Some people are extremely moral, sacrificing much of their lives to help others. Other people are extremely religious, filling their days with prayers and rituals. However, morality and religion can sometimes go so far that people are diagnosed with Scrupulosity, a form of OCD or OCPD whose characteristic obsessions and compulsions focus on morality or religion. What is the difference between patients with scrupulosity and exemplars of morality and religion? Why do we classify the former as mentally ill but not the latter? This talk will describe cases of Scrupulosity and its general characteristics and diagnosis, contrast moral saints and religious extremists with Scrupulosity patients, and argue that Scrupulosity is a mental illness on any plausible definition of mental illness, including the definition in DSM-5.