This thesis develops a novel framework for explaining delusions. In Chapter 1, I introduce the two fundamental challenges posed by delusions: the evidence challenge lies in explaining the flagrant ways delusions flout evidence; and the specificity challenge lies in explaining the fact that patients’ delusions are often about a few specific themes, and patients rarely have a wide range of delusional or odd beliefs. In Chapter 2, I discuss the strengths and weaknesses of current theories of delusions, which typically appeal (...) to one or both of two factors: anomalous experience and reasoning abnormality. I argue that anomalous experience can help explain the specificity of delusions, but has difficulties in addressing the evidence challenge; reasoning abnormality can help address the evidence challenge, but has difficulties in explaining the specificity of delusions. This suggests that there may be an important factor that has not been captured by current theories of delusions. To search for this missing factor, in Chapter 3, I turn to normal believing. Inspired by the literature on Cartesian clarity and phenomenal dogmatism, I develop a dual-force framework of believing, according to which beliefs can be understood as the results of the interaction between the justificatory force and causal force of evidence and the justificatory force and causal force of clear experience, in which something clearly seems to be so to the subject. This framework suggests that the missing factor may be the clear experience with its distinctive phenomenal clarity that compels assent. In Chapter 4, I return to delusions, and argue that the dualforce framework can help us to get a better grip on some personal descriptions of delusions; make progress in addressing the evidence and specificity challenges of delusions; and shed new light on the underpinnings of delusions. In the end, I conclude with some remaining questions for future study. (shrink)

Does the formation of delusions involve abnormal reasoning? According to the prominent ‘two-factor’ theory of delusions (e.g. Coltheart, 2007), the answer is yes. The second factor in this theory is supposed to affect a deluded individual's ability to evaluate candidates for belief. However, most published accounts of the two-factor theory have not said much about the nature of this second factor. In an effort to remedy this shortcoming, Coltheart, Menzies and Sutton (2010) recently put forward a Bayesian account of inference (...) in delusions. I outline some criticisms of this important account, and sketch an alternative account of delusional inference that, I argue, avoids these criticisms. Specifically, I argue that the second factor in delusion formation involves a systematic deviation from Bayesian updating, a deviation that may be characterized as a bias towards ‘explanatory adequacy’. I present a numerical model of this idea and show that my alternative account is broadly consistent with prominent prediction error models of delusion formation (e.g. Corlett, Murray et al., 2007). (shrink)

From an evolutionary standpoint, a default presumption is that true beliefs are adaptive and misbeliefs maladaptive. But if humans are biologically engineered to appraise the world accurately and to form true beliefs, how are we to explain the routine exceptions to this rule? How can we account for mistaken beliefs, bizarre delusions, and instances of self-deception? We explore this question in some detail. We begin by articulating a distinction between two general types of misbelief: those resulting from a breakdown in (...) the normal functioning of the belief formation system (e.g., delusions) and those arising in the normal course of that system's operations (e.g., beliefs based on incomplete or inaccurate information). The former are instances of biological dysfunction or pathology, reflecting “culpable” limitations of evolutionary design. Although the latter category includes undesirable (but tolerable) by-products of “forgivably” limited design, our quarry is a contentious subclass of this category: misbeliefs best conceived as design features. Such misbeliefs, unlike occasional lucky falsehoods, would have been systematically adaptive in the evolutionary past. Such misbeliefs, furthermore, would not be reducible to judicious – but doxastically1noncommittal – action policies. Finally, such misbeliefs would have been adaptive in themselves, constituting more than mere by-products of adaptively biased misbelief-producing systems. We explore a range of potential candidates for evolved misbelief, and conclude that, of those surveyed, onlypositive illusionsmeet our criteria. (shrink)

