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)

Stanford Encyclopedia Entry on Delusions.

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)

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)

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)

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)

This collection of essays focuses on the interface between delusions and self-deception. As pathologies of belief, delusions and self-deception raise many of the same challenges for those seeking to understand them. Are delusions and self-deception entirely distinct phenomena, or might some forms of self-deception also qualify as delusional? To what extent might models of self-deception and delusion share common factors? In what ways do affect and motivation enter into normal belief-formation, and how might they be implicated in self-deception and (...) delusion? The essays in this volume tackle these questions from both empirical and conceptual perspectives. Some contributors focus on the general question of how to locate self-deception and delusion within our taxonomy of psychological states. Some contributors ask whether particular delusions - such as the Capgras delusion or anosognosia for hemiplegia - might be explained by appeal to motivational and affective factors. And some contributors provide general models of motivated reasoning, against which theories of pathological belief-formation might be measured. (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)

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.

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)

Delusions, a key feature of psychosis, are usually thought of as a type of belief, as in the definition of the American Psychiatric Association: A false belief based on incorrect inference about external reality that is firmly sustained despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary. The belief is not one ordinarily accepted by other members of the person’s culture or subculture (e.g. it is not an article of religious (...) faith). This characterization is often criticized, but other definitions typically comprise similar elements. For some, delusions are only loosely considered as beliefs (Jaspers 1963; Moor and Tucker .. (shrink)

Prevailing views of delusional beliefs frame them as pathological and harmful, leaving little room for understanding why delusions may emerge. Lisa Bortolotti’s book, “Why Delusions Matter,” offers a more compassionate perspective on delusions, framing them as adaptive and meaningful responses to crises. Many psychologists and philosophers have asserted that delusions can function as psychological defense mechanisms or adaptive coping strategies that protectively obscure painful realities. However, some delusions, especially those that arise in the context of traumatic experiences and psychosis, can (...) be better understood as the body’s attempt to alert us to sources of harm and reveal, rather than obscure, important information. Drawing from neuroscience literature and the author’s personal encounters with psychosis and trauma, this article explores the ways in which some delusions can help us access interoceptive information from the body, uncovering sources of pathology, as well as previously unconscious information about harmful traumatic experiences. Ultimately, taking an epistemic justice lens to delusions, uplifts their value in revealing very real embodied experiences of the individual expressing them. (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 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)

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)

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)

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.

Monothematic delusions are bizarre beliefs which are often accompanied by highly anomalous experiences. For philosophers and psychologists attracted to the exploration of mental phenomena in an evolutionary framework, these beliefs represent—notwithstanding their rarity—a puzzle. A natural idea concerning the biology of belief is that our beliefs, in concert with relevant desires, help us to navigate our environments, and so, in broad terms, an evolutionary story of human belief formation will likely insist on a function of truth (true beliefs tend to (...) lead to successful action). Monothematic delusions are systematically false and often harmful to the proper functioning of the agent and the navigation of their environment. So what are we to say? A compelling thought is that delusions are _malfunctioning_ beliefs. Compelling though it may be, I argue against this view on the grounds that it does not pay due attention to the circumstances in which monothematic delusions are formed, and fails to establish _doxastic_ malfunction. I argue instead that monothematic delusions are _misfunctioning_ beliefs, that is, the result of mechanisms of belief formation operating in historically abnormal conditions. Monothematic delusions may take their place alongside a host of other strange beliefs formed in difficult epistemic conditions, but for which no underlying doxastic malfunction is in play. (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)

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)

The doxastic status of delusion is inconclusive. The arguments presented for and against it are not strong enough to clinch the issue and convince everyone of a single, general characterization. But that does not mean that we have not gained any clarity from discussing it. In the few decades since the issue became contentious, philosophers have made great strides, not only in accounting for the nature of delusion as a cognitive attitude, but also in developing theories of what (...) kind of cognitive attitude best exemplifies the functional role delusions play in one’s cognitive economy.As is often the case within philosophical debates, it takes a long time and a major collective effort for us to start to get clear on... (shrink)

