This second kind of displacement occurring in dream formation not only possesses great theoretical interest, but is also peculiarly well fitted to explain the semblance of phantastic absurdity in which the dream disguises itself. Displacement usually occurs in such a way that a colourless and abstract expression in the dream-thought is exchanged for one that is visual and concrete. The advantage, and consequently the purpose, of this substitution is obvious. Whatever is visual is _capable of representation_ in the dream, and can be wrought into situations where the abstract expression would confront dream representation with difficulties similar to those which would arise if a political editorial were to be represented in an illustrated journal. But not only the possibility of representation, but also the interests of condensation and of the censor, can be furthered by this change. If the abstractly expressed and unwieldy dream-thought is recast into figurative language, this new expression and the rest of the dream material are more easily furnished with those identities and cross references, which are essential to the dream activity and which it creates whenever they are not at hand, for the reason that in every language concrete terms, owing to their evolution, are more abundant in associations than conceptual ones. It may be imagined that in dream formation a good part of the intermediary activity, which tries to reduce the separate dream-thoughts to the tersest and simplest possible expression in the dream, takes place in the manner above described—that is to say, in providing suitable paraphrase for the individual thoughts. One thought whose expression has already been determined on other grounds will thus exert a separating and selective influence upon the means available for expressing the other, and perhaps it will do this constantly throughout, somewhat after the manner of the poet. If a poem in rhyme is to be composed, the second rhyming line is bound by two conditions; it must express the proper meaning, and it must express it in such a way as to secure the rhyme. The best poems are probably those in which the poet’s effort to find a rhyme is unconscious, and in which both thoughts have from the beginning exercised a mutual influence in the selection of their verbal expressions, which can then be made to rhyme by a means of slight remodification.