Furthermore, it is very extraordinary, particularly in view of circumstances to be mentioned later, that the most vehement opposition has been voiced against the existence of the symbolic relationship between the dream and the unconscious. Even persons of judgment and position, who have otherwise made great progress in psychoanalysis, have discontinued their support at this point. This is the more remarkable since, in the first place, symbolism is neither peculiar to the dream nor characteristic of it, and since in the second place, symbolism in the dream was not discovered through psychoanalysis, although the latter is not poor otherwise in making startling discoveries. The discoverer of dream symbolism, if we insist on a discovery in modern times, was the philosopher K. A. Scherner (1861). Psychoanalysis affirmed Scherner's discovery and modified it considerably. Now you will want to know something of the nature of dream symbolism, and to hear some examples. I shall gladly impart to you what I know, but I admit that our knowledge is not so complete as we could desire it to be. The nature of the symbol relationship is a comparison, but not any desired comparison. One suspects a special prerequisite for this comparison, but is unable to say what it is. Not everything to which we are able to compare an object or an occurrence occurs in the dream as its symbol; on the other hand, the dream does not symbolize anything we may choose, but only specific elements of the dream thought. There are limitations on both sides. It must be admitted that the idea of the symbol cannot be sharply delimited at all times--it mingles with the substitution, dramatization, etc., even approaches the allusion. In one series of symbols the basic comparison is apparent to the senses. On the other hand, there are other symbols which raise the question of where the similarity, the "something intermediate" of this suspected comparison is to be sought. We may discover it by more careful consideration, or it may remain hidden to us. Furthermore, it is extraordinary, if the symbol is a comparison, that this comparison is not revealed by the association, that the dreamer is not acquainted with the comparison, that he makes use of it without knowing of its existence. Indeed, the dreamer does not even care to admit the validity of this comparison when it is pointed out to him. So you see, a symbolic relationship is a comparison of a very special kind, the origin of which is not yet clearly understood by us. Perhaps later we may find references to this unknown factor.