1911 Encyclopædia Britannica:
“Automatic Writing, the name given by students of psychical research to writing performed without the volition of the agent. The writing may also take place without any consciousness of the words written; but some automatists are aware of the word which they are actually writing, and perhaps of two or three words on either side, though there is rarely any clear perception of the meaning of the whole. Automatic writing may take place when the agent is in a state of trance, spontaneous or induced, in hystero-epilepsy or other morbid states; or in a condition not distinguishable from normal wakefulness. Automatic writing has played an important part in the history of modern spiritualism. The phenomenon first appeared on a large scale in the early days (c. 1850-1860) of the movement in America. Numerous writings are reported at that period, many of considerable length, which purported for the most part to have been produced under spirit guidance. Some of these were written in “unknown tongues.” Of those which were published the most notable are Andrew J. Davis’s Great Harmonia, Charles Linton’s The Healing of the Nations, and J. Murray Spear’s Messages from the Spirit Life.
In England also the early spiritualist newspapers were filled with “inspirational” writing,—Pages of Ike Paraclete, &c. The most notable series of English automatic writings are the Spirit Teachings of the Rev. W. Stainton Moses. The phenomenon, of course, lends itself to deception, but there seems no reason to doubt that in the great majority of the cases recorded the writing was in reality produced without deliberate volition. In the earlier years of the spiritualist movement, a “planchette,” a little heart-shaped board running on wheels, was employed to facilitate the process of writing.
Of late years, whilst the theory of external inspiration as the cause of the phenomenon has been generally discredited, automatic writing has been largely employed as a method of experimentally investigating subconscious mental processes. Knowledge which had lapsed from the primary consciousness is frequently revealed by this means; e.g. forgotten fragments of poetry or foreign languages are occasionally given. An experimental parallel to this reproduction of forgotten knowledge was devised by Edmund Gurney. He showed that information communicated to a subject in the hypnotic trance could be subsequently reproduced through the handwriting, whilst the attention of the subject was fully employed in conversing or reading aloud; or an arithmetical problem which had been set during the trance could be worked out under similar conditions without the apparent consciousness of the subject.
Automatic writing for the most part, no doubt, brings to the surface only the debris of lapsed memories and half-formed impressions which have never reached the focus of consciousness—the stuff that dreams are made of. But there are indications in some cases of something more than this. In some spontaneous instances the writing produces anagrams, puns, nonsense verses and occasional blasphemies or obscenities; and otherwise exhibits characteristics markedly divergent from those of the normal consciousness. In the well-known case recorded by Th. Flournoy (Des Indes à la planète Mars) the automatist produced writing in an unknown character, which purported to be the Martian language. The writing generally resembles the ordinary handwriting of the agent, but there are sometimes marked differences, and the same automatist may employ two or three distinct handwritings. Occasionally imitations are produced of the handwriting of other persons, living or dead. Not infrequently the writing is reversed, so that it can be read only in a looking-glass (Spiegelschrift); the ability to produce such writing is often associated with the liability to spontaneous somnambulism. The hand and arm are often insensible in the act of writing. There are some cases on record in which the automatist has seemed to guide his hand not by sight, but by some special extension of the muscular sense (Carpenter, Mental Physiology, § 128; W. James, Proceedings American S.P.R. p. 554).
Automatic writing frequently exhibits indications of telepathy. The most remarkable series of automatic writings recorded in this connexion are those executed by the American medium, Mrs Piper, in a state of trance (Proceedings S.P.R.). These writings appear to exhibit remarkable telepathic powers, and are thought by some to indicate communication with the spirits of the dead.
The opportunities afforded by automatic writing for communicating with subconscious strata of the personality have been made use of by Pierre Janet and others in cases of hystero-epilepsy, and other forms of dissociation of consciousness. A patient in an attack of hysterical convulsions, to whom oral appeals are made in vain, can sometimes be induced to answer in writing questions addressed to the hand, and thus to reveal the secret of the malady or to accept therapeutic suggestions.”