The purpose of this study is to find out how and why the `poetics of fiction' arose, its sources, and the materials from which it was created. A series of cultural choices made in archaic and classical Greece produced a clash between the traditional `poetics of truth', which derived poetry from divine inspiration and in the last analysis did not construe the poem as a work of art at all, and the new `poetics of fiction', which derived poetry from art. The eventual succession of the latter, culminating with the Poetics of Aristotle, amounted to an aesthetic revolution because, as a result of it, literary fiction, which since then has become a necessary framework for both the theory and practice of literature in Western tradition, was for the first time separated from non-fiction and given a status of its own.