American bishops, led by New York's Cardinal Edward Egan, have drawn an important distinction in the wake of the imprudent and likely unauthorized effort by New York Gov. David Paterson to unilaterally promote so-called same-sex marriage by piggybacking on California.

Specifically, the bishops remind states to avoid invidious discrimination (e.g., discrimination against homosexuals in health designations, property ownership) without affirming a practice (same-sex marriage) which denies God's creative plan.

The first rectifies man's prejudice; the second has the implied temerity of ascribing bias to God himself.

Gay and lesbian people are within the humanity acknowledged to be created equal in the Declaration of Independence, but this does not deprive the community through law of making necessary and reasoned distinction for its own survival.

While some public officials like Gov. Paterson carelessly deploy their same-sex ideological agenda, the Catholic prelates of New York more prudently urged "the state [to] review whatever benefits or privileges that it has through the years conferred on married couples and, in cases where true discrimination may be at play, fashion legislative remedies."

Oddly, the California Supreme Court wrote a 170-plus page opinion without discussing among other things single-gender effects on childrearing and the innumerable difficulties of accommodating religious freedom that arise from the legal acceptance of same-sex marriage.

The proponents of same-sex marriage insist that inventing gay and lesbian marriage harms no one. This, however, overlooks the national and global decline in fertility, which threatens the economies of Europe and the U.S.

To say that the availability of same-sex marriage is not the principal cause of this decline in terms of absolute numbers is a fair point, but giving state approval to non-procreative marriage cannot logically be denied as a contributing cause to the decline of families with natural children.

Several European countries, most notably France, have responded to delayed traditional marriage and dramatically reduced fertility with generous child subsidies and legal arrangements making it far easier for women to reconcile work and family.

Our French brothers and sisters, who Americans in the recent past have parodied, turn out to be far more sensitive to the importance of families than, say, a glib U.S. law and economics professor who spurned the suggestion that America follow the French example.

It is shortsighted in the extreme for the keepers of supply-and-demand curves to portray traditional, procreative families as "a stodgy bourgeois construct designed to channel the revolutionary energy of sexuality into diaper changing and carpooling."

Catholic teaching responds differently. Same-sex marriage rests upon separating marriage from procreation. This will have ill consequence.

As a defender of life in its natural form, the Catholic Church understands that even the benign could mask a diabolical push for artificial wombs and the genetic manipulation of intelligence --- a push that will no doubt grow now to accommodate even the minimal same-sex desire for simulating natural childbirth claimed to be of interest for the 20 percent to 30 percent of same-sex couples.

When carefully assessed, the acquisition of unnatural reproductive means often advances the interests of the very affluent through a libertarian exercise that would destroy all hope of democratic equality.

In a depopulating world, the claim that there is a universal right to marry regardless of the genders of those involved becomes a frightening ally of a claimed universal right to genetically engineered children.

Yes, endorse claims of created equality when the distinctions of the past have been shown to lack reason. But do not pretend to make equal that which is not (procreative and nonprocreative relationships) or find a universal right to contradict human nature itself.

As contraception opened the door for abortion, same-sex marriage invites genetic manipulation that not only allows homosexuals to pretend to be parents, but also lends legitimacy to the fashioning of a new superman by genetic manipulation.

Douglas W. Kmiec is chair and professor of constitutional law at Pepperdine University, Malibu, and the former Dean and St. Thomas More professor of law, The Catholic University of America, Washington, D.C.