The Interpretation of Dreams is a book in which Freud introduces his theory of the unconscious with respect to dream interpretation, and also first discusses what would later become the theory of the Oedipus complex, and it is widely considered one of his most important works. Dreams, in Freud's view, are 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. Psychopathology of Everyday Life is a work based on Freud's researches into slips and parapraxes from 1897 onwards, one which became perhaps the best-known of all his writings. Sometimes called the Mistake Book, the work became one of the scientific classics of the 20th century. Through its stress on what Freud called "switch words" and "verbal bridges", it is considered important for psychopathology. Jokes and Their Relation to the Unconscious is a book on the psychoanalysis of jokes and humor. In this work, Freud described the psychological processes and techniques of jokes, which he likened as similar to the processes and techniques of dream-work and the Unconscious. Freud claims that our enjoyment of the joke indicates what is being repressed in more serious talk. Sigmund Freud (1856-1939) was an Austrian neurologist and the father of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst. In creating psychoanalysis, Freud developed therapeutic techniques such as the use of free association and discovered transference, establishing its central role in the analytic process.