第2章 The Scientific Literature of Dream-Problems（up to 1900）

In the following pages, I shall demonstrate that there is a psychological technique which makes it possible to interpret dreams, and that on the application of this technique, every dream will reveal itself as a psychological structure, full of significance, and one which may be assigned to a specific place in the psychic activities of the waking state. Further, I shall endeavour to elucidate the processes which underlie the strangeness and obscurity of dreams, and to deduce from these processes the nature of the psychic forces whose conflict or co-operation is responsible for our dreams.This done, my investigation will terminate, as it will have reached the point where the problem of the dream merges into more comprehensive problems, and to solve these, we must have recourse to material of a different kind.

I shall begin by giving a short account of the views of earlier writers on this subject and of the status of the dream-problem in contemporary science；since in the course of this treatise, I shall not often have occasion to refer to either. In spite of thousands of years of endeavour, little progress has been made in the scientific understanding of dreams.This fact has been so universally acknowledged by previous writers on the subject that it seems hardly necessary to quote individual opinions.The reader will find, in many stimulating observations, and plenty ofinteresting material relating to our subject, but little or nothing that concerns the true nature of the dream, or that solves definitely any of its enigmas.The educated layman, of course, knows even less of the matter.

The conception of the dream that was held in prehistoric ages by primitive peoples, and the influence which it may have exerted on the formation of their conceptions of the universe, and of the soul, is a theme of such great interest that it is only with reluctance that I refrain from dealing with it in these pages. I will refer the reader to the well-known works of Sir John Lubbock（Lord Avebury），Herbert Spencer, E.B.Tylor and other writers；I will only add that we shall not realise the importance of these problems and speculations until we have completed the task of dream interpretation that lies before us.

A reminiscence of the concept of the dream that was held in primitive times seems to underlie the evaluation of the dream which was current among the peoples of classical antiquity. [1]They took it for granted that dreams were related to the world of the supernatural beings in whom they believed, and that they brought inspirations from the gods and demons. Moreover, it appeared to them that dreams must serve a special purpose in respect of the dreamer；that, as a rule, they predicted the future.The extraordinary variations in the content of dreams, and in the impressions which they produced on the dreamer, made it, of course, very difficult to formulate a coherent conception of them, and necessitated manifold differentiations and group-formations, according to their value and reliability.The valuation of dreams by the individual philosophers of antiquity naturally depended on the importance which they were prepared to attribute to manticism in general.

In the two works of Aristotle in which there is mention of dreams, they are already regarded as constituting a problem of psychology. We are told that the dream is not god-sent, that it is not of divine but of daimonic origin.For nature is really daimonic, not divine；that is to say, the dream is not a supernatural revelation, but is subject to the laws of the human spirit, which has, of course, a kinship with the divine.The dream is defined as the psychic activity of the sleeper, inasmuch as he is asleep.Aristotle was acquainted with some of the characteristics of the dream-life；for example, he knew that a dream converts the slight sensations perceived in sleep into intense sensations（one imagines that one is walking through fire, and feels hot, if this or that part of the body becomes only quite slightly warm'），which led him to conclude that dreams might easily betray to the physician the first indications of an incipient physical change which escaped observation during the day. [2]

As has been said, those writers of antiquity who preceded Aristotle did not regard the dream as a product of the dreaming psyche, but as an inspiration of divine origin, and in ancient times, the two opposing tendencies which we shall find throughout the ages in respect of the evaluation of the dream-life, were already perceptible. The ancients distinguished between the true and valuable dreams which were sent to the dreamer as warnings, or to foretell future events, and the vain, fraudulent and empty dreams, whose object was to misguide him or lead him to destruction.

The pre-scientific conception of the dream which obtained among the ancients was, of course, in perfect keeping with their general conception of the universe, which was accustomed to project as an external reality that which possessed reality only in the life of the psyche. Further, it accounted for the main impression made upon the waking life by the morning memory of the dream；for in this memory the dream, as compared with the rest of the psychic content, seems to be something alien, coming, as it were, from another world.It would be an error to suppose that the theory of the supernatural origin of dreams lacks followers even in our own times；for quite apart from pietistic and mystical writers——who cling, as they are perfectly justified in doing, to the remnants of the once predominant realm of the supernatural until these remnants have been swept away by scientific explanation——we not infrequently find that quite intelligent persons, who in other respects are averse to anything of a romantic nature, go so far as to base their religious belief in the existence and co-operation of superhuman spiritual powers on the inexplicable nature of the phenomena of dreams（Haffner）.The validity ascribed to the dream life by certain schools of philosophy——for example, by the school of Schelling——is a distinct reminiscence of the undisputed belief in the divinity of dreams which prevailed in antiquity；and for some thinkers, the mantic or prophetic power of dreams is still a subject of debate.This is due to the fact that the explanations attempted by psychology are too inadequate to cope with the accumulated material, however strongly the scientific thinker may feel that such superstitious doctrines should be repudiated.

To write a history of our scientific knowledge of the dream problem is extremely difficult, because, valuable though this knowledge may be in certain respects, no real progress in a definite direction is as yet discernible. No real foundation of verified results has hitherto been established on which future investigators might continue to build.Every new author approaches the same problems afresh, and from the very beginning.If I were to enumerate such authors in chronological order, giving a survey of the opinions which each has held concerning the problems of the dream, I should be quite unable to draw a clear and complete picture of the present state of our knowledge on the subject.I have therefore preferred to base my method of treatment on themes rather than on authors, and in attempting the solutionof each problem of the dream, I shall cite the material found in the literature of the subject.

But as I have not succeeded in mastering the whole of this literature——for it is widely dispersed and interwoven with the literature of other subjects——I must ask my readers to rest content with my survey as it stands, provided that no fundamental fact or important point of view has been overlooked.

In a supplement to a later German edition, the author adds：

I shall have to justify myself for not extending my summary of the literature of dream problems to cover the period between first appearance of this book and the publication of the second edition. This justification may not seem very satisfactory to the reader；none the less, to me it was decisive.The motives which induced me to summarise the treatment of dreams in the literature of the subject have been exhausted by the foregoing introduction；to have continued this would have cost me a great deal of effort and would not have been particularly useful or instructive.For the interval in question——a period of nine years——has yielded nothing new or valuable as regards the conception of dreams, either in actual material or in novel points of view.In most of the literature which has appeared since the publication of my own work, the latter has not been mentioned or discussed；it has, of course, received the least attention from the so-calledresearch workers on dreams'，who have thus afforded a brilliant example of the aversion to learning anything new so characteristic of the scientist.Les savants ne sont pas curieux'，said the scoffer, Anatole France.If there were such a thing in science as the right of revenge, I，in my turn, should be justified in ignoring the literature which has appeared since the publication of this book.The few reviews which have appeared in the scientific journals are so full of misconceptions and lack of comprehension that my only possible answer to my critics would be a request that they should read this book over again——or perhaps merely that they should read it！

And in a supplement to the fourth German edition which appeared in 1914，a year after I published the first English translation of this work, he writes：

Since then, the state of affairs has certainly undergone a change；my contribution to theinterpretation of dreams'is no longer ignored in the literature of the subject. But the new situation makes it even more impossible to continue the foregoing summary.The Interpretation of Dreams has evoked a whole series of new contentions and problems，which have been expounded by the authors in the most varied fashions.But I cannot discuss these works until I have developed the theories to which their authors have referred.Whatever has appeared to me as valuable in this recent literature, I have accordingly reviewed in the course of the following exposition.