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)

In their target article, McKay & Dennett (M&D) conclude that only “positive illusions” are adaptive misbeliefs. Relying on overly strict conceptual schisms (deficit vs. motivational, functional vs. organic, perception vs. belief), they prematurely discount delusions asbiologicallyadaptive. In contrast to their view that “motivation” plays a psychological but not a biological function in a two-factor model of the forming and maintenance of delusions, we propose asingleimpairment in prediction-error–driven (i.e., motivational) learning in three stages in which delusions play a biologically adaptive role.

We provide a battery of examples of delusions against which theoretical accounts can be tested. Then, we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher’s view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second factor in the (...) aetiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows. But we point out some problems that confront any attempt to say more about the nature of this second factor. (shrink)

In this paper we defend the doxastic conception of delusions against the metacognitive account developed by Greg Currie and collaborators. According to the metacognitive model, delusions are imaginings that are misidentified by their subjects as beliefs: the Capgras patient, for instance, does not believe that his wife has been replaced by a robot, instead, he merely imagines that she has, and mistakes this imagining for a belief. We argue that the metacognitive account is untenable, and that the traditional conception of (...) delusions as beliefs should be retained. (shrink)

“Mad belief” (in analogy with Lewisian “mad pain”) would be a belief state with none of the causal role characteristic of belief—a state not caused or apt to have been caused by any of the sorts of events that usually cause belief and involving no disposition toward the usual behavioral or other manifestations of belief. On token-functionalist views of belief, mad belief in this sense is conceptually impossible. Cases of delusion—or at least some cases of delusion—might be cases of belief (...) gone half-mad, cases in which enough of the functional role characteristic of belief is absent that the subject is in an “in-between” state regarding the delusive content, such that it is neither quite right to say the subject determinately believes the delusive content nor quite right to say that she determinately fails to believe that content. Although Bortolotti (2010) briefly mentions such “sliding scale” approaches to the relationship of delusion and belief, she dismisses such approaches on rather thin grounds and then later makes some remarks that seem consonant with sliding scale approaches. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Spiritual Experience and PsychopathologyMike Jackson and K. W. M. Fulford (bio)AbstractA recent study of the relationship between spiritual experience and psychopathology (reported in detail elsewhere) suggested that psychotic phenomena could occur in the context of spiritual experiences rather than mental illness. In the present paper, this finding is illustrated with three detailed case histories. Its implications are then explored for psychopathology, for psychiatric classification, and for our understanding of (...) the concept of mental illness. It is argued that pathological and spiritual psychotic phenomena cannot be distinguished by 1) form and content alone (as in traditional psychopathology), 2) by their relationship either with other symptoms or with pathological causes (as in psychiatric classification), or 3) by reference to the descriptive criteria of mental illness implied by the “medical” model. The distinction is shown to depend, rather, on the way in which psychotic phenomena themselves are embedded in the values and beliefs of the person concerned. This in turn is shown to have implications for diagnosis (it shows the need for clinicians to attend to the values and beliefs of individual patients), for treatment (it points to a cognitive problem-solving model), and for research in psychopathology (especially as related to the emerging sciences of dynamic brain imaging and cognitive neuroscience).Keywordsfirst rank symptoms, schizophrenia, delusion, hallucination, thought disorder, religious experience, mystical experienceIntroductionThis paper explores some of the conceptual and practical implications of the finding that phenomena which in a medical context would probably be diagnosed as psychotic symptoms, may occur in the context of non-pathological, and indeed essentially benign, spiritual experiences.The existence of non-pathological psychotic experiences of this kind (we will call them “psychotic phenomena” as distinct from “psychotic symptoms”—see also Endnote 1, terminology) was a key finding in a study carried out by one of us (MJ) at the Alister Hardy Research Centre (AHRC) in Oxford. Details are given elsewhere both of the overall empirical findings of the study, including the relationship between spiritual experience and personality variables, and of a hypothetical cognitive problem-solving model of these phenomena (Jackson 1991, and forthcoming a and b). In the present paper, 1) the background to the study is described briefly in relation to earlier work on the possible links between spiritual experience and psychopathology; 2) some of the psychotic phenomena identified are illustrated with three detailed case histories; 3) the significance of these phenomena is reviewed for our understanding respectively of psychopathology, of diagnostic syndromes, and of the concept of mental illness; and 4) some of the practical implications of the study for clinical work and research in psychiatry are indicated.BackgroundIt has long been recognized that there are similarities between spiritual and psychotic experiences. [End Page 41] William James (1902), for example, argued that “in delusional insanity, paranoia as they sometimes call it, we may have a kind of diabolical mysticism, a sort of religious mysticism turned upside down” (426). Other commentators have noted a wide variety of phenomena, such as time distortion, synesthesias, loss of self-object boundaries and the transition from a state of conflict and anxiety to one of sudden “understanding,” all of which are reported in both spiritual and psychotic experiences (Buckley 1981; Watson 1982; Wapnick 1969; and Wootton and Allen 1983).Yet the similarities notwithstanding, the distinction between these two kinds of experience can be crucially important. Spiritual experiences, whether welcome or unwelcome, and whether or not they are psychotic in form, have nothing (directly) to do with medicine (Fulford 1996a). It would be quite wrong, then, to “treat” spiritual psychotic experiences with neuroleptic drugs, just as it is quite wrong to “treat” political dissidents as though they were ill (Fulford, Smirnoff and Snow, 1993). Pathological psychotic experiences, on the other hand, or psychotic symptoms, are by definition a proper object of medical treatment, sometimes even against the wishes of the person concerned. Hence it would be both negligent and, as Wing (1978) put it, morally “repellent,” to leave untreated someone who is genuinely ill (244).Given how much turns on the distinction between spiritual experience and psychopathology, it is perhaps not surprising that scholarly discussion of the relationship between them has at times... (shrink)

