Delusions are a common symptom of schizophrenia and dementia. Though most English dictionaries define a delusion as a false opinion or belief, there is currently a lively debate about whether delusions are really beliefs and indeed, whether they are even irrational. The book is an interdisciplinary exploration of the nature of delusions. It brings together the psychological literature on the aetiology and the behavioural manifestations of delusions, and the philosophical literature on belief ascription and rationality. The (...) thesis of the book is that delusions are continuous with ordinary beliefs, a thesis that could have important theoretical and practical implications for psychiatric classification and the clinical treatment of subjects with delusions. By bringing together recent work in philosophy of mind, cognitive psychology and psychiatry, the book offers a comprehensive review of the philosophical issues raised by the psychology of normal and abnormal cognition, defends the doxastic conception of delusions, and develops a theory about the role of judgements of rationality and of attributions of self-knowledge in belief ascription. Presenting a highly original analysis of the debate on the nature of delusions, this book will interest philosophers of mind, epistemologists, philosophers of science, cognitive scientists, psychiatrists, and mental health professionals. (shrink)

Psychopathological delusions have a number of features that are curiously difficult to explain. Delusions are resistant to counterevidence and impervious to counterargument. Delusions are theoretically, affectively, and behaviorally circumscribed: delusional individuals often do not act on their delusions and often do not update beliefs on the basis of their delusions. Delusional individuals are occasionally able to distinguish their delusions from other beliefs, sometimes speaking of their “delusional reality.” To explain these features, I offer a (...) model according to which, contrary to appearances, delusions are not beliefs at all. Delusions are acceptances that are generated by pathologically powerful cognitive feelings. This model has implications for the way that we should think about non-pathological doxastic states and emotions. (shrink)

Bortolotti’s Delusions and Other Irrational Beliefs defends the view that delusions are beliefs on a continuum with other beliefs. A different view is that delusions are more like illusions, that is, they arise from faulty perception. This view, which is not targeted by the book, makes it easier to explain why delusions are so alien and disabling but needs to appeal to forensic aspects of functioning.

The imperviousness of delusions to counter-evidence makes it tempting to classify them as imaginings. Bayne and Pacherie argue that adopting a dispositional account of belief can secure the doxastic status of delusions. But dispositionalism can only secure genuinely doxastic status for mental states by giving folk-psychological norms a significant role in the individuation of attitudes. When such norms individuate belief, deluded subjects will not count as believing their delusions. In general, dispositionalism won't confer genuinely doxastic status more (...) often than do competing accounts of belief. (shrink)

In this paper we have two main aims. First, we present an account of mood-congruent delusions in depression (hereafter, depressive delusions). We propose that depressive delusions constitute acknowledgements of self-related beliefs acquired as a result of a negatively biased learning process. Second, we argue that depressive delusions have the potential for psychological and epistemic benefits despite their obvious epistemic and psychological costs. We suggest that depressive delusions play an important role in preserving a person’s overall (...) coherence and narrative identity at a critical time, and thus can be regarded as epistemically innocent. (shrink)

Bortolotti argues that the irrationality of many delusions is no different in kind from the irrationality that marks many non-pathological states typically treated as beliefs. She takes this to secure the doxastic status of those delusions. Bortolotti’s approach has many benefits. For example, it accounts for the fact that we can often make some sense of what deluded subjects are up to, and helps explain why some deluded subjects are helped by cognitive behavioral therapy. But there is an (...) alternative approach that secures the same benefits as Bortolotti’s account while bringing additional benefits. The alternative approach treats both many delusions and many of the non-pathological states to which Bortolotti compares them as in-between states. Subjects in in-between states don’t fully believe the beliefs which it is sometimes convenient to ascribe to them. This alternative approach to belief and belief-ascription fits well with an independently attractive account of the varied purposes of our ordinary attitude ascriptions. It also makes it easier to make fine-grained distinctions between intentional attitudes of different kinds. (shrink)

