The difference between reading scripture allegorically and reading it for its plain historical sense sounds like a matter of literary taste, but in the fifth century it became a matter a church council had to settle. The Antiochene habit of insisting that a gospel passage first means what it says about a real human life, taught by Diodore of Tarsus and Theodore of Mopsuestia and carried into famous preaching by John Chrysostom, shaped how its students described Christ: a reading trained on the concrete humanity of the gospel narratives tended toward language that kept Christ's human and divine natures sharply distinct, each fully itself.
Nestorius, formed in that tradition and made patriarch of Constantinople in 428, preached in exactly that vein, and his opponents, chief among them Cyril of Alexandria, heard it as dividing Christ into two subjects rather than one. The Council of Ephesus condemned Nestorius in 431, and more than a century later, in 553, a second council condemned Theodore of Mopsuestia himself, posthumously, for the same underlying tendency, even though Theodore had died in communion with the wider church and had never been formally a Nestorian in his own lifetime.
The condemnation did not end the Antiochene method; it drove it east. The Church of the East, established beyond the Roman Empire's frontier in Persia and so outside Constantinople's reach, kept Theodore as its principal biblical commentator and continued reading him in Syriac translation for centuries after his Greek original had become dangerous to own inside the empire. The episode shows a reading habit carrying theological consequences practitioners had not intended: the same exegetical instinct Antioch prized as fidelity to the text, Alexandria heard as a failure to see Christ whole.