Another feature of the Reformation that harmed the West, according to Brad Gregory in The Unintended Reformation, is the state’s increasing power, including the authority to regulate religious life.

Historians frequently regard the Reformation as a natural extension of secular authorities’ increasing control of the church in the fifteenth century. Such a view distorts more than it discloses, because the doctrinal disagreements introduced by the Reformation radically altered the nature of the long-standing jurisdictional conflicts between ecclesiastical and secular rulers.(146)

What that long-standing relationship was, however, is another question, one settled by Francis Oakley in his book, The Mortgage of the Past. He describes the conflict between pope and emperor during the Investiture Controversy this way:

Historically speaking, “there is really nothing unusual,” Brian Tierney has rightly argued, “in one rule aspiring to exercise supreme spiritual and temporal power. That . . . is a normal pattern of human government.” What was unusual instead about the European Middle Ages “was not that certain emperors and popes aspired to a theocratic role but that such ambitions were never wholly fulfilled.” The governmental dualism that sponsored this novel state of affairs was doubtless the cause of an immense amount of wasteful and destructive conflict. But it was conflict that marked the birth pangs of something new in the history of humankind: a society in which what we now call the state was gradually stripped of its age-old religious aura and in which its overriding claims on the loyalties were balanced and curtailed by those advanced persistently by a rival authority. That rival authority [the papacy], in turn, in no less significant a fashion, found its own imperial ambitions thwarted reciprocally by the competing power of emperors and kings. A society that was distinguished, therefore, by a deeply rooted institutional dualism and racked by the internal instability resulting there from. [40-41]

In other words, well before the Reformation came along to introduce doctrinal pluralism and instigated appeals to magistrates to prevent other magistrates in league with Rome from taking off the heads of Protestants, the medieval church, thanks to the ambitious claims of the papacy, introduced something new. This division between the secular and sacred was, as Oakley says, new in the history of the planet (except for Jesus’ own words about rendering to Caesar and to God). It also created an instability and rivalry in European governing institutions that predated the Reformation.

Another way of putting this is that from the perspective of the Eastern church circa 800, medieval Rome did to the unity and comprehensiveness of Constantinople what Gregory asserts about Protestantism. Not only did the Western church break with the East in 1054 to divide an earlier version of Christendom. But soon after that division came papal claims to supremacy during the Investiture Controversy that unsettled the existing political order in Europe and that further prevented a restoration of the older and historic Christendom.

In which case, Gregory’s decision to start his narrative with medieval Europe is arbitrary. If you start five hundred years earlier, Rome is the one guilty of setting into motion modernity, its pluralism, and its hegemonic nation-states.