After briefly reviewing some of the empirical and philosophical literature suggesting that there may be an adaptive role for delusion formation, we discuss the results of a recent study consisting of in-depth interviews with people experiencing delusions. We analyse three such cases in terms of the circumstances preceding the development of the delusion; the effects of the development of the delusion on the person’s situation; and the potential protective nature of the delusional belief as seen from the first-person perspective. (...) We argue that the development of the delusional belief can play a short-term protective function and we reflect on the implications that this might have for our understanding of psychotic symptoms, for the stigma associated with mental health issues, and for treatment options. (shrink)

In this paper we ask whether the two-factor theory of delusions is compatible with two claims, that delusions are pathological and that delusions are adaptive. We concentrate on two recent and influential models of the two-factor theory: the one proposed by Max Coltheart, Peter Menzies and John Sutton (2010) and the one developed by Ryan McKay (2012). The models converge on the nature of Factor 1 but diverge about the nature of Factor 2. The differences between the (...) two models are reflected in different accounts of the pathological and adaptive nature of delusions. We will explore such differences, considering naturalist and normativist accounts of the pathological and focusing on judgements of adaptiveness that are informed by the shear-pin hypothesis (McKay and Dennett 2009). After reaching our conclusions about the two models, we draw more general implications for the status of delusions within two-factor theories. Are there good grounds to claim that delusions are pathological? Are delusions ever adaptive? Can delusions be at the same time pathological and adaptive? (shrink)

According to the Rationality Constraint, our concept of belief imposes limits on how much irrationality is compatible with having beliefs at all. We argue that empirical evidence of human irrationality from the psychology of reasoning and the psychopathology of delusion undermines only the most demanding versions of the Rationality Constraint, which require perfect rationality as a condition for having beliefs. The empirical evidence poses no threat to more relaxed versions of the Rationality Constraint, which only require only minimal rationality. Nevertheless, (...) we raise problems for all versions of the Rationality Constraint by appealing to more extreme forms of irrationality that are continuous with actual cases of human irrationality. In particular, we argue that there are conceivable cases of “mad belief” in which populations of Lewisian madmen have beliefs that are not even minimally rational. This undermines Lewis’s claim that our ordinary concept of belief is a theoretical concept that is implicitly defined by its role in folk psychology. We argue that introspection gives us a phenomenal concept of belief that cannot be analyzed by applying Lewis’s semantics for theoretical terms. (shrink)

Although delusions are typically regarded as beliefs of a certain kind, there have been worries about the doxastic conception of delusions since at least Bleuler’s time. ‘Anti-doxasticists,’ as we might call them, do not merely worry about the claim that delusions are beliefs, they reject it. Reimer’s paper weighs into the debate between ‘doxasticists’ and ‘anti-doxasticists’ by suggesting that one of the main arguments given against the doxastic conception of delusions—what we might call the functional role (...) objection—is based on a fallacy. She also draws attention to certain parallels between delusions and what she calls “nihilistic philosophical doctrines,” such as the skeptical position that we have no .. (shrink)

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 aetiology 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)

In this paper, I examine a kind of delusion in which the patients judge that their occurrent thoughts are false and try to abandon them precisely because they are false, but fail to do so. I call this delusion transparent, since it is transparent to the sufferer that their thought is false. In explaining this phenomenon, I defend a particular two-factor theory of delusion that takes the proper integration of relevant reasoning processes as vital for thought-evaluation. On this proposal, which (...) is a refinement of Gerrans’s account of delusion as unsupervised by decontextualized processing, I can have all my reasoning processes working reliably and thus judge that my delusion is false but, if I cannot use their outputs when revising the thought itself, the delusion will persist. I also sketch how this framework explains some interesting cases of failed belief-revision in the general population in which people judge that ~p but nonetheless continue to believe that p. (shrink)

Stanford Encyclopedia Entry on Delusions.

