In university, author Patrick Glynn, a Harvard Ph.D, followed English philosopher Bertrand Russell in viewing man as “a curious accident in a backwater,” the inexplicable by-product of a random universe. Today he is a Christian, and science no longer supports atheism with its old enthusiasm either. “The totality of the evidence as I understood it in the mid-1970s suggested one conclusion [atheism],” he writes. “Today the evidence suggests quite a different one.”

He has built his book on the “anthropic principle,” a term coined by Cambridge University astrophysicist Brandon Carter in 1973. Mr. Carter used it to describe a phenomenon which previously had been only dimly perceived, namely the fact that all the seemingly arbitrary and unrelated constants in physics have one strange thing in common. They are precisely the values needed if the goal is a universe capable of producing life.

The existence and action of gravitational and electromagnetic force were known, of course, but simply as separate “constants.” Then came the insight that, in accordance with the anthropic principle, any variation in the gravitational constant in relation to electromagnetism would have resulted in a universe with no intermediate stars like our sun–only cooler “red” or hotter “blue” ones …