and working on the same soil two twin schools, the heathen and the Christian. The history of the one is interwoven with that of the other. They existed side by side, opposed and yet indebted to each other in doctrine and teaching. In such circumstances it was clear that a new era must open for Christianity. Hitherto Christian writers had written only in the interests of practical religion. They had been eminently uncritical, and no system of theology had been elaborated. Now, however, the Alexandrian