Sometimes you have to take an argument to its logical conclusion to see its flaws.

I'd guess, for example, that 95 percent of Minnesotans would oppose redefining our marriage laws to include temporary marriages, where the partners' marriage certificate includes an end date; marriages of three or more people (say, two lesbians rearing their child with a gay male sperm donor), or marriages between siblings in a nonsexual relationship.

Yet how would such marriages hurt anyone else's marriage? If the individuals in question love and care for each other, isn't that all marriage is about? Doesn't love make a family? Don't people bound by affection deserve the benefits of marriage -- and suffer stigma if these are withheld? If you disagree, aren't you discriminating against others' "fundamental right" to marry as they wish?

These questions are, of course, the same as those posed by same-sex marriage advocates to fellow Minnesotans who support preserving one-man/one-woman marriage in our state Constitution.

If you think the marital forms just described are fantasy, you should know that some very smart people are telling us that promotion of such arrangements is the logical next step in the marriage debate. These individuals made their case in a 2006 statement entitled "Beyond Same-Sex Marriage," whose signers include Gloria Steinem; Princeton University's Cornel West, and hundreds of other lawyers, writers and scholars from some of our nation's most prestigious universities.

Why do the marriage permutations they describe strike most of us as inappropriate, just as the marriage of two men or two women did until a few years ago? The reason is that marriage has a unique public purpose, which distinguishes it from all other human relationships, no matter how valuable they may be to the people involved.

Marriage has always and everywhere been a male/female institution because it is rooted in biology and human ecology. Across the globe and through the millennia, its public purpose has been the same: To connect men with their children and the mother who bore them, so that every child has a loving, committed mother and father.

Though the best environment for raising children is a married mother and father, the power and inconstancy of human sexual attractions make this hard to achieve. Marriage brings social norms and pressures to bear to create a socially supported framework to ensure stable unions -- thereby forming the next generation and promoting the common good.

Same-sex marriage supporters are wrong, then, to compare laws enshrining one-man/one-woman marriage to laws barring interracial marriage. Jim Crow-era laws did not challenge the nature or meaning of marriage. On the contrary, they sought to frustrate its natural goods by artificially keeping black and white men and women apart to perpetuate a racist legal order.

What will happen if we buy the civil-rights analogy and redefine marriage as a "unisex" institution on grounds that "equality" requires it?

First, we will weaken the institution's ability to support men and women in forming permanent, sexually exclusive unions. Norms of fidelity and permanence are central to heterosexual marriage, where sex acts can produce children. But they don't have the same logical necessity in unisex relationships, which are more like friendships in this respect.

If marriage becomes the union of any two people based on affection -- losing its core purpose of binding men and women together -- people will find it increasingly difficult to understand the rationale for marital norms, which are hard to live by. As shared, public understanding of its purpose falls by the wayside, marriage will become just one of many lifestyle choices. Increasingly, people may fail to see any intrinsic reasons to marry at all.

As men and women drift away from marriage and its norms, children will suffer. Government will be compelled to play an ever-increasing role in the functions of the family.

Finally, if support for one man/one-woman marriage becomes the social equivalent of racism, people who believe all children need and deserve a mother and father will face persecution in the public square. The state's massive civil-rights enforcement regime will bear down upon them, effectively silencing them and sometimes even putting their employment at risk.

Do traditional marriage laws inappropriately discriminate against people who seek legal recognition for nonmarital, affection-based unions, which can take many forms? The answer is no. It is not "discrimination" to treat different things differently.

The law, by its nature, distinguishes among people. The question is whether it does so on grounds that serve a legitimate public purpose, and whether it employs criteria that are genuinely relevant to the distinctions it makes.

Our marriage laws -- perhaps more than any others -- clearly meet that test.


Katherine Kersten is a senior fellow at the Center of the American Experiment. The views expressed here are her own. She is at