The theories or hypotheses which have been put forward regarding the method by which this telepathic influence or impact is conveyed may be noted as follows: -

(1) That of a vibratory medium, always present and analogous to the atmosphere for propagating sound or the universal ether for propagating light.

(2) An effluence of some sort emanating from the persons concerned and acting as a medium for the time being.

(3) A sixth sense.

(4) A duplex personality or subliminal self. First, then, as regards the vibratory hypothesis; it would demand a variety of media to convey separately something corresponding to the sense of sight, the sense of hearing, and to each of the other senses - touch, taste, and smell - as all these sensations have been telepathically transmitted, or else there must exist one single medium capable of transmitting these many widely different methods of sensation separately, - either of which suppositions are, to say the least, bewildering.

Such a medium must also possess a power of penetrating or acting through intervening obstacles, such as no medium with which we are acquainted possesses; and, lastly, in addition to numerous apparently insurmountable difficulties and insufficiencies, there is no proof whatever that any such vibratory medium exists.

Second. Regarding a vital effluence or some physical emanation or aura belonging to each individual, and by means of which communication is possible between persons separated by too great a distance to permit communication through the ordinary channels; it is at least conceivable that such an aura or personal atmosphere exists, and by some it is claimed to be demonstrated; but admitting its existence, that it would be capable of fulfilling the numerous functions demanded of it in the premises is doubtful.

Third. That the telepathic intercommunication is accomplished by means of a sixth sense - a sort of compend of all the other senses, with added powers as regards distance and intervening obstacles - is a hypothesis which has been urged by some, and is at least intelligible; but, while it presents an intelligible explanation of such facts as clairvoyance and the hearing of voices, there is a large class of facts, as we shall see, which utterly refuse to fall into line or be explained by this hypothesis.

Fourth. The hypothesis of different strata of personality - or of a second or subliminal self - is the one which best fulfils the necessary conditions and also harmonizes the greatest number of facts when arranged with reference to this idea. There is also real, substantial evidence that such a second personality actually exists, some of the facts bearing upon this subject having been presented in former chapters.

Those of my readers who have carefully followed the cases of unusual mental action there presented - cases of thought-transference, of clairvoyance, of remarkable mind-action in the hypnotic trance and in natural somnambulism - in well marked examples of double consciousness as shown in the cases of Felida X., of Alma Z., of Ansel Bourne, and the hypnotic subject, Madame B., in her various personalities of Leonie, Léontine, and Léonore, in automatic action as displayed in Planchette-writ-ing, in trance-speaking and in crystal-gazing, cannot have failed to observe, throughout the whole series, mind acting rationally and intelligently, quite independently of the ordinary consciousness, and even at times independently of the whole physical organization. We have considered the evidence which points to the fact, or at least to the theory of a subliminal self, or another personality, in some manner bound up in that complicated physical and mental mechanism which constitutes what we term an individual. We have seen that there are weighty proofs that such a secondary or subliminal, or, if you choose so to designate it, supranormal self, actually exists, and that it exhibits functions and powers far exceeding the functions and powers of the ordinary self. We have seen it expressing its own personal opinions, its own likes and dislikes, quite different and opposite to the opinions, likes, and dislikes of the ordinary self; having its own separate series of remembered actions or chain of memories, its own antecedent history, and its separate present interests; and especially performing actions altogether beyond the powers of the ordinary self. We have seen it going out to great distances, seeing and describing scenes and events there taking place - for example, Swedenborg at Gottenburg witnessing the conflagration at Stockholm; Dr. Gerault's clairvoyant maid-servant, Marie, in France, seeing the sad death of her neighbor's son, Limoges, the ropemaker, while serving in the Crimea; and also the serious illness of Dr. Gerault's military friend in Algiers. Fitzgerald, at Brunswick, Me., seeing and describing the Fall River fire three hundred miles away, and Mrs. Porter, at Bridgeport, Conn., describing the burning of the steamer Henry Clay while it was occurring on the I fudson River near the village of Yonkers. We have seen this same subliminal self in the case of Mr. Stead, going out and acquiring desired knowledge relating to the location, occupation, and needs of persons from whom he desired such information, and bringing it back and reporting it by means of automatic writing. Again, we have seen this subliminal self in the case of Mrs. Newn-ham, perceiving the silently written and sometimes even the unwritten questions of her husband, and automatically writing the answers by means of Planchette; and we have seen it producing hallucinations of hearing as in the case of Léonore causing Léontine to hear a voice reproving her for her flippancy.

A remarkable series of facts are here pointed out, facts some of which are akin to those which have for ages been lying about in the lumber rooms of history or in out-of-the-way corners of men's memories, neglected and discredited, because unexplained, unaccounted for, forming no part of any recognized system of mental action, and some only recently observed and even now looked at askance for the same reason. They have remained a mass of undigested and un-arranged facts, without system, without any ascertained relation to each other, pointing to no definite principle, defined by no definite law. It is only within the past decade that these facts have been studied with reference to the action of a subliminal self.

But this new and startling idea being once admitted and brought to the front, it is found that not only in the whole series of observed automatic actions in the somnambulism of the hypnotic state, and that of ordinary sleep, are the organs of the unconscious body made use of by this subconscious or subliminal self, but also in dreams, in reverie, in moments of abstraction, of strong emotion or mental excitement, and even in the case of some peculiarly susceptible persons in the ordinary waking condition, this subliminal self can greatly influence and sometimes take entire control of the action of the body.

It will be seen then, how wide and important is the range of phenomena in which the subliminal self appears as an active agent, impressing its own special knowledge, however acquired, its ideas, pictures, and images upon the primary self, and causing them to be perceived, remembered, and expressed by it; and with this unusual power in view, evidently it is in this direction also that we must look for the key to that still more remarkable series of phenomena which are known as phantasms or apparitions.