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, and altered states of consciousness.
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".
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 conditions include all the different states of mind, emotions, moods and daydreams that human beings experience.