We must conclude that Callistus was able as well as persuasive, and we are not surprised to learn that, when Zephyrin died in 217 (or, according to another account, 218) he was chosen Bishop. It was customary, until long afterwards, to choose the bishop from the body of deacons, but Hippolytus and his friends were indignant at the election of the ex-slave, and a schism occurred. Hippolytus had the support of the minority of precisians and correct believers: Callistus was the favourite of the majority. Epithets of which the modern mind can hardly appreciate the gravity were hurled from camp to camp. "Patripassian," thundered Hippolytus; "Ditheist" retorted Callistus. It is quite clear that the scholar set up a rival See at Rome. He says that Callistus, when he was elected, "thought" that he had attained his ambition, and this must mean that he claimed himself to be the true Bishop of Rome. Later tradition, concealing the ugly schism, left the bishopric of Hippolytus in the air, or placed it at the Port of Rome, twenty miles away. But this picture of daily combats implies that both bishops were in Rome, and the little flock was rent and agitated by the first Papal schism. The dogmatic issue between the rivals cannot profitably be discussed here. The Church was then in an early phase of the great Trinitarian controversy, and, under Victor and Zephyrin, the Roman clergy had favoured the simpler, or unitarian, view. Sabellius, who has given his name to one form of unitarianism, was in Rome and was supported by the deacon Callistus: indeed, his rival says that it was Callistus who seduced Sabellius. However that may be, Callistus shrewdly perceived he could not meet his learned opponent on that ground. He disowned Sabellius, and soon lost himself in a maze of technical theology into which I will not venture to follow him. To theologians I leave also the discussion of the charge that Callistus favoured the rebaptizing of converted heretics. It is the charges of a practical or disciplinary nature which best illustrate the character of Callistus and make his Pontificate a milestone in the history of the Papacy. When we have made every possible allowance for exaggeration, they show that Callistus infused a remarkable spirit of liberalism into the Christian discipline and made smooth for the tender feet of the Romans the rough ways of his Church.