Delusions are deeply evidence-resistant. Patients with delusions are unmoved by evidence that is in direct conflict with the delusion, often responding to such evidence by offering obvious, and strange, confabulations. As a consequence, the standard view is that delusions are not evidence-responsive. This claim has been used as a key argumentative wedge in debates on the nature of delusions. Some have taken delusions to be beliefs and argued that this implies that belief is not constitutively evidence-responsive. Others hold fixed the (...) evidenceresponsiveness of belief and take this to show that delusions cannot be beliefs. Against this common assumption, I appeal to a large range of empirical evidence to argue that delusions are evidence-responsive in the sense that subjects have the capacity to respond to evidence on their delusion in rationally permissible ways. The extreme evidence-resistance of delusions is a consequence of powerful masking factors on these capacities, such as strange perceptual experiences, motivational factors, and cognitive biases. This view makes room for holding both that belief is constitutively evidence-responsive and that delusions are beliefs, and it has important implications for the study and treatment of delusions. (shrink)

How many factors, i.e. departures from normality, are necessary to explain a delusion? Maher’s classic one-factor theory argues that the only factor is the patient’s anomalous experience, and a delusion arises as a normal explanation of this experience. The more recent two-factor theory, on the other hand, contends that a second factor is also needed, with reasoning abnormality being a potential candidate, and a delusion arises as an abnormal explanation of the anomalous experience. In the past few years, although there (...) has been an increasing number of scholars offering a variety of arguments in defence of Maher’s one-factor theory, these arguments have not been adequately addressed by two-factor theorists. This paper aims to address this gap by critically examining the arguments on three crucial issues: the intelligibility of delusions, the dissociation between anomalous experiences and delusions, and the empirical evidence of a second factor. I will argue that the Maherian notion of anomalous experience is not sufficient for explaining delusions and the two-factor theory is on the right track in its search for the missing factor in the aetiology of delusions. (shrink)

In recent times, explanations of the Capgras delusion have tended to emphasise the cognitive dysfunction that is believed to occur at the second stage of two-stage models. This is generally viewed as a response to the inadequacies of the one-stage account. Whilst accepting that some form of cognitive disruption is a necessary part of the aetiology of the Capgras delusion, I nevertheless argue that the emphasis placed on this second-stage is to the detriment of the important role played by the (...) phenomenology underlying the disorder, both in terms of the formation and maintenance of the delusional belief. This paper therefore proposes an interactionist two-stage model in which the phenomenal experience of the Capgras patient is examined, emphasised, and its relation to top-down processing discussed. (shrink)

This paper contrasts an interactionist account of delusional misidentification with more traditional one- and two-stage models. Unlike the unidirectional nature of these more traditional models, in which the aetiology of the disorder is said to progress from a neurological disruption via an anomalous experience to a delusional belief, the interactionist account posits the interaction of top-down and bottom-up processes to better explain the maintenance of the delusional belief. In addition, it places a greater emphasis on the patient’s underlying phenomenal experience (...) in accounting for the specificity of the delusional content. The role played by patient phenomenology is examined in light of Ratcliffe’s recent phenomenological account. Similarities and differences are discussed. The paper concludes that a purely phenomenological account is unable to differentiate between non-delusional patient groups, who have what appear to be equivalent phenomenal experiences to patients suffering from delusional misidentification but without the delusional belief, and delusional groups, something the interactionist model is able to do. (shrink)

Delusions are studied in two philosophical traditions: the continental or phenomenological tradition and the Anglo-American or analytic tradition. Each has its own view of delusions. Broadly stated, phenomenologists view delusions as a disturbed experience whilst most analytic researchers view them as beliefs. It is my contention that the most plausible account of delusions must ultimately incorporate valuable insights from both traditions. To illustrate the potential value of integration I provide a novel model of the Capgras delusion which describes how an (...) analytic, cognitive neuropsychological two-factor account of the Capgras delusion and the phenomenological view of delusions might be integrated. (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)

I suggest that we can think of delusional misidentification in terms of systematic errors in the management of mental files. I begin by sketching the orthodox “bottom-up” aetiology of delusional misidentification. I suggest that the orthodox aetiology can be given a descriptivist or a singularist interpretation. I present three cases that a descriptivist interpretation needs to account for. I then introduce a singularist approach, one that is based on mental files, and show how it opens the way for different and (...) potentially more plausible accounts of these three cases. I reflect on how this mental files approach can be viewed either as a supplement to the orthodox aetiology, or as suggesting an altogether different aetiology. I end by addressing a concern surrounding the explanatory power of mental files. (shrink)