In Delusions and Other Irrational Beliefs , Lisa Bortolotti argues that the irrationality of delusions is no barrier to their being classified as beliefs. This comment asks how Bortolotti’s position may be affected if we accept that there are two distinct types of belief, belonging to different levels of mentality and subject to different ascriptive constraints. It addresses some worries Bortolotti has expressed about the proposed two-level framework and outlines some questions that arise for her if the framework (...) is adopted. It also suggests that, rather than being beliefs that fail to meet the relevant standards of rationality, delusions may be non-doxastic acceptances that were never meant to meet them. (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)

Delusions play a fundamental role in the history of psychology, philosophy and culture, dividing not only the mad from the sane but reason from unreason. Yet the very nature and extent of delusions are poorly understood. What are delusions? How do they differ from everyday errors or mistaken beliefs? Are they scientific categories? In this superb, panoramic investigation of delusion Jennifer Radden explores these questions and more, unravelling a fascinating story that ranges from Descartes’s demon to famous (...) first-hand accounts of delusion, such as Daniel Schreber’s Memoirs of My Nervous Illness. Radden places delusion in both a clinical and cultural context and explores a fascinating range of themes: delusions as both individually and collectively held, including the phenomenon of folies á deux ; spiritual and religious delusions, in particular what distinguishes normal religious belief from delusions with religious themes; how we assess those suffering from delusion from a moral standpoint; and how we are to interpret violent actions when they are the result of delusional thinking. As well as more common delusions, such as those of grandeur, she also discusses some of the most interesting and perplexing forms of clinical delusion, such as Cotard and Capgras. (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)

This paper explores the phenomenology of the Capgras and Cotard delusions. The former is generally characterised as the belief that relatives or friends have been replaced by impostors, and the latter as the conviction that one is dead or has ceased to exist. A commonly reported feature of these delusions is an experienced ''defamiliarisation'' or even ''derealisation'' of things, which is associated with an absence or distortion of affect. I suggest that the importance attributed to affect by current (...) explanations of delusional experience can serve to make explicit the manner in which we ordinarily experience the world under a taken-for-granted aspect of affective familiarity. This implicit feeling is, I argue, partly constitutive of our sense of reality. However, so-called ''folk psychology,'' which is generally adopted by philosophers as an initial interpretive backdrop for delusional beliefs and for beliefs more generally, fails to accommodate it. As a consequence, some pervasive philosophical assumptions concerning the manner in which we experience and understand the world, ourselves, and each other are called into question. (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)

_Philosophical Delusion and its Therapy_ provides new foundations and methods for the revolutionary project of philosophical therapy pioneered by Ludwig Wittgenstein. The book vindicates this currently much-discussed project by reconstructing the genesis of important philosophical problems: With the help of concepts adapted from cognitive linguistics and cognitive psychology, the book analyses how philosophical reflection is shaped by pictures and metaphors we are not aware of employing and are prone to misapply. Through innovative case-studies on the genesis of classical problems about (...) the mind and perception, and on thinkers including Locke, Berkeley and Ayer, the book demonstrates how such autonomous habits of thought systematically generate unsound intuitions and philosophical delusions, whose clash with reality, or among each other, gives rise to ill-motivated but maddening problems. The book re-examines models of therapeutic philosophy, due to Wittgenstein and J. L. Austin, and develops an approach that may let us overcome philosophical delusions and the problems they engender. In this way, the book explains where and why therapy in called for in philosophy, and develops techniques to carry it out. (shrink)

In chapter 3 of Delusions and Beliefs, Kengo Miyazono argues that, when delusions are pathological beliefs, they are so due to their being both harmful and malfunctional. In this brief commentary, I put pressure on Miyazono’s account of delusions as harmful malfunctioning beliefs. No delusions might satisfy the malfunction criterion and some delusions might fail to satisfy the harmfulness criterion when such conditions are interpreted as criteria for pathological beliefs. In the end, I raise a (...) general concern about attributing pathological status to single beliefs out of context, and gesture towards the idea of pathology as a failure of agency to which some beliefs can contribute but that can only be identified by considering the person as a whole. (shrink)

