"But, my dear fellows" said Feodor, having diligently deciphered the handwriting.
"This is Ben-Bezalel's problem! Didn't Cagliostro prove that it had no solution?"
"We know that it has no solution, too" said Junta, bristling immediately. "But we wish
to learn how to solve it"
"How strangely you reason, Cristo...How can you look for a solution, where
it does not exist? It's some sort of nonsense."
"Excuse me, Feodor, but it's you who are reasoning strangely. It's nonsense
to look for a solution if it already exists. We are talking about how to deal
with a problem that has no solution. This is a question of profound
principle, which, I can see, is not within your scope, since you are an
applications type. Apparently I started this conversation with you for nothing."
From "Monday starts on Saturday", by Strugatzky brothers.