Healing is a profoundly cultural activity. The labeling and treating of a disease reflect a culture's deepest understandings of the causal powers affecting human well-being. For this reason, the notion of orthodoxy pertains to medical systems as surely as it does to religious or political traditions. Ever since the Enlightenment, medical orthodoxy has been defined by a commitment to the causal role of "material" factors in the etiology of disease. Western medical science thus emerged in direct opposition to the pre-Enlightenment worldview within which the church supplied culturally compelling explanations of nonmaterial or spiritual causes of disease (e.g., sin or spirit possession), as well as corresponding strategies for therapeutic intervention (e.g., confession or exorcism). The continual successes of medical science have understandably garnered wide cultural support for its underlying worldview. As a consequence, most educated Westerners...