To say this is not to depreciate reason. It would be a foolish man who assumed that Abelard was a better thinker than St. Anselm. Abelard's starting point was rationalism, Anselm's was Biblical. Not surprisingly, Anselm's philosophy was centered on the atonement. Rationalism itself is evidence of the radical effect of the fall in that the world of epistemology, the theory of knowledge, has shifted its center from God to man.
Epistemology is now a semi-forgotten branch of philosophy because it is bankrupt.
The modern stream of thought from Descartes through Hume, Kant, Hegel, Sartre, Wittgenstein and others is one of intellectual and moral bankruptcy and a despair of knowledge.