Section 1 articulates a genus-species claim: that knowledge is a kind of success from ability. Equivalently: In cases of knowledge, S’s success in believing the truth is attributable to S’s ability. That idea is then applied to questions about the nature and value of knowledge. Section 2 asks what it would take to turn the genus-species claim into a proper theory of knowledge; that is, into informative, necessary and sufficient conditions. That question is raised in the context of an important (...) line of objection against even the genus-species claim; namely, that there is no way to understand the attribution relation so that it does all the work that it is supposed to do. Section 3 reviews several extant proposals for understanding the attribution relation, and argues that none of them are adequate for answering the objection. Section 4 proposes a different way of understanding the relation, and shows how the resulting view does resolve the objection. Section 5 completes the new account by proposing a way to understand intellectual abilities. Section 6 briefly addresses Barn Façade cases and lottery propositions. Section 7 briefly addresses a question about the scope of knowledge; in particular, it shows how the new view allows a neo-Moorean response to skepticism. (shrink)

Section 1 articulates a genus-species claim: that knowledge is a kind of success from ability. Equivalently: In cases of knowledge, S’s success in believing the truth is attributable to S’s ability. That idea is then applied to questions about the nature and value of knowledge. Section 2 asks what it would take to turn the genus-species claim into a proper theory of knowledge; that is, into informative, necessary and sufficient conditions. That question is raised in the context of an important (...) line of objection against even the genus-species claim; namely, that there is no way to understand the attribution relation so that it does all the work that it is supposed to do. Section 3 reviews several extant proposals for understanding the attribution relation, and argues that none of them are adequate for answering the objection. Section 4 proposes a different way of understanding the relation, and shows how the resulting view does resolve the objection. Section 5 completes the new account by proposing a way to understand intellectual abilities. Section 6 briefly addresses Barn Façade cases and lottery propositions. Section 7 briefly addresses a question about the scope of knowledge; in particular, it shows how the new view allows a neo-Moorean response to skepticism. (shrink)

Section 1 articulates a genus‐species claim: that knowledge is a kind of success from ability. Equivalently: In cases of knowledge, S’s success in believing the truth is attributable to S’s ability. That idea is then applied to questions about the nature and value of knowledge. Section 2 asks what it would take to turn the genus‐species claim into a proper theory of knowledge; that is, into informative, necessary and sufficient conditions. That question is raised in the context of an important (...) line of objection against even the genus‐species claim; namely, that there is no way to understand the attribution relation so that it does all the work that it is supposed to do. Section 3 reviews several extant proposals for understanding the attribution relation, and argues that none of them are adequate for answering the objection. Section 4 proposes a different way of understanding the relation, and shows how the resulting view does resolve the objection. Section 5 completes the new account by proposing a way to understand intellectual abilities. Section 6 briefly addresses Barn Façade cases and lottery propositions. Section 7 briefly addresses a question about the scope of knowledge; in particular, it shows how the new view allows a neo‐Moorean response to skepticism. (shrink)

