The king aspired – and especially when he became the German emperor and as such the continuation of the Holy Roman Empire – and claimed to represent as protector all Christendom, Christendom as a whole, the secular as well as the religious. On the other hand, Pope Gregory VII claimed the same thing from the hierarchical side. He made claims transcending everything which was done before, and of which even he could reach only a limited amount. He identified himself with all bishops; he is the universal bishop. All episcopal grace comes from the pope, who is Peter and in whom Peter is present, and in Peter, Christ is present, So there is no bishop who is not dependent on the pope in his episcopal sacramental power” This is the universal monarchy of the pope in the Church. But he goes beyond this: the Church is the soul of the body; the body is the secular life. Those who represent the secular life are related to him who represents the life of the — soul, as the limbs of the body are to the inner self which is the soul. And so, as the soul shall govern the limbs of the body, so the pope shall govern the kingdoms and all feudal orders.
Now this was expressed –a fter compromises had to be made and became unavoidable – by the famous doctrine of the two swords. There are two swords, the earthly and the spiritual. As the bodily existence is subjected to the spiritual existence, so the earthly sword, that of the king and of the feudal groups, is subjected to the spiritual sword: the pope. Therefore every being on earth has to be subject to the pope at Rome. This was the doctrine of Pope Boniface VIII, in which the papal aspirations are expressed radically.
The emperors fought against it, compromises were made, but generally speaking the popes prevailed – up to a certain moment. They prevailed as long as there was this one reality about which they – emperor and pope – were fighting: namely, the one Christianity. But this was not the final answer. New forces arose in the Middle Ages. The first and main force was the national states. The national states claimed something which neither suited the pope nor the emperor, namely independence from both of them. And since the national feeling is behind them – this is partly the importance of Joan of Arc because, in her, French nationalism first arose and came of course immediately into conf lict with the pope. But others followed, and at the end of the Middle Ages the national states had taken over much of the papal power.