In this paper I discuss the role played by disturbed phenomenology in accounting for the formation and maintenance of the Capgras delusion. Whilst endorsing a two-stage model to explain the condition, I nevertheless argue that traditional accounts prioritise the role played by some form of second-stage cognitive disruption at the expense of the significant contribution made by the patient’s disturbed phenomenology, which is often reduced to such uninformative descriptions as “anomalous” or “strange”. By advocating an interactionist model, I argue that (...) the delusional belief constitutes an attempt on the part of the patient to explain his/her initially odd and somewhat disturbed phenomenal content and, moreover, that the delusion then structures the patient’s experience such that what he/she perceives is an impostor. This fact is used to explain the delusional belief’s maintenance and resistance to revision. Thus, whilst accepting that second-stage cognitive disruption has a part to play in explaining the Capgras delusion, the emphasis here is placed on the role played by the patient’s changing phenomenal content and its congruence with the delusional belief. Unlike traditional two-stage models, which posit a unidirectional progression from experience to belief, the interactionist model advocates a two-way interaction between bottom-up and top-down processes. The application of this model to other delusional beliefs is also considered. (shrink)

Delusions are often portrayed as paradigmatic instances of incomprehensibility and meaninglessness. Here we investigate the relationship between delusions and meaning from a philosophical perspective, integrating arguments and evidence from cognitive psychology and phenomenological psychopathology. We review some of the empirical and philosophical literature relevant to two claims about delusions and meaning: delusions are meaningful, despite being described as irrational and implausible beliefs; some delusions can also enhance the sense that one’s life is meaningful, supporting agency (...) and creativity in some circumstances. Delusions are not incomprehensible representations of reality. Rather, they can help make sense of one’s unusual experiences and in some circumstances even support one’s endeavours, albeit temporarily and imperfectly. Acknowledging that delusions have meaning and can also give meaning to people’s lives has implications for our understanding of psychotic symptoms and for addressing the stigma associated with psychiatric conditions. (shrink)

In this paper I discuss the scientific respectability of delusion as a psychiatric category. First, I present the essentialist objection to the natural kindhood of psychiatric categories, as well as non-essentialism about natural kinds as a response to that objection. Second, I present a nuanced classification of kinds of kinds. Third, drawing on the claim that the attribution of delusion relies on a folk psychological underpinning, I present the mind-dependence objection to the natural kind status of delusion. Finally, I argue (...) that even if delusion as a generic kind stands little chance of being vindicated as a non-essentialist natural kind, we stand to gain from a natural kind methodology regarding subtypes of delusion for which there is evidence of genuine causal signatures and mechanisms. (shrink)

What is the relationship between the concepts of the predictive processing theory of brain functioning and the everyday concepts with which people conduct and explain their mental lives? To answer this question, we focus on predictive processing explanations of mental disorder that appeal to false inference. After distinguishing two concepts of false inference, we survey four ways of understanding the relationship between explanations of mental phenomena at the personal and sub-personal level. We then argue that if predictive processing accurately accounts (...) for psychological and socio-cultural dynamics, then personal and sub-personal concepts must display a looping relationship that can impact the nature of at least some mental phenomena. In particular, explaining the phenomenon of delusion in terms of the sub-personal concept of false inference should change the nature of delusional experiences themselves. (shrink)

In some ways, someone suffering from the delusion that his or her spouse has been kidnapped and replaced with an imposter appears to believe that he or she eats dinner with an imposter every night. But the imperviousness of delusions to counter-evidence makes it hard to classify them as beliefs, and easier to classify them as imaginings. Bayne and Pacherie want to use Schwitzgebel’s dispositional account of belief to restore confidence in the doxastic character of delusion. While dispositionalism appears (...) to allow us to classify delusions as beliefs, this allowance isn’t a robust vindication of doxasticism. The significance of the allowance can be increased by emphasizing the role of folk-psychological norms in individuating propositional attitudes. But letting those norms play a large role in the individuation of belief makes it hard to count as believers the deluded subjects who violate most such norms. Dispositionalism about belief can’t defend doxasticism about delusion. (shrink)

