A writer's diary can be a vehicle for self-examination, a record of reflection on the craft, a place for drafts and experiments, or itself a literary performance. The subjectivity of literature since the eighteenth century has made diaries both a key to the writer's private world and a substantive part of the work itself, in modern times virtually an independent genre. André Gide's Journal was designed to be just that, and he revised it for publication during his lifetime. Franz Kafka's diaries are a mixture of aperçus, sketches for works, and explorations (or doubts) of his calling to be a writer. Virginia Woolf's diary closely observes the creative process and registers the ebb and flow of her confidence. In the case of Thomas Mann, however, it was only in the early days that his diary was a means to literature, consciously worked on and needed for self-expression (letters to Otto Grautoff, 19 March 1896, 4 April and 21 July 1897). Later it was literary at most in patches and in passing, and intended mainly to be a matter-of-fact record of his daily life, in the most basic sense a 'Tage-Buch'.