CALLISTUS (CALIXTUS) (Saint) Pope, Martyr (October 14) (3rd century) A Roman by birth, the successor of Pope Saint Zephyrinus, whose Archdeacon or representative he had been. His five years of vigorous Pontificate were marked by many salutary measures: the moderating of the rigour of the penitential discipline; the repression of the Patripassians, Sabellians and other heretics; the fixing of the Ember Day Fasts, etc. etc. He seems to have met with much opposition, and at length, probably in a riot or outburst of the heathen against the Christians, was flung headlong from the window of a high building in the Trastevere quarter (A.D. 223). He was buried in the Catacombs of Saint Calepodius, his contemporary, and his relics now repose together with those of that Saint in the Church of Santa Maria in Trastevere, close to the scene of his martyrdom. The document called the Philosophoumena, an anonymous production of the heretics of his time, written to besmirch the memory of the holy Pope, notwithstanding the credit given to it by Bunsen and by Protestant writers in general, has been amply refuted by Dollinger and others.