It wasn’t that we hadn’t prepped. Testifying on the Hill was a first for me, and those of us opposing the “Defense of Marriage Act” had been chatting for days about possible questions. But we hadn’t quite expected this one. If a person had an “insatiable desire” to marry more than one wife, Congressman Bob Inglis of South Carolina wanted to know, what argument did gay activists have to deny him a legal, polygamous marriage? It wasn’t a stray question. Republican after Republican returned gleefully to a Democratic witness who, it turned out, was (kind of) in favor of polygamy. I hastily amended my testimony to deal with the question. Before long, we were busy debating on what terms Utah should have been allowed into the Union and whether bisexuals could have legal harems.

Riveting stuff, compared to the Subcommittee on the Constitution's usual fare. But also revealing. In succeeding days, polygamy dominated the same-sex marriage debate. Both Bill Bennett and George Will used the polygamy argument as a first line of defense against same-sex marriage. In The Washington Post and Newsweek, Bennett in particular accused the same-sex marriage brigade of engaging in a “sexual relativism” with no obvious stopping place and no “principled ground” to oppose the recognition of multiple spouses.

Well, here’s an attempt at a principled ground. The polygamy argument rests, I think, on a couple of assumptions. The first is that polygamous impulses are morally and psychologically equivalent to homosexual impulses, since both are diversions from the healthy heterosexual norm, and that the government has a role to prevent such activities. But I wonder whether Bennett really agrees with this. Almost everyone seems to accept, even if they find homosexuality morally troublesome, that it occupies a deeper level of human consciousness than a polygamous impulse. Even the Catholic Church, which believes that homosexuality is an “objective disorder,” concedes that it is a profound element of human identity. It speaks of “homosexual persons,” for example, in a way it would never speak of “polygamous persons.” And almost all of us tacitly assume this, even in the very use of the term “homosexuals.” We accept also that multiple partners can be desired by gays and straights alike: that polygamy is an activity, whereas both homosexuality and heterosexuality are states.

So where is the logical connection between accepting same-sex marriage and sanctioning polygamy? Rationally, it's a completely separate question whether the government should extend the definition of marriage (same-sex or different-sex) to include more than one spouse or whether, in the existing institution between two unrelated adults, the government should continue to discriminate between its citizens. Politically speaking, the connection is even more tenuous. To the best of my knowledge, there is no polygamists’ rights organization poised to exploit same-sex marriage to return the republic to polygamous abandon. Indeed, few in the same-sex marriage camp have anything but disdain for such an idea. And, as a matter of social policy, same-sex marriage is, of course, the opposite of Bennett's relativism. Far from opening up the possibilities of multiple partners for homosexuals, it actually closes them down.

Bennett might argue, I suppose, that any change in marriage opens up the possibility of any conceivable change in marriage. But this is not an argument, it’s a panic. If we’re worried about polygamy, why not the threat of legally sanctioned necrophilia? Or bestiality? The same panic occurred when interracial marriage became constitutional—a mere thirty years ago—and when women no longer had to be the legal property of their husbands. The truth is, marriage has changed many, many times over the centuries. Each change should be judged on its own terms, not as part of some seamless process of alleged disintegration.

So Bennett must move to his next point, which is that homosexuals understand the institution of marriage so differently than heterosexuals do that to admit them into it would be to alter the institution entirely. To argue this, he has to say that gay men are so naturally promiscuous that they are constitutively unable to sustain the monogamous requirements of marriage and so fail to meet the requirements of membership. He has even repeatedly—and misleadingly—quoted my book, Virtually Normal, to buttress this point.

Bennett claims that I believe male-male marriage would and should be adulterous—and cites a couple of sentences from the epilogue to that effect. In context, however, it's clear that the sentences he cites refer to some cultural differences between gay and straight relationships, as they exist today before same-sex marriage has been made legal. He ignores the two central chapters of my book—and several articles—in which I unequivocally argue for monogamy as central to all marriage, same-sex or opposite-sex.

That some contemporary gay male relationships are “open” doesn't undermine my point; it supports it. What I do concede, however, is that, in all probability, gay male marriage is not likely to be identical to lesbian marriage, which isn’t likely to be identical to heterosexual marriage. The differences between the genders, the gap between gay and straight culture, the unique life experiences that divide as well as unite heterosexuals and homosexuals, will probably create an institution not easily squeezed into a completely uniform model. And a small minority of male-male marriages may perhaps fail to uphold monogamy as successfully as many opposite-sex marriages. But what implications does that assertion have for the same-sex marriage debate as a whole?

Bennett argues that non-monogamous homosexual marriages will fatally undermine an already enfeebled institution. He makes this argument for one basic reason: Men are naturally more promiscuous and male-male marriages will legitimize such promiscuity. But this argument has some problems. If you believe that men are naturally more promiscuous than women, then it follows that lesbian marriages will actually be more monogamous than heterosexual ones. So the alleged damage male-male marriages might do to heterosexual marriage would be countered by the good example that lesbian marriages would provide. It’s a wash. And if you take the other conservative argument—that marriage exists not to reward monogamy but to encourage it—then Bennett is also in trouble. There is surely no group in society, by this logic, more in need of marriage rights than gay men. They are the group that most needs incentives for responsible behavior, monogamy, fidelity, and the like.

I’m not trying to be facetious here. The truth is, I think, marriage acts both as an incentive for virtuous behavior—and as a social blessing for the effort. In the past, we have wisely not made nit-picking assessments as to who deserves the right to marry and who does not. We have provided it to anyone prepared to embrace it and hoped for the best.

Imagine the consequences if you did otherwise. The government would spend its time figuring out whether certain groups of people were more or less capable of living up to the responsibilities of marriage and denying their right to it on that basis. The government might try to restrict it for more sexually active men under 20; or for women who have had an abortion. The government could argue, grotesquely, that because African Americans have, in general, higher illegitimacy rates, their right to marry should be abrogated. All these options rightly horrify us—but they are exactly the kind of conditions that Bennett and those who agree with him are trying to impose on gay citizens.

Or, in an equally troubling scenario, we could put conditions on the right to marry for certain individuals. People with a history of compulsive philandery in their relationships could be denied the right to marry; or people who have already failed at marriage once or twice or more; or people who are “free-riders” and marry late in life when the social sacrifice of marriage isn’t quite so heavy. If we imposed these three restrictions, of course, three leading proponents of the Defense of Marriage Act would have their own right to marry taken away: chief-sponsor Congressman Bob Barr of Georgia (married three times), Bill Bennett (married at age 39) and Bill Clinton (ahem).

So how’s this for a compromise: Accept that human beings have natural, cultural and psychological differences. Accept that institutions can act both as incentives and rewards for moral behavior. Grant all citizens the same basic, civil institutions and hope that the mess and tragedy and joy of human life can somehow be sorted out for the better. That, after all, is what marriage does today for over 90 percent of the population. For some, it comes easily. For others, its commitments and responsibilities are crippling. But we do not premise the right to marry upon the ability to perform its demands flawlessly. We accept that human beings are variably virtuous, but that, as citizens, they should be given the same rights and responsibilities—period. That—and not the bogeymen of polygamy and adultery—is what the same-sex marriage debate is really about.