It is sometimes said that humans are unlike other animals in at least one crucial respect. We do not simply form beliefs, desires and other mental states, but are capable of caring about our mental states in a distinctive way. We can care about the justification of our beliefs, and about the desirability of our desires. This kind of observation is usually made in discussions of free will and moral responsibility. But it has profound consequences, or so I shall argue, (...) for our conception of the very nature of beliefs and other mental states. Suitably developed, it allows us to draw a line between two distinct ways in which a creature may possess a belief, represent a scene, and fall into error. The first way (which I shall call the 'mindless' way) involves little more than an encoding of information in some way designed to guide appropriate response. This is the common heritage of humans, and many other animals. The second way (which I shall call the 'mindful' way) requires that the creature be capable in addition of a special kind of second-order reflection, and (importantly) be expert at detecting the kinds of situation in which such reflection is called for. The differences between these two ways of 'believing that P' are sufficiently deep and significant to warrant (or so I claim) our treating them as two distinct classes of mental states. For it is only courtesy of the second layer of complexity, I shall argue, that it becomes proper to hold someone accountable for their beliefs or other mental states, and it is this fact of (something like) accountability that in turn raises the most significant challenge for philosophical attempts to give naturalized accounts of meaning, belief, and mentality. (shrink)

An examination of alien abduction belief can inform how we ought to approach constructing explanations of monothematic delusion formation. I argue that the formation and maintenance of alien abduction beliefs can be explained by a one-factor account, and that this explanatory power generalizes to (other) cases of monothematic delusions. There are no differences between alien abduction beliefs and monothematic delusions which indicate the need for additional explanatory factors in cases of the latter. I make the additional point that whilst alien (...) abduction beliefs can be readily explained using a one-factor framework, the two-factor framework requires adjustment to accommodate them. I conclude that theorists interested in delusion formation have much to learn from the case of alien abduction belief. (shrink)

The text concerns the role of emotions in delusion formation. Provided are definitions from DSM-V and DSM-IV-R and the problems found in those definitions. One of them, the problem of delusion formation, is described when providing cognitive theories of delusions. The core of the paper is a presentation of the emotional and affective disorders in delusions, especially Capgras delusion and Cotard delusion. The author provides a comparison of the kinds of delusions and the conclusions taken from neuroimaging studies. As a (...) result of the fact that an explanation of delusion formation focusing on emotional problems turns out to be insufficient, the author provides examples of the reasoning impairments which coexist with them. At the end of the article, some hypotheses are proposed concerning the role of emotions and reasoning in delusion formation and the relation between belief disorders and emotional disorders. (shrink)

The aim of this article is to analyze those theories that interpret misidentification delusions in terms of mentalization. The hypothesis under examination holds that a mentalization framework is useful for describing misidentification delusions when identification is thought to be partially based on mentalization. The article provides both a characterization and possible interpretations of such delusions, and possible relations between misidentification and mentalization are scrutinized. Whether the mentalization approach may explain or describe such kinds of mental disorders is considered, with the (...) conclusion that while this approach is unsatisfactory, there is some room for future improvement. (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)

The dominant conception of delusion in psychiatry (in textbooks, research papers, diagnostic manuals, etc.) is predominantly epistemic. Delusions are almost always characterized in terms of their epistemic defects, i.e., defects with respect to evidence, reasoning, judgment, etc. However, there is an individualistic bias in the epistemic conception; the alleged epistemic defects and abnormalities in delusions relate to individualistic epistemic processes rather than social epistemic processes. We endorse the social epistemological turn in recent philosophical epistemology, and claim that a corresponding turn (...) is needed in the study of delusions. It is a turn from the (purely) individualistic conception, which characterizes delusions only by individualistic epistemic defects and abnormalities, to the (partially) social epistemic conception, which characterizes delusions by individualistic as well as social epistemic defects and abnormalities. This paper is intended as an initial step toward such a social epistemological turn. In particular, we will develop a new model of the development of delusions according to which testimonial abnormalities, including testimonial isolation and testimonial discount, are a causal factor in the development of delusions. (shrink)

