Historians have often represented prayer as an instrumental response to illness. We argue instead that prayer, together with physic, was part of larger regimes to preserve health and prevent disease. We focus on early modern England, through the philo- sophical writings of the physician, Robert Fludd, and the medical records of the cler- gyman, Richard Napier. Fludd depicted health as a fortress and illness as an invasion by demons; the physician counsels the patient in maintaining and restoring moral and bodily order. Napier documented actual uses of prayer. As in Fludd’s trope, through prayer, Napier and his patients enacted their aspiration for health and their commit- ment to a Christian order in which medicine only worked if God so willed it. Prayer, like physic, was a key part of a regime that the wise practitioner aimed to provide for his patients, and that they expected to receive from him.