conscious material of dream-thoughts now results in the dream. The latter is thereby drawn down into the unconscious, as it were, or to speak more precisely, it is exposed to a treatment which usually takes place at the level of unconscious mental activity, and which is characteristic of this mental level. Only from the results of the “dream-work” have we thus far learned to know the qualities of this unconscious mental activity and its differentiation from the “foreconscious” which is capable of consciousness. _The Unconscious_ A novel and difficult theory that runs counter to our habitual modes of thinking can hardly gain in lucidity by a condensed exposition. I can therefore accomplish little more in this discussion than refer the reader to the detailed treatment of the unconscious in my _Interpretation of Dreams_, and also to Lipps’s work, which I consider most important. I am aware that he who is under the spell of a good old philosophical training, or stands aloof from a so-called philosophical system, will oppose the assumption of the “unconscious psychic processes” in Lipps’s sense and in mine and will desire to prove the impossibility of it preferably by means of definitions of the term psychic. But definitions are conventional and changeable. I have often found that persons who dispute the unconscious on the grounds of its absurdity or impossibility have not received their impressions from those sources from which I, at least, have found it necessary to draw, in order to become aware of its existence. These opponents had never witnessed the effect of a posthypnotic suggestion, and they were immensely surprised at the evidence I imparted to them gleaned from my analysis of unhypnotized neurotics. They had never gained the conception of the unconscious as something which one does not really know, while cogent proofs force one to supplement this idea by saying that one understands by the unconscious something capable of consciousness, something concerning which one has not thought and which is not in the field of vision of consciousness. Nor had they attempted to convince themselves of the existence of such unconscious thoughts in their own psychic life by means of an analysis of one of their own dreams, and when I attempted this with them, they could perceive their own mental occurrences only with astonishment and confusion. I have also gotten the impression that these are essentially affective resistances which stand in the way of the acceptation of the “unconscious,” and that they are based on the fact that no one is desirous of becoming acquainted with his unconscious, and it is most convenient to deny altogether its possibility. _Condensation and Displacement in the Dream-work_