“The Roman polity was only accidentally Christian,” he writes, and the result was a fundamentally secular monarchical republic “masquerading, to itself as much as to others, as an imperial theocracy.” The Byzantines were confused, given to “conflicting modalities of thought” and to shifting “situationally” between secular thinking and religious thinking. Their pragmatism and their republicanism were both products of secular thinking, at odds with Christianity’s supposed idealism and imperialism.

Here Kaldellis’s own reliance on modern Western conceptions of Christianity interferes with his analysis. He writes, for instance, that “secular” is a “fundamental category of Christian thought.” This is arguably true of Western Christianity, which is prone to distinguish sharply between the categories of sacred and profane, natural and supernatural, clergy and laity, “religious” clergymen and “secular” clergymen, “lords spiritual” and “lords temporal,” the City of God and the City of Man. But it is not obviously true of Orthodox Christianity. The Orthodox have no exact theological equivalent of “secular” and think Catholics make too much of such categories.

Kaldellis’s use of “secular” is even further away from Orthodox thinking. He seems to limit Christian thinking to thoughts about the Christian religion, as if all other thoughts are not Christian and therefore “secular.”

So when a Byzantine source attributes a victory to divine intervention, he’s thinking religiously, and when the same source attributes a victory to superior generalship, he’s thinking “secularly.”

Kaldellis therefore cannot understand how Byzantine Christians could reconcile the deposition of an emperor by the people with the ordination of that emperor by God. He can only understand them as inconsistent—and more truly secular than Christian.