In view of the great number of ideas which analysis furnishes for each individual element of the dream content, the chief doubt with many readers will be whether it is permissible to count everything that subsequently comes to mind during analysis as a part of the dream thoughts—to assume, in other words, that all these thoughts have been active in the sleeping state and have taken part in the formation of the dream. Is it not more probable that thought connections are developed in the course of analysis which did not participate in the formation of the dream? I can meet this doubt only conditionally. It is true, of course, that particular thought connections first arise only during analysis; but one may always be sure that such new connections have been established only between thoughts which have already been connected in the dream thoughts by other means; the new connections are, so to speak, corollaries, short circuits, which are made possible by the existence of other more fundamental means of connection. It must be admitted that the huge number of trains of thought revealed by analysis have already been active in the formation of the dream, for if a chain of thoughts has been worked out, which seems to be without connection with the formation of the dream, a thought is suddenly encountered which, being represented in the dream, is indispensable to its interpretation—which nevertheless is inaccessible except through that chain of thoughts. The reader may here turn to the dream of the botanical monograph, which is obviously the result of an astonishing condensation activity, even though I have not given the analysis of it completely. But how, then, is the psychic condition during sleep which precedes dreaming to be imagined? Do all the dream thoughts exist side by side, or do they occur one after another, or are many simultaneous trains of thought constructed from different centres, which meet later on? I am of the opinion that it is not yet necessary to form a plastic conception of the psychic condition of dream formation. Only let us not forget that we are concerned with unconscious thought, and that the process may easily be a different one from that which we perceive in ourselves in intentional contemplation accompanied by consciousness. The fact, however, that dream formation is based on a process of condensation, stands indubitable. How, then, is this condensation brought about?