which is refuted every day in the modern west and, I suspect, in Kenya as well, but be that as it may. Nonetheless, it’s cited as a possible precedent to justify alternatives to “traditional” marriages between men and women.

But what I take from the example is further evidence that the contemporary conservative notion of what “traditional” marriage is bears little resemblance to the reality, either in terms of structure or in terms of purpose. The unions described in the article exist for the purpose of providing continuity for the post-menopausal woman within a tribal system – by providing her with children who can inherit her property and thereby carry on her legacy. Without a marriage, there would be no way for her to have legitimate children who could serve that function. And the reason the story is in the news is that the woman’s blood relatives are suing, claiming that the woman’s son – who, obviously, is not a blood relative – has no legitimate right to her property, which would otherwise go to them.

This is what marriage is fundamentally about, in a traditional world. It’s about property, and it’s about dignity because it’s about property. This two-woman marriage is an exception to the normal rule about how marriage works because without such an exception this woman’s line would end – and it would end because her property would not pass to her heirs, but to some other relative. It is analogous to the biblical institution of levirate marriage, requiring the brother of a dead man to marry his brother’s widow – the purpose of which was not to provide her with shelter and protection but to give his dead brother heirs. It is analogous to the amendment to the law of inheritance instituted by Moses (with God’s blessing) when confronted by the daughters of Zelophehad, who had no brother to inherit their father’s clan portion. It is analogous to the use of concubines by the biblical matriarchs – Sarah deploys Hagar, Rachel deploys Bilhah – to provide their husbands with heirs when they are unable to conceive themselves. All of these are explicitly biblically-sanctioned exceptions to the normal course of marital business and the normal rules of inheritance, and their purpose is to provide for a legitimate line of inheritance for individuals for whom the normal rules have not worked out, because without such a legitimate line their “names” will die out, and their property will be disbursed to other relatives.

This is not the way most modern Westerners think about marriage, because we do not live in a tribal society – it’s not just our relationship to extended family that has changed radically, but also our relationship to property. But it was a huge component of what marriage meant for most of its history, and still is important in large swathes of the world.

More to the point, though, it isn’t how Thomas Aquinas thought about marriage. When I read Aquinas, or his natural-law descendants, writing on the subject, I don’t hear a descriptive anthropology (which is what the words “natural law” would lead one naively to expect). Instead, I hear a prescriptive argument, an argument not about what marriage is but about what marriage should be based on certain premises about both human and divine nature. And that particular line of argument leads to a place with no place for calling what those two Kenyan women have a “marriage.”

You can come to the question of gay marriage from the liberal side with a similarly prescriptive approach, starting with a definition of marriage derived from first principles, whatever they may be. The Supreme Court is probably going to have to do that, because that’s the mode of discourse that a court is most comfortable with – which is one good reason to try to handle the question legislatively if possible. But I’ve never been as comfortable with those kinds of arguments as I am with an empirical, even anthropological approach, one that simply looks at what people actually are doing, how they are actually living their lives. In our actual world, gay couples are living together, supporting each other in sickness and health, and raising children together. That’s what marriage seems to be about to us, as we actually live our lives, in the society we actually live in. And there are enough gay couples living this way, and for long enough, that it’s time the law recognized that fact.

Why should the law recognize it? Well, inasmuch as the state has any legitimate interest in what anybody does in matters of personal status, it’s because the state has an interest in keeping track of the disposition of property and the duties of care for dependent children. That is to say: the state still cares who might have a legitimate claim on your property, and who is responsible for a given child, because confusion on these matters raises the potential for conflict. Marriage already answers a whole host of questions about status that the state cares about. So it’s the right word to use.

I understand where the arguments from so-called “natural law” are coming from. When they say marriage “is” a union of one man and one woman, my objection isn’t really that they don’t understand marriage rightly. We just don’t agree on the what the meaning of the word “is” is.