ABSTRACT
Are the beliefs of fanatics, terrorists, and other extremists epistemically rational? According to the crippled epistemology theory and the echo chamber theory, they are: these people are working with severely impoverished information that supports their worldview, or they are caught up in social networks that justify disparities in trust between like-minded insiders and dissenting outsiders. However, this chapter shows that these theories fail to take into account the higher-order evidence that fanatics typically possess and how fanatics characteristically treat their higher-order evidence. The chapter then appeals to a recently developed account of fanaticism to explain why fanatics treat higher-order evidence the way they do. Fanatics adopt a fragile epistemology, which leads them to treat higher-order evidence, especially disagreement with others, not as reason to rethink their worldview but rather as a threat to their identity. This treatment of higher-order evidence derives from how fanatics understand their values: these values are not to be questioned, and when they are questioned, their status is thereby threatened. By illuminating the characteristic relationship between higher-order evidence and the nature of fanaticism, this chapter shows what kind of treatment of higher-order evidence must be condoned if fanatics’ beliefs are to be judged rational.
