Synod of Diospolis was a 415 synod in Diospolis (now Lod, Israel) in which Pelagius was accused of heresy by the exiled Gallic bishops. It followed a council held earlier that year.
Heros of Arles was installed as bishop in the face of local opposition,[1] and then lost his see in the reprisals which followed the defeat and execution of Constantine III.[2] Together with Lazarus of Aix, who had likewise been appointed by Constantine and then deposed by Constantius, he then spent several years in Palestine.
Pelagius and Jerome were also in Palestine. Pelagius had criticized Jerome's commentary on the Epistle to the Ephesians and Jerome wrote against Pelagius in his Letter to Ctesiphon and Dialogus contra Pelagianos. With Jerome at the time was Orosius, a visiting pupil of Augustine, who had similar views on the dangers of Pelagianism. Together, they publicly condemned Pelagius.
A synod was convoked by John of Jerusalem in the summer of 415. Orosius spoke against Pelagius, and stated that a council at Carthage had condemned Caelestius (a disciple of Pelagius) and his ideas on original sin. Orosius' lack of fluency in Greek rendered him unconvincing and John's Eastern background made him more willing to accept that humans did not have inherent sinfulness, yet the synod rendered no verdict, and it was decided that the controversy should be handed over to the Pope Innocent I.[3] Augustine states that no official records of this meeting were kept and only Orosius kept a few notes.
A further synod was held in December 415. It was summoned by Eulogius, bishop of Caesarea and included thirteen other bishops. The synod was convoked to judge an accusation made by Heros of Arles and Lazarus of Aix, who had written a letter to condemn Pelagianism (They also wrote a second letter together to the Council of Carthage (416)).[4] Heros and Lazarus were allies of Jerome, as was Paul Orosius.[5]
Pelagius spoke Greek and Latin, and as the members of synod could not read Latin in detail, they were limited in how they could question him and his writings.[6] Pelagius defended himself by disavowing the doctrines of Caelestius and was not convicted.
Both Jerome and Augustine were unhappy with the verdict, with Jerome calling it, “the wretched Synod of Diospolis”.[6] Pope Innocent stated that "he could not bring himself to refuse either blame or praise of those bishops."[7] Fragments of the synod's proceedings are preserved in Augustine's work On the Proceedings of Pelagius.[7]