The stream of thought is henceforth subjected to a series of transformations which we no longer recognize as normal psychic processes and which give us a surprising result, viz. a psychopathological formation. Let us emphasize and group the same.
1. The intensities of the individual ideas become capable of discharge in their entirety, and, proceeding from one conception to the other, they thus form single presentations endowed with marked intensity. Through the repeated recurrence of this process the intensity of an entire train of ideas may ultimately be gathered in a single presentation element. This is the principle of compression or condensation. It is condensation that is mainly responsible for the strange impression of the dream, for we know of nothing analogous to it in the normal psychic life accessible to consciousness. We find here, also, presentations which possess great psychic significance as junctions or as end-results of whole chains of thought; but this validity does not manifest itself in any character conspicuous enough for internal perception; hence, what has been presented in it does not become in any way more intensive. In the process of condensation the entire psychic connection becomes transformed into the intensity of the presentation content. It is the same as in a book where we space or print in heavy type any word upon which particular stress is laid for the understanding of the text. In speech the same word would be pronounced loudly and deliberately and with emphasis. The first comparison leads us at once to an example taken from the chapter on “The Dream-Work” (trimethylamine in the dream of Irma’s injection). Historians of art call our attention to the fact that the most ancient historical sculptures follow a similar principle in expressing the rank of the persons represented by the size of the statue. The king is made two or three times as large as his retinue or the vanquished enemy. A piece of art, however, from the Roman period makes use of more subtle means to accomplish the same purpose. The figure of the emperor is placed in the center in a firmly erect posture; special care is bestowed on the proper modelling of his figure; his enemies are seen cowering at his feet; but he is no longer represented a giant among dwarfs. However, the bowing of the subordinate to his superior in our own days is only an echo of that ancient principle of representation.
The direction taken by the condensations of the dream is prescribed on the one hand by the true foreconscious relations of the dream thoughts, an the other hand by the attraction of the visual reminiscences in the unconscious. The success of the condensation work produces those intensities which are required for penetration into the perception systems.