It's not every day a court gets to stand against all of recorded history. That's what the Massachusetts Supreme Judicial Court did Nov. 18 when, in Goodridge v. Department of Health, it ruled that marriage in Massachusetts is no longer the union of a man and a woman but the union of “two persons.” The court argued that forbidding a man to marry another man constituted unlawful and irrational sex discrimination.

The Bait-and-Switch. The court drew on several laws and state constitutional provisions in making its case, including anti-discrimination laws, hate-crimes laws and a constitutional provision modeled on the failed Equal Rights Amendment forbidding discrimination on the basis of sex.

There's just one problem: When Massachusetts legislators voted for these laws, they were assured again and again that same-sex marriage would not be the result. There is virtually no chance that these laws would have passed if voters and legislators had believed they would lead to the radical redefinition of marriage.

The Massachusetts court is saying to citizens, “You all go ahead and vote for the laws. Then we'll tell you what you really voted for. Don't expect it to look much like what you thought you agreed to.” The rule of law requires that laws be predictable and stable — that laws not be yanked out from under citizens like a carpet in a Tom and Jerry cartoon. The Massachusetts court (like the Supreme Court in Roe v. Wade) has ignored this principle.

The funny thing is, this bait-and-switch approach to judging may be turned against the Goodridge decision itself in the future. As UCLA law professor Eugene Volokh (who supports same-sex marriage) has pointed out, the language the majority used in its decision gives no good reason to bar polygamy or adult incestuous marriages. If marriage is simply about commitment, well, obviously we can make commitments to more than one person. And we can make commitments to people who are already members of our families — for example, siblings. Why should these commitments not be recognized in law as marriages?

Although the Goodridge decision insists that the plaintiffs, and therefore its decision, do not “attack the binary nature of marriage [i.e. you can't marry more than one person], the consanguinity provisions [anti-incest provisions] or any of the other gate-keeping provisions of the marriage licensing law,” why should the court expect its wishes to have any more force than the wishes of the voters and legislators the court has already ignored? If the court is willing to proceed from what it deems as the internal logic of various pieces of legislation, rather than either the plain text or the legislators' common understanding of what they were doing, why should later courts not apply the same test to Goodridge?

Procreation. The majority in Goodridge rejected the argument that marriage is an essentially procreative union, pointing out that couples who cannot have children are still permitted to marry. But this objection misses the point.

Marriage — civil marriage, not just sacramental marriage — is essentially a procreative union in two ways. First, marriage only exists because of procreation. Marriage developed as a univer-sal human institution because when a man and a woman have sex, very often a baby is conceived. We've tried to convince ourselves that we have gotten around this “problem.” But no matter how many hormones a woman pumps into her body, no matter how much latex we swathe ourselves in, intercourse still makes babies. If nothing else, the existence of almost 4,000 crisis-pregnancy centers in this country should prove that. Marriage developed because the children conceived by men and women need to be protected, and, especially, need strong legal ties to their fathers, whom biology allows to walk away far more easily than mothers.

And marriage developed because sexual risk is asymmetrical: Men and women face different risks when they sleep together. Men risk committing resources to care for children that may not be their own. Women risk being abandoned and left to care for a fatherless child. Marriage developed to minimize these risks. That's why no society — even among those that did have

a social role for some expressions of male homosexuality — has instituted same-sex marriage until the past decade.

Second, marriage is procreative because marriage is society's way of ensuring that as many children as possible have mothers and fathers. A couple who cannot conceive children on their own can adopt, thus providing children with a mother and a father. Two men, however, can't replace a mother, nor can two women replace a father.

We see this most obviously in the inner cities, where many families consist of a grandmother, a mother and a child. Here, two women struggle to raise a child without a father. And the children say, again and again, that they need daddies. The sons say they had no

one to teach them how to be men. The daughters say they had no one to teach them what to look for in a man, what role a man should play in the family.

Same-sex marriage says that men — fathers — are unnecessary in forming a family. This is one of the most detrimental messages a society can send.

What Now? At first glance, the Massachusetts court seemed to have left a loophole for the Legislature: The court's ruling would not take effect for 180 days. In that time, court-watchers initially speculated, the legislature could seek to amend the Massachusetts Constitution, defining marriage as the union of one man and one woman. Such an amendment would override the court's decision.

But the Massachusetts constitution is difficult to amend, and it is impossible to amend in 180 days. So that route is out.

The Goodridge decision makes the question of the Federal Marriage Amendment all the more pressing. This amendment would prevent both courts and legislatures from enacting same-sex marriage. The most basic version of this amendment would read, “Marriage in America is and shall be exclusively the union of one woman and one man.”

Amending the Constitution of the United States is a major project and not a step to be taken lightly. But if we do not take this step, we may lose the fundamental building block of society. [g^

Eve Tushnet writes from Washington, D. C.