Probably most dream-representations are really illusions, inasmuch as they emanate from the slight sensory impressions which are never extinguished during sleep" (p. 359, et seq.). Weygandt has adopted this view, and generalizes upon it. He asserts that "the most immediate causes of all dream-representations are sensory stimuli to which reproductive associations then attach themselves" (p. 17). Tissie goes still further in suppressing the psychic sources of excitation (p. 183): "Les reves d'origine absolument psychique n'existent pas"; * and elsewhere (p. 6), "Les pensees de nos reves nous viennent de dehors...." *(2)

* Dreams do not exist whose origin is totally psychic.

*(2) The thoughts of our dreams come from outside.

Those writers who, like the eminent philosopher Wundt, adopt a middle course, do not hesitate to assert that in most dreams there is a cooperation of the somatic stimuli and psychic stimuli which are either unknown or are identified with the interests of the day.

We shall learn later that the problem of dream-formation may be solved by the disclosure of an entirely unsuspected psychic source of excitation. In the meanwhile we shall not be surprised at the over-estimation of the influence of those stimuli which do not originate in the psychic life. It is not merely because they alone may easily be found, and even confirmed by experiment, but because the somatic conception of the origin of dreams entirely corresponds with the mode of thought prevalent in modern psychiatry. Here, it is true, the mastery of the brain over the organism is most emphatically stressed; but everything that might show that the psychic life is independent of demonstrable organic changes, or spontaneous in its manifestations, is alarming to the contemporary psychiatrist, as though such an admission must mean a return to the old-world natural philosophy and the metaphysical conception of the nature of the soul. The distrust of the psychiatrist has placed the psyche under tutelage, so to speak; it requires that none of the impulses of the psyche shall reveal an autonomous power. Yet this attitude merely betrays a lack of confidence in the stability of the causal concatenation between the physical and the psychic. Even where on investigation the psychic may be recognized as the primary cause of a phenomenon, a more profound comprehension of the subject will one day succeed in following up the path that leads to the organic basis of the psychic. But where the psychic must, in the present state of our knowledge, be accepted as the terminus, it need not on that account be disavowed.

D. Why Dreams Are Forgotten After Waking

That a dream fades away in the morning is proverbial. It is, indeed, possible to recall it. For we know the dream, of course, only by recalling it after waking; but we very often believe that we remember it incompletely, that during the night there was more of it than we remember. We may observe how the memory of a dream which in the morning was still vivid fades in the course of the day, leaving only a few trifling remnants. We are often aware that we have been dreaming, but we do not know of what we have dreamed; and we are so well used to this fact- that the dream is liable to be forgotten- that we do not reject as absurd the possibility that we may have been dreaming even when, in the morning, we know nothing either of the content of the dream or of the fact that we have dreamed. On the other hand, it often happens that dreams manifest an extraordinary power of maintaining themselves in the memory. I have had occasion to analyse, with my patients, dreams which occurred to them twenty-five years or more previously, and I can remember a dream of my own which is divided 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 Strumpell. This forgetting is evidently a complex phenomenon; for Strumpell attributes it not to a single cause, but to quite a number of causes.

In the first place, all those factors which induce forgetfulness in the waking state determine also the forgetting of dreams. In the waking state we commonly very soon forget a great many sensations and perceptions because they are too slight to remember, and because they are charged with only a slight amount of emotional feeling. This is true also of many dream-images; they are forgotten because they