Endings are not just singular moments in time, but the outcomes of a process. And whatever a book's conclusion, its form has a history. Literary Conclusions presents a new theory of textual endings in eighteenth-century literature and thought. Analyzing essential works by Gotthold Ephraim Lessing, Johann Wolfgang von Goethe, and Heinrich von Kleist, Oliver Simons shows how the emergence of new kinds of literary endings around 1800 is inextricably linked to the history of philosophical and scientific concepts. Simons examines the interrelations of Lessing's literary endings with modes of logical conclusion; he highlights how Goethe's narrative closures are forestalled by an uncontrollable vital force that was discussed in the sciences of the time; and he reveals that Kleist conceived of literary genres themselves as forms of reasoning. Kleist's endings, Simons demonstrates, mark the beginning of modernism. Through close readings of these authors and supplemental analyses of works by Walter Benjamin, Friedrich Hölderlin, and Georg Wilhelm Friedrich Hegel, his study crafts an elegant theory of conclusions that revises established histories of literary genres and forms.