From my attempts synthetically to construct dreams from the dream thoughts, I know that the material which is obtained from interpretation varies in value. For a part of it consists of the essential dream thoughts which would, therefore, completely replace the dream, and which would in themselves be sufficient for this replacement if there were no censor for the dream. The other part may be summed up under the term "collaterals"; taken as a whole they represent the means by which the real wish that arises from the dream thoughts is transformed into the dream-wish. A first part of these "collaterals" consists of allusions to the actual dream thoughts, which, considered schematically, correspond to displacements from the essential to the non-essential. A second part comprises the thoughts which connect these non-essential elements, that have become significant through displacement with one another, and which reach from them into the dream content. Finally a third part contains the ideas and thought connections which (in the work of interpretation) conduct us from the dream content to the intermediary collaterals, all of which need not necessarily have participated in the formation of the dream.
At this point we are interested exclusively in the essential dream thoughts. These are usually found to be a complex of thoughts and memories of the most intricate possible construction, and to possess all the properties of the thought processes which are known to us from waking life. Not infrequently they are trains of thought which proceed from more than one centre, but which do not lack points of connection; almost regularly a chain of thought stands next to its contradictory correlative, being connected with it by contrast associations.
The individual parts of this complicated structure naturally stand in the most manifold logical relations to one another. They constitute a foreground or background, digressions, illustrations, conditions, chains of argument, and objections. When the whole mass of these dream thoughts is subjected to the pressure of the dream activity, during which the parts are turned about, broken up, and pushed together, something like drifting ice, there arises the question, what becomes of the logical ties which until now had given form to the struc-
