Clinical delusions are difficult to investigate in the laboratory because they co-occur with other symptoms and with intellectual impairment. Partly for these reasons, researchers have recently begun to use hypnosis with neurologically intact people in order to model clinical delusions. In this paper we describe striking analogies between the behavior of patients with a clinical delusion of mirrored self misidentification, and the behavior of highly hypnotizable subjects who receive a hypnotic suggestion to see a stranger when they look in the (...) mirror. Based on these analogies, we argue that the use of hypnosis is a reliable method to investigate the surface features of clinical delusions. But to what extent can hypnosis successfully recreate delusions? Can it also contribute to a better understanding of delusion formation? Although clinical delusions and hypnotically induced beliefs are different in etiology, some analogies can be identified in the underlying processes that characterise them, based on the two-factor theory of delusion formation. (shrink)

In this paper we ask whether the two-factor theory of delusions is compatible with two claims, that delusions are pathological and that delusions are adaptive. We concentrate on two recent and influential models of the two-factor theory: the one proposed by Max Coltheart, Peter Menzies and John Sutton (2010) and the one developed by Ryan McKay (2012). The models converge on the nature of Factor 1 but diverge about the nature of Factor 2. The differences between the two models are (...) reflected in different accounts of the pathological and adaptive nature of delusions. We will explore such differences, considering naturalist and normativist accounts of the pathological and focusing on judgements of adaptiveness that are informed by the shear-pin hypothesis (McKay and Dennett 2009). After reaching our conclusions about the two models, we draw more general implications for the status of delusions within two-factor theories. Are there good grounds to claim that delusions are pathological? Are delusions ever adaptive? Can delusions be at the same time pathological and adaptive? (shrink)

Logic was understood by the Stoics in a broad sense, as the doctrine that included analysis of the forms of argumentation, rhetoric, theory of concepts and propositions, epistemology, and philosophy of language. The distinguishing characteristic of Stoic logic is the fact that it is fundamentally a logic of propositions, unlike the logic of terms belonging to the Aristotelian tradition. This study offers a new treatment of Stoic logic, in which the various topics are retraced and critically assessed.

Since the first decade of the 14th Century, Thomas Aquinas’s disciples have struggled to explain and defend his doctrine of analogy. Analogy after Aquinas: Logical Problems, Thomistic Answers relates a history of prominent Medieval and Renaissance Thomists’ efforts to solve three distinct but interrelated problems arising from their reading both of Aquinas’s own texts on analogy, and from John Duns Scotus’s arguments against analogy and in favor of univocity in Metaphysics and Natural Theology. The first of these three problems concerns (...) Aquinas’s at least apparently disparate statements on whether a name is said by analogy through a single concept or through diverse concepts. The second problem concerns the model of analogy suited for predicating names analogously across the categories of being or about God and creatures. Is “being” said analogously about God and creatures, or substance and accidents, on the model of how “healthy” is said of medicine and an animal, or on the model of how “principle” is said of a point and a line? The third problem comes from outside challenges to Aquinas’s thought, in particular Scotus’ claims that univocal names alone can mediate valid demonstrations, and any demonstration that failed to use its mediating terms univocally would fail by the fallacy of equivocation. Analogy after Aquinas makes a unique contribution to the study of philosophical theology in the tradition of Thomas Aquinas by showing the historical and philosophical connection between these three problems, as well as the variety of solutions proposed by leading representatives of this tradition. Thomists considered in the book include: Hervaeus Natalis (1250-1323), Thomas Sutton (1250-1315), John Capreolus (1380-1444), Dominic of Flanders (1425-1479), Paul Soncinas (d. 1494), Thomas dio vio Cajetan (1469-1534), Francis Silvestri of Ferrara (1474-1528), and Chrysostom Javelli (1470-1538). (shrink)

This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value c, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of light has a universal value. We (...) also discuss an old incomplete proof by Weyl which is important from an historical perspective. (shrink)

It is often taken for granted in standard theories of interpretation that there cannot be intentionality without rationality. According to the background argument, a system can be interpreted as having irrational beliefs only against a general background of rationality. Starting from the widespread assumption that delusions can be reasonably described as irrational beliefs, I argue here that the background argument fails to account for their intentional description.

