This paper explores the possibility of understanding schizophrenic delusion through the role of a primary alteration of subjective experience. Two approaches are contrasted: the first defines schizophrenic delusion as a primary symptom resisting any attempt to understand, whereas the second describes delusion as a secondary symptom, to be understood as a rational reaction of the self. The paper discusses the possibility of applying this second approach to schizophrenic delusion. This leads us to raise the issue of the specificity of psychotic (...) experiences and to wonder whether some accounts of delusion arising in neurological disorders can be generalized into psychotic delusion. A few points are addressed, demanding clarification and the rephrasing of some assumptions implied by the model of a secondary delusion. These points call for an interaction between clinical descriptions, neurocognitive explorations and a philosophical analysis of psychotic subjective experiences. (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)

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)

Emotion Review, Volume 14, Issue 3, Page 206-216, July 2022. This paper develops the claim that epistemic feelings are affective experiences. To establish some diagnostic criteria, characteristic features of affective experiences are outlined: valence and arousal. Then, in order to pave the way for showing that epistemic feelings have said features, an initial challenge coming from introspection is addressed. Next, the paper turns to empirical findings showing that we can observe physiological and behavioural proxies for valence and arousal in epistemic (...) tasks that typically rely on epistemic feelings. Finally, it is argued that the affective properties do not only correlate with epistemic feelings but that we, in fact, capitalise on these affective properties to perform the epistemic tasks. In other words: the affective properties in question constitute epistemic feelings. (shrink)

The Spinozan theory of belief fixation holds that mentally representing truth-apt propositions leads to immediately believing them. In this paper, I explore how the theory fares as a defence of doxasticism about delusions (the view that they are beliefs). Doxasticism has been criticised on the grounds that delusions typically do not abide by rational standards that we expect beliefs to conform to. If belief fixation is Spinozan, I argue, these deviations from rationality are not just compatible with, but supportive of, (...) their status as beliefs. (shrink)

In certain startling neurological and psychiatric conditions, what is ordinarily most intimate and familiar to us—our own body—can feel alien. For instance, in cases of somatoparaphrenia subjects misattribute their body parts to others, while in cases of depersonalization subjects feel estranged from their bodies. These ownership disorders thus appear to consist in a loss of any feeling of bodily ownership, the felt sense we have of our bodies as our own. Against this interpretation of ownership disorders, I defend Sufficiency, the (...) thesis that every experience of bodily awareness suffices for a feeling of bodily ownership. Since Sufficiency conflicts with a face‐value interpretation of these ownership disorders, the burden is on me to explain away the apparent tension. To do so, I identify and correct what I believe to be the fundamental mistake in the extant literature on the feeling of bodily ownership, namely the tendency to treat the notion of a feeling of bodily ownership as a single psychological construct. Instead, I distinguish the feeling of minimal ownership, the first‐personal character of bodily awareness, from the feeling of affective ownership, the distinctive type of felt concern we have for our bodies. I motivate this distinction by raising the disownership puzzle, the fact that subjects suffering from ownership disorders display an ambiguous set of symptoms, arguing the distinction I draw between minimal and affective ownership is just what is required to resolve the puzzle. (shrink)

To introduce the issue of the tracking and identification of human agents, I examine the ability of an agent to track a human person and distinguish this target from other individuals: The ability to perform person identification. First, I discuss influential mechanistic models of the perceptual recognition of human faces and people. Such models propose detailed hypotheses about the parts and activities of the mental mechanisms that control the perceptual recognition of persons. However, models based on perceptual recognition are incomplete (...) theories of person identification because they do not explain several identification behaviors that are fundamental to human social interactions. Furthermore, recognition-based models tend to appeal to the controversial concept of the “identity” of a person without explaining what determines personal identity and persistence. To overcome these limitations, I propose to integrate the face-recognition program into a broader causal-historical theory of identification. The causal-historical theory of identification complements models focused on perceptual recognition because it can account for the types of non-perceptual identification overlooked by the face-recognition program. Moreover, it can decompose the identification behaviors into tracking processes that succeed or fail to be sensitive to causal characteristics of a target. I illustrate these advantages with a discussion of the difference between the tracking of a person understood as either a causally continuous biological organism or a psychologically continuous mind. Finally, I argue that the causal-historical theory provides a theoretical framework for investigating the tracking of relations between a target and its contextual and historical attributes, such as a target's possessions. (shrink)

I would like to thank Sullivan-Bissett and Noordhof for their stimulating comments on my 2023 paper in Neuroethics. In this reply, I will (1) articulate some deeper disagreements that may underpin our disagreement on the nature of delusion, (2) clarify their misrepresentation of my arguments as a defence of the two-factor theory in particular, and (3) finally conduct a comparison between the Maherian one-factor theory and the two-factor theory, showing that the two-factor theory is better supported by evidence.

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)

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

There is evidence indicating that the Capgras delusion is grounded in some kind of anomalous experience. According to the endorsement model, the content of the delusion is already encoded in the Capgras subject's experience, and the delusion is formed simply by endorsing that content as veridical. Elisabeth Pacherie and Sam Wilkinson have in different ways attempted to articulate a comprehensive defence of this strategy, but here I argue that the endorsement model cannot be defended along the lines envisioned by either (...) of them. I then offer a more promising way of spelling out the model, according to which the anomalous experience implicated in Capgras is metaphorical in character. (shrink)

In this paper we review two debates in the current literature on clinical delusions. One debate is about what delusions are. If delusions are beliefs, why are they described as failing to play the causal roles that characterise beliefs, such as being responsive to evidence and guiding action? The other debate is about how delusions develop. What processes lead people to form delusions and maintain them in the face of challenges and counter-evidence? Do the formation and maintenance of delusions require (...) abnormal experience alone, or also reasoning biases or deficits? We hope to show that the focus on delusions has made a substantial contribution to the philosophy of the mind and continues to raise issues that are central to defining the concept of belief and gaining a better understanding of how people process information and learn about the world. (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)

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)

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 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)

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)

Zygon®, Volume 56, Issue 4, Page 846-873, December 2021.