Delusions are usually depicted in one of two contrasting ways. They are either characterized as harmful and dysfunctional beliefs or as fostering engagement with the environment and sometimes even psychological wellbeing in the face of psychological or biological difficulties – something which, according to some accounts, would make them biologically adaptive. It is this “adaptive hypothesis” that I focus on in this paper, by empirically investigating the adaptiveness of delusions in a sample of people suffering from OCD. The paper shows (...) that delusions in OCD entertain complex and heterogeneous relationships with psychological wellbeing and engagement with the environment, highlighting some future directions that clinical and philosophical research on the topic should take. (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)

Over the last 20 years the comparator model for delusions of control has received considerable support in terms of empirical studies. However, the original version clearly needs to be replaced by a model with a much greater degree of sophistication and specificity. Future developments are likely to involve the specification of the role of dopamine in the model and a generalisation of its explanatory power to the whole range of positive symptoms. However, we will still need to explain why symptoms (...) can be so variable and we still do not understand the origin of the most mysterious symptom of all: thought insertion. (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)

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)

We propose that typical schizophrenic delusions develop on the background of preexisting anomalies of self-experience. We argue that disorders of the Self represent the experiential core clinical phenomena of schizophrenia, as was already suggested by the founders of the concept of schizophrenia and elaborated in the phenomenological psychiatric tradition. The article provides detailed descriptions of the pre-psychotic or schizotypal anomalies of self-experience, often illustrated through clinical vignettes. We argue that delusional transformation in the evolution of schizophrenic psychosis reflects a global (...) reorganization of consciousness and existential reorientation, both of which radiate from a fundamental alteration of the Self. We critically address the contemporary cognitive approaches to delusion formation, often finding them inconsistent with the clinical features of schizophrenia or implausible from a phenomenological point of view. (shrink)

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

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)

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)

Unworkable discusses the ongoing implosion of our globalized world from three distinct angles: the capitalist elimination of labor through technological automation, the dissolution of our shared social narratives, and the subtle imposition of an increasingly pervasive ideological order. Aiming to root out the lost cause of this implosion, Fabio Vighi returns to Marx by way of Hegel, Lacan, Gorz, Baudrillard, and other thinkers who, in different ways, have reflected on the complex dialectical structure of modernity and its hidden conditions of (...) possibility. Capitalism, Vighi argues, fundamentally redefined the meaning of work and prevented the emergence of alternative forms of life. In our own time, the delusions of work and the values that propel life under capitalism have become, in Vighi's analysis, unworkable. And yet, even as we become an increasingly "workless" society, we continue to abide by the same laws of productivity and profit. (shrink)

A growing number of studies in both the scientific and the philosophical literature have drawn on a Bayesian predictive processing framework to account for the formation of delusions. The key here is that delusions form because of disrupted prediction error signalling. Parrott’s recent critique argues that the framework is incomplete in two respects: it leaves unclear why delusional hypotheses are selected over none at all or over more plausible alternatives; it leaves unclear how exactly it is that delusional hypotheses are (...) generated in the first place. In this paper, we defend the framework’s explanatory power by way of showing how it can go a long way in helping disentangle these concerns. We take up each of them in turn. As for the first, our argument turns on two claims: a) believing nothing, although possible in principle, may not be a viable procedure in the circumstances; b) alternative hypotheses may be rendered unavailable for selection, due to aberrant prediction errors. As for the second concern, we distinguish three ways in which delusional hypotheses may be initially acquired, all of which are based on experience broadly construed. (shrink)

