Catholics believe that the basic requirements of morality are accessible in principle to all human beings through the natural law. We also believe that Christ conferred on the church special insight into the requirements of natural law. Ideally, this two-source framework for moral insight results in a harmonious, mutually reinforcing relationship. But what happens if there is a conflict? We have a real methodological challenge on our hands.

Take the matter of contraception, a timely subject because the U.S. Conference of Catholic Bishops issued a statement last month (“Married Love and the Gift of Life”) reaffirming the church’s teaching that contraception violates God’s plan for married love.

For centuries, the Catholic Church (and most of Western Christianity) taught that it was a sin for a couple deliberately to impede the fertility of an act of marital intercourse. This sin was seen as a violation of the natural law, binding all people, not merely Catholics. In the first part of the twentieth century, the broad consensus about the immorality of contraception began to break down. Most other branches of Christianity no longer believe that contraception is always immoral. Polls show that over 90 percent of Americans, including Catholics, think it is not immoral to use contraception. If the law of nations (the ius gentium) is any clue as to the natural law, it might be important to note that most Western countries not only have repealed laws banning contraception but have endorsed it as a legitimate form of family planning.

So how do we think about a situation in which many, if not all, apparently reasonable and good people (including Catholics) now hold that the use of contraception by married couples is sometimes justified, while the church continues to maintain it is always objectively immoral? There are four main ways of dealing with the tension between faith and reason in this case. One dissolves the tension, one diminishes it, one denies it, and one attempts to reframe it. All four ways are employed by people on both sides of the question. In my view, only the last one has any hope of moving us beyond the impasse. Even so, a quick resolution of the conflict does not seem likely.

First, you can dissolve the tension by letting go of either faith or reason. If you’re a conservative, you can downplay reason and emphasize the church’s role as a privileged interpreter of natural law—especially the role of the magisterium. The trouble with this view is that it essentially relinquishes the fundamental insight of a natural-law approach, which is that moral norms have to “make sense” to good people of all stripes, not merely to pious Catholics. If you’re a liberal, you can minimize any role for the church in interpreting natural law, especially on matters of sexual ethics. But this approach throws the baby out with the bath water. Church teaching can be wrong on occasion, but it is never irrelevant.

Second, you can diminish the tension by blunting the force of church teaching. For example, you could recast the prohibition against contraception as a matter of religious law, binding only on Catholics, or present it as an ideal for Catholics to strive for rather than a moral requirement for everyone. Both liberals and conservatives might find this approach congenial, but to do that would be to ignore the fact that the precepts of Catholic sexual morality are not meant to be analogous to arcane liturgical requirements binding only for Catholics. And presenting the teaching as an ideal begs the question of whether it is actually a good ideal for everyone.

Third, you can deny the tension, pretending that the disjunction between broadly settled moral opinion and official church teaching is just temporary; you can tell yourself that everything will work out in the end. Conservatives tell themselves that the world will come around to see that the church is right, and liberals tell themselves that the church will admit that the world is right. But this is just wishful thinking.

The fourth approach is more radical: it attempts to eliminate the conflict by reframing the question. A successful example of this type of reframing was the Second Vatican Council’s declaration on religious liberty. The church’s old approach was that “error had no rights,” while its new frame puts the issue in terms of people’s consciences, not abstract propositions. The Declaration on Religious Liberty proclaims that a person has a right to worship God according to the dictates of his or her conscience—even if one’s conscience is mistaken.

What would such reframing look like in the case of contraception? Interestingly, both liberals and conservatives have attempted to recast the question of contraception’s morality by shifting the focus from each sexual act to the marriage as a whole. Some liberals maintain that it is the whole marriage that has to be open to new life, not each individual marital act—the position taken by the majority report of the birth-control commission appointed by Paul VI, but rejected in Humanae vitae. Some conservatives contend that marriage is a total gift of the self, including one’s capacity to generate new life—a view based on John Paul II’s theology of the body.

So which view of marriage is more persuasive? The Catholic Church can live with an apparent conflict between faith and the judgment of practical reason for a long time, but not indefinitely. Ultimately, our commitment to a natural-law approach itself—to the view that moral norms must make sense to people of good will—has to be more fundamental than our position on this particular application of the natural law.