People often assert that they are ill or that another person is sick. It is an error to believe that people say these things only because they have a disease or only because the person they call sick has a disease. People are often sick but do not say so or say so only to a few confidants, and they often assert, for a variety of reasons, that othersabout whom they know next to nothingare sick: thus, people simulate illness or malinger (to avoid military service), simulate health or deny illness (to avoid medical attention), and claim that others are sick by diagnosing them (to justify treating them as patients). These elementary truths have not been lost on artists, who provide us with perceptive accounts of the often complex and devious motives of patients and doctors.
Having a demonstrable disease is not enough to explain why the subject asserts that he is ill (assumes the sick role) or why others assert that he is ill (place him in the sick role). To understand the myriad nonmedical meanings and consequences of illnessthat is, the tactical rather than descriptive uses of terms such as "ill" and "patient"we must, at least temporarily, ignore the pathological dimensions of the concept and instead focus on the classic problem, Cui bono? Cicero explained the importance of posing this question, primarily to oneself, as follows: "When trying a case L. Cassius never failed to inquire, 'Who gained by it?' Man's character is such that no man undertakes crimes without hope of gain."
No man asserts that he or someone else has an illness without hope of gain. The potential gains, for oneself or others, from asserting such a claimfor example, securing medical help, monetary compensation, excusing crime, and so forthare virtually endless. They depend on the claimant's character and motives, the social context in which the claim is advanced, and the ever-changing legal and social milieu in which medicine is practiced.
Thomas Szasz, Pharmacracy: Medicine and Politics in America (2001:6-7)