Nor, again, is there any analogy, and still less identity, between the process whereby we grasp a dream when we awake, and the process whereby the memory of a dream is transformed during months of waking life. The latter is part of a general process affecting all our memories in greater or less degree. I visit, for instance, a foreign cathedral, and take careful note of the character and arrangement of buttresses and piers; a few months later, if I have failed to set the facts down, my memory of them will become uncertain, confused, and incorrect. But I need not, therefore, lose faith in the tolerable exactitude of my original impressions. In the same way, we cannot argue that the shifting memory of a dream during a long period of time throws the slightest doubt on the accuracy of our original impression of it. We never catch a dream in course of formation. As it presents itself to consciousness on awakening there may be doubtful points and there may be missing links, but the dream is, once for all, completed, and if there are doubtful points or missing links we recognise them as such. We make no attempt to supply a logic that is not there, and we never see any such process going on involuntarily. I should, indeed, myself be inclined to say that there is always a kind of gap between sleeping consciousness and waking consciousness; the change from the one to the other kind of consciousness seems to be effected by a slight shock, and the perception of the already completed dream is the first effort of waking consciousness. The existence of such a shock is indicated by the fact that, even at the first moment of waking consciousness, we never realise that a moment ago we were asleep. As soon as we realise that we are awake it seems to us that we have already been awake for an uncertain but distinct period of time; some people, indeed, especially old people, on awaking, feel this so strongly that they deny they have been asleep. It once happened to me to be in the neighbourhood of a dynamite factory at the moment when a very disastrous explosion occurred; at the time my back was to the factory, and I am quite unable to say how long an interval occurred between the shock of the explosion and my own action in turning round to observe the straight shaft of smoke and solid material high in the air; there was a gap in consciousness, an interval of unknown and seemingly considerable length, caused by the deafening shock of the explosion, although it is probable that my action in turning round was almost or quite instantaneous. It seems to me that the transition from sleeping consciousness to waking consciousness occurs in a similar manner on a smaller scale.
Although the view of Foucault that the dream is logically organised after sleep has ended seems, when we examine the evidence in its favour, to be unacceptable, we may still admit that, in some cases at all events, the dream only assumes final shape at the moment when sleeping consciousness is breaking up, that the dream, as we know it, is a final synthetic attempt of sleeping consciousness as it dissolves on the approach of waking consciousness. Sleeping consciousness, we may even imagine as saying to itself in effect: 'Here comes our master, Waking Consciousness, who attaches such mighty importance to reason and logic and so forth. Quick! gather things up, put them in order—any order will do—before he enters to take possession.' That is to say, in other words, that as sleeping consciousness comes nearer to the threshold of waking consciousness it is possible that the need for the same kind of causation or sequence which is manifested in waking consciousness may begin to make itself felt even to sleeping consciousness. Even this assumption seems, however, as regards most dreams, to be extravagant. In any case, and at whatever stage the dream is finally constituted, we are not entitled, it seems to me, to believe that any stage of its constitution falls outside the frontiers of sleep. It is satisfactory to be able to feel justified in reaching this conclusion. For if dreams were chiefly or mainly the product of waking consciousness they would certainly lose a considerable part of their significance and interest.
Even, however, when we have reached this conclusion the path of the student is still far from easy. The undoubted fact that in any case the difficulties of observing and recording dreams are very great cannot fail to make us extremely careful. Although the dreams of some persons, who may be regarded as themselves of vivid and dramatic temperament, seem to be habitually vivid and dramatic to an extent which, in my own case, is extremely rare, one is usually justified in feeling a certain amount of suspicion in regard to dream-narratives which are at every point clear, coherent, connected, and intelligible. Dreams, as I know them on awaking from sleep, occasionally present episodes to which these epithets may be applied, but on the whole they are full of obscurities, of uncertainties, of inexplicable lacunae. The memory of dream events is lost so rapidly that one is constantly obliged to leave the exact nature of a detail in doubt. One seems to be recalling a landscape seen by a lightning flash. It is for this reason that I have made it a rule only to admit dreams which are noted very shortly, and if possible immediately, after the moment of awakening. It is further of importance in recording one's dreams, to note the emotional attitude experienced during the dream as well as any physical sensations felt on awakening. The attitude of dream consciousness towards dream visions usually varies from that of waking consciousness, although the normal extent of the difference is a disputable point. When I read dream narratives of landscapes which, as described, appear at every point as beautiful and impressive to waking consciousness as they appeared to dreaming consciousness, I usually suspect that, granting the good faith and accuracy of the narrator, we are really concerned, not with dreams in the proper sense, but with visions experienced under more abnormal conditions, and especially with drug visions. In the present inquiry I am only concerned to ascertain the most elementary and fundamental laws of the dream world, as they occur in fairly ordinary and normal persons, and therefore it becomes necessary to be very strict as to the conditions under which they were recorded. It is the most ordinary dreams that are most likely to reveal the ordinary laws of dream life, but for this end it is necessary that they should be recorded with the greatest accuracy attainable.
I am myself neither a constant nor, usually, a very vivid dreamer, and in these respects I am probably a fairly ordinary and normal person; the personal material which I have accumulated, though it spreads over twenty years, is not notably copious. Nor have I ever directed my attention in any systematic and concentrated manner to my dream life. To do so would be, I believe, to distort the phenomena. I have merely recorded any significant phenomena as they occurred.
