However, the serious shortcomings of his work cannot be overlooked. Some of the more notable imperfections include his historical analyses of the schisms, which have largely been superseded by later scholarship as the readings of history have, in most cases, changed. Similarly, he was mistaken in his prediction that the office of patriarch would recede from prominence in the Orthodox world. He also failed to anticipate the ecumenical obstacle posed by the existence of the Eastern Catholic Churches. [p.211]

n his treatment of the Eastern Christian Churches, Fortescue approach his subject largely from the vantage point of an apologist. Conscious of his place as part of England's Catholic minority, as well as being the son of a prominent convert, Fortescue was always insistent on explaining and defending his faith. This heavily colored his exposition of Eastern Christianity, and led to a lack of objectivity and an often polemical tone. These tendencies were manifest in his penchant for assigning the lion's share of responsibility for the schisms to the East and acquitting Rome of its portion of culpability.

Moreover, Fortescue was not very critical in most of his arguments, as he largely echoed what the Catholic Church was teaching in his lifetime. He unquestioningly defended the Catholic positions on such hot-button issues as the exercise of papal primacy and the addition of the Filioque to the creed, sometimes hastily dismissing non-Catholic objections. Rarely did he challenge what was the dominant Catholic opinion on any given topic. . . [pp.211-212]