have lost for the waking life the stimulus of actuality. Hence in the analysis of the dream life we are reminded at every step that it is inadmissible to frame general rules without making provision for qualifications expressed by such terms as "frequently," "as a rule," "in most cases," and without preparing for the validity of the exceptions.
If the conscious interest, together with the inner and outer sleep stimuli, sufficed to cover the etiology of the dreams, we ought to be in a position to give a satisfactory account of the origin of all the elements of a dream; the riddle of the dream sources would thus be solved, leaving only the task of separating the part played by the psychic and the somatic dream stimuli in individual dreams. But as a matter of fact no such complete solution of a dream has ever been accomplished in any case, and, what is more, every one attempting such solution has found that in most cases there have remained a great many components of the dream, the source of which he was unable to explain. The daily interest as a psychic source of dreams is evidently not far-reaching enough to justify the confident assertions to the effect that we all continue our waking affairs in the dream.
Other psychic sources of dreams are unknown. Hence, with the exception perhaps of the explanation of dreams given by Scherner,58 which will be referred to later, all explanations found in the literature show a large gap when we come to the derivation of the material for the presentation pictures, which is most characteristic for the dream. In this dilemma the majority of authors have developed a tendency to depreciate as much as possible the psychic factor in the excitations of dreams which is so difficult to approach. To be sure, they distinguish as a main division of dreams the nerve-exciting and the association dreams, and assert that the latter has its source exclusively in reproduction (Wundt,76 p. 365), but they cannot yet dismiss the doubt whether "they do not appear without being impelled by the psychical stimulus" (Volkelt,72 p. 127). The characteristic quality of the pure association dream is also found wanting. To quote Volkelt (p. 118): "In the association dreams proper we can no longer speak of such a firm nucleus. Here the loose grouping penetrates also into the centre of the dream. The ideation which is already set free from reason and intellect is here no longer held together by the more important psychical and mental stimuli, but is left to its own aimless shifting and complete confusion." Wundt, too, attempts to depreciate the psychic factor in the stimulation of dreams by declaring that the "phantasms of the dream certainly are unjustly regarded as pure hallucinations, and that probably most dream presentations are really illusions, inasmuch as they emanate from slight sensory impressions which are never extinguished during sleep" (p. 338, &c.). Weygandt75 agrees with this view, but generalises it. He asserts that "the first source of all dream presentations is a sensory stimulus to which reproductive associations are then joined" (p. 17). Tissié68 goes still further in repressing the psychic exciting sources (p. 183): "Les rêves d'origine absolument psychique n'existent pas"; and elsewhere (p. 6), "Les pensées de nos rêves nous viennent de dehors..."
Those authors who, like the influential philosopher Wundt, adopt a middle course do not fail to remark that in most dreams there is a co-operation of the somatic stimuli with the psychic instigators of the dream, the latter being either unknown or recognised as day interests.
We shall learn later that the riddle of the dream formation can be solved by the disclosure of an unsuspected psychic source of excitement. For the present we shall not be surprised at the over-estimation of those stimuli for the formation of the dream which do not originate from psychic life. It is not merely because they alone can easily be found and even confirmed by experiment, but the somatic conception of the origin of dreams thoroughly corresponds to the mode of thinking in vogue nowadays in psychiatry. Indeed, the mastery of the brain over the organism is particularly emphasized; but everything that might prove an independence of the psychic life from the demonstrable organic changes, or a spontaneity in its manifestations, is alarming to the psychiatrist nowadays, as if an acknowledgment of the same were bound to bring back the times of natural philosophy and the metaphysical conception of the psychic essence. The distrust of the psychiatrist has placed the psyche under a guardian, so to speak, and now demands that none of its feelings shall divulge any of its own faculties; but this attitude shows slight confidence in the stability of the causal concatenation which extends between the material and the psychic. Even where on investigation the psychic can be recognised as the primary course of a phenomenon, a more profound penetration will some day succeed in finding a continuation of the path to the organic determination of the psychic. But where the psychic must be taken as the terminus for our present knowledge, it should not be denied on that account.
(d) Why the Dream is Forgotten after Awakening.—That the dream "fades away" in the morning is proverbial. To be sure, it is capable of recollection. For we know the dream only by recalling it after awakening; but very often we believe that we remember it only incompletely, and that during the night there was more of it; we can observe how the memory of a dream which has been still vivid in the morning vanishes in the course of the day, leaving only a few small fragments; we often know that we have been dreaming, but we do not know what; and we are so well used to the fact that the dream is liable to be forgotten that we do not reject as absurd the possibility that one may have been dreaming even when one knows nothing in the morning of either the contents or the fact of dreaming. On the other hand, it happens that dreams manifest an extraordinary retentiveness in the memory. I have had occasion to analyse with my patients dreams which had occurred to them twenty-five years or more previously, and I can remember a dream of my own which is separated from the present day by at least thirty-seven years, and yet has lost nothing of its freshness in my memory. All this is very remarkable, and for the present incomprehensible.
The forgetting of dreams is treated in the most detailed manner by Strümpell.66 This forgetting is evidently a complex phenomenon; for Strümpell does not explain it by a single reason, but by a considerable number of reasons.
In the first place, all those factors which produce forgetfulness in the waking state are also determinant for the forgetting of dreams. When awake we are wont soon to forget a large number of sensations and perceptions because they are too feeble, and because they are connected with a slight amount of emotional feeling. This is also the case with many dream pictures; they are forgotten because they are too weak, while stronger pictures in proximity will be remembered. Moreover, the factor of intensity in itself is not the only determinant for the preservation of the dream pictures; Strümpell, as well as other authors (Calkins), admits that dream pictures are often rapidly forgotten, although they are known to have been vivid, whereas among those that are retained in memory there are many that are very shadowy and hazy. Besides, in the waking state one is wont to forget easily what happened only once, and to note more easily things of repeated occurrence. But most dream pictures are single experiences,7 and this peculiarity equally contributes towards the forgetting of all dreams. Of greater significance is a third motive for forgetting. In order that feelings, presentations, thoughts and the like, should attain a certain degree of memory, it is important that they should not remain isolated, but that they should enter into connections and associations of a suitable kind. If the words of a short verse are taken and mixed together, it will be very difficult to remember them. "When well arranged in suitable sequence one word will help another, and the whole remains as sense easily and firmly in the memory for a long time. Contradictions we usually retain with just as much difficulty and rarity as things confused and disarranged." Now dreams in most cases lack sense and order. Dream compositions are by their very nature incapable of being remembered, and they are forgotten because they usually crumble together the very next moment. To be sure, these conclusions are not in full accord with the observation of Radestock54 (p. 168), that we retain best just those dreams which are most peculiar.
According to Strümpell, there are still other factors effective in the forgetting of dreams which are derived from the relation of the dream to the waking state. The forgetfulness of the waking consciousness for dreams is evidently only the counterpart of the fact already mentioned, that the dream (almost) never takes over successive memories from the waking state, but only certain details of these memories which it tears away from the habitual psychic connections in which they are recalled while we are awake. The dream composition, therefore, has no place in the company of psychic successions which fill the mind. It lacks all the aids of memory." In this manner the dream structure