Strange as it may seem, Pope Paul VI—writing from a rather different perspective—offered much the same analysis in his 1968 encyclical Humanae Vitae that once again declared the Catholic Church's age-old condemnation of contraception. While delicately using the terms "unitive" and "procreative" to describe the purposes of sex instead of Stansell's "pregnancy" and "sex," Paul left no doubt that, no matter what you call them, separating them leads to trouble in the social as well as personal spheres.

"How wide and easy a road would thus be opened up towards conjugal infidelity and the general lowering of morality," he wrote. Four decades' experience in the United States and other countries amply illustrates why admirers of Humanae Vitae call it prophetic.

I don't propose that 19th-century Protestant-backed laws banning contraception be re-enacted. Rather, for people who see the bad social consequences that contraception helps cause, the aim should be persuading their fellow citizens freely to forgo contraception—for their sakes and the sake of the common good.

What's just been said is a brief statement of what might be called a social science argument against dropping the subject of contraception. There's also a theological argument, relevant at least to some Catholics and, perhaps, a few others who see it as they do.

In brief, the teaching against contraception wasn't something Paul VI dreamed up in 1968. It's been part of the Christian moral tradition from very early on, and it was only starting in the 1930s that so many other Christian churches and denominations bailed out—with many Catholics eventually joining in.

Catholics who continue to oppose contraception have no illusions that they're currently winning this argument. No matter. Some day that may change, and winning arguments isn't what being faithful is all about anyway. These Catholics think they owe that to themselves, to their Church, to the Christian tradition, to the common good of society, and ultimately to God. That's big time indebtedness.