In Delusions and Beliefs, Kengo Miyazono proposes an extended and convincing argument for the thesis that delusions are malfunctional beliefs. One of the key assumptions for this argument is that belief is a biological notion, and that the function of beliefs is a product of evolution. I challenge the thesis that evolutionary accounts can furnish an epistemologically satisfying account of beliefs because evolutionary success does not necessarily track epistemic success. Consequently, also delusions as beliefs cannot be explained (...) in a satisfactory manner by looking at beliefs’ evolutionary function. How can we then salvage the notion of delusions as epistemologically relevant malfunctioning beliefs? I propose that knowledge-first epistemology gives us a way out. Knowledge-first accounts argue that knowledge is more primitive than belief. That is, knowledge is not a kind of successful beliefs ; instead, beliefs are failed attempts at knowledge. Being a belief derives from the norms of knowledge. Explaining the epistemology of beliefs through the primitive norms of knowledge, we can also explain why delusions are malfunctional beliefs: The cognitive and psychological defects that produce delusions block the beliefs from becoming knowledge. Consequently, delusions are attempts at knowledge that have failed particularly badly. (shrink)

This chapter offers an overview of the phenomenological approach to delusions, emphasizing what Karl Jaspers called the "true delusions" of schizophrenia. Phenomenological psychopathology focuses on the experience of delusions and the delusional world. Several features of this approach are surveyed, including emphasis on formal qualities of subjective life and questioning of standard assumptions about delusions as erroneous belief. The altered modalities of world-oriented and self-oriented experience that precede and ground delusions in schizophrenia, especially the experiences (...) of revelation that Klaus Conrad termed the outer and inner apophany, are then discussed. The chapter first considers the famous "delusional mood", then the role of ipseity-disturbance. In both cases it is explained how delusions can develop out of these distinctive alterations of perception and feeling. The classic question of the understandability or comprehensibility of schizophrenic delusion, together with the related issues of wish-fulfillment and rationalizing motives are then considered. The chapter addresses the crucial but neglected issue of the felt reality-status of delusions or the delusional world, discussing derealization, "double bookkeeping", and "double exposure". The chapter concludes by discussing delusions typically found in paranoid and affective psychoses, and monothematic delusions found in certain organic conditions. (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)

Three challenges to a unified understanding of delusions emerge from Radden's On Delusion (2011). Here, I propose that in order to respond to these challenges, and to work towards a unifying framework for delusions, we should see delusions as arising in inference under uncertainty. This proposal is based on the observation that delusions in key respects are surprisingly like perceptual illusions, and it is developed further by focusing particularly on individual differences in uncertainty expectations.

It has recently been suggested that delusions be conceived of as symptoms on the harmful dysfunction account of disorder: delusions sometimes arise from dysfunction, but can also arise through normal cognition. Much attention has thus been payed to the question of how we can determine whether a delusion arises from dysfunction as opposed to normal cognition. In this paper, we consider another question, one that remains under-explored: which delusions warrant treatment? On the harmful dysfunction account, this question (...) dissociates from the question about dysfunction—there are a broad range of “treatable conditions” beyond mere harmful dysfunctions. As such, many conditions that arise from normal cognition are also eligible for medical intervention. We argue that some delusions that arise from normal cognition may well fall under the banner of treatable conditions. We examine the practical and ethical questions surrounding such treatment, including the issue of coercive and deceptive treatment options. (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 need to be met for (...) the background of rationality to be in place. (shrink)

