The belief that a text is, or ought to be, a unity often plays a crucial role in literary interpretation and evaluation; but critics of classical literature do not seem sufficiently alert to the possibility that their criteria may be different from those which underlay the composition and reception of literary texts in the ancient world. The aim of this book is to reconstruct ancient Greek assumptions about literary unity. It discusses some literary examples, but its main concern is with ancient secondary texts - literary theory and criticism - undertaking a systematic survey from Plato and Aristotle down to the later Neoplatonists. There is also a brief review of the post-classical history of the concept of literary unity.