For although theology is a science, it does not propose as its end the transformation of the belief by which it adheres to its principles into understanding; to do that would be to destroy its proper object. Nor will the Christian philosopher on the other hand, any more than the theologian, attempt to transform faith into science, as if by some queer chemistry you could combine contradictory essences. What he asks himself is simply this: whether, among those propositions which by faith he believes to be true, there are not a certain number which reason may know to be true. Insofar as the believer bases his affirmations on the intimate conviction gained from faith he remains purely and simply a believer, he has not yet entered the gates of philosophy; but when amongst his beliefs he finds some that are capable of becoming objects of science then he becomes a philosopher, and if it is to the Christian faith that he ows this new philosophical insight, he becomes a Christian philosopher.
Etienne Gilson, The Spirit of Medieval Philosophy p.36