Kengo Miyazono, in his work Delusions and Beliefs, defends a teleo-functional account of delusions. In my contribution to this symposium, I question one of Miyazono’s motivations for appealing to teleo-functionalism over its main rival, dry-functionalism. Miyazono suggests that teleo-functionalism, unlike dry-functionalism, can account for the compatibility of the theses that delusions are genuine doxastic states and that delusions do not perform the typical causal roles of beliefs. I argue, however, that there are also ways for dry-functionalism (...) to account for this compatibility. If what I have to say is correct, then Miyazono is perhaps too hasty—at least in one important respect—to opt for teleo-functionalism over dry-functionalism. Dry-functionalism has an equally good chance of satisfying some of Miyazono’s explanatory goals. (shrink)

Delusional misidentification is commonly understood as the product of an inference on the basis of evidence present in the subject's experience. For example, in the Capgras delusion, the patient sees someone who looks like a loved one, but who feels unfamiliar, so they infer that they must not be the loved one. I question this by presenting a distinction between “recognition” and “identification.” Identification does not always require recognition for its epistemic justification, nor does it need recognition for its psychological (...) functioning. Judgments of identification are often the product of a non-inferential mechanism. Delusional misidentification arises as the product of this mechanism malfunctioning. (shrink)

Jennifer Radden argues that delusions play an important role in modernist epistemology, which is preoccupied with the justification and evaluation of beliefs. Another theme running through the book is the importance of culture for attribution of delusion. Beliefs that look delusional will not be treated as pathological if they are expressions of religious views or other culturally acceptable forms of life. It is hard to see why cultural acceptability should play a role in the modernist project of justification. I (...) suggest that we think less about a philosophical project of justification and turn our attention instead to commonsense judgements of the circumstances in which we see a belief as evidence of underlying pathology. I discuss cases in which unjustified beliefs are nonetheless treated as phenomena that are consistent with our views of how healthy human beings act, and suggest that alongside folk psychology we should acknowledge a folk epistemology that embraces such instances. I suggest that delusions are beliefs that folk epistemology treats as inexplicable, and that this approach solves some of the puzzles that Radden identifies as growing out of the modernist epistemic project. (shrink)

Discussion on the Cotard delusion often focuses on the patient’s delusional belief that he/she is dead. Of interest to this paper, however, is the little referred to claim made by some Cotard patients that they are immortal. How might one explain the juxta-position of death and immortality evident in patients sharing the same clinical diagnosis, and how might these delusional beliefs inform our understanding of patient phenomenology, particularly regarding experiences of existential change? This paper sets out to explain delusions (...) of death and immortality in Cotard patients with reference to changes in their experience of being, owed in part to a conflict in recognition evident in other delusional disorders such as the Capgras and Frégoli delusions. This experiential change is positioned within an interactionist framework of bottom-up and top-down processing that is also compatible with explanationist and endorsement approaches to delusions. (shrink)

What sort of mental state is a delusion? What causes delusions? Why are delusions pathological? This book examines these questions, which are normally considered separately, in a much-needed exploration of an important and fascinating topic, Kengo Miyazono assesses the philosophical, psychological and psychiatric literature on delusions to argue that delusions are malfunctioning beliefs. Delusions belong to the same category as beliefs but - unlike healthy irrational beliefs - fail to play the function of beliefs. (...) class='Hi'>Delusions and Beliefs: A Philosophical Inquiry will be of great interest to students of philosophy of mind and psychology and philosophy of mental disorder, as well as those in related fields such as mental health and psychiatry. (shrink)

The papers in this volume are drawn from a workshop on delusion and self-deception, held at Macquarie University in November of 2004. Our aim was to bring together theorists working on delusions and self-deception with an eye towards identifying and fostering connections—at both empirical and conceptual levels—between these domains. As the contributions to this volume testify, there are multiple points of contact between delusion and self-deception. This introduction charts the conceptual space in which these points of contact can be (...) located and introduces the reader to some of the general issues that frame the discussion of subsequent chapters. (shrink)