Why Delusions Matter is a reflection on the importance of the study of delusions for better understanding and reshaping our mutual interactions. The study of delusions has transformed the philosophy of mind and psychology in the last thirty years, helping redefine the relationship between rationality and intentionality. It has still a lot to offer to emerging areas at the intersection of ethics and epistemology. These are areas where the focus of the investigation of beliefs is moving from a painstaking assessment (...) of the individual’s cognitive achievements and failures to a broader examination of the environmental and social pressures on the adoption, revisions, and maintenance of beliefs at individual and collective levels. In the book, there is an exploration of the notion of delusionality across clinical and non-clinical contexts which shows how delusions are meaningful beliefs that matter to the speaker's identity but are received by the interpreter as implausible and unshakeable. Delusions are not pathological by default, but they can bring epistemic and psychological costs as well as temporary benefits. Although a speaker's delusions can make collaboration difficult, this should not discourage interpreters from attempts at genuine engagement. Delusions are not a sign of a breakdown in the speaker's capacity for agency and thus understanding them can help interpreters appreciate the speaker's perspective. (shrink)

The notion of evil spirits influencing human behavior or mental processes is used in many cultures to justify various symptoms or experiences. It is also expressed in psychotic delusions of possession, but there is limited research in this area. This study explores how patients with schizophrenia came to the conclusion that they were possessed, and how this affected help-seeking. Interviews with two men and two women about their experiences and meaning-making were subjected to interpretative phenomenological analysis. Three main themes were (...) identified: Links between traumatic experiences and psychotic symptoms, The emergence of religious themes in delusional contents, and Reluctance to use medical treatment and instead to seek exorcism. In each case, attributing problems to possession was supported by the local environment and media, led to seeking spiritual help, and delayed diagnostic assessment and treatment. However, using religious coping contributed to the sense of predictability and social support. Clinicians are encouraged to explore the experiences and conflicts expressed by the symptoms which people ascribe to possession and to negotiate alternative explanatory models with their patients. (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)

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)

After reviewing factors implicated in the generation of delusional beliefs, we conclude that whilst a perceptual aberration coupled with a particular type of attri‐butional bias may be necessary to explain the specific thematic content of a bizarre delusion, neither of these factors, whether in isolation or in combination, is sufficient to explain the presence of delusional beliefs. In contrast to bias models (theories which explain delusion formation in terms of extremes of normal reasoning biases), we advocate a deficit (...) model of delusion formation–that is, delusions arise when the normal cognitive system which people use to generate, evaluate, and then adopt beliefs is damaged. Mere bias we think inadequate to explain bizarre delusions which defy commonsense and persist despite overwhelming rational counter‐argument. In particular, we propose that two deficits must be present in the normal cognitive system to explain bizarre delusions: (1) there must be some damage to sensory and/or attentional‐orient‐ing mechanisms which causes an aberrant perception–this explains the bizarre content of the causal hypothesis generated to explain what is happening; and (2) there must also be a failure of normal belief evaluation–this explains why a hypothesis, implausible in the light of general commonsense, is adopted as belief. This latter deficit occurs, we suggest, when an individual is incapable of suspending the natural favoured status of direct first‐person evidence in order to critically evaluate hypotheses, given equal pri‐ority whether based on direct or indirect sources of information. In contrast, delusions with ‘ordinary’ content may arise when a single deficit of normal belief evaluation occurs in the context of an extreme (but normal) attentional bias, thus causing failure to critically evaluate hypotheses based on misperceptions and misintrepretations of ambiguous (but ordinary) first‐person experience. (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)

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 chapter connects the phenomenon of double bookkeeping to two critical debates in the philosophy of delusion: one from the analytic tradition and one from the phenomenological tradition. First, I will show how the failure of action guidance on the part of some delusions suggests an argument to the standard view that delusions are beliefs (doxasticism about delusion) and how its proponents have countered it by ascribing behavioral inertia to avolition, emotional disturbances, or a failure of the surrounding (...) environment in supporting the agent’s motivation to act. Second, I will show how the mismatch between the experience of double bookkeeping and that of having the usual propositional attitudes of folk psychology suggests another, more recalcitrant argument not only against doxasticism but against the very attempt to fit delusion into folk psychology. Third, I will show how phenomenologically inspired theories of delusion, such as the multiple realities hypothesis, bypass the debates above and focus on describing and understanding the disturbances in the structure of experience undergone by patients. I conclude that the philosophical discussions ensuing from an appreciation of double bookkeeping show some of the limitations of the analytic philosophical approach to delusion. (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)

