When Amariah Brigham, physician and Utica Asylum superintendent, published his medical inquiry into the 1830s revivals centered in upstate New York and the Western frontier, he found himself courting religious controversy. Not that this was unexpected. In Observations on the Influence of Religion upon the Health and Physical Welfare of Mankind (1835), he notes his embarrassment in trying to account for the “gravity” of the subject without questioning the religious beliefs of those he discusses. Arguing that religious worship is progressive and that it has become “more pure and spiritual as mankind have progressed in knowledge,” he laments what he sees as the unfortunate recidivism of the revivals surrounding him in upstate New York. He concentrates his intervention therefore on what he believes are the physiological facts about revivalism: The religious enthusiasm displayed at revivals is a “nervous affection,” and its operations on the body can be accounted for by the “important but still mysterious subject” of animal magnetism. In Brigham's diagnosis, the bodily exercises – the fainting, sobbing, and groaning at revivals – are the symptoms of a nervous system run amok and are a profound threat both to the health of all citizens and to “reasonable,” “calm,” and progressive Christianity.