The object of opening the mind, as of opening the mouth, is to close it again on something solid.
-- G.K. Chesterton
A "friend" of mine was a fan of using this to argue for Christianity. The idea of never changing one's mind doesn't seem very rational.
A monthly thread for posting rationality-related quotes you've seen recently (or had stored in your quotesfile for ages).
ETA: It would seem that rationality quotes are no longer desired. After several days this thread stands voted into the negatives. Wolud whoever chose to to downvote this below 0 would care to express their disapproval of the regular quotes tradition more explicitly? Or perhaps they may like to browse around for some alternative posts that they could downvote instead of this one? Or, since we're in the business of quotation, they could "come on if they think they're hard enough!"