Maher proposed in 1974 that schizophrenic delusions are hypotheses formed to explain anomalous experiences. He stated that they are “rational, given the intensity of the experiences that they are developed to explain.” Two-factor theorists of delusion criticized Maher’s theory because 1) it does not explain why some patients with anomalous experiences do not develop delusions, and 2) adopting and adhering to delusional hypotheses is irrational, considering the totality of experiences and patients’ other beliefs. In this paper, the notion of the (...) intensity of experience is reappraised to uphold Maher’s basic conception. Regarding 1), I propose that differences in the intensity of anomalous experience are vital to whether the patient forms delusions, while partially reforming his rationality claim regarding 2). Although adopting delusions is irrational, it is inevitable and excusable, given the intensity of the patient’s anomalous experience. With the aid of this notion, it is maintained that anomalous experience is sufficient for the development of delusions, at least in some cases of schizophrenia. Compared to other theories of schizophrenic delusion, Maher’s theory, which embraces the notion of intensity of experience, better explains why such irrational mental states as delusions develop from anomalous experiences, and why delusional patients persist in believing specific thematic content. (shrink)

The impact of our desires and preferences upon our ordinary, everyday beliefs is well-documented [Gilovich, T. . How we know what isn’t so: The fallibility of human reason in everyday life. New York: The Free Press.]. The influence of such motivational factors on delusions, which are instances of pathological misbelief, has tended however to be neglected by certain prevailing models of delusion formation and maintenance. This paper explores a distinction between two general classes of theoretical explanation for delusions; the motivational (...) and the deficit. Motivational approaches view delusions as extreme instances of self-deception; as defensive attempts to relieve pain and distress. Deficit approaches, in contrast, view delusions as the consequence of defects in the normal functioning of belief mechanisms, underpinned by neuroanatomical or neurophysiological abnormalities. It is argued that although there are good reasons to be sceptical of motivational theories , recent experiments confirm that motives are important causal forces where delusions are concerned. It is therefore concluded that the most comprehensive account of delusions will involve a theoretical unification of both motivational and deficit approaches. (shrink)

Young and colleagues . Betwixt life and death: case studies of the Cotard delusion. In P. W. Halligan & J. C. Marshall , Method in madness: Case studies in cognitive neuropsychiatry. Mahway, NJ: Lawrence Erlbaum Associates.) have suggested that cases of the Cotard delusion result when a particular perceptual anomaly occurs in the context of an internalising attributional style. This hypothesis has not previously been tested directly. We report here an investigation of attributional style in a 24-year-old woman with Cotard (...) delusion . LU’s attributional style was assessed using the Internal, Personal and Situational Attributions Questionnaire . A new measure of causal locus: the internal, personal and situational attributions questionnaire. Personality and Individual Differences, 20, 261–264.). LU showed a significantly greater proportion of internalising attributions than the control group, both overall and for negative events specifically. The results obtained thus support an association of Cotard delusion with an internalising attributional style, and are therefore consistent with the account of Young and colleagues. The potential brain basis of Cotard delusion is discussed. (shrink)

This paper draws on studies of the Capgras delusion in order to illuminate the phenomenological role of affect in interpersonal recognition. People with this delusion maintain that familiars, such as spouses, have been replaced by impostors. It is generally agreed that the delusion involves an anomalous experience, arising due to loss of affect. However, quite what this experience consists of remains unclear. I argue that recent accounts of the Capgras delusion incorporate an impoverished conception of experience, which fails to accommodate (...) the role played by ‘affective relatedness’ in constituting (a) a sense of who a particular person is and (b) a sense of others as people rather than impersonal objects. I draw on the phenomenological concept of horizon to offer an interpretation of the Capgras experience that shows how the content ‘this entity is not my spouse but an impostor’ can be part of the experience, rather than something that is inferred from a strange experience. (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)

