Philosophy of the Unconscious of the scales, and his 'World-process' in the other. There are some who believe they weigh equally; for in each scale there is an evil word—and a good joke." Hartmann's work has been seen as preparing the way for Freud's later theory of the unconscious. Freud consulted "Philosophy of the Unconscious" while writing "The Interpretation of Dreams" (1899), in which he called Hartmann the firmest opponent of the theory that dreams are wish fulfillments. The philosopher Hans Vaihinger was influenced by "Philosophy of the Unconscious", relating in his "The Philosophy of 'As if'" (1911) how it led him to Schopenhauer.
The Dream - Introduction into the Psychology of Dreams fascinated by the putative meaning of their dreams and desired to discover their unconscious selves by means of interpreting them. In the following years, Silberer noticed that while the literature on the interpretation of dreams was increasing in amount and complexity, general information on basic elements of dreams was deficient. Therefore, he began to give public lectures on fundamental knowledge about dreams as well as his specific findings in this field in Vienna. After various listeners of one of such lectures had assured him that he had succeeded in providing an understandable introduction into the psychology of dreams, Silberer decided