Fanaticism is usually conceived as an epistemic attitude of individuals, founded on a set of rationally not justified beliefs, and amounting to an unwavering commitment to threatened, sacred values. Moreover, it has been routinely pointed out that there is an intimate connection between fanatics’ irrational commitments and passions as well as fanatics’ social identification with a group that purportedly shares one’s values. However, in all these accounts, both the group-based and the affective aspects remained underdetermined.

In this paper, I defend an alternative, non-individualist and non-cognitive, account of fanaticism, and elaborate in detail on its affective and social nature. I argue that fanaticism is an affective-intentional mechanism, transforming individual commitments to values into what I define as a “derivatively shared” antagonistic and collaboratively biased “affective convictions.” I contend that it is the affective and group-based, antagonistic nature of these convictions, not their insufficient justification, that makes the values morally or rationally unquestionable, or sacred. I conclude by addressing the issue of how to resist fanaticism and argue that, given its affective and group-based nature, it can only be resisted by affective reappraisal of the alleged threat and a re-personalization of the scared values.