Abstract In this paper I discuss one apparent counterexample to the rationality constraint on belief ascription. The fact that there are inconsistent believers does not seem compatible with the idea that only rational creatures can be ascribed beliefs. I consider Davidson's explanation of the possibility of inconsistent believers and claim that it involves a reformulation of the rationality constraint in terms of the believers' subscription to norms of rationality. I shall argue that Davidson's strategy is partially successful, but that the (...) emphasis on the notion of subscription badly fits with the motivations behind his theory of interpretation. (shrink)

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)

This paper gives two complete and elementary proofs that if the speed of light over closed paths has a universal value c, then it is possible to synchronize clocks in such a way that the one-way speed of light is c. The first proof is an elementary version of a recent proof. The second provides high precision experimental evidence that it is possible to synchronize clocks in such a way that the one-way speed of light has a universal value. We (...) also discuss an old incomplete proof by Weyl which is important from an historical perspective. (shrink)

The strongly innovative theory of whole-parts relations outlined by Husserl in his Third logical Investigation—to which he attributed a basic value for his entire phenomenology—has recently attracted a renewed interest. Although many important issues have been clarified (especially by Kit Fine) the subject seems still worth being revisited. To this aim Husserlian universes are introduced. These are lower bounded distributive lattices endowed with a unary operation of defect and a binary relation of isogeneity. Husserl's contents are identified with nonzero elements (...) of a Husserlian universe and the dependence relations among contents are defined and studied starting from the idea that the defect of xis what x needs in order to ‘exist’ i.e., in order to be ‘closed’ with respect to the closure operation defined as the sup of x and its defect. It turns out that there are (at least) eight dependence relations which are worth to be considered. Many other questions concerning the world of contents (among them the proofs of the famous Husserl's Sätze) may now be discussed and clarified. Then the theory of species and genera is developed. Ultimate species (for short: species) are identified with equivalence classes of contents modulo isogeneity, and species in general (for short: genera) are identified with arbitrary unions of species. On the basis of the relation obtaining among two contents when they are isogeneous to two contents the first of which is a part of the second it becomes possible to develop a rather satisfying interpretation of Husserl's theory of the dependencies among species and genera and of the material a priori laws. By strengthening the notion of Husserlian universe into the notion of rigid Husserlian universe, the theory of species and genera obtains a stronger version. Three models of the theory are exhibited. The first one, suggested by combinatorial-topological considerations, identifies contents with finite non-empty sets of natural numbers; the second one identifies contents with non-empty sets of formulas of a formal language; the third one (not totally ‘rigid’) identifies contents with positive integers. (shrink)

Per uscire dalle aporie delle proprie conseguenze, la scienza deve vedere riconosciuto l'atto come uno dei propri principi fondamentali (accanto all'ente e alla parola). Scienza è, infatti, mettere in relazione le cose (la "natura") con delle leggi matematiche (vale a dire con dei simboli e dei concetti). Ma mettere in relazione è un atto. Sicché, la scienza si fonda su tre principi (ente, parola, atto) e sui corrispettivi campi filosofici (ontologia, logica, etica). Tenere conto di quest'ambito triadico serve a mostrare (...) che l'epistemologia non è un sapere neutro e descrittivo, ma è un prendere partito: al tempo stesso dal punto di vista etico, politico, morale e giuridico. (shrink)

After briefly reviewing some of the empirical and philosophical literature suggesting that there may be an adaptive role for delusion formation, we discuss the results of a recent study consisting of in-depth interviews with people experiencing delusions. We analyse three such cases in terms of the circumstances preceding the development of the delusion; the effects of the development of the delusion on the person’s situation; and the potential protective nature of the delusional belief as seen from the first-person perspective. We (...) argue that the development of the delusional belief can play a short-term protective function and we reflect on the implications that this might have for our understanding of psychotic symptoms, for the stigma associated with mental health issues, and for treatment options. (shrink)

On both sides of the debate on the use of embryos in stem cell research, and in reproductive technologies more generally, rhetoric and symbolic images have been evoked to influence public opinion. Human embryos themselves are described as either “very small human beings” or “small clusters of cells.” The intentions behind the use of these phrases are clear. One description suggests that embryos are already members of our community and share with us a right to life or at least respectful (...) treatment, whereas the other focuses on the differences between embryos and adult human beings with normal capacities, that is, their lack of sentience and of personal identity. The research on stem cells has been nicknamed “Frankenstein science” or presented as “research that could stop Parkinson disease.” Again, one description reminds us of scary science-fiction scenarios where the scientist is guilty of “playing God,” whereas the other description highlights the worth and potential benefits of the research outcomes. (shrink)

