The discourse of the patient as an active agent in managing illness and health care has become very important in medicine. It is seen in the significance attached to patient empowerment and participation, and in the burgeoning research into patients' coping with illness. The discourse cannot be fully understood from within conventional scientific frameworks because it is part of those frameworks. Instead, its current prominence can be understood by examining how it meets the needs of those who use it. Specifically, it has combined with earlier discourses of disease in a way that allows clinicians to withdraw from responsibility for areas of patient need that are problematic for medicine, such as unexplained symptoms, chronic disease and pain. This view is supported by evidence about how the discourse of patient as agent has been used in clinical consultation to constrain doctors' responsibility for patients' suffering. This discourse and other ways in which doctors and patients influence the boundaries of medical responsibility should be subjects for, rather than constraints on, empirical research.