While premodern poets and preachers viewed leprosy as a "disease of the soul," physicians in the period understood it to be a "cancer of the whole body." In this innovative study, medical historian Luke Demaitre explores medical and social perspectives on leprosy at a time when judicious diagnosis could spare healthy people from social ostracization and help the afflicted get a license to beg. Extending his inquiry from the first century to late in the eighteenth century, Demaitre draws on translations of academic treatises and archival records to illuminate the professional standing, knowledge, and conduct of the practitioners who struggled to move popular perceptions of leprosy beyond loathing and pity. He finds that, while not immune to social and cultural perceptions of the leprous as degenerate, and while influenced by their own fears of contagion, premodern physicians moderated society's reactions to leprosy and were dedicated to the well-being of their patients.