Raye Ploeger

ABSTRACT Most people are suspicious of conspiracy theories. The claims that water fluoridation is mass poisoning, that the UN deliberately released the COVID‐19 virus, and that George Bush was responsible for 9/11 are, to many of us, obviously absurd. Nevertheless, it has proven surprisingly difficult to explain why we should be suspicious of conspiracy theories as a class, in any general way. In this article, I present a solution to this problem. I identify a general feature of conspiracy theories and argue that this feature makes it impossible for high credences regarding conspiracy theories to be rationally justified. More specifically, I argue that conspiracy theories are claims that, if true, imply that certain skeptical‐hypothesis‐like claims “cover‐up claims” are extremely likely to be true. As a consequence, if we think that high credences regarding skeptical hypotheses cannot be rationally justified, we should also think that high credences regarding conspiracy theories cannot be justified.

Most people are suspicious of conspiracy theories. The claims that water fluoridation is mass poisoning, that the UN deliberately released the COVID-19 virus, and that George Bush was responsible for 9/11 are, to many of us, obviously absurd. Nevertheless, it has proven surprisingly difficult to explain why we should be suspicious of conspiracy theories as a class, in any general way. In this article, I present a solution to this problem. I identify a general feature of conspiracy theories and argue that this feature makes it impossible for high credences regarding conspiracy theories to be rationally justified. More specifically, I argue that conspiracy theories are claims that, if true, imply that certain skeptical-hypothesis-like claims (“cover-up claims”) are extremely likely to be true. As a consequence, if we think that high credences regarding skeptical hypotheses cannot be rationally justified, we should also think that high credences regarding conspiracy theories cannot be justified.