Could it be because of the papacy?
Difficult as had been the situation with which the Popes were confronted during the sixteenth century and the first half of the seventeenth century, when heresy was rampant throughout Europe, and when Catholic nations were obliged to fight for their very existence, it was not a whit more difficult or more critical than that created by the increasing and selfish demands of Catholic rulers, which confronted their successors during the age of absolute government. The Peace of Westphalia (1648), by giving official sanction to the principle of state neutrality, meant nothing less than a complete revolution in the relations that had existed hitherto between Church and State. So long as the Christian world was united in one great religious family, acknowledging the Pope as the common Father of Christendom, it was not strange that in disputes between princes and subjects or between the rulers of independent states the authority of the Pope as supreme arbitrator should have been recognised, or that his interference even in temporal matters should not have been regarded as unwarrantable. But once the religious unity of Europe was broken by the separation of entire nations from the Church, and once the politico-religious constitution of the Holy Roman Empire was destroyed by the acceptance of the principle of religious neutrality, the Popes felt that their interference even indirectly in temporal matters, however justifiable it might be in itself, could produce no good results. Hence apart from their action as temporal sovereigns of the Papal States, a position that obliged the Popes to take part in political affairs, the whole tendency was to confine themselves strictly to spiritual matters, and to preserve harmony if possible between Church and State. This policy did not, however, satisfy the selfish designs of rulers, who had determined to crush all representative institutions and to assert for themselves complete and unlimited authority. Catholic rulers, jealous of the increased powers secured by Protestant princes through the exercise of supreme ecclesiastical jurisdiction, determined to assert for themselves a somewhat similar authority over the Catholic Church in their own territories. It was no longer the supposed inroads of the Church upon the domain of the State but the attacks of the State upon the rights of the Church, that were likely to disturb the good relations between Catholic princes and the Pope. These rulers demanded an overwhelming voice in all ecclesiastical appointments; they insisted upon exercising the Royal Placet upon papal documents and episcopal pronouncements; they would tolerate no longer the privileges and exemptions admitted by their predecessors in favour of clerics or of ecclesiastical property; they claimed the right of dictating to the cardinals who should be Pope and of dictating to the Pope who should be cardinals; of controlling education in their own dominions; of determining the laws and rules concerning marriages and matrimonial dispensations, and of fixing the constitutions of those religious orders the existence of which they were willing to tolerate.
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The Catholic doctrine on Grace, round which such fierce controversies had been waged in the fifth and sixth centuries, loomed again into special prominence during the days of the Reformation. The views of Luther and Calvin on Grace and Justification were in a sense the very foundation of their systems, and hence it was of vital importance that these questions should be submitted to a searching examination, and that the doctrine of the Catholic Church should be formulated in such a way as to make cavilling and misunderstanding impossible. This work was done with admirable lucidity and directness in the fifth and sixth sessions of the Council of Trent, but nevertheless these decrees of the Council did not prevent the theories of Luther and Calvin being propagated vigorously, and from exercising a certain amount of influence even on some Catholic theologians who had no sympathy with the religious revolt.