RECENTLY ONE-HALF of the lesbian couple seeking “same-sex divorce” in Rhode Island courts told a judge she has moved to Massachusetts, meaning she may now pursue a legal divorce in the state where she and her partner first traveled to evade Rhode Island’s marriage laws.

She could not pursue a divorce under Rhode Island law because marriage in Rhode Island is a union of husband and wife; people in other kinds of unions do not need a divorce in this state because they are not married.

Same-sex divorce is thus part of a campaign to get Rhode Island law to recognize unions of two men and two women as marriages.

What is at stake in the marriage debate today in Rhode Island? Why should anyone besides Adam and Steve care?

The answer, in my personal and professional opinion, is the common good and the welfare of Rhode Island’s children. The public definition and meaning of marriage profoundly serves both ends.

Marriage is a core social institution, the only one we have that is dedicated to communicating and reinforcing a unique and vitally important task: bringing together men and women to make and raise the next generation together.

How do we make sure a child begins life with a mother and a father committed to his or her care? Marriage serves many important private and personal purposes, but its great public purpose, and the source of marriage as a unique legal and civil status, is its role in sustaining this social ideal.

Existing scientific data suggests that the law of marriage protects children to the extent it increases the likelihood that children will be born to and raised by their own mother and father in a harmonious, lasting union.

It takes great effort on the part of young people attracted to the opposite sex to make sure that their own children will be given the gift of a committed mother and father. It doesn’t happen by accident. It will happen less often in a society that views this idea of marriage as a form of discrimination.

As a psychiatrist and a clinical assistant professor at Brown, I am well aware that proponents of same-sex marriage will cite the American Psychiatric Association and other professional organizations to justify their view: There is nothing scientific at all about the view that a child needs his mother and father.

The scientific reality is that there are only a handful of studies on same-sex parenting (less than 50 total), and almost none of them are based on nationally representative data, which means we simply do not know how typical or atypical the gay parents and their children studied are.

The point I wish to underscore here is not that gay people cannot be good parents (just as many single mothers and fathers are good parents), but that there is something special and distinctive about sexual unions that can both create life and connect those babies to a mother and father.

But if Rhode Island law teaches that a same-sex relationship is a marriage, that there is no difference between same-sex and opposite-sex couples, and only bigotry and hatred explain our state’s historic marriage tradition, then the idea that children need a mother and father, if possible, will cease to be a common-sense social ideal and will become a stigmatized expression of bigotry.

It is this public repudiation of a core and historic part of our marriage tradition that endangers children and the public good, not what same-sex couples may choose to do in their personal lives.

All Rhode Islanders have a right to live as they choose, but none of us has a private and individual right to redefine marriage, for the purpose of divorce law, or for any other purpose.

Daniel Harrop, M.D., of Providence, is a psychiatrist and a member of the National Organization for Marriage-Rhode Island’s advisory board ( www.NOMRhodeIsland.org). He is also president of Rhode Island’s Catholic Medical Society.