Mary Baker Eddy was the founder of Christian Science and the associated Church of Christ, Scientist. Eddy doubted the existence of physical matter, insisting instead that all was ultimately spirit, just as God was spirit. It followed that diseases were primarily spiritual rather than physical ailments, which should be treated with prayer rather than medicine. Eddy’s most prominent work, Science and Health with Key to the Scriptures, first appeared in 1875 and went through over 400 editions within the next 40 years. The text ends with an anthology of personal testimonies that describe miraculous recoveries and healings via the tenets of Christian Science.