Delusions and Other Irrational Beliefs

Delusions are a common symptom of schizophrenia, dementia and other psychiatric disorders. 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 evenirrational. 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 delusionsare continuous with ordinary beliefs, a thesis that could have not only significant theoretical implications for debates in the philosophy of mind and psychology, but also 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 therole of judgements of rationality and self-knowledge in belief ascription.

Lisa Bortolotti is Senior Lecturer in Philosophy at the University of Birmingham (UK). Her main research interests are in the philosophy of the cognitive sciences and in the intersection between philosophy of mind and ethics. She has published a number of articles on belief ascription, rationality and delusions in journals such as Mind & Language and Philosophical Psychology. She is the author of An Introduction to the Philosophy of Science for Polity Press, the editor of Philosophy and Happiness for Palgrave and the co-editor (with M.R. Broome) of Psychiatry as Cognitive Neuroscience: Philosophical Perspectives for Oxford University Press.