This paper explores the two-factor theoretical model currently widely used to provide an explanatory analysis of the delusions that regularly accompany neurological disease or damage. The model hypothesizes a combination of an experiential factor – a strange or untoward experience – and a cognitive factor, such as an impairment of reasoning. The two-factor model has been devised formonothematicdelusions that are usually manifested in a single, implausible idea. These have to be distinguished from the more elaborated,polythematicdelusions that are found in psychiatry. (...) Psychiatric delusions exceed neurological ones in frequency and, often, semantic complexity. This text offers a preliminary clarification of underlying assumptions about the breadth, terminology and presuppositions of two-factor theorizing, exploring its potential application to psychiatric delusions. (shrink)

Clinical delusions have traditionally been characterized as beliefs in psychiatry. However, philosophers have recently engaged with the empirical literature and produced a number of objections to the so-called doxastic status of delusion, stemming mainly from the mismatch between the functional role of delusions and that expected of beliefs. In response to this, an appeal to dispositionalism about the nature of belief has been proposed to vindicate the doxastic status of delusion. In this paper, I first present the objections to attributing (...) beliefs to delusional patients and the application of dispositionalism in the attempt to vindicate doxasticism. I then assess this application and some responses to the objections to the doxastic characterization. Finally, I offer some conclusions about the limits of folk-psychological concepts in the characterization and explanation of complex psychological phenomena such as delusions. (shrink)

This essay presents a new account of thought insertion. Prevailing views in both philosophy and cognitive science tend to characterize the experience of thought insertion as missing or lacking some element, such as a ‘sense of agency’, found in ordinary first-person awareness of one's own thoughts. By contrast, I propose that, rather than lacking something, experiences of thought insertion have an additional feature not present in ordinary conscious experiences of one's own thoughts. More specifically, I claim that the structure of (...) an experience of thought insertion consists of two distinct elements: a state of ordinary first-person awareness and a sense that this state of awareness is highly unusual. In addition to modeling the experience of thought insertion, I also explain how a delusional pattern of thinking could lead someone who has this kind of experience to adopt a belief that some other entity is inserting thoughts into her mind. Finally, I briefly sketch a neurocomputational framework that could be developed to explain the sense that one's state of first-person awareness is highly irregular. (shrink)

In both cognitive science and philosophy, many theorists have recently appealed to a predictive processing framework to offer explanations of why certain individuals form delusional beliefs. One aim of this essay will be to illustrate how one could plausibly develop a predictive processing account in different ways to account for the onset of different kinds of delusions. However, the second aim of this essay will be to discuss two significant limitations of the predictive processing framework. First, I shall draw on (...) the structure of explanatory why-questions to argue that predictive processing theories can only partially explain the formation of delusional beliefs. Second, I shall argue that predictive processing theories cannot explain how implausible delusional hypotheses are generated. Yet understanding why an agent even generates a delusional hypothesis is a crucial step to understanding why she eventually comes to believe it. The final section of the essay presents three alternative ways the process of hypothesis generation might be functionally divergent in cases of delusional cognition. (shrink)

The Capgras delusion is a condition in which a person believes that an imposter has replaced some close friend or relative. Recent theorists have appealed to Bayesianism to help explain both why a subject with the Capgras delusion adopts this delusional belief and why it persists despite counter-evidence. The Bayesian approach is useful for addressing these questions; however, the main proposal of this essay is that Capgras subjects also have a delusional conception of epistemic possibility, more specifically, they think more (...) things are possible, given what is known, than non-delusional subjects do. I argue that this is a central way in which their thinking departs from ordinary cognition and that it cannot be characterized in Bayesian terms. Thus, in order to fully understand the cognitive processing involved in the Capgras delusion, we must move beyond Bayesianism. 1 The Simple Bayesian Model2 Anomalous Evidence and the Capgras Delusion3 Impaired Reasoning4 Setting Priors5 Epistemic Modality6 Delusions of Possibility7 Delusions of Possibility in Different Contexts8 How Many Factors? (shrink)

