Frankenstein is a novel written by English author Mary Shelley that tells the story of Victor Frankenstein, a young scientist who creates a grotesque but sapient creature in an unorthodox scientific experiment. Frankenstein is infused with elements of the Gothic novel and the Romantic movement. At the same time, it is an early example of science fiction. Brian Aldiss has argued that it should be considered the first true science fiction story because, in contrast to previous stories with fantastical elements resembling those of later science fiction, the central character "makes a deliberate decision" and "turns to modern experiments in the laboratory" to achieve fantastic results. It has had a considerable influence in literature and popular culture and spawned a complete genre of horror stories, films and plays. Since the novel's publication, the name "Frankenstein" has often been used to refer to the monster itself, as it is in the stage adaptation by Peggy Webling. This usage is sometimes considered erroneous, but usage commentators regard it as well-established and acceptable. In the novel, the monster is identified by words such as "creature", "monster", "demon", "wretch," "abortion," and "it". Speaking to Victor Frankenstein, the wretch refers to himself as "the Adam of your labours", and elsewhere as someone who "would have" been "your Adam", but is instead "your fallen angel" (which ties to Lucifer in Paradise Lost, which the monster reads, and relates to the "modern" Prometheus of the book's subtitle). Frankenstein is written in the form of a frame story that starts with Captain Robert Walton writing letters to his sister. It takes place at an unspecified time in the 18th century, as the letters' dates are given as "17".