Exorcism, the term used by the Fathers of the Church to denote the act of conjuring evil spirits, in the name of God or Christ, to depart out of the person possessed. The first Christians adjured evil spirits in the name of Jesus Christ, who had conquered the devil; but as the opinion was at the same time entertained that all idolaters belonged to the kingdom of Satan—who suffered himself to be worshipped under the form of idols—it was customary to exorcise heathens previous to their receiving Christian baptism. After Augustine's theory of original sin had found acceptance in the 5th century, and all infants were regarded as belonging to Satan's kingdom, exorcism became general at the baptism even of Christian children. Following the practice of the Roman Catholic Church, Luther retained it, and the baptismal office in the first prayer-book of Edward VI. (1549) contained a short form, omitted at Bucer's intervention in the 1552 revision. The seventy-second canon (1603) of the Church of England forbids any minister attempting to expel a devil or devils, without first obtaining the license of his bishop. Although abandoned by illustrious and orthodox Protestant theologians, such as Chemnitz and Gerhard, or deemed unessential, and in modern times done away with by the 'Protestant' Church, since 1822 baptismal exorcism has been revived by the Old Lutheran or High Church party.
In the Catholic Church the function of exorcism belongs peculiarly to the third of the so-called 'minor orders' (see ORDERS). Our Lord having not only himself in person (Matt. ix. 32; Mark, i. 25; Luke, iv. 35, viii. 29) cast out devils, but having also given the same power to his disciples, it is believed to be permanent in the church. Of its exercise in the early church, both in relation to 'energunens,' or persons possessed, and in the administration of baptism, there are numerous examples. Tertullian and Origen speak of it as of ordinary occurrence, and the Council of Carthage, in 255, alludes to its use in baptism. The rite of exorcism is used by the modern church in three different cases: in the case of actual or supposed demoniacal possession, in the administration of baptism, and in the blessing of the chrism or holy oil, and of holy water. This last practice is alluded to by Cyprian (Ep. 70). The use of exorcism in cases of possession is now extremely rare, and in many diseases is prohibited, unless with the special permission of the bishop. In baptism it precedes the ceremony of applying the water and the baptismal form. It is used equally in infant and in adult baptism, and Catholic writers appeal to the earliest examples of the administration of the sacrament as evidence of the use of exorcism in both alike. The rite of baptismal exorcism in the Roman Catholic Church follows closely the Scriptural model in Mark, viii. 33. The exorcisms in the blessing of the oil and water resemble very closely the baptismal form, but are more diffuse.