No support is given by what we know of this group to the theory which regards subliminal mentation as necessarily a sign of some morbid dissociation of physical elements. Is there, on the other hand, anything to confirm a suggestion which will occur in some similar cases, namely, that,—inasmuch as the addition of subliminal to supraliminal mentation may often be a completion and integration rather than a fractionation or disintegration of the total individuality,—we are likely sometimes to find traces of a more than common activity of the right or less used cerebral hemisphere? Finding no mention of ambidexterity in the meagre notices which have come down to us of the greater "prodigies," I begged the late Mr. Bidder, Q.C., and Mr. Blyth, of Edinburgh (the well-known civil engineer and perhaps the best living English representative of what we may call the calculating diathesis), to tell me whether their left hands possessed more than usual power. And I find that in these—the only two cases in which I have been able to make inquiry—there is somewhat more of dextro-cerebral capacity than in the mass of mankind.
We may now pass on to review some further instances of subliminal co-operation with conscious thought;—first looking about us for any cases comparable in definiteness with the preceding; and then extending our view over the wider and vaguer realm of creative and artistic work.
But before we proceed to the highly-specialised senses of hearing and sight, we must note the fact that there are cases of subliminal intensification of those perceptions of a less specialised kind which underlie our more elaborate modes of cognising the world around us. The sense of the efflux of time, and the sense of weight, or of muscular resistance, are amongst the profoundest elements in our organic being. And the sense of time is indicated in several ways as a largely subliminal faculty. There is much evidence to show that it is often more exact in men sleeping than in men awake, and in men hypnotised than in men sleeping. The records of spontaneous somnambulism are full of predictions made by the subject as to his own case, and accomplished, presumably by self-suggestion, but without help from clocks, at the precise minute foretold. Or this hidden knowledge may take shape in the imagery of dream, as in a case published by Professor Royce, of Harvard,[30] where his correspondent describes "a dream in which I saw an enormous flaming clock-dial with the hands standing at 2.20. Awaking immediately, I struck a match, and upon looking at my watch found it was a few seconds past 2.20."
Similarly we find cases where the uprush of subliminal faculty is concerned with the deep organic sensation of muscular resistance. We need not postulate any direct or supernormal knowledge,—but merely a subliminal calculation, such as we see in the case of "arithmetical prodigies," expressing itself supraliminally, sometimes in a phantasmal picture, sometimes as a mere "conviction," without sensory clothing.[31]
Passing on here to subliminal products of visual type, I am glad to be able to quote the following passage which seems to me to give in germ the very theory for which I am now contending on the authority of one of the most lucid thinkers of the last generation.
The passage occurs in an article by Sir John Herschel on "Sensorial Vision," in his Familiar Lectures on Scientific Subjects, 1816. Sir John describes some experiences of his own, "which consist in the involuntary production of visual impressions, into which geometrical regularity of form enters as the leading character, and that, under circumstances which altogether preclude any explanation drawn from a possible regularity of structure in the retina or the optic nerve."[32] Twice these patterns appeared in waking daylight hours,—with no illness or discomfort at the time or afterwards. More frequently they appeared in darkness; but still while Sir John was fully awake. They appeared also twice when he was placed under chloroform; "and I should observe that I never lost my consciousness of being awake and in full possession of my mind, though quite insensible to what was going on.... Now the question at once presents itself—What are these Geometrical Spectres? and how, and in what department of the bodily or mental economy do they originate? They are evidently not dreams. The mind is not dormant, but active and conscious of the direction of its thoughts; while these things obtrude themselves on notice, and by calling attention to them, direct the train of thought into a channel it would not have taken of itself.... If it be true that the conception of a regular geometrical pattern implies the exercise of thought and intelligence, it would almost seem that in such cases as those above adduced we have evidence of a thought, an intelligence, working within our own organisation distinct from that of our own personality." And Sir John further suggests that these complex figures, entering the mind in this apparently arbitrary fashion, throw light upon "the suggestive principle" to which "we must look for much that is determinant and decisive of our volition when carried into action." "It strikes me as not by any means devoid of interest to contemplate cases where, in a matter so entirely abstract, so completely devoid of any moral or emotional bearing, as the production of a geometrical figure, we, as it were, seize upon that principle in the very act, and in the performance of its office."
From my point of view, of course, I can but admire the acumen which enabled this great thinker to pierce to the root of the matter by the aid of so few observations. He does not seem to have perceived the connection between these "schematic phantasms," to borrow a phrase from Professor Ladd,[33] and the hallucinatory figures of men or animals seen in health or in disease. But even from his scanty data his inference seems to me irresistible;—"we have evidence of a thought, an intelligence, working within our own organisation, distinct from that of our own personality." I shall venture to claim him as the first originator of the theory to which the far fuller evidence now accessible had independently led myself.
Cases observed as definitely as those just quoted are few in number; and I must pass on into a much trodden—even a confusedly trampled—field;—the records, namely, left by eminent men as to the element of subconscious mentation, which was involved in their best work. Most of these stories have been again and again repeated;—and they have been collected on a large scale in a celebrated work,—to me especially distasteful, as containing what seems to me the loose and extravagant parody of important truth. It is not my business here to criticise Dr. Von Hartmann's Philosophy of the Unconscious in detail; but I prefer to direct my readers' attention to a much more modest volume, in which a young physician has put together the results of a direct inquiry addressed to some Frenchmen of distinction as to their methods especially of imaginative work.[34] I quote a few of the replies addressed to him, beginning with some words from M. Sully Prudhomme,—at once psychologist and poet,—who is here speaking of the subconscious clarification of a chain of abstract reasoning. "I have sometimes suddenly understood a geometrical demonstration made to me a year previously without having in any way directed thereto my attention or will. It seemed that the mere spontaneous ripening of the conceptions which the lectures had implanted in my brain had brought about within me this novel grasp of the proof."
With this we may compare a statement of Arago's—"Instead of obstinately endeavouring to understand a proposition at once, I would admit its truth provisionally;—and next day I would be astonished at understanding thoroughly that which seemed all dark before."
Condillac similarly speaks of finding an incomplete piece of work finished next day in his head.