Full Idea
With respect to the mysteries of the Christian religion, reason is a blind whore.
Gist of Idea
With respect to religion, reason is a blind whore
Source
Martin Luther (talk [1525]), quoted by Robert Fogelin - Walking the Tightrope of Reason n4.2
Book Reference
Fogelin,Robert: 'Walking the Tightrope of Reason' [OUP 2004], p.181
A Reaction
Reason is presumably a blind whore with respect to all impenetrable mysteries. Since the reason of Aquinas endorsed the mysteries of Christianity, the remark seems a bit strong, but it is appropriate if you think that only faith (in Christianity) matters.