Caelestius was a disciple of Pelagius, involved in the discussions over the free will, original sin and grace at the beginning of the 5th c. in Rome, North Africa and Palestine. He was ordained presbyter between 411 and 416 during his travel to the East (see [497] and [503]). Caelestius went back to Rome in 417 after the election of Zosimus as the bishop of Rome. There he appealed to Zosimus asking him to judge his writings and opinions against those who were accusing him of heresy [1467]. Zosimus interrogated Caelestius, and did not found him guilty, instead he condemned his accusers Heros and Lazarus, and summoned the accusers - mainly Paulinus, deacon of Milan, who at the council in Carthage in 411 accused Caelestius in his libellus of heresy - to Rome in order to prosecute Caelestius. In a present letter Paulinus indicates that Zosimus already agreed with him because he asked Caelestius about the accusations of Paulinus and demanded Caelestius to condemn the heretical assertions ascribed to him by Paulinus. Thus, Paulinus considers the guilt of Caelestius obvious and his opinions already condemned both by Innocentius I and Zosimus, and he declines to come to Rome.