* Freudian psychology: Sigmund Freud's theories about the unconscious mind had a profound influence on surrealism. Surrealists were fascinated by the irrational and illogical aspects of human psychology and sought to tap into these unconscious forces through their art.
* Dream imagery: Surrealists were inspired by the dream world, which they saw as a realm of pure imagination and creativity. They often incorporated dream imagery into their artworks, using techniques such as collage, photomontage, and automatic drawing to capture the irrational and dreamlike quality of the unconscious mind.
* The occult and spiritualism: Surrealists were interested in the occult, spiritualism, and other non-rational phenomena. They believed that these realms could provide access to a deeper understanding of the human mind and the universe.
* Literature: Surrealism was also influenced by literature, particularly the works of French poets such as Arthur Rimbaud and Stéphane Mallarmé. These poets explored the irrational and dreamlike aspects of human experience, which resonated with surrealist artists.