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)

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)

Stanford Encyclopedia Entry on Delusions.

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 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)

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.

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)

Delusions are standardly defined as attitudes that are not amenable to change in light of conflicting evidence. But what evidence do people with delusion have for and against it? Do delusions really go against their total evidence? How are the answers affected by different conceptions of evidence? -/- This chapter focuses on how delusions relate to evidence. I consider what delusions-relevant evidence people with delusions have. I give some reasons to think that people typically have (...) evidence for their delusions, and that the evidence they have against them is often overstated. I draw on this discussion to consider whether delusions are evidentially supported and epistemically rational. Finally, I discuss implications for the nature of delusion, responsibility, and treatment and suggest directions for future research. Throughout, the discussion is sensitive to different conceptions of evidence and rationality in epistemology. -/- A central upshot is that what we should say about the epistemic standing of delusions depends substantively on our positions in epistemology, in particular, on the debate between internalists and externalists about evidence. If we want clarity on the epistemic standing of delusions, we need to incorporate more sophisticated tools from epistemology. (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)

Monothematic delusions are delusions whose contents pertain to a single subject matter. Examples include Capgras delusion, the delusion that a loved one has been replaced by an impostor, and Cotard delusion, the delusion that one is dead or does not exist. Two-factor accounts of such delusions hold that they are the result of both an experiential deficit, for instance flattened affect, coupled with an aberrant cognitive response to that deficit. In this paper we develop a new expressivist (...) two-factor account of delusion. In contrast to existing endorsement and explanationist accounts, which treat delusions as either explanations or endorsements of the contents of these disordered experiences, we hold that delusional beliefs have an expressive function: they characterize, in impressionistic terms, what the subject’s experience is like for them. We show how our account improves upon existing two-factor views in explaining the central features of monothematic delusions, in particular the way in which delusional subjects fall short of the ideal of rationality. (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)

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)

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)

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)

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)

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)

ABSTRACTEmpiricists about monothematic delusion formation agree that anomalous experience is a factor in the formation of these attitudes, but disagree markedly on which further factors need to be specified. I argue that epistemic innocence may be a unifying feature of monothematic delusions, insofar as a judgment of epistemic innocence to this class of attitudes is one that opposing empiricist accounts can make. The notion of epistemic innocence allows us to tell a richer story when investigating the epistemic status of (...) monothematic delusions, one which resists the trade-off view of pragmatic benefits and epistemic costs. Though monothematic delusions are often characterized by appeal to their epistemic costs, they can play a positive epistemic role, and this is a surprising conclusion on which, so I argue, all empiricists can agree. Thus, I show that all empiricists have the notion of epistemic innocence at their disposal. (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)

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)

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)

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)

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

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)

Cognitive approaches contribute to our understanding of delusions by providing an explanatory framework that extends beyond the personal level to the sub personal level of information-processing systems. According to one influential cognitive approach, two factors are required to account for the content of a delusion, its initial adoption as a belief, and its persistence. This chapter reviews Bayesian developments of the two-factor framework.

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)

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)

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)

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)

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.

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

This commentary on Adam Pautz's excellent book, Perception, explores the consequences of “spatial illusionism,” the view that the spatial properties presented in experience aren't instantiated in the extra-mental world. First, I consider whether spatial illusionism entails that our ordinary beliefs about the physical world are mostly false. I then argue that spatial illusionism threatens to undermine two arguments Pautz's defends in Perception: his argument that sense data theory is incompatible with physicalism, and his central argument against the internal physical state (...) view of perception. (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)

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)

Cognitive psychologists have recently identified alterations in perception and reasoning that contribute to the formation and maintenance of beliefs that happen to be delusional. Clinically significant delusions, however, are often deeply unusual. An account of their formation and maintenance must explain not merely how someone can come to hold false or uncommon beliefs, but also how someone can arrive at beliefs that seem profoundly improbable and even bizarre. This paper uses the philosophical concepts of the Bedrock and the Background (...) to provide an account of that foundational, nonrepresentational, non–rule-governed, dispositional structure of everyday understanding that underpins both our perception and our reasoning. The central claim is that the formation and maintenance of delusions becomes intelligible once they are seen to reflect disturbances to this foundational dispositional structure. Different dimensions of the Background are described along with the delusions that might follow from distortions to these dimensions. We challenge the assumption of much recent cognitive psychological theorizing that delusions can be understood as explanations of unusual experiences or as the product of hasty reasoning. Finally, the implications of the theory for the therapy of the delusional patient are briefly discussed. (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)

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)