A nugget from _A Canticle for Leibowitz_
This brilliant bit is almost a throwaway paragraph on page 304, near the end.
[Two men in a satirical dialog] managed only to demonstrate that the mathematical limit of an infinite sequence of “doubting the certainty with which something doubted is known to be unknowable when the ‘something doubted’ is still a preceding statement ‘unknowability’ of something doubted,” that the limit of this process at infinity can only be equivalent to a statement of absolute certainty, even though phrased ans an infinite series of negations of certainty.
It’s not like the whole book is like this…far from it. But it is chock full of little gems.