This is one of the simplest forms of thought-transference; it is, of course, liable to many errors, and is useless as a scientific test.
Bishop, Cumberland, and other mind readers who have exhibited their remarkable powers all over the world, were doubtless sensitives who possessed this power of perception or receiving impressions in a high degree, so that minute objects, such as an ordinary watch-key, hidden in a barrel of rubbish in a cellar and in a distant part of an unfamiliar city, is quickly found, the sensitive being connected with the agent by the slightest contact, or perhaps only by a string or wire.
The question at issue in all these cases is the same, namely, do the sensitives receive their impressions regarding what they have to do from the mind of the agent by some process other than the ordinary means of communication, such as seeing, hearing, or touch; or do they, by the exceeding delicacy of their perception, receive impressions from slight indications unintentionally and unconsciously conveyed to them by the agent through the slight contact which is kept up between them?
The opinion of a majority of scientific persons has been altogether averse to the theory of thought-transference from one mind to another without the aid of the senses and the ordinary means of communication; and they have maintained that intimations of the thing to be done by the sensitive were conveyed by slight muscular movements unconsciously made by the agent and perhaps unconsciously received by the sensitive. To explain, or rather to formulate these cases, Dr. William B. Carpenter, the eminent English physiologist, proposed the theory of “unconscious muscular action” on the part of the agent and “unconscious cerebration” on the part of the sensitive; and his treatment of the whole subject in his “Mental Physiology,” which was published twenty years ago, and also in his book on “Mesmerism and Spiritualism,” was thought by many to be conclusive against the theory of mind-reading or thought-transference. Especially was this view entertained by the more conservative portion of the various scientific bodies interested in the subject, and also by that large class of people, scientific and otherwise, who save themselves much trouble by taking their opinions ready made.
It was a very easy way of disposing of the matter, so thoroughly scientific, and it did not involve the necessity of studying any new force or getting into trouble with any new laws of mental action; it was simply delightful, and the physiologists rubbed their hands gleefully over the apparent discomfiture of the shallow cranks who imagined they had discovered something new. There was only one troublesome circumstance about the whole affair. It was this: that cases were every now and then making their appearance which absolutely refused to be explained by the new theory of Dr. Carpenter, and the only way of disposing of these troublesome cases was to declare that the people who observed them did not know how to observe, and did not see what they thought they saw.
This was the state of the question, and this the way in which it was generally regarded, when it was taken up for investigation by the Society for Psychical Research.
Experiments on the subject of thought-transference fall naturally into four classes:
(1) Those where some prearranged action is accomplished, personal contact being maintained between the operator and the sensitive.
(2) Similar performances where there is no contact whatever.
(3) Where a name, number, object, or card is guessed or perceived and expressed by speech or writing without any perceptible means of obtaining intelligence by the senses or through any of the ordinary channels of communication.