The Greek Series of the Corpus Christianorum is meant to replace Jacques-Paul Migne's Patrologia Graeca (161 volumes, Paris, 1857-1866). The PG will of course continue to be of use to generations of scholars and still represents a summa of almost five centuries of research on the Greek Christian literature. It is clear, however, that this compilation does not fulfil any longer the requirements of today's scholarship. Anyone who intends to thoroughly study the thought of any ancient or medieval author must nowadays base their research on a scholarly edition. The Corpus Christianorum, Series Graeca been set up with the aim of filling PG's gaps and replacing its insufficient editions.