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

Monothematic delusions involve a single theme, and often occur in the absence of a more general delusional belief system. They are cognitively atypical insofar as they are said to be held in the absence of evidence, are resistant to correction, and have bizarre contents. Empiricism about delusions has it that anomalous experience is causally implicated in their formation, whilst rationalism has it that delusions result from top down malfunctions from which anomalous experiences can follow. Within empiricism, two approaches to the (...) nature of the abnormality/abnormalities involved have been touted by philosophers and psychologists. One-factor approaches have it that monothematic delusions are a normal response to anomalous experiences whilst two-factor approaches seek to identify a clinically abnormal pattern of reasoning in addition to anomalous experience to explain the resultant delusion. In this paper we defend a one-factor approach. We begin by making clear what we mean by atypical, abnormal, and factor. We then identify the phenomenon of interest and overview one and two-factor empiricism about its formation. We critically evaluate the cases for various second factors, and find them all wanting. In light of this we turn to our one-factor account, identifying two ways in which ‘normal response’ may be understood, and how this bears on the discussion of one-factor theories up until this point. We then conjecture that what is at stake is a certain view about the epistemic responsibility of subjects with delusions, and the role of experience, in the context of familiar psychodynamic features. After responding to two objections, we conclude that the onus is on two-factor theorists to show that the one-factor account is inadequate. Until then, the one-factor account ought to be understood as the default position for explaining monothematic delusion formation and retention. We don’t rule out the possibility that, for particular subjects with delusions there may be a second factor at work causally implicated in their delusory beliefs but, until the case for the inadequacy of the single factor is made, the second factor is redundant and fails to pick out the minimum necessary for a monothematic delusion to be present. (shrink)

It is often taken for granted in standard theories of interpretation that there cannot be intentionality without rationality. According to the background argument, a system can be interpreted as having irrational beliefs only against a general background of rationality. Starting from the widespread assumption that delusions can be reasonably described as irrational beliefs, I argue here that the background argument fails to account for their intentional description.

The central hypothesis of this book, Delusions and Beliefs: A Philosophical Inquiry (Routledge, 2019), is that delusions are malfunctional beliefs (Chapter 1); they belong to the category of belief (Chapter 2) but, unlike mundane false or irrational beliefs, they fail to perform some functions of belief (Chapter 3). More precisely, delusions directly or indirectly involve some malfunctioning cognitive mechanisms, which is empirically supported by the two-factor account of delusion formation (Chapter 4).

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)

Despite the diagnostic relevance of thought insertion for disorders such as schizophrenia, the debates about its aetiology are far from resolved. This paper claims that in paying exclusive attention to the perceptual and cognitive impairments leading to delusional experiences in general, current deficit approaches overlook the role that affective disturbances might play in giving rise to cases of thought insertion. In the context of psychosis, affective impairments are often characterized as a consequence of the stress and anxiety caused by delusional (...) episodes. However, here I explore some of the conceptual and empirical reasons to think that affective problems might in fact play a crucial doxastic role in the aetiology of thought insertion. Finally, I conclude by proposing a way of integrating the main insights of my analysis with the current ‘two-factor’ deficit approach to thought insertion and I explore the potential adaptive role that some delusions might have within this framework. (shrink)

Addiction is almost universally held to be characterized by a loss of control over drug-seeking and consuming behavior. But the actions of addicts, even of those who seem to want to abstain from drugs, seem to be guided by reasons. In this paper, I argue that we can explain this fact, consistent with continuing to maintain that addiction involves a loss of control, by understanding addiction as involving an oscillation between conflicting judgments. I argue that the dysfunction of the mesolimbic (...) dopamine system that typifies addictions causes the generation of a mismatch between the top-down model of the world that reflects the judgment that the addict ought to refrain from drugs, and bottom-up input caused by cues predictive of drug availability. This constitutes a powerful pressure toward revising the judgment and thereby attenuating the prediction error. But the new model is not stable, and shifts under the pressure of bottom-up inputs in different contexts; hence the oscillation of all-things-considered judgment. Evidence from social psychology is adduced, to suggest that a similar process may be involved in ordinary cases of weakness of will. (shrink)

