"Sex and Character: Principles of Research" is an outstanding work of the Austrian philosopher Otto Weininger, which influenced the development of the Viennese school of psychoanalysis. The author analyzes the connection between gender and character, considers the psychology of gender and the difference between men and women through the prism of philosophy, psychology and society. The book contains insightful reflections on how gender and identity interact and influence each other, provoking debate and reflection on the nature of gender and identity. "Gender and character" is a fundamental study that leaves the reader with many new thoughts and views on the world.