Abstract

In an important and timely book, Anneli Jefferson outlines a view according to which a given mental disorder is a brain disorder if it is a (harmful) mental dysfunction realised by a brain dysfunction. Prima facie, Jefferson’s book is a study in the metaphysics of dysfunction: how does mental dysfunction relate to brain dysfunction, and what does this imply for the status of mental disorders and brain disorders? In what follows, I shall argue that Jefferson’s contribution to this debate is better understood as a conceptual explication of how psychiatrists, some philosophers, scientists and clinicians in the field (broadly construed) think of the label ‘brain disorder’. I infer this on the basis that Jefferson’s thesis would not follow from any serious, well-worked out theory of proper function. Despite initial appearances, Jefferson’s book about brain dysfunction is not about function at all.