When I interviewed Leon Kass for Christianity Today on his appointment to chair the President's Council on Bioethics back in 2002, I asked why he got into bioethics. One reason he gave was a short and stunning essay by C. S. Lewis.

As the world awaits the Narnia movie, and Lewis's extraordinary work receives the acclaim of a fresh generation, nothing demonstrates his genius like that little essay with the strange title, The Abolition of Man. It runs to just over a dozen pages. Not only are they the most profound pages he ever wrote, they may also be the most significant pages written by any writer of the 20th century. They are certainly the most relevant to the technological challenges of the 21st century.

The Abolition of Man is readable, but its argument is tightly packed. It is spotted with references to classic literature, but it is hardly written from an ivory tower. Lewis was writing—and, more importantly, thinking—in wartime. His examples of technology include Nazi propaganda on the radio and advanced weapons of war, as well as early biotechnologies such as contraception and—looking ahead—the manipulation of human genes. And he was not unaware of the terrible story of eugenics that was even then coming to its climax in the bestial "science" of the death camps.

Lewis's key idea is that technology gives us power, power to do good or to do evil and modern technologies give us more and more power. But such power is not simply "power over nature," as we tend to say. It is the power some people exercise over other people, with "nature" as their instrument.

Lewis foresees that the result of the use and abuse of our "power over nature" could be the end of human nature itself. Decades later, others saw that ...