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)

Stanford Encyclopedia Entry on Delusions.

This chapter introduces the rationalist model of delusions. It begins by presenting John Campbell’s seminal proposal that delusions are caused top-down by pathological Wittgensteinian framework or hinge beliefs. After presenting Campbell’s rationalist account of delusions, the chapter raises and examines prominent objections by Tim Bayne & Elisabeth Pacherie as well as by Tim Thornton. The former make an important distinction between the aetiological top-down cognitive part and the epistemological rationalist framework part of Campbell’s account. The thesis that delusions are caused (...) top-down by pathological beliefs is not equivalent to the thesis that delusions are Wittgensteinian framework certainties. This chapter endorses this distinction. While the arguments against the top-down aspect are found to be more convincing – which motivates popular two-factor theories – the rationalist framework model of delusions is defended as an epistemologically promising account of delusion. Finally, this chapter examines a range of developments that have been made taking Campbell’s rationalism as a starting point. Most prominently the section examines Eilan’s early development of rationalism and Rhodes and Gipps’ proposal that delusions are not framework propositions but a product of their absence. (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)

Some of the most well-known arguments against epistemic externalism come in the form of thought experiments involving subjects who acquire beliefs through anomolous means such as clairvoyance. These thought experiments purport to provide counterexamples to the reliabilist conception of justification: their subjects are intuitively epistemically unjustified, yet meet reliabilist externalist criteria for justification. In this article, I address a recent defence of externalism due to Daniel Breyer, who argues that externalists need not consider such subjects justified, since they fail to (...) own those beliefs in a way required for epistemic evaluability. I argue that the concept of belief ownership Breyer adopts leaves his account open to related counterexamples, and suggest a modification, drawing on analogies between these cases and cases of delusions, such as thought insertion. I will argue that a concept of authorship developed in the literature on delusions better grounds the sense of attribution required for epistemic evaluability. (shrink)

The computational approach to psychiatric disorders, including delusions, promises explanation and treatment. Here, we argue that an information processing approach might be misleading to understand psychopathology and requires further refinement. We explore the claim of computational psychiatry being a bridge between phenomenology and physiology while focussing on the ontological commitments and corresponding methodology computational psychiatry is based on. Interconnecting ontological claims and methodological practices, the paper illustrates the structure of theory-building and testing in computational psychiatry.First, we will explain the ontological (...) commitments computational psychiatry is grounded in, theBayesian Brain hypothesis(BBH) of unconscious inference, paired with normative deontic approaches applied to gauge psychopathology. We then turn to the steps taken in empirical paradigms, from definitions, which are used as starting points, to the operationalisation and isolation of cognitive processes and hypothesis testing based on algorithmic models, to consecutive interpretations regarding the aetiology of psychiatric disorders. We outline how experimental paradigms in computational psychiatry are specifically designed to confirm aberrations in assumed inferential processes, which are thought of as being the underlyingcore invariant features.We will illustrate a gap between the ontological commitments of computational psychiatry and the operationalisation and testing of the cognition assumed to be relevant for psychopathology. This conceptual gap is of utmost importance when designing computational paradigms and may impede a crisp understanding of the approach. Lastly, in evaluating the conceptual gap, it becomes apparent that the information processing formalism used in computational psychiatry is still grounded in rational cognitive psychology. (shrink)

In this article, I respond to Jennifer Duke-Yonge’s (2012) discussion of my article ‘Reflective Luck and Belief Ownership’ (Breyer, Acta Analytica, 25:133–154, 2010) and defend my Taking Responsibility account of belief ownership against her insightful criticisms.

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.

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)

It has been argued that schizophrenic delusions are “behaviourally inert.” This is evidence for the phenomenon of “double bookkeeping,” according to which people are not consistent in their commitment to the content of their delusions. The traditional explanation for the phenomenon is that people do not genuinely believe the content of their delusions. In the article, we resist the traditional explanation and offer an alternative hypothesis: people with delusions often fail to acquire or to maintain the motivation to act on (...) their delusional beliefs. This may be due to avolition, to emotional disturbances, or to the fact that, given the peculiar content of some delusions, the surrounding environment does not support the agent’s motivation to act. (shrink)

Delusions are often thought of as the hallmark of irrationality. Accepted definitions of delusion are cast in terms of epistemic features that reflect irrationality: impossibility or falsity of con...

Philosophical Investigations, Volume 45, Issue 1, Page 91-97, January 2022.

The papers included in the thesis, and summarized in this covering document, were selected, in discussion with my supervisor, Dr. Roessler, from papers I have published in the philosophy of psychiatry. In parallel to this philosophical work, I have worked clinically as a psychiatrist and academically as a research psychiatrist. My clinical work has largely been working with Early Intervention Services, both in South London and in Coventry and Warwickshire, and this work has been acting as a psychiatrist in clinical (...) teams who work with young people who may either be at risk of developing a psychotic illness, or are in the earliest stages of such an illness. My empirical work has been in the same clinical group and has used functional neuroimaging and cognitive neuropsychology to characterize those at risk of psychosis and to chart the onset of psychosis and the formation of delusions. As required by the university guidelines, a full list of publications, both empirical and philosophical, is detailed in appendix 1. The papers included in the thesis hence parallel many of these clinical and empirical interests: papers 2 and 4, in particular, examine the role neuroimaging may play in studying delusions and relate the prodromal phase of psychosis to both the neurodevelopmental and continuum models of psychosis. Paper 3 is one of two papers written with Lisa Bortolotti drawing on Richard Moran’s work and examining delusions. Paper 1 is perhaps the paper least connected to my empirical and clinical work as has a wider focus and tries to examine what mental illnesses are and to begin to describe a position Lisa Bortolotti and I later expanded on and referred to as ‘psychological realism’, with Paper 2 being a case example of this account being applied to a particular area of psychopathology, namely delusions. The papers form a progression with Paper 1 outlining a general conception of mental disorder, Paper 2 being a case study of this approach specifically in the area of delusion. Paper 3 takes the example of thought insertion and develops ideas from Paper 2 that reason giving is a crucial feature that helps highlight what is pathological about certain experiences. Paper 4 brings together the philosophical concerns regarding a wholly neuroscientific conception of psychopathology, and how this is of clinical and scientific relevance when we use psychopathology to demarcate the various stages of psychotic experience and illness. (shrink)