Scherner connects no useful function with the activity of the symbolising phantasy in dreams. In the dream the psyche plays with the stimuli at its disposal. One might presume that it plays in an improper manner. One might also ask us whether our thorough study of Scherner’s dream theory, the arbitrariness and deviation of which from the rules of all investigation are only too obvious, can lead to any useful results. It would then be proper for us to forestall the rejection of Scherner’s theory without examination by saying that this would be too arrogant. This theory is built up on the impression received from his dreams by a man who paid great attention to them, and who would appear to be personally very well fitted to trace obscure psychic occurrences. Furthermore it treats a subject which, for thousands of years, has appeared mysterious to humanity though rich in its contents and relations; and for the elucidation of which stern science, as it confesses itself, has contributed nothing beyond attempting, in entire opposition to popular sentiment, to deny the substance and significance of the object. Finally, let us frankly admit that apparently we cannot avoid the phantastical in our attempts to elucidate the dream. There are also phantastic ganglia cells; the passage cited on p. 63 from a sober and exact investigator like Binz,[4] which depicts how the aurora of awakening flows along the dormant cell masses of the cerebrum, is not inferior in fancifulness and in improbability to Scherner’s attempts at interpretation. I hope to be able to demonstrate that there is something actual underlying the latter, though it has only been indistinctly observed and does not possess the character of universality entitling it to the claim of a dream theory. For the present, Scherner’s theory of the dream, in its contrast to the medical theory, may perhaps lead us to realise between what extremes the explanation of dream life is still unsteadily vacillating. (_h_) _Relations between the Dream and Mental Diseases._—When we speak of the relation of the dream to mental disturbances, we may think of three different things: (1) Etiological and clinical relations, as when a dream represents or initiates a psychotic condition, or when it leaves such a condition behind it. (2) Changes to which the dream life is subjected in mental diseases. (3) Inner relations between the dream and the psychoses, analogies indicating an intimate relationship. These manifold relations between the two series of phenomena have been a favourite theme of medical authors in the earlier periods of medical science—and again in recent times—as we learn from the literature on the subject gathered from Spitta,[64] Radestock,[54] Maury,[48] and Tissié.[68] Sante de Sanctis has lately directed his attention to this relationship. For the purposes of our discussion it will suffice merely to glance at this important subject.