Das Ich und das Es (The Ego and the Id), published in 1923, represents Freud's most comprehensive and definitive statement of his structural theory of the psyche, fundamentally revising his earlier topographical model of consciousness and unconsciousness. Written during a period when Freud was battling both cancer and the increasing complexity of psychoanalytic theory, this work introduced the now-famous tripartite model of the psyche: the id (das Es), ego (das Ich), and superego (das Über-Ich). This new framework allowed Freud to better account for the role of aggression, the complexity of moral development, and the various internal conflicts that shape human behavior. The work emerged partly in response to clinical observations that challenged his earlier theories, demonstrating Freud's willingness to revise his fundamental concepts based on therapeutic experience. The book's reception marked a significant turning point in psychoanalytic theory, effectively establishing the vocabulary and conceptual framework that would dominate psychoanalytic thinking for decades to come. While some of Freud's contemporaries struggled with the complexity of the new model, it quickly became central to psychoanalytic practice and theory. The work's influence extended far beyond clinical practice, profoundly impacting fields such as psychology, philosophy, and cultural criticism. Its concepts became deeply embedded in popular culture, with terms like "ego" and "id" entering common usage, though often in ways that departed from Freud's original meanings. The timing of its publication, coming late in Freud's career, meant that this model represented his final major theoretical innovation, serving as a kind of capstone to his life's work in understanding the structure and dynamics of the human psyche. This edition includes an introduction by the translator on the philosophic differences between Carl Jung and Sigmund Freud, a glossary of Freudian Psychological terminology and a timeline of Freud’s life & works. This fresh, modern translation from the original German manuscript breathes new life into this historically important work. Freud's massive body of work has historically been inaccessible to the lay philosopher, and this edition seeks to provide greater, direct access to his original works. This new Reader's Edition introduces Freud's original work in context, with an illuminating Afterword explaining his philosophic project, nesting it in the historical milieu he wrote within (in this case, Modernism), and his impact on the contemporary world. This Afterword focuses on the relationship and debate between Carl Jung and Sigmund Freud, a conflict which has great relevance to the debates of modern culture. This is accompanied by a timeline of his life and works, an index of philosophic terminology and background (especially on his greatest influence- Schopenhauer), and a short biography.