Philosophical ideas about the mind, brain, and behavior can seem theoretical and unimportant when placed alongside the urgent questions of mental distress and disorder. However, there is a need to give direction to attempts to answer these questions. On the one hand a substantial research effort in going into the investigation of brain processes and the development of drug treatments for psychiatric disorders, and on the other, a wide range of psychotherapies is becoming available to adults and children with mental health problems. These two strands reflect traditional distinctions between...