The cognitive experience view of thought holds that the content of thought is determined by its cognitive-phenomenal character. Adam Pautz argues that the cognitive experience view is extensionally inadequate: it entails the possibility of mix-and-match cases, where the cognitive-phenomenal properties that determine thought content are combined with different sensory-phenomenal and functional properties. Because mix-and-match cases are metaphysically impossible, Pautz argues, the cognitive experience view should be rejected. This paper defends the cognitive experience view from Pautz’s argument. I build on resources (...) in the philosophy of mind literature to show that cognitive-phenomenal properties are modally independent from sensory-phenomenal and functional properties. The result is that mix-and-match cases, though modally remote, are metaphysically possible. The possibility of mix-and-match cases allows us to move from defensive posture to a critical one: it poses problems for any theory of content that imposes rationality constraints, including Pautz’s positive view, phenomenal functionalism. (shrink)

Delusions are usually considered as harmful and dysfunctional beliefs, one of the primary symptoms of a psychiatric illness and the mark of madness in popular culture. However, in recent times a much more positive role has been advocated for delusions. More specifically, it has been argued that delusions might be an answer to a problem rather than problems in themselves. By delivering psychological and epistemic benefits, delusions would allow people who face severe biological or psychological difficulties to survive in their (...) environment - although this has obvious epistemic costs, as the delusion is fixed and irresponsive to compelling counterevidence. In other words, it has been argued that delusions are biologically adaptive. The adaptiveness of delusions has been compared by Ryan McKay and Daniel Dennett to a shear pin, a mechanism installed in the drive engine of some machines which is designed to shear whenever the machine is about to break down. By breaking, shear pins prevent the machine from collapsing and allow it to keep functioning, although in an impaired manner. Similarly, when delusions form, they would allow a cognitive or psychological system which is about to collapse to continue its functioning, although in an impaired manner. However, this optimistic picture of delusions risks being undermined by both theoretical and empirical considerations. Using Sarah Fineberg and Philip Corlett’s recent predictive coding account as a paradigmatic model of the biological adaptiveness of delusions, I develop two objections to it: principles of parsimony and simplicity suggest that maladaptive models of delusions have an upper hand over adaptive models; and the available empirical evidence suggests that at least some delusions stand good chances of being psychologically adaptive, but it is unlikely that they also qualify as biologically adaptive. (shrink)

Some monothematic types of delusions may arise because subjects have unusual experiences. The role of this experiential component in the pathogenesis of delusion is still not understood. Focussing on delusions of alien control, we outline a model for reality testing competence on unusual experiences. We propose that nascent delusions arise when there are local failures of reality testing performance, and that monothematic delusions arise as normal responses to these. In the course of this we address questions concerning the tenacity with (...) which delusions are maintained, their often bizarre content, the patients’ inability to dismiss them, and their often circumscribed character. (shrink)

Some monothematic types of delusions may arise because subjects have unusual experiences. The role of this experiential component in the pathogenesis of delusion is still not understood. Focussing on delusions of alien control, we outline a model for reality testing competence on unusual experiences. We propose that nascent delusions arise when there are local failures of reality testing performance, and that monothematic delusions arise as normal responses to these. In the course of this we address questions concerning the tenacity with (...) which delusions are maintained, their often bizarre content, the patients' inability to dismiss them, and their often circumscribed character. (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)

We propose another positive illusion that fits with McKay & Dennett's (M&D's) criteria for adaptive misbeliefs. This illusion is pervasive in adult reasoning but we focus on its prevalence in children's developing theories. It is a strongly held conviction arising from normal functioning of the doxastic system that confers adaptive advantage on the individual.

