Relatively few works of ancient literature survive intact. Many more are known only as fragments or through the testimony of other authors. How should literary history acknowledge the fact and the consequences of such extensive loss? This chapter reviews the difficulties in identifying and presenting the evidence for lost works, explores what (besides their hypothetical reconstruction) can be learned from their remains, and considers how accommodation of the lost and the fragmentary challenges historians of literature to rethink the objectives and the methods of their enterprise.