The theory of psychoanalysis was founded by Sigmund Freud. He was an Austrian neurologist and the father of psychoanalysis, a clinical method for treating psychopathology through dialogue between a patient and a psychoanalyst. Freud's theories emphasized the unconscious mind, the influence of childhood experiences on adult behavior, and the importance of dream analysis. He introduced key concepts such as the id, ego, and superego, which describe the three parts of the human psyche. Freud's work has significantly impacted psychology, psychiatry, and various fields of the humanities, sparking debate and leading to the development of numerous therapeutic approaches based on his insights.