With all the deserved hoopla over the new version of Carl Sagan’s classic TV series “Cosmos,” I wanted to call attention to his wonderful but often overlooked book: The Demon-Haunted World: Science as a Candle in the Dark. It was an excellent text for my college courses in critical thinking, deftly distinguishing science from pseudo-science, and the reasonable from the unreasonable. The tools that guide critical or skeptical thinking and allow us to detect irrationality in all its form he aptly calls the “baloney detection kit.” With the medieval mindset that characterizes so much of contemporary American culture today—with its stories of ghosts and angels—Sagan’s calm rationalism shines as a beacon.
But the book deeply inspires too. Sagan, one of the promoters of the SETI project and responsible for the gold record aboard the Voyager spacecraft, denounces the absurdity of belief in ET visits and alien abductions. He wasn’t interested in believing in the fanciful, but in knowing what was true. His intellectual honesty is itself inspiring, as is his belief in the power of reason and science to understand and transform our world.
The book also warns against the temptation of believing what we want to be true, rather than in what the evidence suggests. Sagan knew the truth of Francis Bacon’s claim that: “Man prefers to believe what he prefers to be true.”Such sentiments lead down a dangerous road, to beliefs in demons, witches and similar superstitions. Such beliefs are not innocuous; people have been killed over them—absurd beliefs often lead to atrocities.
Science and reason are the only means that humans have to educe a little truth from reality. Sagan’s book testifies to the glory of the rational mind; it should inspire and warn us all.
At the heart of science is an essential tension between two seemingly contradictory attitudes- an openness to new ideas, no matter how bizarre or counter-intuitive they may be, and the most ruthless skeptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense…. ~ Carl Sagan