subliminal is now generally admitted. During the last quarter of the 19th and the opening years of the 20th century, there has been accumulated a mass of observations which suffices, in the opinion of many of those best qualified to judge, to establish the reality of processes which express themselves in purposeful actions and which bear all the marks from which we are accustomed to infer conscious cognition and volition, but of which nevertheless the subject or normal personality has no knowledge or awareness other than such as may be shared by any second person observing his actions.
Among the commonest and most striking of such manifestations is the automatic writing which a considerable proportion of normal persons are capable of producing. A person who has this power may sit absorbed in reading or, in conversation, while his hand produces written words or sentences, of which he knows nothing until he afterwards reads them. The matter so written varies in different cases from illegibly scrawled fragments of words and sentences to long, connected, sometimes eloquent, frequently more or less dramatic, disquisitions. In some cases the automatically writing hand can be induced to make intelligible replies to questions whispered or otherwise put to the subject in such a way as not to draw his attention from some other object or topic with which it seems to be fully occupied. In some cases the matter so written states facts previously known to the subject but which he is unable to recollect by any voluutary effort. And in rare cases the matter written seems to imply knowledge or capacities which the subject was not believed to possess either by himself or by his friends. Other actions, including connected speech, may be produced in a similar fashion, and in the last case the subject hears and understands the words uttered from his own mouth in the same way only as those from the mouth of another person. Table-tilting, planchette-writing, and the various similar modes of spelling out by the aid of a code intelligible replies to questions, which have long been current in spiritistic circles and which, by those who practise them, are often regarded as the operations of disembodied intelligences, seem to belong to the same class of process. In extreme cases the manifestations of such subconscious or (better) co-conscious operations are so frequent, exhibit so much continuity and express so clearly a train of thought, purpose and memory, that they compel us to infer an organized personality of which they are the expression; such are the cases of double or multiple consciousness or personality. Very similar manifestations of a co-consciousness may be produced in a considerable proportion of apparently normal persons by means of post-hypnotic suggestion; as when suggestions are made during hypnosis, which afterwards the subject carries out without being aware of the actions, or of the signals in response to which he acts, and without any awareness or remembrance of the nature of the suggestions made to him. The more sober-minded of the investigators of these phenomena have sought to display all such cases as instances of division of the normal personality, and as explicable by the principle of cerebral dissociation (see Hypnotism); the more adventurous, concentrating their attention on the more extreme instances, regard all such manifestations as instances of the possession and control (partial or complete) of the organism of one person by the spirit or soul of another, generally a deceased person. Myerss hypothesis of the subliminal self was a brilliant attempt to follow a middle way in the explanation of these strange cases, to reconcile the two kinds of explanation with one another, and at the same time to bring into line with these other alleged facts of perplexing character, especially veridical hallucinations (qv.), various types of communication at a distance (see Telepathy), and all the more striking instances of the operation of suggestion and of hypnosis, including the exaltation of the powers of the senses, of the memory and of control over the organic processes.
Meyers conceived the soul of man as capable of existing independently of the body in some super-terrestrial or extraterrene realm. He regaided our normal mental life as only a very partial exoression of the capacities of the soul, so much only as can manifest itself through the human brain. He regarded the brain as still at a comparatively early stage of ith evolution as an instrument through which the soul operates in the material world. So much of the life of the soul as fails to find expression in our conscious and organic life through its interactions with this very inadequate material mechanism remains beneath the threshold of consciousness and is said to constitute the subliminal self. The subliminal self as thus conceived would be better described as the subliminal part of the self, a part which surpasses the supraliminal or normal conscious self to an. indefinitely great degree as regards its range of psychical faculties. It was further conceived as being in touch with a realm of psychical forces from which it is able to draw supplies of energy which it infuses into the organism, normally in limited quantities, but, in exceptionally favorable circumstances, in great floods, which for the time being raise the mental operations and the powers of the mind over the body to an abnormally high level.
It is a leading feature of,this protean conception, that many of the abnormal mental manifestations that have commonly been regarded as symptoms of mental or nervous disease or degeneration are by its aid brought into line with mental processes that are by common consent of an unusually high type, the intuitions of genius, the outbursts of inspired poesy, the emotional fervour or the ecstasy that carries the martyr triumphantly through the severest trials, the enthusiasm that enables the human organism to carry through incredible labors. Myerss hypothesis thus boldly inverts the dominant view, which sees in all departures from the normal symptoms of weakness and degeneracy and which seeks to bring genius and ecstasy down to the level of madness and hysteria; the hypothesis of the subliminal self seeks to level up, rather than. to level down, and to display many of these departures from normal mental life as being of the same nature as the operations of genius, as being, in common with these, uprushes of the subliminal self, which temporarily acquires a more complete control of the organism and therefore achieves at such times a more complete expression of its powers. And these rare displays of subliminal capacities are held to foreshadow the further course of mental evolution, to afford us a glimpse of tha higher plane on which the mind of man may habitually and normally live, if further evolution of the nervous system shall render it a less inadequate medium for the exercise of the spiritual faculties and for the influx of the psychical energies which at present, owing to its imperfections, are for the most part latent or confined to the subliminal self.
This bold and far-reaching hypothesis has not up to the present time been accepted by any considerable number of professional psychologists, though its authors great literary power has secured for him a respectful hearing. The comparative indifference shown to it by the scientific and philosophical world must be ascribed to considerations of two kinds, In the first place, it is rightly felt that a very large proportion of the alleged facts which it is designed to explain are not yet supported by evidence of such a nature as warrants an unreserved acceptance of them. Secondly, even if further investigations of the type of those carried on by the Society for Psychical Research should prove Myerss belief in the reality of all or most of these facts to have been well-founded, there will remain difficulties arid weaknesses intrinsic to the hypothesis, which at present seem very serious. In addition to all the great difficulties that must attach to any conception of human personality as a spiritual entity capable of existing independently of the body, Myerss conception raises many difficulties peculiar to itself, the chief of which may be briefly indicated. First, the conception of the relation of the subliminal to the normal or supraliminal self is in Myerss presentation extremely vacillating and uncertain, and it is probably radically incapable of definition and consistency. Secondly, two alleged supernormal phenomena, to the establishment of which psychical research has been devoted most energetically and (in the view of many of the workers) with the greatest success, and which from every point of view are the most important and interesting, are supernormal communications