“His influence in the field of patristic studies has been more permanent. He was a voracious reader of the Fathers. He knew the works of all the major figures such as Origen, Augustine, Chrysostom, Jerome, and Gregory of Nazianzus, but he also knew and made reference to many less celebrated figures such as Ephraem Syrus, Euthymius, Georgius Syncellus, Melito of Sardis, Eusebius of Emesa, Diodore of Tarsus, Theodore of Cyrene, Procopius, Gaeus, and Polychromius. The range of his patristic references shows an amazing industry at a time when editions with a critical apparatus and a scholarly introduction were rare.”
R. Buick Knox, James Ussher: Archbishop of Armagh (Cardiff: University of Wales Press, 1967), 101.