To remark that one is not a constant dreamer is not to assert that dreaming is rare, but merely that one's recollection of it is rare. Though we may only catch a glimpse of our latest vision of the night as we leave the house of sleep, it may well be that there were many earlier adventures of the night which are beyond the reach of waking consciousness. Sometimes, it is curious to note, we become vaguely conscious, during the day, for the first time, of a dream we have had during the night. Many psychologists, as well as metaphysicians—fearful to admit that the activity of the soul could ever cease—believe that we dream during the whole period of sleep; this has of recent years been the opinion of Vaschide, Foucault, Näcke, and Sir Arthur Mitchell, as it formerly was of Sir Benjamin Brodie, Sir Henry Holland, and Schaaffhausen. In earlier days Hippocrates, Descartes, Leibnitz, and Cabanis seem to have been of the same opinion. On the other hand, Locke, Macnish, and Carpenter held that deep sleep is dreamless; this is also the opinion of Wundt, Beaunis, Strümpell, Weygandt, Hammond, and Jastrow. Moreover, there are some people, like Lessing, who, so far as they know, never dream at all. My own personal experience scarcely inclines me to accept without qualification the belief that we are always dreaming during sleep. I find that my remembered dreams tend to be correlated with some slight mental or physical disturbance, and therefore it seems to me probable that, if dreams are continuous during sleep, they must, during completely undisturbed sleep, be of an extremely faint and shadowy character. To return to a metaphor I have before used, we may say that sleeping consciousness in its descent from the surface of the waking life may fall to a point at which its specific gravity being practically the same as that of its environment, a state approaching complete repose is attained.[8] It cannot of course be said that the failure to remember dreams is any argument against their occurrence. It is well known that when the psychic activity of sleep assumes a definitely motor shape, as in talking in sleep and in somnambulism, it is very rare for any recollection to remain on awakening, though we cannot doubt that psychic activity has been present. In the same way the dream that we remember when awakened from sound sleep by another person is by no means always due to that awakening. This is shown by the fact that if we were turning round or making other movements just before being thus awakened, the dream we remember—in one such case a dream of making one's way with difficulty between a sofa and a chair—may have no relation to the circumstance of the awakening, but clearly be suggested by the movements made during sleep, though these movements themselves remain unknown to waking consciousness. The movements of dogs during sound sleep—the rhythmical lifting of the paws, the wagging of the tail—point in the same direction.[9]
The fact that failure of memory by no means proves the absence of dreaming may be illustrated, not only by the forgetfulness of what takes place during hypnotic sleep, but by what we sometimes witness during partial anaesthesia maintained by drugs. This was well shown in a case I was once concerned with, where it was necessary to administer chloroform (preceded by the alcohol-chloroform-ether mixture) for a prolonged period during a difficult first confinement. The drug was not given to the point of causing complete abolition of mental activity, and the patient talked, and occasionally sang, throughout, referring to various events in her life, from childhood onwards. The sensation and the expression of pain were not altogether abolished, for slight cries and remarks about the discomfort and constraint imposed upon her were sometimes mingled in the same sentence with quite irrelevant remarks concerning, for instance, trivial details of housekeeping. Confusions of incompatible ideas also took place, as during ordinary dreaming. 'Where is the three-cornered nurse,' she thus asked, 'who does not mind what she does?' There was also the abnormal suggestibility of dream consciousness. The questions of bystanders were answered but always with a tendency to agree with everything that was said, this tendency even displaying itself with a certain ingenuity as when in reply to the playful random query: 'Were you drunk or sleeping last night?' she answered, with some hesitation: 'A little of both, I think.' To the casual observer, it might seem that there was a state of full consciousness on the basis of which a partial delirium had established itself. Yet on recovery from the drug there was no recollection of anything whatever that had taken place during its administration, and no sense of the lapse of time.
Fantastic and marvellous as our dreams may sometimes be, they are in practically all cases made up of very simple elements. It is desirable that we should at the outset have a provisional notion as to the sources of these simple elements. Most writers on dreams hold that there are two great sources from which these elements are drawn: the vast reservoir of memories and the actual physical sensations experienced at the moment of dreaming, and interpreted by sleeping consciousness. Various names have been given to these two groups, the recognition of which is at least as old as Aristotle.[10] Thus Sully calls them central and peripheral, Tissié, psychic and sensorial, Foucault, imaginative and perceptive. Fairly convenient names are those adopted by Miss Calkins, who calls the first group representative, the second group presentative, meaning by representative 'connected through the fact of association with the waking life of the past,' and by presentative 'connected through sense excitation with the immediate present.'[11]
The representative group falls into two subdivisions, according as the memories are of old or of recent date; these subdivisions are often quite distinct, recent dream memories belonging—probably with most people—to the previous day, while old dream memories are usually drawn from the experience of many years past, and frequently from early life. In the same way presentative impressions fall into two subdivisions, according as they refer to external stimuli present to the senses, or to internal disturbances within the organism. It is scarcely necessary to observe that any or all of these four sub-groups, into which the whole of our dream life may be analysed, may become woven together in the same dream.
I have called the classification 'provisional' because, though it is convenient to adopt it for the sake of orderly arrangement, when we come to consider the matter it will be found that the material of dreams is in reality all of the same order, and purely psychic, though it may be differentiated in accordance with the character of the stimulus which evokes the psychic material of which it is made. Strictly speaking, the source of the dream as a dream can only be central, and a truly presentative dream is impossible. If our senses receive an impression, external or internal, and we recognise and accept that impression for what we should recognise and accept it when awake, then we cannot be said to be dreaming. The internal and external stimuli which act upon sleeping consciousness are not a part of that consciousness, nor in any real sense its source or its cause. The ray of sunlight that falls on the dreamer, the falling off of his bedclothes, the indigestible supper he ate last night—these things can no more 'account' for his dream than the postman's knock can account for the contents of the letter he delivers. Whatever the stimuli from the physical world that may knock at the door of dreaming consciousness, that consciousness is apart from them, and stimuli can only reach it by undergoing transformation. They must put off the character which they wear as phenomena of the waking world; they must put on the character of phenomena of another world, the world of dreams.