The Church had any number of opportunities of dying and even of being respectfully interred. But the younger generation always began once again to knock at the door; and never louder than when it was knocking at the lid of the coffin in which it had been prematurely buried. Islam and Arianism were both attempts to broaden the basis to a sane and simple theism, the former supported by great military success and the latter by great imperial prestige. They ought to have finally established the new system, but for the one perplexing fact that the old system preserved the only seed and secret of novelty. Anyone reading between the lines of the twelfth-century record can see that the world was permeated by potential pantheism and paganism; we can see it in the dread of the Arabian version of Aristotle, in the rumor about great men being Moslems in secret; the old men, seeing the simple faith of the Dark Ages dissolving, might well have thought that the fading of Christendom into Islam would be the next thing to happen. If so, the old men would have been much surprised at what did happen.
What did happen was a roar like thunder from thousands and thousands of young men, throwing all their youth into one exultant counter-charge: the Crusades. The actual effect of danger from the younger religion was renewal of our own youth. It was the sons of St. Francis, the Jugglers of God, wandering singing over all the roads of the world; it was the Gothic going up like a flight of arrows; it was a rejuvenation of Europe. And though I know less of the older period, I suspect that the same was true of Athanasian orthodoxy in revolt against Arian officialism. The older men had submitted it to a compromise, and St. Athanasius led the younger like a divine demagogue. The persecuted carried into exile the sacred fire. It was a flaming torch that could be cast out, but could not be trampled out.
— Where All Roads Lead (1922).