Sigmund Freud was an Austrian neurologist and the founder of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst. In his seminal work, 'The Interpretation of Dreams,' Freud proposed that human behavior is largely driven by unconscious desires and childhood experiences. He introduced concepts like the id, ego, and superego, as well as the 'Oedipus complex.' While many of his specific theories have been challenged or superseded in modern psychology, his emphasis on the importance of talk therapy and the existence of the unconscious mind fundamentally reshaped Western culture, literature, and art. Freud's work moved the study of the human mind from a branch of philosophy to a clinical discipline, sparking a revolution in mental health treatment.