The term séance is used in a few different ways, and can refer to any of four different activities, each with its own social norms and conventions, its own favoured tools, and its own range of expected outcomes.
In the religion of Spiritualism, and the religion of Divine Metaphysics (a federally recognized religious branch out of Spiritualism in the United States), it is generally a part of services to communicate with living personalities in the spirit world. Usually, this is only called "séance" by outsiders; the preferred term for Spiritualists is "receiving messages". In these sessions, which generally take place in well-lit Spiritualist churches or outdoors at Spiritualist camps (such as Lily Dale in upstate New York or Camp Cassadaga in Florida), an ordained minister or gifted contact medium will relate messages from spirit personalities to those here in the physical form. Generally Spiritualist "message services" or "demonstrations of the continuity of life" are open to the public. Sometimes the medium stands to receive messages and only the sitter is seated; in some churches, the message service is preceded by a "healing service" involving some form of faith healing.

In addition to communicating with the spirits of people who have a personal relationship to congregants, some Spiritual Churches also deal with spirits who may have a specific relationship to the medium or a historic relationship to the body of the church. An example of the latter is the spirit of Black Hawk, a Native American warrior of the Fox tribe who lived during the 19th century. Black Hawk was a spirit who was often contacted by the Spiritualist medium Leafy Anderson and he remains the central focus of special services in the African American Spiritual Churches that she founded.

In the Latin American religion of Espiritismo, which somewhat resembles Spiritualism, séance sessions in which congregants attempt to communicate with spirits are called misas (literally "masses"). The spirits addressed in Espiritismo are often those of ancestors or Catholic saints.
Mediums who give performances on stage of contacting spirits, with audience members seated before them, are not literally holding a séance, because they themselves are not seated; however, this is still called "séance". One of the foremost early practitioners of this type of contact with the dead was Paschal Beverly Randolph, who worked with the spirits of the relatives of audience members, but was also famed for his ability to contact and deliver messages from ancient seers and philosophers, such as Plato.
Leader-assisted séances are generally conducted by small groups of people, with participants seated around a table in a dark or semi-dark room. The leader is typically asserted to be a medium and he or she may go into a trance that theoretically al…

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Mediumship involves an act where the practitioner attempts to receive messages from spirits of the dead and from other spirits that the practitioner believes exist. Some self-ordained mediums are fully conscious and awake while functioning as contacts; others may slip into a partial or full trance or into an altered state of consciousness. These self-called "trance-mediums" often state that, when they emerge from the trance state, they have no recollection of the messages they conveyed; it is customary for such practitioners to work with an assistant who writes down or otherwise records their words.
Spirit boards, also known as talking boards, or ouija boards (after a well-known brand name) are flat tablets, typically made of wood, Masonite, chipboard, or plastic. On the board are a number of symbols, pictures, letters, numbers and/or words. The board is accompanied by a planchette (French for "little board"), which can take the form of a pointer on three legs or magnifying glass on legs; homemade boards may employ a shot glass as a planchette. A most basic Ouija board would contain simply the alphabet of whatever country the board is being used in, although it is not uncommon for whole words to be added.

The board is used as follows: One or more of the participants in the séance place one or two fingers on the planchette which is in the middle of the board. The appointed medium asks questions of the spirit(s) with whom they are attempting to communicate.
During the latter half of the 19th century, a number of Spiritualist mediums began to advocate the use of specialized tools for conducting séances, particularly in leader-assisted sessions conducted in darkened rooms. "Spirit trumpets" were horn-shaped speaking tubes that were said to magnify the whispered voices of spirits to audible range. "Spirit slates" consisted of two chalkboards bound together that, when opened, were said to reveal messages written by spirits. "Séance tables" were special light-weight tables which were said to rotate, float, or levitate when spirits were present. "Spirit cabinets" were portable closets into which mediums were placed, often bound with ropes, in order to prevent them from manipulating the various aforementioned tools.

Scientific skeptics and atheists generally consider both religious and secular séances to be scams, or at least a form of pious fraud, citing a lack of empirical evidence. The exposure of supposed mediums whose use of séance tools derived from the techniques of stage magic has been disturbing to many believers in spirit communication. In particular, the 1870s exposures of the Davenport Brothers as illusionists and the 1887 report of the Seybert Commission brought an end to the first historic phase of Spiritualism. Stage magicians like John Nevil Maskelyne and Harry Houdini made a side-line of exposing fraudulent mediums during the late 19th and early 20th centuries. In 1976, M. Lamar Keene described deceptive techniques that he himself had used in séances; however, in the same book, Keene also stated that he still had a firm belief in God, life after death, ESP, and other psychic phenomena. In his 2004 television special Seance, magician Derren Brown held a séance and afterwards described some of the tricks used by him (and 19th-century mediums) to create the illusion of paranormal events.

Critics of channeling—including both skeptics and believers—state that since the most commonly reported physical manifestations of channeling are an unusual vocal pattern or abnormal overt behaviors of the medium, it can be quite easily faked by anyone with theatrical talent. Critics of spirit board communication techniques—again including both skeptics and believers—state that the premise that a spirit will move the planchette and spell out messages using the symbols on the board is undermined by the fact that several people have their hands on the planchette, which allows any of them to spell out anything they want without the others knowing. They say that this is a common trick, used on occasions such as teenage sleepover parties, to scare the people present.

Another criticism of spirit board communication involves what is called the ideomotor effect which has been suggested as an automatism, or subconscious mechanism, by which a Ouija-user's mind unknowingly guides his hand upon the planchette, hence he will honestly believe he is not moving it, when, in fact, he is. This theory rests on the embedded premise that human beings actually have a "subconscious mind," a belief not held by all.

The exposures of fraud by tool-using mediums have had two divergent results: skeptics have used historic exposures as a frame through which to view all spirit mediumship as inherently fraudulent, while believers have tended to eliminate the use of tools but continued to practice mediumship in full confidence of its spiritual value to them.

Jews and Christians are taught that it is sinful to attempt to conju…

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