Carl Sagan’s baloney detection kit: How to improve your critical thinking skills

Science Writer
January 24, 2018

In 1995, just a few months before his death, astrophysicist Carl Sagan published The Demon-Haunted World: Science as a Candle in the Dark. In that book, he wrote a chapter called 'The Fine Art of Baloney Detection', and from it sprang what skeptics call the 'baloney detection kit'. This is a set of tools for critical thinking that has continued to develop since Sagan's death, 22 years ago. Here, skeptic and science writer Michael Shermer explains key lessons from Sagan, and from his own college freshman course 'Skepticism 101', where teaches students ten basic questions that will help them debunk untruths, and call out baloney when they see it.

1. How reliable is the source of the claim?

2. Does the source make similar claims?

3. Have the claims been verified by somebody else?

4. Does this fit with the way the world works?

5. Has anyone tried to disprove the claim?

6. Where does the preponderance of evidence point?

7. Is the claimant playing by the rules of science?

8. Is the claimant providing positive evidence?

9. Does the new theory account for as many phenomena as the old theory?

10. Are personal beliefs driving the claim?

Michael Shermer's new book is Heavens on Earth: The Scientific Search for the Afterlife, Immortality, and Utopia.