Epistemic Criteria for Delusionality

Abstract

Recently, in the mainstream media and cognitive science research, there has been a tendency not only to compare beliefs in conspiracy theories with clinical delusions but also to label as delusional various non-clinical beliefs that are considered epistemically problematic. Sam Wilkinson proposed that when we call a belief delusional, we express our common-sense epistemic disapproval for a belief that we do not share. In this respect, it is part of Wilkinson’s proposal that the attribution of delusional character to beliefs plays an expressive rather than a descriptive role. The implication is that calling certain beliefs delusional is not mediated by the fact that those beliefs satisfy certain conditions, and the expression of disapproval cannot be further unpacked. In this article, we accept that calling beliefs ‘delusional’ is a way of expressing disapproval, but we resist the idea that the reasons for disapproval cannot be further unpacked. We propose that a belief is called ‘delusional’ when it is considered (1) implausible, in the sense that it has no appearance of truth because it is in tension with existing beliefs, and (2) unshakable, in the sense that it is not usually abandoned under the pressure of counterarguments or counterevidence. Although other features of the beliefs also shed light on why we call them delusional, we will focus on implausibility and unshakeability as epistemic criteria for the delusional character of beliefs.