A good therapeutic relationship in mental health services is a predictor of positive clinical outcomes for people who seek help for distressing experiences, such as voice hearing and paranoia. One factor that may affect the quality of the therapeutic relationship and raises further ethical issues is the impact of the clinical encounter on users’ sense of self, and in particular on their sense of agency. In the paper, we discuss some of the reasons why the sense of epistemic agency may (...) be especially fragile in young people with unusual experiences and beliefs. We argue that it is important to identify and avoid behaviours that can undermine young people’s contributions as epistemic agents in the clinical encounter. (shrink)

The mental representation of one’s own body does not necessarily correspond to the physical body. For instance, a dissociation between perceived and actual reach-ability has been shown, that is, individuals perceive that they can reach objects that are out of grasp. We presented participants with 3D pictures of objects located at four different distances, namely near-reaching space, actual-reaching space, perceived-reaching space and non-reaching space. Immediately after they were presented with function, manipulation, observation or pointing verbs and were required to judge (...) if the verb was compatible with the object.Participants were faster with function and manipulation verbs than with observation and pointing verbs. Strikingly, with both function and manipulation verbs participants were faster when objects were presented in actual than the perceived reaching space. These findings suggest that our knowledge of the world is implicitly built online through behaviour, and is not necessarily reflected in explicit estimates or conscious representations. (shrink)

In this paper we have two main aims. First, we present an account of mood-congruent delusions in depression (hereafter, depressive delusions). We propose that depressive delusions constitute acknowledgements of self-related beliefs acquired as a result of a negatively biased learning process. Second, we argue that depressive delusions have the potential for psychological and epistemic benefits despite their obvious epistemic and psychological costs. We suggest that depressive delusions play an important role in preserving a person’s overall coherence and narrative identity at (...) a critical time, and thus can be regarded as epistemically innocent. (shrink)

Understood in their historical context, current debates about psychiatric classification, prompted by the publication of the DSM-5, open up new opportunities for improved translational research in psychiatry. In this paper, we draw lessons for translational research from three time slices of 20th century psychiatry. From the first time slice, 1913 and the publication of Jaspers’ General Psychopathology, the lesson is that translational research in psychiatry requires a pluralistic approach encompassing equally the sciences of mind (including the social sciences) and of (...) brain. From the second time slice, 1953 and a conference in New York from which our present symptom-based classifications are derived, the lesson is that, while reliability remains the basis of psychiatry as an observational science, validity too is essential to effective translation. From the third time slice, 1997 and a conference on psychiatric classification in Dallas that brought together patients and carers with researchers and clinicians, the lesson is that we need to build further on collaborative models of research combining expertise-by-training with expertise-by-experience. This is important if we are to meet the specific challenges to translation presented by the complexity of the concept of mental disorder, particularly as reflected in the diversity of desired treatment outcomes. Taken together, these three lessons – a pluralistic approach, reliability and validity, and closer collaboration – provide an emerging framework for more effective translation of research into practice in 21st century psychiatry. (shrink)

The two-factor theory (Davies, Coltheart, Langdon & Breen 2001; Coltheart 2007; Coltheart, Menzies & Sutton 2010) is an influential account of delusion formation. According to the theory, there are two distinct factors that are causally responsible for delusion formation. The first factor is supposed to explain the content of the delusion, while the second factor is supposed to explain why the delusion is adopted and maintained. Recently, another remarkable account of delusion formation has been proposed, in which the notion of (...) “prediction error” plays the central role (Fletcher & Frith 2009; Corlett, Krystal, Taylor & Fletcher 2009; Corlett, Taylor, Wang, Fletcher & Krystal 2010). According to this account, the prediction-error theory, delusions are formed in response to aberrant prediction-error signals, those signals that indicate a mismatch between expectation and actual experience. -/- In this chapter, we examine the relationship between the two-factor theory and the prediction-error theory in some detail. Our view is that the prediction-error theory does not have to be understood as a rival to the two-factor theory. We do not deny that there are some important differences between them. However, those differences are not as significant as they have been presented in the literature. Moreover, the core ideas of the prediction-error theory may be incorporated into the two- factor framework. For instance, the aberrant prediction-error signal that is posited by prediction-error theorists can be (or underlie) the first factor contributing to the formation of some delusions, and help explain the content of those delusions. Alternatively, the aberrant prediction-error signal can be (or underlie) the second factor, and help explain why the delusion is adopted and maintained. (shrink)

