On the individual level, I think you make a compelling case. There are many millions of couples who use contraception exactly as you describe—to plan for children rather than reject them—and who experience birth control as a means to intimacy rather than as a barrier to self-giving. And the Catholic Church’s teaching on the subject can seem at once obscure, hair-splitting, and willfully unrealistic. More brilliant minds than mine have made strong arguments on its behalf, but on the spectrum of Catholic moral prohibitions, the judgment being passed on (say) the faithful couple with three kids that feels ill-equipped to master NFP and uses condoms instead can seem unduly harsh, and uniquely difficult to follow intellectually. (And indeed, given some of his comments on the subject over the years, I have the sense that Pope Benedict shares some of these sentiments.)
But step back and look at the culture as a whole, and I think the church’s argument becomes somewhat more comprehensible. Technologies are not intrinsically good or evil, for the most part, but they often have a moral valence—they confront human beings with a particular set of moral challenges which can have clear general effects even if every individual response is different. And in general, the world that contraception has made is a world that de-emphasizes the moral weight of the sexual act, while insisting on the centrality of a perpetually-fulfilled libido to human contentment. (This is certainly the message that my own municipality sends in its public health campaigns.) In general, the world that contraception has made has been a world characterized by steadily declining marriage rates, steadily rising numbers of children born out of wedlock, birthrates that have fallen well below replacement levels across the developed West (threatening a very different kind of population crisis from the one you invoke), and millions upon millions upon millions of abortions. In general, the sexual culture that contraception has created is a culture that treats the stuff of human life and even life itself as a commodity to be bought, sold, mass produced, experimented upon and kept on ice when necessary.
Now, there are defenses one can make of such a world. Maybe widespread abortion is necessary for female advancement. Maybe it isn’t a big deal if Europeans aren’t having enough children to replace themselves. Maybe children don’t need a mother and a father; maybe marriage itself is an outdated institution. Maybe the human embryo is no different, morally and commercially, from a fingernail clipping or skin-cell sample.
But these aren’t arguments that serious Christians can accept. A society that does not have enough children to even reproduce itself is not a Christian society. A culture that kills 40 percent of the offspring it conceives in utero (that would be the abortion rate in New York City, where Planned Parenthood’s influence over public policy is ever-so-slightly larger than the Vatican’s) is not a Christian culture. A culture that practices a kind of de facto polygamy, with men fathering children with many different women—the state of affairs in underclass America, and increasingly in working-class America as well—is not a Christian culture.
Maybe, as you’ve suggested, what’s needed across all of these fronts is a different moral narrative around contraception, rather than the Catholic Church’s rejection of artificial birth control outright. But I tend to think that what’s needed is a different moral narrative, period. And given the role that contraception—which is already cheap, widely available, and taken as a given across the landscape of popular culture—plays in the existing post-sexual-revolution narrative, a Christianity that places its hopes for cultural change in marginally better access to birth control pills and a slightly more moralistic frame around a condoms-first approach to sex seems like a Christianity that’s essentially giving up on the kind of more radical transformation that believers should be seeking.
This doesn’t mean that I think Christians should be campaigning against contraception, necessarily. (And to return to your initial question, no, I don’t think the kind of small-o Christian orthodoxy that I’m writing about in the book requires agreement with the specifics of my own church’s moral teaching on the issue.) Certainly the pill shall always be with us, and most people—most Christians, most Catholics—will use birth control of some form at some time in almost any future I can imagine. But it matters how that use is shaped and influenced, and here I think any Christianity worth its salt needs to stand clearly for the principle that—as the future pope put it, in the interview I quoted above—“we cannot resolve great moral problems simply with techniques, with chemistry, but must solve them morally, with a life-style.” In the conversation about what a healthy sexual lifestyle should look like, I think it’s entirely appropriate for the Christian emphasis to be on encouraging people to be more morally discerning about whom they sleep with, and when, rather than focusing on technologies that promise (falsely, based on the record of the last few decades) to make such moral discernment unnecessary.