A Christian Science practitioner is an individual who prays for others according to the teachings of Christian Science. Treatment is non-medical, rather it is based on the Bible and the Christian Science textbook, Science and Health with Key to the Scriptures (1875) by Mary Baker Eddy (1821–1910), who said she discovered Christian Science in 1866 and founded the Christian Science church in 1879. According to the church, Christian Science practitioners address physical conditions, as well as relationship or financial difficulties and any other problem or crisis. Despite the non-medical nature of their practice, Christian Science practitioners were aggressively prosecuted in the late 19th century by newly established state medical societies across the United States. Most state courts dismissed these actions because the courts ruled that they did not practice medicine. Practitioners are either "listed" or "unlisted," a designation that refers to a form of international accreditation maintained by The Mother Church, in Boston, Massachusetts. "Listed" practitioners are included in the directory of Christian Science practitioners on the church website, and printed in the Christian Science Journal.