Online research in philosophy

Some otherwise rational people appear to believe strange things. Sometimes people believe that someone, usually a near relative or member of their family - often their spouse - has been replaced by an impostor. Sometimes people believe that they are dead. These two delusions – known as the Capgras and Cotard delusion respectively – are instances of monothematic delusions, for they are limited to very specific topics. Other monothematic delusions involve the delusion that one is being followed by known people (...) in disguise (the Frégoli delusion), or that the person one sees in the mirror is someone else (mirrored-self misidentification). We will focus on the Capgras delusion. (shrink)

The present article proposes a logical account of delusions, which are regarded as conclusions resulting from fallacious arguments. This leads to distinguish between primary, secondary, ..., n-ary types of delusional arguments. Examples of delusional arguments leading to delusion of reference, delusion of influence, thought-broadcasting delusion and delusion of grandeur are described and then analyzed. This suggests finally a way susceptible of improving the efficiency of cognitive therapy for delusions.

1923; Young, this volume); the Cotard delusion (Cotard, 1882; Berrios and Luque, 1995; Young, this volume); the Fregoli delusion (Courbon and Fail, 1927; de Pauw, Szulecka and Poltock, 1987; Ellis, Whitley and Luaute´, 1994); the delusion of mirrored-self misidentifi- cation (Foley and Breslau, 1982; Breen et al., this volume); a delusion of reduplicative param- nesia (Benson, Gardner and Meadows, 1976; Breen et al., this volume); a delusion sometimes found in patients suffering from unilateral neglect (Bisiach, 1988); and the delusions of (...) alien control and of thought insertion, which are characteristic of schizophrenia (Frith, 1992). (shrink)

I argue that some cases of delusions show the inadequacy of those theories of interpretation that rely on a necessary rationality constraint on belief ascription. In particular I challenge the view that irrational beliefs can be ascribed only against a general background of rationality. Subjects affected by delusions seem to be genuine believers and their behaviour can be successfully explained in intentional terms, but they do not meet those criteria that according to Davidson (1985a) need to be met for the (...) background of rationality to be in place. (shrink)

Subjects with delusions profess to believe some extremely peculiar things. Patients with Capgras delusion sincerely assert that, for example, their spouses have been replaced by impostors. Patients with Cotard’s delusion sincerely assert that they are dead. Many philosophers and psychologists are hesitant to say that delusional subjects genuinely believe the contents of their delusions.2 One way to reinterpret delusional subjects is to say that we’ve misidentified the content of the problematic belief. So for example, rather than believing that his wife (...) is has been replaced by an impostor, we might say that the victim of Capgras delusion believes that it is, in some respects, as if his wife has been replaced by an impostor. Another is to say that we’ve misidentified the attitude that the delusional subject bears to the content of their delusion. So for example, Gregory Currie and co-authors have suggested that rather than believing that his wife has been replaced by an impostor, we should say that the victim of Capgras delusion merely imagines that his wife has been replaced by an impostor.3. (shrink)

Current models of delusion converge in proposing that delusional beliefs are based on unusual experiences of various kinds. For example, it is argued that the Capgras delusion (the belief that a known person has been replaced by an impostor) is triggered by an abnormal affective experience in response to seeing a known person; loss of the affective response to a familiar person’s face may lead to the belief that the person has been replaced by an impostor (Ellis & Young, 1990). (...) Similarly, the Cotard delusion (which involves the belief that one is dead or unreal in some way) may stem from a general.. (shrink)