On the one hand, it seems obvious that marriage is between a man and a woman - the basic biological unit, society's foundation, civilization's keystone. On the other, what's wrong with allowing people of the same sex to live together under the same civil protections permitted heterosexual couples?

The questions are further complicated by the fact that most of us know and/or love someone who is gay. We have gay children, gay friends, gay uncles and cousins. Some have gay fathers and lesbian mothers. Who wants to deny them respect and happiness?

And so we sit back quietly and watch the reordering of society for fear of hurting a loved one's feelings or offending a co-worker or losing the affection of entire blocks of people.

I figure I'm a fairly typical middle-of-the-road heterosexual married woman when I say: I love gays and, well, the whole gay thing. I love all my gay friends and relatives, not to mention my hairdresser; I love what gays do to urban neighborhoods; I love gay humor, gay style and whatshisname in "My Best Friend's Wedding."

I was what we used to call a "fag hag" when you could still use the term affectionately without fear of offending - before most of today's gays were out of diapers (changed most likely by a mom or a dad, not by Heather's two mommies or Douggie's two daddies). Thanks to my very best friendship with my gay first cousin, I've had many a gay time as a token belle in the heart of San Francisco's Castro district.

In other words, no one who knows me would call me a homophobe.

Nevertheless, I do not worship gayness, and I'm certain that society needn't be restructured in order to accommodate even my loveliest gay friends.

Leaving God out of the equation, it is irrefutable that Nature had a well-ordered design. Male plus female equals offspring. It is a certainty that male/male and female/female unions don't meet Nature's standard. They may occur "naturally" in that one does not consciously elect to Be Gay, but such unions fall short of any design that matches Nature's intentions. It also seems clear that our moral codes and institutions were created primarily to protect that design in the interest of the species and civilization.

Thus, marriage - for all its flaws and miseries - has evolved to promote, support and nurture that basic necessary unit. If the state goes out of its way to make marriage attractive, it is because marriage is so difficult and, in many ways, unnatural. It is far more natural for humans, animals that we are, to enjoy gratification whenever and wherever than it is to settle for decades into a system of monogamy.

That many fail, however, is no justification for eliminating the goal of the nuclear, male-female, monogamous family, which has worked well if not perfectly for most of civilized memory.

One might argue logically for extending certain benefits to same-sex couples, but marriage isn't necessary to that end. Surely next-of-kin issues for corporate and death benefits can be managed outside of marriage. Moreover marriage isn't only about civil rights. Marriage is mostly the institutionalization of an ideal that we honor in observation of a higher natural order.

The fact that some homosexual households already include children isn't sufficiently compelling to redefine marriage either. To extend marriage rights to gays on that basis presupposes that raising children in homosexual households is just as good as raising children in heterosexual homes with two parents.

Surely no one needs a scientific study, or God forbid, a poll, to "prove" what is written in our human DNA - that sons and daughters need the qualities of both their parents, Mother and Father.

That said, it is unlikely that a few thousand married homosexuals will topple civilization, as some have warned. Or that homosexual men will suddenly opt to marry ducks, as Bill "No Spin" O'Reilly recently proposed.

But this is not an insignificant social experiment to be tittered over in cappuccino bars. Making homosexual unions equal to heterosexual unions - the superior natural order of which cannot be disputed - is not just a small step for equality. It is a gargantuan leap from a natural order that has served mankind throughout civilized human society.

We should look long and hard before we leap.