In recent years there has been considerable discussion and controversy concerning the concepts of mental health and mental illness. The controversy has centered around the problem of providing criteria for an adequate conception of mental health and illness, as well as difficulties in specifying a clear and workable system for the classification, understanding, and treatment of psychological and emotional disorders. In this paper I shall examine a cluster of these complex and important issues, focusing on attempts to define ‘mental health’ (...) and ‘mental illness’; diverse factors influencing the ascription of the predicates ‘is mentally ill’ and ‘is mentally healthy’; and some specific problems concerning these concepts as they appear in various theories of psychopathology. The approach here will be in the nature of a survey, directed at the specification of a number of problems—conceptual, methodological, and pragmatic—as they arise in various attempts to define and to provide criteria for applying the concepts of mental health and mental illness. (shrink)