Imperfect Cognitions

Today's post is by  Chenwei Nie  on his recent paper, " Revisiting Maher’s one-factor theory of delusion " ( Neuroethics , 2023). Currently, he is a Teaching Fellow in Philosophy at the University of Warwick, UK. Chenwei Nie Suppose your friend, Ava, is suffering from a delusional belief that her partner is replaced by an imposter. Despite overwhelming evidence to the contrary - such as the supposed imposter's identical appearance to her partner and knowledge of intimate details, and reassurances from you and her other friends - Ava steadfastly maintains this belief. In this unfortunate circumstance, it is obvious that something must have gone wrong in the formation and maintenance of Ava’s belief. It is likely that Ava would be diagnosed with the Capgras delusion. Unravelling what exactly has gone wrong, however, has proven challenging. According to a classic one-factor theory of delusion developed by Brendan Arnold Maher (1924-2009), the only factor, i.e. departure ...

This post is by  Eisuke Sakakibara , psychiatrist working at  The University of Tokyo Hospital . In this post he writes about his paper “ Intensity of experience: Maher’s schizophrenic delusion revisited ” recently published in Neuroethics. Delusion is one of the most frequently discussed themes in philosophy of psychiatry, and this is my second publication regarding delusions. In my first paper, entitled “ Irrationality and pathology of beliefs ,” I proposed that not all delusions are pathological, and some delusions are formed without any physical or mental dysfunction. In my second paper , I focused on delusions accompanied by schizophrenia. As for schizophrenic delusions, it is beyond question that they are the result of dysfunction of some kind. The problem, then, is what kind of dysfunction is relevant for the development of schizophrenic delusions. The theory of schizophrenic delusion has developed by the consecutive works made by Brendan Maher. He proposed ...