Sagan discusses his feelings of grief after the death of his parents, to whom he was very close, and his natural longing to believe that aspects of them remained in one form or another after death. He then disparages those who capitalize on this human need, such as mediums and channeling spiritualists, before providing an exhaustive list of what he calls “cases of proved or presumptive baloney” (209), in which people knowingly deceived someone else by assuming beliefs to which they do not actually subscribe. To counter this, Sagan presents what he calls the “baloney detection kit” full of “Tools for skeptical thinking” (210), which provide a foundation of falsifiability against spurious claims, such as abduction by aliens:

• seek independent confirmation of facts
• encourage debate on the evidence from experts of opposing points of view
• construct multiple working hypothesis
• do not overly emotionally attach to your own hypothesis
• quantify (put into numbers) data as often as possible
• every link in the chain of argument must work
• adhere to Occam’s Razor, the idea that the simplest solution is often the correct solution
• always ask if the hypothesis is falsifiable

After providing tools for proactive thinking, Sagan next reveals what not to do by listing 20 logical fallacies, which are common errors in reasoning that weaken or invalidate arguments.