Editor's Note: This piece is published as a part of a symposium hosted by Patheos' Catholic Portal and Evangelical Portal, entitled, "For Life and Family: Faith and the Future of Social Conservatism."

In the winter 1993 issue of the Phi Beta Kappa journal American Scholar, the late Daniel Patrick Moynihan published a much-noted article on the arresting topic "defining deviancy down." Drawing on social science literature, he argued that a society with an over-supply of troublesome behavior may handle the problem by redefining behavior previously regarded as deviant so as to make it normal according to new standards of deviance and normality. Moynihan, at the time a U.S. senator from New York, said this permitted the society "not to notice behavior that would otherwise be controlled, or disapproved, or even punished."

Redefinition, he suggested, took place under three distinct headings: altruistic (example: the deinstitutionalization of the mentally ill that got underway in the U.S. in the 1950s); opportunistic (example: approval of "alternative" family structures besides the traditional family); and normalizing (example: "growing acceptance of unprecedented levels of violent crime").

Since then, many other examples of downward defining and its consequences have been noted. Fair enough. The right to cite instances of a phenomenon isn't confined to the inventor of a clever term. I suggest adding contraception to the list. That helps explain why, from the perspective of the common good of society, Catholics shouldn't scrap opposition to contraception as a burdensome relic.

Moynihan's list didn't include the approval of contraception that had been growing in the United States for decades when he wrote, and if by some chance it had, I suspect he'd have put this in his "altruistic" category. But for me it's a toss-up between "opportunistic" and "normalizing." In other words, approving contraception has had bad results for society.

In brief, it has opened the door to other behaviors—cohabitation, illegitimacy, single-parenthood, abortion, the decline of traditional marriage (fewer and fewer Americans marry every year), same-sex marriage, and much more—that many people still recognize as deviancy with destructive social consequences.

It isn't all that hard to see to how it works either; you don't even have to be opposed to contraception.

In a long review of several books about abortion in the April 28 New Republic, Christine Stansell, a history professor at the University of Chicago writing from a pro-choice feminist perspective, says introduction of the birth control pill in the United States in 1963 launched "a revolution in assumptions about sex and its consequences." To be precise, it did that by establishing "the central tenet of modern heterosexual life, the separation of pregnancy from sex."

At a stroke, what Professor Stansell calls "worry-free contraception" via The Pill separated pleasure from procreation, with abortion as "a method of birth control when other measures failed" soon to be legalized by the Supreme Court. Stansell naturally thinks that's all to the good. She doesn't mention other consequences like those in the catalogue of bad results mentioned above.