wall

Good Lord! What have I to do with the laws of Nature, or with arithmetic, when all the time those laws and the formula that twice two make four do not meet with my acceptance! Of course, I am not going to beat my head against a wall if I have not the requisite strength to do so; yet I am not going to accept that wall merely because I have run up against it, and have no means to knock it down.

-- Fyodor Dostoevsky Letters from the Underworld
Translated by C.J. Hogarth