Unclean spirit

In English translations of the Bible, unclean spirit is a common rendering of Greek pneuma akatharton (πνεῦμα ἀκάθαρτον; plural pneumata akatharta (πνεύματα ἀκάθαρτα)), which in its single occurrence in the Septuagint translates Hebrew ruaḥ tum'ah (רוח טומאה).

The Greek term appears 21 times in the New Testament in the context of demonic possession. It is also translated into English as spirit of impurity or more loosely as "evil spirit." The Latin equivalent is spiritus immundus.

The association of physical and spiritual cleanliness is, if not universal, widespread and continues into the 21st century: "To be virtuous is to be physically clean and free from the impurity that is sin," notes an article in Scientific American published 10 March 2009. Some scholarship seeks to differentiate between "unclean spirit" and "evil spirit" (pneuma ponêron) or "demon" (daimonion).

In the Christian scriptures, the word pneuma (plural pneumata) is used variously for the human soul, angelic or demonic spirits, and the Holy Spirit, depending on context or with a grammatical modifier.New Testament usage of the words pneuma and daimonion in relation to demons follows that of later Judaism; the two words are to be distinguished from daimon, which appears only once (at Matthew 8:31) and in classical antiquity has a neutral meaning of "spirit" or "god, demigod." For those who practiced the traditional religions of antiquity, possession by a pneuma could be a desired state of visionary trance.

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