Exorcism (from Late Latin exorcismus, from Greek ἐξορκισμός, exorkismos - binding by oath) is the religious practice of evicting demons or other spiritual entities from a person or place which they are believed to have possessed. Depending on the spiritual beliefs of the exorcist, this may be done by causing the entity to swear an oath, performing an elaborate ritual, or simply by commanding it to depart in the name of a higher power. The practice is quite ancient and part of the belief system of many cultures and religions.
In Christian practice the person performing the exorcism, known as an exorcist, is often a member of the church, or an individual thought to be graced with special powers or skills. The exorcist may use prayers, and religious material, such as set formulas, gestures, symbols, icons, amulets, etc. The exorcist often invokes God, Jesus and/or several different angels and archangels to intervene with the exorcism.
In general, possessed persons are not regarded as evil in themselves, nor wholly responsible for their actions. Therefore, practitioners regard exorcism as more of a cure than a punishment. The mainstream rituals usually take this into account, making sure that there is no violence to the possessed, only that they be tied down if there is potential for violence.
In Islam, exorcism is called ruqya. It is used to repair the damage caused by sihr or witchcraft. It consists of reciting some specific verses from the Quran which glorify God, and invoke God's help. In some cases, the adhan (the call for daily prayers) is also read, as this has the effect of repelling non-angelic unseen beings or the jinn.
In Buddhism, exorcism exists depending on the Buddhist sect. Each differs from the others: some view it as metaphorical, some esoteric, and some even literal. Some Tibetan Buddhists view exorcism as being nothing more than a metaphor for expelling negative thoughts and transforming them into enlightened mind.
Certain Buddhists believe in blessings rather than exorcisms to rid themselves or property of negative thoughts and/or negative spirits.
In Mahayana Buddism (or rather Tibetan Vajrayana Buddhism) evil spirits are rather conversed, and turned into becoming serving, especially wrathful protecting spirits of the Dharma. The tantra (lineage of spiritual craftsmanship) of exorcism in Buddhism may be identified with Vajrakilaya tantra
Demonic possesion is not a valid psychiatric or medical diagnosis recognized by either the DSM-IV or the ICD-10. Those who profess a belief in demonic possession have sometimes ascribed the symptoms associated with mental illnesses, such as hysteria, mania, psychosis, Tourette's syndrome, epilepsy, schizophrenia or dissociative identity disorder, to possession. Additionally, there is a form of monomania called demonomania or demonopathy in which the patient believes that he or she is possessed by one or more demons.
The illusion that exorcism works on people experiencing symptoms of possession is attributed by some to placebo effect and the power of suggestion. Some supposedly possessed persons are actually narcissists or are suffering from low self-esteem and act like a "demon possessed person" in order to gain attention.