The word "exorcism" entered English in the 15th century from Late Latin exorcismus, borrowed from Greek exorkismos (a binding by oath, an adjuration). The Greek noun derived from the verb exorkizein (to administer an oath to, to adjure, to bind by oath), combining ex- (out) with horkizein (to make someone swear), from horkos (an oath). An exorcism is, at its etymological core, not a battle but a legal proceeding: the exorcist places the evil spirit under oath and commands it to depart.
This oath-based understanding of exorcism shaped early Christian practice profoundly. In the New Testament, Jesus is described casting out demons by commanding them with authority — not through physical combat but through verbal command. The demon is adjured (put under oath) to identify itself and to obey the command to leave. Early Christian exorcism formulae explicitly employed
The Catholic Church formalized exorcism into a liturgical rite. The Rituale Romanum, first published in 1614, contained the official rite of exorcism, specifying the prayers, commands, and procedures to be used. This rite remained essentially unchanged until 1999, when Pope John Paul II authorized a revised version — De Exorcismis et Supplicationibus Quibusdam — that updated the language while preserving the essential structure of adjuration and command. The revised rite emphasizes that exorcism should be performed only after medical and
The 1973 William Friedkin film The Exorcist, based on William Peter Blatty's 1971 novel — itself inspired by a reported 1949 exorcism case — transformed the word's cultural associations. Before the film, "exorcism" was primarily a theological and historical term. After the film, it became permanently associated with horror cinema: spinning heads, projectile vomiting, and demonic possession entered the popular imagination alongside the liturgical reality of prayer and adjuration. The film's success spawned an entire sub-genre of horror and renewed public
Every major religious tradition has some form of spirit expulsion practice: Jewish tradition has the dybbuk exorcism, Islam has ruqyah (recitation of Quranic verses against jinn), Hinduism and Buddhism have various ritual frameworks. The universality of the concept — commanding hostile spiritual entities to depart — suggests it addresses a deep human need to assert agency over unseen forces that are perceived as causing harm.