Article copyright 2002. We provide a battery of examples of delusions against which theoretical accounts can be tested. Then we identify neuropsychological anomalies that could produce the unusual experiences that may lead, in turn, to the delusions in our battery. However, we argue against Maher's view that delusions are false beliefs that arise as normal responses to anomalous experiences. We propose, instead, that a second factor is required to account for the transition from unusual experience to delusional belief. The second (...) factor in the etiology of delusions can be described superficially as a loss of the ability to reject a candidate for belief on the grounds of its implausibility and its inconsistency with everything else that the patient knows, but we point out some problems that confront any attempt to say more about the nature of this second factor. (shrink)

Delusional beliefs have sometimes been considered as rational inferences from abnormal experiences. We explore this idea in more detail, making the following points. Firstly, the abnormalities of cognition which initially prompt the entertaining of a delusional belief are not always conscious and since we prefer to restrict the term “experience” to consciousness we refer to “abnormal data” rather than “abnormal experience”. Secondly, we argue that in relation to many delusions (we consider eight) one can clearly identify what the abnormal cognitive (...) data are which prompted the delusion and what the neuropsychological impairment is which is responsible for the occurrence of these data; but one can equally clearly point to cases where this impairments is present but delusion is not. So the impairment is not sufficient for delusion to occur. A second cognitive impairment, one which impairs the ability to evaluate beliefs, must also be present. Thirdly (and this is the main thrust of our chapter) we consider in detail what the nature of the inference is that leads from the abnormal data to the belief. This is not deductive inference and it is not inference by enumerative induction; it is abductive inference. We offer a Bayesian account of abductive inference and apply it to the explanation of delusional belief. (shrink)

Delusions are defined as irrational beliefs that compromise good functioning. However, in the empirical literature, delusions have been found to have some psychological benefits. One proposal is that some delusions defuse negative emotions and protect one from low self-esteem by allowing motivational influences on belief formation. In this paper I focus on delusions that have been construed as playing a defensive function (motivated delusions) and argue that some of their psychological benefits can convert into epistemic ones. Notwithstanding their epistemic costs, (...) motivated delusions also have potential epistemic benefits for agents who have faced adversities, undergone physical or psychological trauma, or are subject to negative emotions and low self-esteem. To account for the epistemic status of motivated delusions, costly and beneficial at the same time, I introduce the notion of epistemic innocence. A delusion is epistemically innocent when adopting it delivers a significant epistemic benefit, and the benefit could not be attained if the delusion were not adopted. The analysis leads to a novel account of the status of delusions by inviting a reflection on the relationship between psychological and epistemic benefits. (shrink)

To be a doxastic deontologist is to claim that there is such a thing as an ethics of belief (or of our doxastic attitudes in general). In other words, that we are subject to certain duties with respect to our doxastic attitudes, the non-compliance with which makes us blameworthy and that we should understand doxastic justification in terms of these duties. In this paper, I argue that these duties are our all things considered duties, and not our epistemic or moral (...) duties, for example. I show how this has the surprising result that, if deontologism is a thesis about doxastic justification, it entails that there is no such thing as epistemic or moral justification for a belief that p. I then suggest why this result, though controversial, may have some salutary consequences: primarily that it helps us make some sense of an otherwise puzzling situation regarding doxastic dilemmas. -/- . (shrink)

In this paper we defend the doxastic conception of delusions against the metacognitive account developed by Greg Currie and collaborators. According to the metacognitive model, delusions are imaginings that are misidentified by their subjects as beliefs: the Capgras patient, for instance, does not believe that his wife has been replaced by a robot, instead, he merely imagines that she has, and mistakes this imagining for a belief. We argue that the metacognitive account is untenable, and that the traditional conception of (...) delusions as beliefs should be retained. (shrink)

Contemporary virtue epistemology (hereafter ‘VE’) is a diverse collection of approaches to epistemology. At least two central tendencies are discernible among the approaches. First, they view epistemology as a normative discipline. Second, they view intellectual agents and communities as the primary focus of epistemic evaluation, with a focus on the intellectual virtues and vices embodied in and expressed by these agents and communities. -/- This entry introduces many of the most important results of the contemporary VE research program. These include (...) novel attempts to resolve longstanding disputes, solve perennial problems, grapple with novel challenges, and expand epistemology’s horizons. In the process, it reveals the diversity within VE. Beyond sharing the two unifying commitments mentioned above, its practitioners diverge over the nature of intellectual virtues, which questions to ask, and which methods to use. -/- It will be helpful to note some terminology before proceeding. First, we use ‘cognitive’, ‘epistemic’ and ‘intellectual’ synonymously. Second, we often use ‘normative’ broadly to include not only norms and rules, but also duties and values. Finally, ‘practitioners’ names contemporary virtue epistemologists. (shrink)