FURTHER PRELIMINARY EXPLANATION I must assume it known that messages purporting to come from various deceased people have been received through various mediums, and that the Society for Psychical Research has especially studied those coming through Mrs. Piper--a resident in the neighbourhood of Boston, U.S.A.--during the past thirty years. We were introduced to her by Professor William James. My own experience with this lady began during her visit to this country in 1889, and was renewed in 1906. The account has been fully published in the _Proceedings_ of the Society for Psychical Research, vols. vi. and xxiii., and an abbreviated version of some of the incidents there recorded can be referred to in my book _The Survival of Man_. It will be convenient, however, to explain here that some of the communicators on the other side, like Mr. Myers and Dr. Richard Hodgson, both now deceased, have appeared to utilise many mediums; and that to allow for possible sophistication by normal mental idiosyncrasies, and for any natural warping due to the physiological mechanism employed, or to the brain-deposit from which selection has to be made, we write the name of the ostensible communicator in each case with a suffix--like Myers_{P}, Myers_{V}, etc.; meaning by this kind of designation to signify that part of the Myers-like intelligence which operates through Mrs. Piper or through Mrs. Verrall, etc., respectively. We know that communication must be hampered, and its form largely determined, by the unconscious but inevitable influence of a transmitting mechanism, whether that be of a merely mechanical or of a physiological character. Every artist knows that he must adapt the expression of his thought to his material, and that what is possible with one 'medium,' even in the artist's sense of the word, is not possible with another. And when the method of communication is purely mental or telepathic, we are assured that the communicator 'on the other side' has to select from and utilise those ideas and channels which represent the customary mental scope of the medium; though by practised skill and ingenuity they can be woven into fresh patterns and be made to convey to a patient and discriminating interpreter the real intention of the communicator's thought. In many such telepathic communications the physical form which the emergent message takes is that of automatic or semiconscious writing or speech; the manner of the utterance being fairly normal, but the substance of it appearing not to emanate from the writer's or speaker's own mind: though but very seldom is either the subject-matter or the language of a kind quite beyond the writer's or speaker's normal capabilities.