In his recent book Delusions and Beliefs, Kengo Miyazono offers a thoroughgoing defence of delusions as biologically malfunctioning beliefs, greatly elaborating on his earlier defence of this view. Miyazono has it that delusions have biological doxastic functions, and that delusions involve direct or indirect malfunctions of this kind. In this short piece, I focus on Miyazono’s defence of a two-factor approach to delusion formation as it appears in Chapter Four. Miyazono approaches his discussion of the debate between one- and two-factor (...) theories having already defended the key thesis of the book: that delusions are malfunctioning beliefs. Of course, that thesis might be thought to mesh nicely with the two-factor theorist’s claim that there is a cognitive abnormality present in delusion formation or maintenance. However, I will discuss Miyazono’s defence of the two-factor position in isolation from its role in his overall account of delusion. Miyazono abstracts away from the particulars of Max Coltheart’s two-factor view, and takes himself to be investigating the plausibility of two-factor theories without the specific commitments of Coltheart’s view. Miyazono also captures under the two-factor heading theories which locate the second factor in belief maintenance rather than just in belief formation. He puts forward a new argument for a two-factor approach which goes via inference to the best explanation. I begin by arguing that Miyazono’s starting motivation for a two-factor approach rests on a misrepresentation of the one-factor approach. Then, I turn to the four components of Miyazono’s inference to the best explanation argument, and argue that in each case, we do not have grounds for positing a second factor. (shrink)

In chapter 3 of Delusions and Beliefs, Kengo Miyazono argues that, when delusions are pathological beliefs, they are so due to their being both harmful and malfunctional. In this brief commentary, I put pressure on Miyazono’s account of delusions as harmful malfunctioning beliefs. No delusions might satisfy the malfunction criterion and some delusions might fail to satisfy the harmfulness criterion when such conditions are interpreted as criteria for pathological beliefs. In the end, I raise a general concern about attributing pathological (...) status to single beliefs out of context, and gesture towards the idea of pathology as a failure of agency to which some beliefs can contribute but that can only be identified by considering the person as a whole. (shrink)

Chenwei Nie ([22]) argues against a Maherian one-factor approach to explaining delusion. We argue that his objections fail. They are largely based on a mistaken understanding of the approach (as committed to the claim that anomalous experience is sufficient for delusion). Where they are not so based, they instead rest on misinterpretation of recent defences of the position, and an underestimation of the resources available to the one-factor theory.

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)

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 previous 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.

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

Are conspiracy theory beliefs pathological? That depends on what is meant by "pathological." This paper begins by unpacking that ill-defined and value-laden term before making the case that widespread conspiracy theory belief should not be conceptualized through the “othering’ perspective of individual psychopathology. In doing so, it adopts a phenomenological perspective to argue that conspiracy theory beliefs can be reliably distinguished from paranoid delusions based on falsity, belief conviction, idiosyncrasy, and self-referentiality. A socio-epistemic model is then presented that characterizes the (...) broader phenomenon of conspiracy theory belief as a product of a sick society plagued by epistemic mistrust and vulnerability to misinformation that is ubiquitous in today’s post-truth world. Finally, it is proposed that for individuals, the harmfulness of conspiracy theory belief is less related to belief content as it is to belief conviction and degree of self-relevant consequentiality. Staging conspiracy theory belief in terms of ideological commitment offers a conceptual framework to estimate behavioral risks and test hypotheses about the effectiveness of interventions along a continuum of belief conviction and associated socio-epistemic dynamics. Interventions should target not only individuals, but the dysfunctional social conditions that give rise to the pervasive and enduring phenomenon of conspiracy theory belief. (shrink)

I argue for a kind of sub-category generalism about conspiracy theories. I identify four features that negatively contribute to the evaluation of any conspiracy theory that has them. I argue that particularism about conspiracy theories is in conflict even with this moderate position. I explain the implications of sub-category generalism for questions about the epistemic environment in which epistemic agents operate. I argue that even if there are pragmatic reasons for being vigilant about the possibility of malign conspiracies, this does (...) not support rejecting the claim that it is a prima facie epistemically wrong to believe a conspiracy with any of the four features I identify. I discuss how the favoured sub-category generalism may help to refine discussion about the relationship between the psychology of those who believe conspiracy theories and subjects who have delusions. There are grounds for thinking that believers in conspiracy theories display irrationality at least as bad as those suffering from delusions. This is not to pathologise believers in conspiracy theories but recognise the continuities between those who have delusions and believers who are not the subject of clinical attention. (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)