Unclean spirit

What it is

An unclean spirit, in the wording of English Bibles, is an impure spirit believed to slip into a person and take over body and voice. The English phrase translates a Greek expression that turns up 21 times in the New Testament, nearly always in stories of possession. Translators also give it as 'spirit of impurity' or the looser 'evil spirit'. The label belongs less to morality than to purity: the Greek modifier names something not cleansed, a ritual state rather than a simply wicked one. Casting such spirits out counted among the miracles ascribed to Jesus, and it stands as the most fully documented magical art of Second Temple Judaism.

Where it comes from

The phrase descends from Hebrew ruaḥ tum'ah, a spirit of impurity met with in the Pseudepigrapha, rabbinic writing and the Hebrew Bible itself. Its single appearance in the Hebrew scriptures sits at Zechariah 13:2, where false prophets speaking for Yahweh are said to be ridden by such a spirit; the Septuagint, the Greek Jewish translation, renders that verse with the Greek words English Bibles later echoed. The Greek term then recurs throughout the Christian scriptures, and Latin writers carried it over as spiritus immundus. Both the Greek and the Latin words reach back to an older sense of breath, of air that moves.

How it is done

The records describe expulsion rather than summoning. A practitioner adjures the spirit, invoking divine names to order it out; a formula preserved by Gregory the Thaumaturge calls on Elohim, Adonai and Sabaoth to make the spirits leave. Because the spirit was imagined as air in motion, ritual breath was released or drawn in alongside the words, and smoke had its own logic: a room thick with incense was held to crowd the air and shove the occupant elsewhere. Charms against personified illness, spoken aloud or written on an amulet, worked the same way. The Babylonian Talmud preserves the reverse rite: fasting and a night in a cemetery to draw an impure spirit near.

Tools and materials

Because both pneuma and spiritus first meant moving breath, the officiant's own breath became a tool, sent out or drawn in over the afflicted person in the rites called insufflation and exsufflation. Incense supplied the counter-force, odour and smoke occupying the air the spirit was thought to inhabit. Written charms on amulets and other ritual objects carried adjurations against illness, addressed to the sickness as though it could hear. One compiler of the Greek Magical Papyri, advertising his spell as Hebraic, told the user to remain ritually pure and to keep away from pork.

What it is for

Expulsion aimed at freeing a person whose body or mind had been seized. In some rabbinic texts demons are said to afflict people partly through disease, so casting out could sit close to healing, and a charm might order a fever to flee like a person. Purification drove the practice too: candidates for baptism in early Christianity were exorcised as a matter of routine, even when no possession was suspected, and for adult converts the spirits to be driven out could be named as the gods of rival religions. A reverse intent existed as well, since some seekers hoped for visions by inviting a spirit in.

Who does it

Jesus is portrayed performing these expulsions himself and passing the authority on: the twelve disciples, and later seventy-two missionaries, are said to receive the power to cast spirits out and to heal. When John reports having stopped an outsider who cast out demons in Jesus's name, Jesus tells the disciples to let him continue. Second Temple Judaism had its own exorcists, whose craft is the era's best-attested magical practice, and a tradition of exorcism in Solomon's name lasted into medieval Europe. In the old Greek world, by contrast, a visionary might welcome such possession as a trance worth seeking.

Peoples and places

The belief runs through Jewish and Christian writing, and each tradition grew its own cast. Jewish lore fills the category with dybbuks, spirits of the dead left unrested, with shedim, a loan-word that once named a protective spirit in Akkadian, and with the goat-like se'irim said to haunt ruins. Christian texts add the frog-shaped spirits of Revelation and the Legion story set among the Gerasene tombs. John Chrysostom assigned the Delphic oracle's trance to an evil spirit of this family, and peoples across the Near East and Europe slept at tombs of ancestors or heroes hoping for revelation.

What people believe

Behind the phrase stands a physics of spirit: a spiritual being imagined as air in motion, 'invisible yet active', so that breath, wind and smoke all touch it. Purity rules govern contact; whatever has not been cleansed, animal or person, can host the spirit, and pigs, frogs and goats carry the taint in different ways. The spirits favour edges: deserts, ruins, tombs, places where human order is giving way to wildness. Restlessness defines them, for Matthew has a wandering spirit find no rest in empty land and hunt for a new body to enter.

How scholars and sceptics see it

Scholars note that translation choices blur the picture. Some work tries to keep 'unclean spirit' apart from 'evil spirit' and 'demon', yet in Mark's Gospel the terms seem interchangeable, and even specialists find the line hard to draw in Judaic theology. Classical Greek daimon carried no evil sense at all, meaning simply a spirit or lesser god, a reminder of how much biblical usage shifted the word. Historians also struggle to separate exorcism from ordinary magico-medical healing, since both treated illness as a person to be ordered out. Bertrand Russell remarked that the Gerasene pigs got a poor deal, and a 2009 Scientific American article traced the old marriage of virtue and physical cleanliness into the present day.

Compare and confuse

The phrase sits among near-neighbours that readers often merge. Pneuma poneron, 'evil spirit', appears in the Septuagint, the New Testament and patristic texts as an alternative wording, and daimonion, 'demon', frequently stands in for it when the same story is told twice. Daimon, by contrast, was a neutral Greek word for a spirit or demigod. Within Judaism the wider field holds dybbuks, shedim and se'irim, kindred but distinct beings.

Questions people ask about Unclean spirit

Good reading and sources

• Unclean spirit on WikipediaEncyclopedia
• Wikidata recordOpen data