Salvador Dalí's reputation as one of the 20th century's most important and influential artists rests on the paintings he produced from about 1929 to 1939 as a leading member of the Surrealist movement. Inspired by the theories of Sigmund Freud (1856-1939) and the new science of psychoanalysis, Surrealist artists and writers believed that true reality can be understood only through knowledge of the unconscious.

One of Dalí's most powerful Surrealist paintings, The Dream gives visual form to the strange, often disturbing world of dreams and hallucinations. The central figure has ants clustered over its face where a mouth should be, and has sealed bulging eyelids, suggesting the sensory confusion and frustrations of a dream. The man at the far left-with a bleeding face and amputated left foot-may refer to the classical myth of Oedipus, who unwittingly killed his father and married his mother. Freud interpreted this ancient tale as symbolic of a child's conflicting feelings toward his parents (the "Oedipus complex"). A column grows from the man's back, then sprouts into the bust of a bearded man, perhaps a reference to the Freudian father, the punishing super-ego who condemns the son's sexual fantasies about his mother. In the distance, two men embrace, one holding a golden key or scepter, which may symbolize access to the unconscious. Behind them, a naked man reaches into a permeable red form, as if trying to enter it.

This painting was particularly significant to Dalí. He insisted that it represent his work at the First International Surrealist Exhibition, organized in London in 1936.