On January 2, 2007, Cameron Hollopeter had a seizure on a subway platform in New York City. Three people rushed to help him, including Wesley Autrey, who jammed Hollopeter’s jaw open with a pen. Then, as the lights of an approaching train filled the station, Hollopeter tumbled off the platform and onto the tracks. Autrey jumped in after him and tried to lift Hollopeter back onto the platform. But the train was too close, so Autrey dragged him into a drainage trench beneath the tracks and lay on top of him. The train roared over the two men, so close that it left a grease stain on Autrey’s hat.

Why would someone risk his life for a stranger? Francis Collins, the prominent biologist who currently serves as the head of the National Institutes of Health, raises the heroism of Wesley Autrey as an example of a selfless act that cannot easily be understood as the product of the amoral forces of biological evolution. To Collins, such acts suggest divine intervention.

As someone who studies morality, I hear this argument a lot. People can be selfish and amoral and appallingly cruel, but we are also capable of transcendent kindness, of great sacrifice and deep moral insight. Isn’t this evidence for God? This version of “intelligent design” is convincing to many people—including scientists who are otherwise unsympathetic to creationism—and it’s worth taking seriously. Like other intelligent design arguments, it doesn’t work, but its failure is an interesting one, touching on findings about evolution, moral psychology, and the minds of babies and young children.

For most of human history, it was easy enough to believe in a loving and all-powerful God. The natural world appears to teem with careful and complex design, and, as scholars from Cicero to Paley have argued, design implies a designer. This is a powerful argument: The evolutionary theorist and well-known atheist Richard Dawkins notes at the start of The Blind Watchmaker that he would certainly have been a believer before 1859—any observant and intellectual person would have to be. But Darwin changed everything, as he proposed a mechanistic account of where this complexity could come from. The theory of natural selection has been supported by abundant evidence from paleontology, genetics, physiology, and other fields of science, and denying it now is as intellectually disgraceful as denying that the Earth orbits the Sun.

But, as we see from Collins, the design argument persists, in a subtler and perhaps more promising form. Even if biological evolution can explain the bodies of humans and other creatures, it might be inadequate for understanding certain features of our minds, and, in particular, our moral and spiritual natures. This was the position of Pope John Paul II. In 1996, in a speech to the Pontifical Academy of Sciences plenary session at the Vatican, the Pope shocked many Catholics by supporting the Darwinian account of biological evolution. But he drew the line at the soul; theories that "consider the spirit as emerging from the forces of living matter, or as a mere epiphenomenon of this matter, are incompatible with the truth about man."