Just as great authors need great stories, the seminal theorists of psychoanalysis needed great patients to elucidate their theories. Breuer had "Agnes O," Freud had "Dora," and for Carl Jung, unquestionably the patient of his life was Sabina Spielrein (pronounced Shpeel-rine), the first patient upon which he applied the Freudian method.  Jung would go on to use Spielrein's  symptoms and treatment as the foundation for many of his lectures, books and essays, and her case was a regular topic for discussion in his lengthy correspondence with his mentor Sigmund Freud.  After her treatment, when she became Jung's lover and a brilliant psychoanalytical theorist in her own right, Spielrein was intellectually and personally present in the lives of Jung and Freud during and after the years of their friendship.

Bruno Bettelheim has said that if Spielrein had remained in Europe, she would have been among "the greatest pioneers of psychoanalysis," but during her lifetime she and her ideas were treated condescendingly by Freud and Jung—they both referred to her in letters as "the little girl"—and largely rejected within the psychoanalytic community.  Aside from a footnote in Freud's Beyond the Pleasure Principle, where he credits her idea of the destructive component of the sexual instinct, Spielrein's name was largely forgotten by history until a cache of her diaries and correspondence were found in Geneva in 1977 in the former headquarters of the Institute of Psychology, followed by a second discovery in 1982 in the family archives of Genevan psychologist Edouard Claparède.