Carl Sagan, The Varieties of Scientific Experience; A Personal View of the Search for God, edited by Ann Druyan (New York: Penguin Press, 2006), 284pp.

           In 1985 Carl Sagan (1934–1996) delivered the Gifford Lectures on natural theology at the University of Glasgow to overflow audiences. In them he presented what he called the "definitive statement" of his personal views on the relationship between science and religion and the nature of the sacred. For twenty years these lectures lay hidden in a drawer until his wife, Ann Druyan, rediscovered them and published them in the present book. Her choice of the book's title, of course, is a play on William James' own Gifford Lectures which were published as The Varieties of Religious Experience.

           Sagan's nine chapters traverse a broad and diverse intellectual terrain, from the size of the cosmos, the nature of science, extraterrestrial intelligence, UFO's, proofs for the existence of God, environmentalism, and the threat of nuclear war. Sagan does not believe that the proofs for God are very impressive, nor that there is any definitive evidence for the existence of God, but like Einstein and Spinoza to whom he appeals, he acknowledges a reverence for the sum total of the laws of nature. In interviews he has described himself as an agnostic rather than as an atheist, and whatever the case it's clear that he is far from any traditional notion of God or the afterlife.

           Central to Sagan's program is an aggressive rebuttal of "anthropocentric arrogance." Given the unimaginably vast size and complexity of the universe(s?!), says Sagan, humanity should not claim any privileged status either in space or time. He thus wants to demote humanity from any central position in the universe to a mere incidental status. But if religious believers should not draw any "positive" conclusions about the deity or humanity based upon nature, it seems contradictory for Sagan to draw "negative" ones. At one point he seems to admit this, as when he writes that "there is no particular theological conclusion that comes out of an exercise such as the one we have just gone through" (p. 28). At other times he admits when his opinions are no more than "speculations" or even "wild guesses."

          Many of Sagan's descriptions of religion stoop to shallow caricatures: "What about the idea that we are all made in God's image? Is that also a failure of the imagination? Do we, for example, imagine that God has nostrils and breathes? If so, what does He breathe? Air? Where is the air? Air with oxygen in it? No other planet in the solar system has oxygen except the earth. Why restrict God to very few places? Why would He need nostrils? What about a navel? What about hair?" (p. 122). Is it really a "perfectly typical tenet of modern religion" to believe that "if you only have enough faith, you can levitate"? (p. 143). Straw man arguments like this are demeaning for one of the most brilliant intellectuals of our time. Furthermore, when Sagan discusses proofs for the existence of God, the nature of miracles, the problem of evil, and the like, he never interacts with serious Christian literature on the subject (eg, philosophers like Richard Swineburne and Alvin Plantinga, or scientists who are believers like Francis Collins, John Polkinghorne or Owen Gingerich). The result is a brilliant version of science pitted against a ridiculous presentation of religion. Guess who wins? A final and important area that Sagan does not address is the possibility of knowledge that the scientific method cannot verify, like aesthetics or ethics. What might a Mozart symphony tell us about the nature of ultimate reality? Or what are the implications for science that it can build a nuclear bomb, but not tell us whether, when, or under what conditions to use it? The "is" of scientific description, as many people have observed, does not by itself address matters of "ought."