In this paper, I re-elaborate some of the ideas presented in Why Delusions Matter (Bloomsbury 2023) in response to four commentaries on the book. My proposed conception of delusionality cuts across clinical and non-clinical contexts: an interpreter calls a speaker’s belief delusionalwhen the belief seems to be central to the speaker’s identity, but the interpreter finds it both implausible and unshakeable. Here I frame the emphasis on what all delusional beliefs have in common as an attempt to resist simplistic dichotomies (...) about human agency. Ideal agents seek the truth and accurately represent the world, engaging with it in such a way as to further their goals, exercise control over themselves and the surrounding environment, and successfully coordinate with others. Human agents can sometimes rely on comforting illusions and constructed worlds to establish or restore a connection with other agents and the shared environment at challenging times. But coordination can fail, and control is always limited. Delusions are an expression of agency in the sense that they can be understood as a response to the epistemic and psychological needs of human agents. Delusions are meaningful and may contain germs of truth about the speaker. But they should be replaced when better strategies for engaging with the world become available to the speaker. (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 "Why Delusions Matter", Lisa Bortolotti argues both that the concept of delusions should be extended to cover certain beliefs that bear no relationship to pathology, and that delusions deserve a more positive reputation. Drawing attention to the role of self-serving propaganda in prominent examples of non-clinical delusions, I argue that there is a tension between these parts of the project.

This article contrasts the cognitive neuropsychiatric approach with the traditional psychiatric approaches to delusions to develop testable cognitive theories of delusions so as to render the generation of delusions psychologically understandable. It illustrates how cognitive neuropsychiatrists use the Bruce and Young model of face processing to explain the generation of misidentification delusions. The study of facial expression highlights that future cognitive neuropsychiatric study of self and non-self face processing using different representational media in patients with mirrored-self misidentification delusions will likely (...) be informative with regard to advancing scientific understanding of the putative differences between self and non-self recognition. It reviews cognitive neuropsychiatric research into the Capgras delusion and shows the distinction between overt face recognition and person identity authentication, and suggests the need for further modification of Bruce and Young's model to remove direct pathways between the person's identity module and the affective response system and to incorporate a separate integrative device. (shrink)

Anorexia nervosa involves seemingly irrational beliefs about body size and the value of thinness. Historically, researchers and clinicians have avoided referring to such beliefs as delusions, instead opting for the label ‘overvalued ideas’. I discuss the relationship between the beliefs associated with anorexia nervosa and the distinction between delusions and overvalued ideas, as it is conceived in both European and American psychiatric traditions. In doing so, I question the benefit of applying the concepts of delusion and overvalued idea to (...) anorexia nervosa and raise some issues with contemporary use of the Brown Assessment of Beliefs scale for assessing the level of delusionality associated with the disorder. (shrink)

Introduction: Cotard delusion—the delusional belief “I am dead”—is named after the French psychiatrist who first described it: Jules Cotard (1880, 1882). Ramachandran and Blakeslee (1998) proposed that the idea “I am dead” comes to mind when a neuropathological condition has resulted in complete abolition of emotional responsivity to the world. The idea would arise as a putative explanation: if “I am dead” were true, there would be no emotional responsivity to the world. Methods: We scrutinised the literature on people (...) who expressed the delusional belief “I am dead”, looking for data on whether such patients are reported as entirely lacking in emotional responsivity. Results: In numerous cases, patients with Cotard delusion are described as experiencing emotions including anxiety, fear, guilt, distress, euphoria and worry. Conclusions: We conclude that complete absence of emotional responsivity cannot be what prompts the delusional idea that one is dead. We propose that, in at least some cases, the idea “I am dead” comes to mind in response to symptoms of depersonalisation or derealisation, often present in cases of Cotard delusion, and give examples of Cotard patients with abnormalities in various neural areas that could be responsible for the presence of such symptoms. (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)