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)

Jakob Ohlhorst | : This paper introduces the concept of tragic self-deception. Taking the basic notion that self-deception is motivated belief against better evidence, I argue that there are extreme cases of self-deception even when the contrary evidence is compelling. These I call cases of tragic self-deception. Such strong evidence could be argued to exclude the possibility of self-deception; it would be a delusion instead. To sidestep this conclusion, I introduce the Wittgensteinian concept of certainties or hinges: acceptances that are (...) beyond evidential justification. One particular type of certainties—iHinges, which are adopted for motivational reasons—explain the phenomenon of tragic self-deception: they warrant the subject’s dismissal of the evidence without loss of rationality from the subject’s point of view. Subsequently, I deal with some objections that can be raised against this account of self-deception. | : Cet article présente le concept d’auto-illusion tragique. En prenant la notion de base selon laquelle l’auto-illusion consiste en une croyance motivée à l’encontre de meilleures preuves, je soutiens qu’il existe des cas extrêmes d’auto-illusion qui persistent même face à des preuves contradictoires incontestables. J’appelle ces cas : auto-illusion tragique. On pourrait soutenir que des preuves d’une telle force excluent la possibilité d’auto-illusion et qu’il s’agirait plutôt de délire. Afin d’éviter cette conclusion, j’introduis le concept wittgensteinien de certitudes ou de propositions charnières : des admissions qui se situent au-delà d’une justification de nature probante. Un type de certitudes en particulier – iHinges, qui sont adoptées pour des raisons d’ordre motivationnel – rend compte du phénomène d’auto-illusion tragique. Ces certitudes justifient que le sujet rejette la preuve sans que cela implique, de son propre point de vue, une perte de rationalité. Subséquemment, je traite de certaines objections qui peuvent être soulevées contre cette explication de l’auto-illusion. (shrink)

Clinicians and cognitive scientists typically conceive of delusions as doxastic—they view delusions as beliefs. But some philosophers have countered with anti-doxastic objections: delusions cannot be beliefs because they fail the necessary conditions of belief. A common response involves meeting these objections on their own terms by accepting necessary conditions on belief but trying to blunt their force. I take a different approach by invoking a cognitive-phenomenal view of belief and jettisoning the rational/behavioural conditions. On this view, the anti-doxastic claims can (...) be rejected outright, and doxasticism can be defended. I call this the cognitive phenomenological defence of doxasticism. (shrink)

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

People suffering from severe monothematic delusions, such as Capgras, Fregoli, or Cotard patients, regularly assert extraordinary and unlikely things. For example, some say that their loved ones have been replaced by impostors. A popular view in philosophy and cognitive science is that such monothematic delusions aren't beliefs because they don't guide behaviour and affect in the way that beliefs do. Or, if they are beliefs, they are somehow anomalous, atypical, or marginal beliefs. We present evidence from five studies that folk (...) psychology unambiguously views monothematic delusions as stereotypical beliefs. This calls into question widespread assumptions in the professional literature about belief's stereotypical functional profile. We also show that folk psychology views delusional patients as holding contradictory beliefs. And we show that frequent assertion is a powerful cue to belief ascription, more powerful than even a robust and consistent track record of non-verbal behaviour. (shrink)

Here I reply to the main points raised by the commentators on the arguments put forward in my Delusions and Other Irrational Beliefs (OUP, 2009). My response is aimed at defending a modest doxastic account of clinical delusions, and is articulated in three sections. First, I consider the view that delusions are inbetween perceptual and doxastic states, defended by Jacob Hohwy and Vivek Rajan, and the view that delusions are failed attempts at believing or not-quitebeliefs, proposed by Eric Schwitzgebel and (...) Maura Tumulty. Then, I address the relationship between the doxastic account of delusions and the role, nature, and prospects of folk psychology, which is discussed by Dominic Murphy, Keith Frankish, and Maura Tumulty in their contributions. In the final remarks, I turn to the continuity thesis and suggest that, although there are important differences between clinical delusions and non-pathological beliefs, these differences cannot be characterised satisfactorily in epistemic terms. (shrink)

In this paper, I will present and advocate a view about what we are doing when we attribute delusion, namely, say that someone is delusional. It is an “expressivist” view, roughly analogous to expressivism in meta-ethics. Just as meta-ethical expressivism accounts for certain key features of moral discourse, so does this expressivism account for certain key features of delusion attribution. And just as meta-ethical expressivism undermines factualism about moral properties, so does this expressivism, if correct, show that certain attempts to (...) objectively define delusion are misguided. I proceed as follows. I start by examining different attempts at defining delusion, separating broadly psychiatric attempts from epistemic ones. I then present a change of approach, according to which we question whether the term “delusion” is in the business of (merely) describing reality. I then support this proposal, first, by borrowing standard lines of argument from meta-ethics (including ontological reluctance, intrinsic motivation, and deep disagreement) but also, by inference to the best explanation of some the features we see when we try to theorise about delusion (namely that it is hard to define, and that our delusion attributions are elicited by a plurality of norms). (shrink)

On one influential view, the problems that should attract medical attention involve a disorder, because the goals of medical practice are to prevent and treat disorders. Based on this view, if there are no mental disorders then the status of psychiatry as a medical field is challenged. In this paper, I observe that it is often difficult to establish whether the problems that attract medical attention involve a disorder, and argue that none of the notions of disorder proposed so far (...) offers a successful demarcation criterion between medical and non-medical problems. As an illustration, I consider why delusions are considered pathological and whether they attract medical attention in virtue of being pathological, where ‘pathological’ stands for ‘being caused by a disorder’. Although there are several promising answers to what makes delusions pathological, available accounts of the pathological nature of delusions fail to distinguish delusions from other irrational beliefs that are not typically thought of as pathological; and cannot explain why delusions typically attract medical attention whereas other irrational beliefs do not. (shrink)

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

Here I summarise the main arguments in Delusions and Other Irrational Beliefs [1]. The book addresses the question whether there is a rationality constraint on belief ascription and defends a doxastic account of clinical delusions.

Stanford Encyclopedia Entry on Delusions.

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)

The present thesis surveys different philosophical approaches to the nature of delusions: specifically, their ontology. However, since none of the various theories of the nature of delusions succeeds, I argue that there must be something problematic about the form of the analyses commonly offered. My general conclusion is that one cannot characterize delusions without taking away what it is distinctive about them.