Despite the currency of the notion of mental illness, its legal and medical legitimacy, and the panoply of psychiatry and other mental health services which claim to treat it, there are those who take the radical sceptical line that mental illness is a fabrication. This is a book which takes this sceptical line seriously - perhaps more seriously than almost any other book not written by sceptics themselves. The Metaphor of Mental Illness is a revaluation of the traditional philosophical disputes about the existence and nature of mental illness. Sceptics and apologists have generally focused on the legitimacy of extending illness from the physical to the mental, by means of the likeness argument. This says that claimed mental illnesses, from ADHD to schizophrenia, really are illnesses providing they are sufficiently similar to agreed physical illnesses.