Robert A. Heinlein: "One may bask at the warm fire of faith or choose to live in the bleak certainty of reason- but one cannot have both."

"A religion is sometime a source of happiness, and I would not deprive anyone of happiness. But it is a comfort appropriate for the weak, not for the strong. The great trouble with religion - any religion - is that a religionist, having accepted certain propositions by faith, cannot hereafter judge those propositions by evidence. One may bask at the warm fire of faith or choose to live in the bleak certainty of reason- but one cannot have both."

Robert A. Heinlein, Friday

A bit of inconsistency on the part of whoever collected the quotes for the "My Favorite Quotes" page, since both the above citation and the one from Voltaire that I posted yesterday ("Doubt is not a pleasant condition, but certainty is absurd.") appear there.  While Voltaire disparages certainty, Heinlein links it to reason.
Furthermore, the statement that "a religionist, having accepted certain propositions by faith, cannot hereafter judge those propositions by evidence" is false.  Although I would concede that it has happened, it doesn't necessarily have to.