In this paper we defend the doxastic conception of delusions against the metacognitive account developed by Greg Currie and collaborators. According to the metacognitive model, delusions are imaginings that are misidentified by their subjects as beliefs: the Capgras patient, for instance, does not believe that his wife has been replaced by a robot, instead, he merely imagines that she has, and mistakes this imagining for a belief. We argue that the metacognitive account is untenable, and that the traditional conception of (...) delusions as beliefs should be retained. (shrink)

Chris Frith has argued that a loss of the sense of agency is central to schizophrenia. This suggests a connection between hallucinations and delusions on the one hand, and the misidentification of the subject’s imaginings as perceptions and beliefs on the other. In particular, understanding the mechanisms that underlie imagination may help us to explain the puzzling phenomena of thought insertion and withdrawal. Frith sometimes states his argument in terms of a loss of metarepresentational capacity in schizophrenia. I argue that (...) this formulation is unhelpful. (shrink)

Recreative Minds develops a philosophical theory of imagination that draws upon the latest work in psychology. This theory illuminates the use of imagination in coming to terms with art, its role in enabling us to live as social beings, and the psychological consequences of disordered imagination. The authors offer a lucid exploration of a fascinating subject.

In 1910, Karl Jaspers wrote a seminal essay on morbid jealousy in which he laid the foundation for the psychopathological phenomenology that through his work and the work of Hans Gruhle and Kurt Schneider, among others, would become the ...

Article copyright 2002. We provide a battery of examples of delusions against which theoretical accounts can be tested. Then we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher's view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second (...) factor in the etiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows, but we point out some problems that confront any attempt to say more about the nature of this second factor. (shrink)

Circumscribed delusional beliefs can follow brain injury. We suggest that these involve anomalous perceptual experiences created by a deficit to the person's perceptual system, and misinterpretation of these experiences due to biased reasoning. We use the Capgras delusion (the claim that one or more of one's close relatives has been replaced by an exact replica or impostor) to illustrate this argument. Our account maintains that people voicing this delusion suffer an impairment that leads to faces being perceived as drained of (...) their normal affective significance, and an additional reasoning bias that leads them to put greater weight on forming beliefs that are observationally adequate rather than beliefs that are a conservative extension of their existing stock. We show how this position can integrate issues involved in the philosophy and psychology of belief, and examine the scope for mutually beneficial interaction. (shrink)

In the formative years of psychiatry Freud, Bleuler, and Jaspers all studied Daniel Paul Schreber's Memoirs of My Nervous Illness as a model of psychotic thought. Sass provides a nuanced interpretation of Schreber's Memoirs in the context of Wittgenstein's analysis of philosophical solipsism. A dauntless critic of the illusions of philosophy, Wittgenstein likened the speculative excesses of traditional metaphysics to mental illness. Sass observes that many of the "intellectual diseases" that Wittgenstein discerned - diseases involving detachment from social existence and (...) practical concerns, and exaggerated processes of abstraction and self-consciousness - have striking affinities with the symptoms of schizophrenia. Like the philosophical solipsist, the schizophrenic may define his or her own consciousness as the center of the universe - and may experience his or her delusional world as a product of that same consciousness. (shrink)

Delusions are explanations of anomalous experiences. A theory of delusion requires an explanation of both the anomalous experience _and _the apparently irrational explanation generated by the delusional subject. Hence, we require a model of rational belief formation against which the belief formation of delusional subjects can be evaluated. _Method. _I first describe such a model, distinguishing procedural from pragmatic rationality. Procedural rationality is the use of rules or procedures, deductive or inductive, that produce an inferentially coherent set of propositions. Pragmatic (...) rationality is the use of procedural rationality _in context_. I then apply the distinction to the explanation of the Capgras and the Cotard delusions. I then argue that delusions are failures of pragmatic rationality. I examine the nature of these failures employing the distinction between performance and competence familiar from Chomskian linguistics. _Results. _This approach to the irrationality of delusions reconciles accounts in which the explanation of the anomalous experience exhausts the explanation of delusion, accounts that appeal to further deficits within the reasoning processes of delusional subjects, and accounts that argue that delusions are not beliefs at all. (Respectively, one-stage, two-stage, and expressive accounts.) _Conclusion. _In paradigm cases that concern cognitive neuropsychiatry the irrationality of delusional subjects should be thought of as a performance deficit in pragmatic rationality. (shrink)

Detailed studies of people who have experienced the Capgras delusion (the delusion that certain other people, usually close relatives, have been replaced by impostors) have led to advances in constructing an account which can deal with the basic symptomatology, testing alternative possibilities, generating and testing non‐trivial predictions, and broadening the scope of the basic account to encompass other delusions. This paper outlines these developments. It uses them to explore implications for understanding the formation and maintenance of beliefs, and to discuss (...) basic principles of what has come to be known as cognitive neuropsychiatry. (shrink)

Although a common clinical phenomenon, delusions are difficult to explain and have a problematic conceptual status. Advances in understanding delusions have come from studies which involve detailed investigation of particular types of delusion. Some of this work is summarised, with the Capgras and Cotard delusions as specific examples. These are used to high-highlight questions for which there is the potential for fruitful dialogue with philosophers. Such questions include the criteria for deciding that a statement represents a belief, the extent to (...) which we integrate our beliefs into a coherent web, and the nature and limits of human rationality. (shrink)

Chris Frith has argued that a loss of the sense of agency is central to schizophrenia. This suggests a connection between hallucinations and delusions on the one hand, and the misidentification of the subject’s imaginings as perceptions and beliefs on the other. In particular, understanding the mechanisms that underlie imagination may help us to explain the puzzling phenomena of thought insertion and withdrawal. Frith sometimes states his argument in terms of a loss of metarepresentational capacity in schizophrenia. I argue that (...) this formulation is unhelpful. (shrink)