Many people are aware--and, indeed, have themselves tried the experiment--that mind can influence mind without the intervention of matter, such as the organs of speech and hearing operating in a sound-conveying atmosphere. A common phenomenon is the mental impression of a person being present who has approached without being seen or heard. A somewhat less frequent, but still sufficiently familiar, instance of the same order of things is to be found in the fact that persons who are looked at intently (even behind their backs) often become uneasy and turn to meet the gaze. So, also, it is found that cases occur of persons suddenly, and without any apparent cause, finding themselves thinking earnestly of certain other persons and learning subsequently that those other persons were at, or a little before, the time of the impression thinking of the persons impressed. Facts such as these--which are positive and undisputed--have led to experimental tests, conducted scientifically, for the purpose of determining whether it is possible, at will, to establish intelligent communications between transmitters and percipients who are at a distance from each other; and the name “telepathy” has been given to the kind of intercourse in question. The work has been conducted chiefly by the Society for Psychical Research, whose Reports on the subject have become classics. Telepathy is recognised in so far as it is a grouping of observed facts; but it has not hitherto advanced beyond the status of a “working hypothesis,” which, however, still awaits precise formulation. Thus, Sir Oliver Lodge, F.R.S., in his “Raymond,” first published in November, 1916, says-- “The fact of telepathy proves that bodily organs are not absolutely essential to communication of ideas. Mind turns out to be able to act directly on mind, and stimulate it into response by other than material means. Thought does not belong to the material region, although it is able to exert an influence on that region through mechanism provided by vitality. Yet the means whereby it accomplishes the feat are essentially unknown, and the fact that such interaction is possible would be strange and surprising if we were not too much accustomed to it. It is reasonable to suppose that the mind can be more at home, and more directly and more exuberantly active, when the need for such interaction between psychical and physical--or let us more safely and specifically say between mental and material--no longer exists, when the restraining influence of brain and nerve mechanism is removed, and when some of the limitations connected with bodily location in space are ended.