But if you are talking with someone who is not suffering but wants to disprove God on this basis, Keller offered a more direct answer. Citing the philosopher Alvin Plantinga, Keller said that if you believe in God, evil and suffering are a great problem, “but if you don’t believe in God, it’s a bigger one.” To believe in evil requires a belief in moral absolutes grounded in some transcendent truth. If that doesn’t exist, then how do you even define evil?

“If there is no God, then evil and suffering and violence are perfectly natural,” Keller told me. “The weak are killed off; the stronger survive. That’s the way the world is. There is no right and wrong—there is just what is. To believe that some things that happen are evil requires some supernatural standard of good—something from outside of nature—by which to judge which natural things are truly natural and which things are unnatural. But as Nietzsche says, there is nothing outside of nature.”

This theological argument doesn’t explain why God allows evil and suffering; it only claims that you can’t use evil and suffering to disprove the existence of God. “That’s all they can do,” Keller said. “That’s it, and that’s not much. It’s the cross that helps us actually live this life. That’s what matters.”

Staying with this line of inquiry, I asked Keller to sketch the limitations of or problems with the secular view of scientism (the belief that science is the only source of real knowledge) and materialism (that physical matter is the fundamental reality).

Keller told me that recent books such as Science and the Good, by James Davison Hunter and Paul Nedelisky, and Atheist Overreach, by Christian Smith, do a good job of making the case that has also been made by the German philosopher Jürgen Habermas.

In a nutshell, their point is that science can tell you what you can do and how to do it efficiently, but it can never tell you whether you ought to do it. Science can’t get you from the “is” to the “ought”; it can’t give us a basis for morality. And if science and objective human reasoning can’t give us that, Keller told me, “we will not be able to order our society without recourse to religion or faith of some kind.”

“Right now, a big part of the polarization we are seeing is due to ‘warring moralities’ that come from differing assumptions about the big questions,” Keller said. “What are human beings for? How do we make moral judgments? What are the highest goods? Science can’t adjudicate these controversies.”

Beyond that, Keller said, the philosophy of secular materialism—the view that there is no transcendent, supernatural dimension; no God; no soul—can’t really support its own moral values.

“This is a major theme of the philosopher Charles Taylor,” Keller told me. “In short, he says that secular materialism has to explain our moral beliefs as merely the result of evolution and biology, or of social construction, or both. There are no moral absolutes grounded in a cosmic order, as the Greeks thought, or in God and heaven.



“Materialism logically leads to at least soft relativism,” he added. “And yet modern secular people are highly moral—committed to the values of human rights and justice for the poor and marginalized. So, Taylor and others conclude, the conundrum of modern society is that we don’t have the moral sources to support our high moral ideals. We teach people in college that all facts and moral claims are socially constructed, and then we demand they give up their power and privilege to lift up the marginalized. But why, then? As C. S. Lewis said about this very dynamic [in The Abolition of Man], ‘We castrate and bid the geldings be fruitful.’”