Chapter 5 - Delusion and the Norms of Rationality

Abstract

According to the epistemic conception of delusions, delusional thought can be distinguished from nondelusional thought by the degree to which it involves departures from the norms of epistemic rationality. This conception is enshrouded in the DSM characterization of delusions and is presupposed by most theoretical accounts of delusions. This paper presents a number of objections to the epistemic conception and argues that the view is less plausible than an alternative approach that centers on the notion of proper function. According to the proper function view, delusions occur when the systems responsible for belief fixation fail to function in the way that they were designed to function. Thus understood, delusions can involve departures from the norms of epistemic rationality but they need not.