Delusions are symptoms of psychiatric disorders such as schizophrenia and dementia. By and large, delusions are characterized by their behavioral manifestations and defined as irrational beliefs that compromise good functioning. In this overview paper, we ask whether delusions can be adaptive notwithstanding their negative features. Can they be a response to a crisis rather than the source of the crisis? Can they be the beginning of a solution rather than the problem? Some of the psychological, psychiatric, and philosophical literature has (...) recently suggested that they can. We consider different types of delusions and different ways in which they can be considered as adaptive: psychologically (e.g., by increasing wellbeing, purpose in life, intrapsychic coherence, or good functioning) and biologically (e.g., by enhancing genetic fitness). Although further research is needed to map the costs and benefits of adopting and maintaining delusional beliefs, a more nuanced picture of the role of delusions in people's lives has started to emerge. (shrink)

Delusions are a common symptom of schizophrenia and dementia. Though most English dictionaries define a delusion as a false opinion or belief, there is currently a lively debate about whether delusions are really beliefs and indeed, whether they are even irrational. The book is an interdisciplinary exploration of the nature of delusions. It brings together the psychological literature on the aetiology and the behavioural manifestations of delusions, and the philosophical literature on belief ascription and rationality. The thesis of the book (...) is that delusions are continuous with ordinary beliefs, a thesis that could have important theoretical and practical implications for psychiatric classification and the clinical treatment of subjects with delusions. By bringing together recent work in philosophy of mind, cognitive psychology and psychiatry, the book offers a comprehensive review of the philosophical issues raised by the psychology of normal and abnormal cognition, defends the doxastic conception of delusions, and develops a theory about the role of judgements of rationality and of attributions of self-knowledge in belief ascription. Presenting a highly original analysis of the debate on the nature of delusions, this book will interest philosophers of mind, epistemologists, philosophers of science, cognitive scientists, psychiatrists, and mental health professionals. (shrink)

Findings from the cognitive sciences suggest that the cognitive mechanisms responsible for some memory errors are adaptive, bringing benefits to the organism. In this paper we argue that the same cognitive mechanisms also bring a suite of significant epistemic benefits, increasing the chance of an agent obtaining epistemic goods like true belief and knowledge. This result provides a significant challenge to the folk conception of memory beliefs that are false, according to which they are a sign of cognitive frailty, indicating (...) that a person is less reliable than others or their former self. Evidence of memory errors can undermine a person’s view of themselves as a competent epistemic agent, but we show that false memory beliefs can be the result of the ordinary operation of cognitive mechanisms found across the species, which bring substantial epistemic benefits. This challenge to the folk conception is not adequately captured by existing epistemological theories. However, it can be captured by the notion of epistemic innocence, which has previously been deployed to highlight how beliefs which have epistemic costs can also bring significant epistemic benefits. We therefore argue that the notion of epistemic innocence should be expanded so that it applies not just to beliefs but also to cognitive mechanisms. (shrink)

In this chapter we argue that some beliefs present a problem for the truth-aim teleological account of belief, according to which it is constitutive of belief that it is aimed at truth. We draw on empirical literature which shows that subjects form beliefs about the real world when they read fictional narratives, even when those narratives are presented as fiction, and subjects are warned that the narratives may contain falsehoods. We consider Nishi Shah’s teleologist’s dilemma and a response to it (...) from Asbjørn Steglich-Petersen which appeals to weak truth regulation as a feature common to all belief. We argue that beliefs from fiction indicate that there is not a basic level of truth regulation common to all beliefs, and thus the teleologist’s dilemma remains. We consider two objections to our argument. First, that the attitudes gained through reading fiction are not beliefs, and thus teleologists are not required to account for them in their theory. We respond to this concern by defending a doxastic account of the attitudes gained from fiction. Second, that these beliefs are in fact appropriately truth-aimed, insofar as readers form beliefs upon what they take to be author testimony. We respond to this concern by suggesting that the conditions under which one can form justified beliefs upon testimony are not met in the cases we discuss. Lastly, we gesture towards a teleological account grounded in biological function, which is not vulnerable to our argument. We conclude that beliefs from fiction present a problem for the truth-aim teleological account of belief. (shrink)

Irrational beliefs are often seen as beliefs that are either costly or even pathological and it is assumed that we should eliminate them when possible. In this paper we argue that not only irrational beliefs are a widespread feature of human cognition and agency but also that, depending on context, they can be beneficial to the person holding them, not only psychologically but also epistemically. Given that rationality is highly valued, judgements of rationality have wide-ranging implications for interpersonal relations at (...) an individual and societal level. We suggest that a better understanding of rationality and its role in cognition can lead to a more compassionate treatment of people who express beliefs that are judged as irrational. (shrink)