Psychologists and cultural historians typically have argued that early modern theologians such as Martin Luther, John Bunyan, and Ignatius Loyola exhibited behavior that the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) classifies as a subtype of obsessive-compulsive disorder termed “religious scrupulosity.” This essay argues that, although early modern theologians do manifest scrupulosity, such religiosity was a culturally acceptable, even recommended component of spiritual progress, a necessary means of receiving an unmerited bestowal of God’s grace. The larger aim of the essay is to point out some of the limitations of current DSM criteria when attempting retrospectively to diagnose historical figures with mental pathology.