I am aware that it is reported by the pagans that Constantine, after slaying some of his nearest relations, and particularly after assenting to the murder of his own son Crispus, repented of his evil deeds, and inquired of Sopater, the philosopher, who was then master of the school of Plotinus, concerning the means of purification from guilt. The philosopher -- so the story goes -- replied that such moral defilement could admit of no purification. The emperor was grieved at this repulse, but happening to meet with some bishops who told him that he would be cleansed from sin, on repentance and on submitting to baptism, he was delighted with their representations, and admired their doctrines, and became a Christian, and led his subjects to the same faith. It appears to me that this story was the invention of persons who desired to vilify the Christian religion. Crispus, on whose account, it is said, Constantine required purification, did not die till the twentieth year of his father's reign; he held the second place in the empire and bore the name of Cæsar and many laws, framed with his sanction in favor of Christianity, are still extant. That this was the case can be proved by referring to the dates affixed to these laws, and to the lists of the legislators. It does not appear likely that Sopater had any intercourse with Constantine whose government was then centered in the regions near the ocean and the Rhine; for his dispute with Maxentius, the governor of Italy, had created so much dissension in the Roman dominions, that it was then no easy matter to dwell in Gaul, in Britain, or in the neighboring countries, in which it is universally admitted Constantine embraced the religion of the Christians, previous to his war with Maxentius, and prior to his return to Rome and Italy: and this is evidenced by the dates of the laws which he enacted in favor of religion. But even granting that Sopater chanced to meet the emperor, or that he had epistolary correspondence with him, it cannot be imagined the philosopher was ignorant that Hercules, the son of Alcmena, obtained purification at Athens by the celebration of the mysteries of Ceres after the murder of his children, and of Iphitus, his guest and friend. That the Greeks held that purification from guilt of this nature could be obtained, is obvious from the instance I have just alleged, and he is a false calumniator who represents that Sopater taught the contrary.
I cannot admit the possibility of the philosopher's having been ignorant of these facts; for he was at that period esteemed the most learned man in Greece.