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)

One of the leading and central figures in research on delusions, Max Coltheart, presents and summarises his heretofore work in a short text. Miyazono and Bortolotti present an interesting argument aimed at the charges against the doxastic concept of delusions. Adams, Brown and Friston showcase a predictive-Bayesian concept of delusions. Young criticizes the current changes in the two-factor account of delusions and argues that the role of experience should not be dismissed within it. Kapusta presents an (...) interesting, phenomenological approach to delusions, rooted in the classic works of Karl Jaspers. In the last article, Carruthers takes a look at delusions from a different perspective. He uses them in order to show the weakness of the sense of agency concept as proposed by Wegner. The issue also contains an interview with Jakob Hohwy. In Hohwy’s still-recent book, we can find an interesting, predictive approach to delusions. Hohwy points towards the unobvious connections between delusions and illusions. (shrink)

This collection of essays focuses on the interface between delusions and self-deception.

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)

Delusional beliefs are typically pathological. Being pathological is clearly distinguished from being false or being irrational. Anna might falsely believe that his husband is having an affair but it might just be a simple mistake. Again, Sam might irrationally believe, without good evidence, that he is smarter than his colleagues, but it might just be a healthy self-deceptive belief. On the other hand, when a patient with brain damage caused by a car accident believes that his father was replaced by (...) an imposter or another patient with schizophrenia believes that “The Organization” painted the shops on a street in red and green to convey a message, these beliefs are not merely false or irrational. They are pathological. What makes delusions pathological? This paper explores the negative features because of which delusional beliefs are pathological. First, I critically examine the proposals according to which delusional beliefs are pathological because of (1) their strangeness, (2) their extreme irrationality, (3) their resistance to folk psychological explanations or (4) impaired responsibility-grounding capacities of people with them. I present some counterexamples as well as theoretical problems for these proposals. Then, I argue, following Wakefield’s harmful dysfunction analysis of disorder, that delusional beliefs are pathological because they involve some sorts of harmful malfunctions. In other words, they have a significant negative impact on wellbeing (=harmful) and, in addition, some psychological mechanisms, directly or indirectly related to them, fail to perform the jobs for which they were selected in the past (=malfunctioning). An objection to the proposal is that delusional beliefs might not involve any malfunctions. For example, they might be playing psychological defence functions properly. Another objection is that a harmful malfunction is not sufficient for something to be pathological. For example, false beliefs might involve some malfunctions according to teleosemantics, a popular naturalist account of mental content, but harmful false beliefs do not have to be pathological. I examine those objections in detail and show that they should be rejected after all. (shrink)

[About the book]: Neuroscience has long had an impact on the field of psychiatry, and over the last two decades, with the advent of cognitive neuroscience and functional neuroimaging, that influence has been most pronounced. However, many question whether psychopathology can be understood by relying on neuroscience alone, and highlight some of the perceived limits to the way in which neuroscience informs psychiatry. Psychiatry as Cognitive Neuroscience is a philosophical analysis of the role of neuroscience in the study of psychopathology. (...) The book examines numerous cognitive neuroscientific methods, such as neuroimaging and the use of neuropsychological models, in the context of a variety of psychiatric disorders, including depression, schizophrenia, dependence syndrome, and personality disorders. Psychiatry as Cognitive Neuroscience includes chapters on the nature of psychiatry as a science; the compatibility of the accounts of mental illness derived from neuroscience, information-processing, and folk psychology; the nature of mental illness; the impact of methods such as fMRI, neuropsychology, and neurochemistry, on psychiatry; the relationship between phenomenological accounts of mental illness and those provided by naturalistic explanations; the status of delusions and the continuity between delusions and ordinary beliefs; the interplay between clinical and empirical findings in psychopathology and issues in moral psychology and ethics. With contributions from world class experts in philosophy and cognitive science, this book will be essential reading for those who have an interest in the importance and the limitations of cognitive neuroscience as an aid to understanding mental illness. (shrink)

