Caelestius also went much further than Pelagius in stating that the sin of Adam, as chronicled in the Biblical Book of Genesis, had only harmed himself, and not all of humanity, as Augustine had taught in his writings and sermons.
(Pelagius has been accused of starting this teaching, but in fact he anathematized the opinions of Caelestius at the Synod of Lydda in 415, as well as in a letter to the pope shortly afterwards.)
His accuser, the deacon Paulinus of Milan, listed six of Caelestius' ideas to be counted as heresies, but it is worth noting there is no recorded confirmation that Caelestius identified his views in the same way: The fragmented transcripts of this council can be found under the section below entitled Related links and sources.
This same view is also shared by the German Protestant theologian Hans von Campenhausen in his book "The Fathers of the Church" when discussing the relationship of Pelagianism with the orthodox champion Saint Augustine.
However, after a new synodal letter of the African council of May 1, 418 to the pope and steps were taken by Emperor Honorius against the Pelagians, Zosimus was convinced both Caelestius and Pelagius were heretics.