Mental illness and the mind-brain problem: delusion, belief and Searle's theory of intentionality.

Until recently there has been little contact between the mind-brain debate in philosophy and the debate in psychiatry about the nature of mental illness. In this paper some of the analogies and disanalogies between the two debates are explored. It is noted in particular that the emphasis in modern philosophy of mind on the importance of the concept of action has been matched by a recent shift in the debate about mental illness from analyses of disease in terms of failure of functioning to analyses of illness in terms of failure of action. The concept of action thus provides a natural conduit for two-way exchanges of ideas between philosophy and psychiatry. The potential fruitfulness of such exchanges is illustrated with an outline of the mutual heuristic significance of psychiatric work on delusions and philosophical accounts of Intentionality.