is generally a healthy thing. Requiring evidence and questioning other people's claims can help us avoid falling prey to quacks and con artists of all stripes. It can keep us from throwing our time, money and hope into a pit from which we can never get it back.
However, the tools of skepticism, like any other tools, can be misused. They can be selectively and inappropriately applied to create doubt even where almost no doubt remains. This tactic is referred to as bogus skepticism, or denialism. It's used frequently in discussion of politically charged topics, such as man-made and the very existence of the .
PalMD is an internist (a doctor of internal medicine) who has blogged extensively about medical denialism at White Coat Underground, Science-Based Medicine and previously at denialism blog. He also hosts a podcast (or PalCast) in which he talks about many of the same issues. The contentious topics he's covered include the dangers of secondhand smoke, claims of a vaccine-autism link, "alternative" medicine and diagnoses of diseases without any physiological basis. He'll talk with us about the difference between skepticism and denialism and how to spot a denialist.