According to current representationalist concepts, delusion is considered the result of faulty information processing or incorrect inference about external reality. In contrast, the paper develops a concept of delusion as a disturbance of the enactive and intersubjective constitution of a shared reality. A foundation of this concept is provided by a theory of the objectivity of perception which is achieved on two levels: (1) On the first level, the sensorimotor interaction with the environment implies a mobility and multiplicity of perspectives (...) that relativizes the momentary point of view. (2) On the second level, the social interaction with others implies a virtual shifting and contrast of perspectives which helps to overcome a merely subject-centered worldview through participatory sense-making.On this basis, the alteration of experience in beginning psychosis is phenomenologically described as a subjectivization of perception, resulting in an overall experience of self-centrality and derealization. Delusion then converts the disturbance of perception into a reframing of the perceived world, namely an assumed persecution by mundane enemies. Through this, a new sense-making is established, yet in a way that is fundamentally decoupled from the shared world. The possibility of intersubjective understanding is thus sacrificed for the new coherence of the delusion. Further implications of the loss of the intersubjective co-constitution of reality are analyzed, in particular related to disturbances of communication. (shrink)

The condition known as Multiple Personality Disorder (MPD) or Dissociative Identity Disorder (DID) is metaphysically strange. Can there really be several distinct persons operating in a single body? Our view is that DID sufferers are single persons with a severe mental disorder. In this paper we compare the phenomenology of dissociation between personality states in DID with certain delusional disorders. We argue both that the burden of proof must lie with those who defend the metaphysically extravagant Multiple Persons view and (...) that there is little theoretical motivation to yield to that view in light of the fact that the core symptoms of DID bear remarkable similarity to the symptoms of these other disorders where no such extravagance is ever seriously entertained. (shrink)

Discussion on the Cotard delusion often focuses on the patient’s delusional belief that he/she is dead. Of interest to this paper, however, is the little referred to claim made by some Cotard patients that they are immortal. How might one explain the juxta-position of death and immortality evident in patients sharing the same clinical diagnosis, and how might these delusional beliefs inform our understanding of patient phenomenology, particularly regarding experiences of existential change? This paper sets out to explain delusions (...) of death and immortality in Cotard patients with reference to changes in their experience of being, owed in part to a conflict in recognition evident in other delusional disorders such as the Capgras and Frégoli delusions. This experiential change is positioned within an interactionist framework of bottom-up and top-down processing that is also compatible with explanationist and endorsement approaches to delusions. (shrink)

Among psychiatric conditions, delusions have received significant attention in the philosophical literature. This is partly due to the fact that many delusions are bizarre, and their contents interesting in and of themselves. But the disproportionate attention is also due to the notion that by studying what happens when perception, cognition, and belief go wrong, we can better understand what happens when these go right. In this paper, I attend to delusions for the second reason—by evaluating the epistemology (...) of delusions, we can better understand the epistemology of ordinary belief. More specifically, given recent advancements in our understanding of how delusions are formed, the epistemology of delusions motivates a proper functionalist account of the justification of belief. Proper functionalist accounts of the justification of belief hold that whether a belief is justified is partly determined by whether the system that produces the belief is functioning properly. Whatever pathology is responsible for delusion formation, restoring it to its proper function resolves the epistemic condition, an effect which motivates proper functionalism. (shrink)

In their target article, McKay & Dennett (M&D) conclude that only are adaptive misbeliefs. Relying on overly strict conceptual schisms (deficit vs. motivational, functional vs. organic, perception vs. belief), they prematurely discount delusions as biologically adaptive. In contrast to their view that plays a psychological but not a biological function in a two-factor model of the forming and maintenance of delusions, we propose a single impairment in prediction-error–driven (i.e., motivational) learning in three stages in which delusions play (...) a biologically adaptive role. (shrink)