This year, we are exploring a single big question—How can followers of Christ be a counterculture for the common good?—with leaders inside and outside of evangelical Christianity. The Catholic legal scholar Robert P. George is a friendly outsider. As McCormick professor of jurisprudence and director of the James Madison program in American ideals and institutions at Princeton University, he has been a vigorous advocate for the Catholic natural law tradition's relevance to debates about morality in the public square. In an age when even many Christians question the effectiveness of reasoned argument toward truth, George offers a bracing counterpoint. Editorial director Andy Crouch spoke with George at his Princeton office.

Before we can talk about becoming a counterculture, we have to understand the culture. What's your reading of our culture right now?

I've argued in my book The Clash of Orthodoxies that the contemporary moment is marked by profound cultural division. We have a clash of two worldviews. On the one side are those who maintain traditional Judeo-Christian principles, such as the principle of the sanctity of human life, the principle that marriage is the union of a man and a woman, the principle that sex is integral to marriage but that sex ought not to be engaged in outside of marriage, and so forth.

On the other side of the cultural divide are people who have abandoned those principles in favor of some alternative ideology. Often it celebrates personal autonomy and freedom from traditional moral constraints, mixed with certain utilitarian elements. Sometimes it manifests itself in radical forms of feminism or quasi-pantheistic forms of environmentalism.

This division runs between elite and popular opinion. ...