Because the danger of obsession is a core belief within Spiritism, dealing with it is one of the cornerstones of Spiritist religious activity, and it is treated at Spiritist centres by means of prayer and teaching. Its centrality to Spiritist doctrine and practice is one of the marks that generally distinguishes Spiritism from both Spiritualism and the Spiritual Church Movement. However, the 19th century Spiritualist author Paschal Beverly Randolph also recognized the dangers of obsession to mediums, and claimed to have been harmed by evil spirits during his own career as a Spiritualist lecturer and trance medium.