«In the pages that follow I shall bring forward proof that there is a psychological technique which makes it possible to interpret dreams, and that, if that procedure is employed, every dream reveals itself as a psychical structure which has a meaning and which can be inserted at an assignable point in the mental activities of the waking life. I shall further endeavour to elucidate the processes to which the strangeness and obscurity of dreams are due and to deduce from those processes the nature of the psychical forces by whose concurrent or mutually opposing actions dreams are generated. »

Sigmund Freud, The Interpretation of Dreams