Sigmund Freud (1856-1939) was an Austrian neurologist and the founder of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst, which is sometimes known as "talk therapy." Freud was born in Freiberg, Moravia (now Pribor, Czech Republic), and grew up in Vienna, Austria. He studied medicine at the University of Vienna, where he was particularly interested in the work of Ernst Brücke, a physiologist who emphasized the importance of the nervous system.

After graduating in 1881, Freud worked at the Vienna General Hospital and later opened a private practice specializing in nervous disorders. He developed his theory of the unconscious mind, which he believed contained repressed thoughts and memories that influenced behavior. He also emphasized the importance of early childhood experiences in shaping adult personality and behavior.

In 1899, Freud published his landmark work, The Interpretation of Dreams, which introduced the concept of the Oedipus complex and described his theory of dream interpretation. He later developed his theories on human sexuality, including the concepts of the id, ego, and superego and the psychosexual stages of development.

Freud's work was controversial and often criticized, but it had a profound impact on psychology and popular culture.