The Demon-Haunted World: Science as a Candle in the Dark

25. The Demon-Haunted World: Science as a Candle in the Dark, by Carl Sagan

Carl Sagan's death was a great loss, not only to the world of science, but to society as a whole. His popular science books were accessible to the intelligent but untrained mind, yet they did not lack in intellectual rigor. This book discusses the importance of approaching matters of science and pseudo-science with that same intellectual rigor.

Sagan addresses here a number of commonly-held, but false, beliefs -- alien abduction stories, crop circles, faith-healing, and the like -- and shows where these fall down in the face of examination. It really is surprising how many people continue to believe in such things, even when fraud is admitted! You can analyze such stories yourself. You don't need Sagan to do it for you, but, in one very valuable section, he provides the tools you'll need, what you need to do, to look for, to develop the ability to think skeptically. They bear repeating, so I will summarize:
1. There should be independent confirmation of the "facts".
2. Substantive debate by knowledgeable proponents of all points of view should be encouraged.
3. Spin more than one hypothesis, and test them.
4. Don't get too enamored of your hypothesis.
5. If what you are explaining as some measure or numerical quality, it's easier to discriminate among competing hypotheses.
6. Every link in the chain of argument, including the premise, must work. If you are going from A to G, and there's a hole between B and C, you can't get there.
7. Remember Occam's Razor (if two explanations fit the data equally well, the simpler is probably the true one).
8. Ask whether the hypothesis can be falsified. You have to be able to check things out., using carefully designed and controlled experiments.

Much of what you need in what Sagan calls your "baloney detection kit" can be learned in any basic logic course. Unfortunately, logic isn't taught in the schools anymore.

Sagan also addresses the disturbing trend in the U.S. (one that hasn't changed since the book was published nearly fifteen years ago) of attacking science, of making policy decisions relating to science based on political considerations rather than the facts. He points out that our founding fathers had a strong belief in science, that Thomas Jefferson, in fact, described himself as a scientist, not as a planter or a politician. These men read, they studied, they argued, they delved into the world of science. That has not been the case in recent decades (there may be some hope, though, in the appointment of a Nobel laureate in physics as President Obama's Secretary of Energy!).

It is, however, in discussing politics that this book is weakest. Sagan's attacks on Edward Teller, while perhaps warranted, seem a bit over the top, and so one naturally questions the objectivity of some of his other political statements. This is, however, a minor part of an otherwise excellent book.

The pity is that the people who ought to read it, won't.