Online research in philosophy

In this paper, I articulate the thesis that most delusional beliefs are continuous with other irrational beliefs. Any interpreter with some knowledge about the cognitive and affective life of subjects with delusions can at least partially understand their reports, and explain and predict their behavior in intentional terms. I identify similarities and differences between this approach to the nature of delusions and the approach adopted by Rhodes and Gipps, who have recently defended the view that people with delusions do not share the same bedrock beliefs as people without (the Background Theory of Delusions).

Some otherwise rational people appear to believe strange things. Sometimes people believe that someone, usually a near relative or member of their family - often their spouse - has been replaced by an impostor. Sometimes people believe that they are dead. These two delusions – known as the Capgras and Cotard delusion respectively – are instances of monothematic delusions, for they are limited to very specific topics. Other monothematic delusions involve the delusion that one is being followed by known people in disguise (the Frégoli delusion), or that the person one sees in the mirror is someone else (mirrored-self misidentification). We will focus on the Capgras delusion.

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.

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.

Bortolotti argues that the irrationality of many delusions is no different in kind from the irrationality that marks many non-pathological states typically treated as beliefs. She takes this to secure the doxastic status of those delusions. Bortolotti’s approach has many benefits. For example, it accounts for the fact that we can often make some sense of what deluded subjects are up to, and helps explain why some deluded subjects are helped by cognitive behavioral therapy. But there is an alternative approach that secures the same benefits as Bortolotti’s account while bringing additional benefits. The alternative approach treats both many delusions and many of the non-pathological states to which Bortolotti compares them as in-between states. Subjects in in-between states don’t fully believe the beliefs which it is sometimes convenient to ascribe to them. This alternative approach to belief and belief-ascription fits well with an independently attractive account of the varied purposes of our ordinary attitude ascriptions. It also makes it easier to make fine-grained distinctions between intentional attitudes of different kinds.

Lisa Bortolotti argues convincingly that opponents of the doxastic view of delusion are committed to unnecessarily stringent standards for belief attribution. Folk psychology recognises many non-rational ways in which beliefs can be caused, and our attributions of delusions may be guided by a sense that delusions are beliefs that we cannot explain in any folk psychological terms.

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.

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.

Are delusions best understood as a species of belief? Can I be deluded that p without believing that p? Because delusion is a clinical symptom, there are conflicting data at every turn. Perhaps it is best to think of delusions as beliefs not because they necessarily are beliefs, but because doing so helps patients. If one thinks that “denying that delusions are beliefs” means denying deluded patients “a voice in their own treatment” and that this would cut them off from alternative and healthier ways of thinking of themselves or the world, then one may wish to classify delusions as beliefs (see Kinderman and Bentall 2007, 288). I do not wish to classify delusions as beliefs (and I doubt ..

The imperviousness of delusions to counter-evidence makes it tempting to classify them as imaginings. Bayne and Pacherie argue that adopting a dispositional account of belief can secure the doxastic status of delusions. But dispositionalism can only secure genuinely doxastic status for mental states by giving folk-psychological norms a significant role in the individuation of attitudes. When such norms individuate belief, deluded subjects will not count as believing their delusions. In general, dispositionalism won't confer genuinely doxastic status more often than do competing accounts of belief.