 The severity of hallucinations and delusions, with almost unfailing consequences for their subject in clinical, legal, social, and personal settings, serves to distinguish them from many of the general controversies about disorder noted thus far. The incidence of and pathology associated with hallucinations has been questioned, as has their origins, and phenomenology (Leudar &amp; Thomas 2000; Ratcliffe 2017; Henriksen, Raballo, &amp; Parnas 2015). And delusions have attracted the particular attention of philosophers for their incomprehensibility, which challenges standard epistemology and theories about meaning, language, belief, and intention (Coltheart &amp; Davies 2000; Bortolotti 2009). They have also been the impetus for important collaborative work between several sciences: in addition to being psychiatric disorders delusions occur as symptoms of neurological diseases of and injury to the brain, and as such have been subject to considerable empirical study. Philosophical research on delusions primarily addresses issues about their intelligibility; about their status in relation to more normal doxastic states; and about explanatory models.