Understanding delusions to improve our mutual interactions: A précis of <i>"Why Delusions Matter"</i>

Why Delusions Matter is a reflection on the importance of the study of delusions for better understanding and reshaping our mutual interactions. The study of delusions has transformed the philosophy of mind and psychology in the last thirty years, helping redefine the relationship between rationality and intentionality. It has still a lot to offer to emerging areas at the intersection of ethics and epistemology. These are areas where the focus of the investigation of beliefs is moving from a painstaking assessment of the individual’s cognitive achievements and failures to a broader examination of the environmental and social pressures on the adoption, revisions, and maintenance of beliefs at individual and collective levels. In the book, there is an exploration of the notion of delusionality across clinical and non-clinical contexts which shows how delusions are meaningful beliefs that matter to the speaker's identity but are received by the interpreter as implausible and unshakeable. Delusions are not pathological by default, but they can bring epistemic and psychological costs as well as temporary benefits. Although a speaker's delusions can make collaboration difficult, this should not discourage interpreters from attempts at genuine engagement. Delusions are not a sign of a breakdown in the speaker's capacity for agency and thus understanding them can help interpreters appreciate the speaker's perspective.