Trance is a state of semi-consciousness in which a person is not self-aware and is either altogether unresponsive to external stimuli (but nevertheless capable of pursuing and realizing an aim) or is selectively responsive in following the directions of the person (if any) who has induced the trance. Trance states may occur involuntarily and unbidden.
The term trance may be associated with hypnosis, meditation, magic, flow, prayer, psychedelic drugs, and altered states of consciousness.
Etymology
Trance in its modern meaning comes from an earlier meaning of "a dazed, half-conscious or insensible condition or state of fear", via the Old French transe "fear of evil", from the Latin transīre "to cross", "pass over".
Working models
Wier, in his 1995 book, Trance: from magic to technology, defines a simple trance (p. 58) as a state of mind being caused by cognitive loops where a cognitive object (a thought, an image, a sound, an intentional action) repeats long enough to result in various sets of disabled cognitive functions. Wier represents all trances (which include sleep and watching television) as taking place on a dissociated trance plane where at least some cognitive functions such as volition are disabled; as is seen in what is typically termed a 'hypnotic trance'. With this definition, meditation, hypnosis, addictions and charisma are seen as being trance states. In Wier's 2007 book, The Way of Trance, he elaborates on these forms, adds ecstasy as an additional form and discusses the ethical implications of his model, including magic and government use which he terms "trance abuse".
John Horgan in Rational Mysticism (2003) explores the neurological mechanisms and psychological implications of trances and other mystical manifestations. Horgan incorporates literature and case-studies from a number of disciplines in this work: chemistry, physics, psychology, radiology and theology.
Trance states
Trance conditions include all the different states of mind, emotions, moods and daydreams that human beings experience. All activities which engage a human involve the filtering of information coming into sense modalities, and this influences brain functioning and consciousness. Therefore, trance may be understood as a way for the mind to change the way it filters information in order to provide more efficient use of the mind's resources.
Trance states may also be accessed or induced by various modalities and are considered by some people to be a way of accessing the unconscious mind for the purposes of relaxation, healing, intuition and inspiration. There is an extensive documented history of trance as evidenced by the case-studies of anthropologists and ethnologists and associated and derivative disciplines. Principles of trance are being explored and documented as are methods of trance induction. Mind functioning during trance and benefits of trance states are being explored by medical and scientific inquiry. Many traditions and rituals employ trance. Trance also has a function in religion and mystical experience.
Castillo (1995) states that: "Trance phenomena result from the behavior of intense focusing of attention, which is the key psychological mechanism of trance induction. Adaptive responses, including institutionalized forms of trance, are 'tuned' into neural networks in the brain and depend to a large extent on the characteristics of culture. Culture-specific organizations exist in the structure of individual neurons and in the organizational formation of neural networks."
Hoffman (1998: p. 9) states that: "Trance is still conventionally defined as a state of reduced consciousness, or a somnolent state. However, the more recent anthropological definition, linking it to 'altered states of consciousness' (Charles Tart), is becoming increasingly accepted."
Hoffman (1998, p. 9) asserts that: "...the trance state should be discussed in the plural, because there is more than one altered state of consciousness significantly different from everyday consciousness."
History
Mystics
As the mystical experience of mystics generally entails direct connection, communication and communion with the divine; trance and cognate experience are endemic. (see Yoga, Sufism, Shaman, Umbanda, Crazy Horse, etc.)
As shown by Jonathan Garb, trance techniques also played a role in Lurianic Kabbalah, the mystical life of the circle of Moshe Hayyim Luzzatto and Hasidism.
Military
Joseph Jordania proposed the term "battle trance" in 2011 for a mental state when combatants do not feel fear and pain, and they lose their individual identity and acquire a collective identity.