A major theme of Sybil is its status in the nonfiction genre, and Schreiber’s assertion that what she is presenting is fact. Sybil’s status as nonfiction is crucial to the initial conception of the book: Dr. Wilbur seeks out Flora because she believed it was not “sufficient[…]to present this history-making case in a medical journal, because in addition to great medical significance, the case had broad psychological and philosophical implications for the general public” (xiii).

From the beginning, Schreiber’s book must split the difference between two tasks: it hopes to reach a wide audience, to entertain, to serve as literature that speaks to philosophical subjects, while also being of a piece with a medical report. Correspondingly, in the Preface, Schreiber underlines Sybil’s facticity by emphasizing what she calls the “formal research” that had to be done for writing of the book:

The confidences I shared with Sybil and Dr. Wilbur and my direct contacts with the other selves had to be supplemented by a systematized approach to the case as a whole and to Sybil’s total life. I read widely in the medical literature about multiple personality, and I discussed the general aspects of the case with various psychiatrists in addition to Dr.