CALIXTUS I., pope from 2 I 7 to 222, was little known before the discovery of the book of the Philosophumena. From this work which is in part a pamphlet directed against him, we learn that Calixtus was originally a slave and engaged in banking. Falling on evil times, he was brought into collision with the Jews, who denounced him as a Christian and procured his exile to Sardinia. On his return from exile he was pensioned by Pope Victor, and, later, was associated with Pope Zephyrinus in the government of the Roman Church. On the death of Zephyrinus (217) he was elected in his place and occupied the papal chair for five years. His theological adversary Hippolytus, the author of the Philo sophumena, accused him of having favoured the modalist or Patripassian doctrines and of certain relaxations of discipline. Calixtus died in 222. In the time of Constantine the Roman Church reckoned him officially among the martyr popes.
(L. D.)