When, in abstraction, in wrapt attention to a single idea, we are carried past the door at which we had intended to stop, or continue to read aloud, unobservantly of the sense of words, or otherwise betray that we are buried deep in one absorbing thought; it is not, in the first case, that our automaton has unwontedly borne us along, or in the second, that we are not permitting it to take a partial holiday, for it is our automaton that serves our commonest daily needs; but only that we have, in the first case, forgotten to arrest its movements in due time, and in the second, have not thought it worth while to do so; for when decrepitude overtakes us, and our automaton, sharing in the misfortune, toils wearily along, or requires intense purposiveness for special brain-accomplishment, ideation can no longer afford to give to it its former liberty, but dwells in concentration on a single action; unless, indeed, when that still lower grade is reached, when the automatic man is almost all that remains, and ideation but the fitful glow that may start to futile movement the once efficient mechanism of the human frame. By easy stages, receptivity and communicability, ever lowering in degree, in quantity, and in quality, may dwindle to a single point, and movement be but faint automatic habit; the former high being now occupying the opposite extreme from rapid thought-transmission and receipt, and bodily response to ideation, upon the basis of life's whole energised experience.
Max Dessoir remarks, in a passage shortly following the one already quoted at length:
"Closer investigation teaches further, that in dreams, states of intoxication, in somnambulistic and epileptic attacks, not only does a consciousness different from the normal consciousness rule, but that also between successive periods memory-links of greater or less stability are wont to form."
As to the greater or less closeness, as well as greater or less stability, of the memory-links to which Max Dessoir refers, there can be no dispute; but it is demonstrable that sleeping and waking consciousness of both kinds exactly correspond. The difference observable in waking and dream thought-evolution does not chiefly relate to modified consciousness, but to modified conscientiousness; the defect in both being the necessary consequence of temporary abeyance of normal co-ordination between the nerve-centres. Determinately directed thought, which is necessarily waking thought, proceeds upon the basis of memorabilia that are the cash in hand of the kind of currency that is temporarily available for logical transactions; while in sleep, conscious cerebration only partially controls its treasures, and often regretfully sees them squandered before its face. Determinately directed thought is necessarily derived from the will, unless one believes with Lord Kames, that thought preserves unbroken heredity; in which case the ego becomes only the witness through life of pure automatism—a position which is easily refuted. The will directs the thought upon the basis of cognate memorabilia, be the channels many or few, by means of semi-synchronous, rotative attention.
The great lapse of time during which the action of subconsciousness may remain unrevealed until, through unconscious cerebration, it reaches self-consciousness, through the medium of recognition of a particular event as of actual occurrence, and how, finally, this recognition, as true, of a particular event, may be restricted for a while to the condition of sleep, and after a long period of incubation at last rise to waking knowledge, is so admirably exemplified by an experience of my own that I here put it on record.
About five years ago I had a dream of a landscape, where there were rocky escarpments partially covered with trees, with a plain as foreground, upon which a carriage drew up to take me home after a day's topographical surveying. Both in dreaming and upon awaking I was vividly impressed with the idea that the place was one in which the topography remained to be finished by me. But when awake, I fruitlessly went over in memory all parts of the coast where I had ever executed topographical surveys, and where by any chance, at any time, I could have left unfinished anything that I was in duty bound to finish. Some time elapsed, and I had the same dream again. Coming at once to the conclusion that, if I should dream it a third time, I should be told (as I should be, if I mentioned it at the second to any indifferent person) that I had dreamed that I dreamed it, I at once described in detail to a member of my family the landscape, the rocks, the trees, the plain, and the coming of the carriage, and requested that all these be memorised. Some months again passed, and the dream in all its vividness recurred, and was repeated to the same person, agreeing as to its details with those introduced in the recital of the preceding ones.
I never had from the first a doubt that the dream had a foundation in some one concrete fact, but from the lapse of time without a solution of it being afforded, I was all but hopeless that its subject-matter would ever rise into the sphere of full waking knowledge. However, at moderate intervals I dreamt it again and again, each time simply saying to my confidant, "I have had that dream again," and at length, without any special effort directed to its solution, that which had heretofore eluded all efforts to explain, was presented solved.
The uncomfortableness of the dream, it is to be borne in mind, lay in the impression, although contradicted by memory, that I had neglected to finish some piece of topography which it was my duty to finish. Hence the direction of self-conscious thought towards its solution had always been wrong. There was no piece of work of any kind that I had ever neglected to finish. There was, however, a piece of topographical work, which, when I was about to finish it, I was prevented from completing by orders taking me away from the locality to another far distant. The whole tract originally intended to be executed in topography was of about one hundred square miles, a tract of much geological as well as topographical interest, over a portion of which I had been accompanied two or three times by Prof. James D. Dana, who was deeply interested in the execution of the topography, on account of his development from it of the minute geological characteristics of the region. At one boundary of the area mentioned there was a ridge and summit of some nine hundred feet in height, densely covered with a stunted growth of trees. How to get the contours of this ridge by some original plan I had been obliged in advance to settle in my mind, for on the ridge itself nothing could, on account of the dense growth, be seen for any great distance, and over it no roads passed. I had concluded to have simultaneous horizontal and vertical angles taken to staffs, from a line of foot-hills lying parallel with the ridge, when I was ordered to Florida to make there a survey. This was succeeded by surveys in other far-distant localities during successive years. Not, however, as it appears, until seven years after leaving the locality intimately described, did the first dream related to it take place, and not until rather more than two years thereafter did its repetitions cease with its solution. I said to my confidant when, about three years ago, that solution was reached, "I shall never have that dream again," and it has never since appeared; as why should it, the mystery with which the uncoördinated ego struggled being solved?
We can readily comprehend, from such an experience as this, how it has been possible, as we have learned from well authenticated cases, for a person to lead two somewhat independent thought-lives. What, however, is clearly shown by it is the possibility, for it has been proved, of subconscious record remaining for years dormant, proceeding at last through unconscious cerebration to reach conscious cerebration, but even then conscious cerebration only during sleep, until finally conscious cerebration of waking moments being reached, the judgment seat of co-ordinated faculties, the dream departs, no longer abusing the curtained sleeper, nor ghost-like rising to disturb his waking self-consciousness.