[a.d. 205-240-265.] Alexandria continues to be the head of Christian learning. It is delightful to trace the hand of God from generation to generation, as from father to son, interposing for the perpetuity of the faith. We have already observed the continuity of the great Alexandrian school: how it arose, and how Pantænus begat Clement, and Clement begat Origen. So Origen begat Gregory, and so the Lord has provided for the spiritual generation of the Church's teachers, age after age, from the beginning. Truly, the Lord gave to Origen a holy seed, better than natural sons and daughters, as if, for his comfort, Isaiah had written, forbidding him to say, "I am a dry tree.