The "Three Essays on the Theory of Sexuality," along with "The Interpretation of Dreams," lay the foundation for psychoanalysis, representing Freud's most significant contribution to human knowledge and, in a way, the intellectual hallmark of the 20th century.

Freudian psychoanalysis, which initially served as a therapeutic method for mental illness, subsequently broadens into a general theory of the unconscious, a methodological tool for interpreting human relationships, an ideology, and a worldview. It is the discovery of a new epistemological continent.

[Excerpt from the text on the back cover of the edition]