Reason Versus Rationalism

Lady Reason talks with John

...

"They could not have, for their sciences are not concerned at all with the general relations of this country to anything that may lie East of it or West of it. The indeed will tell you that their researches have proved that if two things are similar, the fair one is always the copy of the foul one. But their only reason to say so is that they have already decided that the fairest things of all--that is the Landlord, and, if you like, the mountains and the Island--are a mere copy of this country. They pretend that their researches lead to that doctrine:but in fact they assume that doctrine first and interpret their researches by it."

"But they have reasons for assuming it."

"They have none, for they have ceased to listen to the only people who can tell them anything about it."

"Who are they?"

"They are younger sisters of mine, and their names are Philosophy and Theology."

C.S.Lewis
Pilgrim's Regress
Book Four, Chapter II: Archtype and Ectype (p.49)