Delusional thinking and cognitive disorder

A hypothesis is presented regarding the genesis of paranoid delusion that attempts to take into account certain data. The data of interest are (a) the failure to find evidence of cognitive impairment in diagnosed paranoid patients, (b) the evidence of perceptual disorder as a primary and prior condition in the natural history of the clinical development of delusions and the empirical relationship of the perceptual disorder to presence of “thought disorder,” (c) the failure to find evidence supporting universal psychodynamic patterns of etiology, (d) appearance of “delusional” phenomena in normal subjects in situations of deviant sensory experience, and (e) the reports of articulate patients writing of their experiences.