This paper reviews the difficulties that have developed between the legal and the mental health system. The author contends that many of these difficulties have arisen because of confusion between the two terms of a dichotomy madness v mental illness, and a lack of common understanding of what these two concepts mean to the social theorist and to the physician. Following an epistemological look at the relationship between the two systems, the author explores these ideas through specific areas that, in his opinion, exemplify the difficulties. The areas covered include the concept of mental illness, the issue of commitment, the troubles caused by de-institutionalization, and the problems posed by decisions on competency. Finally, the author looks at forensic psychiatry and considers whether this specialty has had anything to do with the difficulties in the relationship between mental health and law. At the end, some thoughts about reconciling the two systems are advanced.