Standard accounts of delusion explain them as responses to experience. Cognitive models of feature binding in the face recognition systems explain how experiences of mismatch between feelings of "familiarity" and faces can arise. Similar mismatches arise in phenomena such as déjà and jamais vu in which places and scenes are mismatched to feelings of familiarity. These cognitive models also explain similarities between the phenomenology of these delusions and some dream states which involve mismatch between faces, feelings of familiarity and identities. (...) Given these similarities it makes sense to retain that aspect of the standard account in the face of revisionist arguments that feature binding anomalies which lead to delusions of misidentification are not consciously experienced. (shrink)

Jennifer Radden has drawn attention to two features of delusion, ambivalence and subjectivity, which are problematic for theories of delusion that treat delusions as empirical beliefs. She argues for an ‘attitude’ theory of delusion. I argue that once the cognitive architecture of delusion formation is properly described the debate between doxastic and attitude theorists loses its edge. That architecture suggests that delusions are produced by activity in the ‘default mode network’ unsupervised by networks required for decontextualized processing. The cognitive properties (...) of these networks explain the features of delusion which generate the debate between doxastic and attitude theorists. (shrink)

Explanations of Capgras delusion and prosopagnosia typically incorporate a dual-route approach to facial recognition in which a deficit in overt or covert processing in one condition is mirror-reversed in the other. Despite this double dissociation, experiences of either patient-group are often reported in the same way – as lacking a sense of familiarity toward familiar faces. In this paper, deficits in the facial processing of these patients are compared to other facial recognition pathologies, and their experiential characteristics mapped onto the (...) dual-route model in order to provide a less ambiguous link between facial processing and experiential content. The paper concludes that the experiential states of Capgras delusion, prosopagnosia, and related facial pathologies are quite distinct, and that this descriptive distinctiveness finds explanatory equivalence at the level of anatomical and functional disruption within the face recognition system. The role of skin conductance response as a measure of ‘familiarity’ is also clarified. (shrink)

Dans ce qui suit, je décrirai un modèle pour la formation et la maintenance des délires polythématiques rencontrés dans la schizophrénie, en adéquation avec le modèle pour les délires décrit par Brendan Maher. Les délires polythématiques y sont considérés comme les conclusions d’arguments déclenchés par l’apophénie et qui comportent des erreurs de raisonnement très communes, telles que le sophisme post hoc et le bais de confirmation. Je décris tout d’abord la structure du raisonnement qui conduit au délire de référence, de (...) télépathie et d’influence, en distinguant entre les arguments délirants de type primaire, secondaire, tertiaire et quaternaire. Ces quatre niveaux d’arguments correspondent respectivement à une phase de nature instancielle, inductive, interprétative au niveau monothématique et, enfin, interprétative au niveau polythématique. Je m’attache ensuite à déterminer de manière précise quelles sont les étapes fallacieuses dans le raisonnement correspondant. J’expose également le rôle de l’apophénie dans l’élaboration des idées délirantes. Enfin, je m’attache à décrire le rôle joué par les hallucinations dans le présent modèle.We proceed to describe a model for the formation and maintenance of polythematic delusions encountered in schizophrenia, which is in adequation with Brendan Maher’s account of delusions. Polythematic delusions are considered here as the conclusions of arguments triggered by apophenia that include some very common errors of reasoning such as post hoc fallacy and confirmation bias. We describe first the structure of reasoning which leads to delusions of reference, of telepathy and of influence, by distinguishing between the primary, secondary, tertiary and quaternary types of delusional arguments. These four levels of arguments correspond to a stage the nature of which is repectively instantial, inductive, interpretative at a monothematic level and interpretative at a polythematic level. We also proceed to identify accurately the fallacious steps in the corresponding reasoning. We expose then the role of apophenia in the elaboration of delusional ideas. Lastly, we describe the role played by the hallucinations in the present model. (shrink)

A common reaction to functional diversity is to group entities into clusters that are functionally similar. I argue here that people are diverse with respect to reasoning-related processes, and that these processes satisfy the basic requirements for evolving entities: they are heritable, mutable, and subject to selective pressures. I propose a metric to quantify functional difference and show how this can be used to place psychological processes into a structure akin to a phylogenetic or evolutionary tree. Three species concepts are (...) repurposed from biology and used to understand relationships in that tree. (shrink)

I here defend my earlier doubts that VM patients serve as counterexamples to motivational internalism by highlighting the difficulties of belief attribution in light of holism about the mental and by suggesting that a better understanding of the role of emotions in the self-attribution of moral belief places my earlier Davidsonian "theory of mind" argument in a clearer light.