Σαν σήμερα γεννήθηκε ο Sigmund Freud, ο πρώτος που θεώρησε το όνειρο γέννημα του ασυνειδήτου:
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A boat has no business to be on the roof of a house, and a headless man cannot run. Moreover, the man is bigger than the house; and if the whole picture is intended to represent a landscape, letters of the alphabet are out of the place in it since such objects do not occur in nature. But obviously we can only form a proper judgement of the rebus if we put aside criticisms such as these of the whole composition and its parts, and if, instead, we try to replace each separate element by a syllable or word that can be represented by that element in some way or other. The words which are put together in this way are no longer nonsensical but may form a poetical phrase of the greatest beauty and significance. A dream is a picture-puzzle of this sort and our predecessors in the field of dream-interpretation have made the mistake of treating the rebus as a pictorial composition: and as such it has seemed to them nonsensical and worthless.

The dream work, from the Interpretation of Dreams