This essay examines a six-year campaign against the radical faith healer John Alexander Dowie mounted in the 1890s by Chicago doctors, public health officials, and their “respectable” middle-class allies. The incident demonstrates the important role of religion in the process of medical professionalization. Medical professionals established cultural authority by aligning themselves with a broader discourse of “orthodoxy”—an ill-defined set of beliefs and practices thought necessary to maintain social order. Protestants used this discourse both to exclude outsiders and unite elites across denominational lines. An initial attempt to prosecute Dowie based on legalistic claims of practicing medicine without a license led to a backlash against medical professionals by middle-class Protestants who believed it compromised the integrity of religious liberty. This suggests that the growing efficacy of medical advances was an insufficient basis of social authority. Only when medical professionals self-consciously aligned themselves with the Protestant establishment and portrayed themselves as defenders of the social order (focused especially on the integrity of the family) were they able to rally the middle classes to their cause. This shift in rhetoric was an important step in the process of creating a discourse of “orthodox” medicine. It helped grant medical professionals the right to oversee the public body just as elite Protestants superintended its soul.