Biographies can be such intrusive things. Say an individual manages, through talent, work and luck, to make something good, something worth remembering. Now, that’s a difficult, desirable achievement but the is the world satisfied with it? No. When something wonderful is created, some Nosy Parker of a biographer will follow behind, trying to uncover the life and soul of the creator. On the other hand, a good biography, like Judy Oppenheimer’s Private Demons, can answer questions and provide context to that person’s accomplishments. The subject here is Shirley Jackson and Ms. Oppenheimer’s tale illuminates a few corners of this complicated, compelling, and private writer. To enjoy Shirley Jackson’s work you must be comfortable with complexity. In the middle of the twentieth century, she became an acclaimed writer in two genres that seemed mutually exclusive. The best known samples of her work are psychologically disturbing stories of alienation and evil. However, she also published popular stories of domestic recounted in a well-humored, dry and ironic voice. In a culture that likes to pigeon-hole the work of its creative artists, Shirley defied easy categorization to the consternation of some of her fans. Could the same person write stories in turn that made…