This from Vox Hiberionacum, in a post outlining the bad opinion the classical world had of the Irish:
Perhaps the most appropriate example is that of St. Jerome. Writing against an apparently British opponent Pelagius in the early fifth century, he found it most suitable to insult him using scotti subtext; stolidissimus et scotorum pultibus proagravatus, ‘most stupid and heavily weighed down/pregnant with Irish porridge‘ (Jerome CCL 74 Praef. in Jerem., Lib. I and III). Not only was he engaging in the late antiquity equivalent of calling him fat and stupid (‘Yes, Pelagius, your bum DOES look big in that…’) he also found room for a double insult by labelling the bodily excess as tainted with Irish origins/characteristics.
Pelagius had been acclaimed for his piety and learning, but fell foul of Jerome, Augustine and others while opposing the idea of predestination. They understood him as saying that divine aid was not required to perform good works, that human reason was capable of providing implicit knowledge of God and as denying original sin. For Pelagius, sin was a matter of custom and habit rather than an inherent part of fallen human nature. Pelagius was declared a heretic by the Council of Carthage.
In A History of Irish Thought (pp. 2-3), Duddy mentions this inauspicious first appearance of Irishness in the philosophical canon. While it is possible Pelagius was from an Irish settlement in Britain, most scholars accept he was not from Ireland. Duddy mentions James Kenney’s theory that Jerome did not actually believe Pelagius was Irish, but was merely sacrificing accuracy to insult. Jerome had a bad opinion of the Irish, reporting elsewhere that the Irish were promiscuous and fed on human flesh.
There is a possible link between Pelagius and the Irish monastic tradition, however. Kenney claims that one of his few remaining works, Commentaries on the Epistles of St. Paul, survived due to its preservation in the Irish Schools.
Note: in later years the Irish didn’t let Jerome’s attitude to them (typical of the time) put them off…
@IrishPhilosophy Yes, he had typical Roman attitudes towards barbarians. The Irish really liked him though – he is cited very frequently
— Peritia (@PeritiaEditors) September 30, 2015