under him, who increased in number as time went on. A crowd of learned men, bishops, saints, and martyrs, came out of this school. The envy and hatred of the heathens were so incited by it, that they often surrounded the house with soldiers, seized upon students, and led them away to execution. The renown of the school was so great in the middle of the third century, that Anatolius, a pupil of it, was sought by the heathen themselves to succeed Aristoteles in the headship of the Alexandrian university. Another school of the like kind was set up by Origen at Cæsarea in Palestine, and became famous. Rome also possessed a learned school, founded by Justin, concerning which, however, we know very little.[174] Edessa and Antioch possessed the like. It is apparent how important such schools must have been for the formation of a learned clergy. The more the Christian Church increased, and spread to all ranks of society, the more need there became for learning in its defenders. But great as was the renown won by these schools, and important as were the services rendered by them to the Christian Church in the advance of learning, in building up that progress from faith to knowledge—that growth of knowledge founded upon faith which marks the whole ante-nicene period—nevertheless the development of the sacred science was connected not so much with a regular course of teaching in the schools as with the vehement struggle for life which the Church was then waging on the one hand against Judaism and heathendom, on the other hand against the great heresies which successively attacked all the main truths of religion and the chief mysteries of Christianity.[175] Also, it must ever be remembered that the gift of infallible teaching, derived from the assistance of the Holy Spirit, is lodged, not in science, even not in theological science, but in the magisterium of the Church.[176] The most accomplished defence during all this period of the Church against the attacks of heathenism is, by common consent, allotted to the work of Origen in reply to Celsus. There is also a like consent that the same author's work upon Principles is the first attempt at systematic theology; but with all its ability, learning, and acuteness, it is not free from great errors. The one is a pure success, the other shows that the contact with Platonic philosophy had led the author in certain points astray. Again, all his genius and all his zeal did not save Tertullian from falling into Montanism, nor from discharging upon the chief ruler of the Church the sarcasm which he had so often employed against its enemies. In inquiring closely into the belief of some of those whose conversion from heathenism I have above instanced, an illustrious writer says: "It must be considered that the authors whom I have above cited whatever be the authority of some of them, cannot be said to speak _ex cathedra_, even if they had the right to do so, and do not speak as a Council may speak.