... The air of paradox resulted from the fact that those theologians who defended the view that revelation provided the only knowledge of God and that reason, in the form of philosophical enquiry, was insufficient in all those areas in which revelation was authoritative, found themselves making use of philosophical argument in order to rebut the claims of the philosophers. And, insofar as they were aware of this, they had therefore to distinguish that in philosophy which can serve in the defense of revelation by providing grounds for this rebuttal and that which must be rejected. And in so doing they too became philosophers.
Alasdair MacIntyre, God, Philosophy, Universities: A Selective History of the Catholic Philosophical Tradition p. 44.