 The standard reference text in psychiatry, the Diagnostic and Statistical Manual of Mental Disorders (DSM-V, 2013) characterizes delusions (e.g., persecutory delusions, delusions of grandiosity) as beliefs. However, delusions often do not appear to connect with behavior in the usual way. For example, a victim of Capgras delusion—a delusion in which the subject asserts that a family member or close friend has been replaced by an identical-looking imposter—may continue to live with the “imposter” and make little effort to find the supposedly missing loved one. Some philosophers have therefore suggested that delusions do not occupy quite the functional role characteristic of belief and thus are not, in fact, beliefs (e.g., Currie 2000; Stephens and Graham 2004; Gallagher 2009; Matthews 2013). Others have defended the view that delusions are beliefs (e.g., Campbell 2001; Bayne and Pacherie 2005; Bortolotti 2010, 2012) or in-between cases, with some features of belief but not other features (e.g., Egan 2009; Tumulty 2011). See the entry on  delusion,  especially §4.2  Are Delusions Beliefs? 