Sagan wrote that "extraordinary claims require extraordinary proof."10 He dedicated much ink to a rational investigation of extraordinary claims. He felt most, or nearly all, were susceptible to simpler and more parsimonious explanations. UFOs, paranormal activity, telepathy, and a hundred other seemingly mystifying occurrences could be better explained with a few simple real world variables. And as Hume suggested, if they couldn't, it was a lot more likely that we needed to update our understanding of the world than that a miracle had occurred.