The Book of Disquiet (Livro do Desassossego: Composto por Bernardo Soares, ajudante de guarda-livros na cidade de Lisboa), published posthumously, is a work by Fernando Pessoa (1888–1935), signed under the semi-heteronym Bernardo Soares. With a preface by Fernando Pessoa, orthonym, the book is a fragmentary lifetime project, left unedited by the author, who introduced it as a "factless autobiography".