The Interpretation of Dreams is a book by psychoanalyst Sigmund Freud. The first edition describes his work thus:

In the following pages, I shall demonstrate that there is a psychological technique which makes it possible to interpret dreams, and that on the application of this technique, every dream will reveal itself as a psychological structure, full of significance, and one which may be assigned to a specific place in the psychic activities of the waking state. Further, I shall endeavour to elucidate the processes which underlie the strangeness and obscurity of dreams, and to deduce from these processes the nature of the psychic forces whose conflict or co-operation is responsible for our dreams.

The book introduces Freud's theory of the unconscious with respect to dream interpretation. Dreams, in Freud's view, were all forms of "wish-fulfillment" — attempts by the unconscious to resolve a conflict of some sort, whether something recent or something from the recesses of the past (later in Beyond the Pleasure Principle, Freud would discuss dreams which did not appear to be wish-fulfillment). However, because the information in the unconscious is in an unruly and often disturbing form, a "censor" in the preconscious will not allow it to pass unaltered into the conscious. During dreams, the preconscious is more lax in this duty than in waking hours, but is still attentive: as such, the unconscious must distort and warp the meaning of its information to make it through the censorship. As such, images in dreams are often not what they appear to be, according to Freud, and need deeper interpretation if they are to inform on the structures of the unconscious.

Freud makes his argument by first reviewing previous scientific work on dream analysis, which he finds interesting but inadequate. He then describes a number of dreams which illustrate his theory. Many of his most important dreams are his own — his method is inaugurated with an analysis of his dream "Irma's injection" — but many also come from patient case studies. Much of Freud's sources for analysis are in literature, and the book is itself as much a self-conscious attempt at literary analysis as it is a psychological study. Freud here also first discusses what would later become the theory of the Oedipus complex.

text from Wikipedia