If the Crusades had strengthened the power of the Church, they had at the same time brought about an expansion of thought which was undermining it.

Men were beginning to think, to inquire, and then to doubt.

How could sensuality and vice at Rome be reconciled with a divine infallibility?
If the ballad-poetry of Provence satirized the lives and manners of the priests, was it not dealing with what was true?
During the reign of Philip's father, a pale studious youth was pacing the cloisters on the banks of the Seine, by the side of Notre Dame.

He was thinking upon these things.

And "as he mused the fire burned." This was Abelard.