It is wisdom to recognize necessity, when all other courses have been weighed, though as folly it may appear to those who cling to false hope. Well, let folly be our cloak, a veil before the eyes of the Enemy! For he is very wise, and weighs all things to a nicety in the scales of this malice. But the only measure that he knows is desire, desire for power; and so he judges all hearts. Into his heart the thought will not enter that any will refuse it.
--Tolkien, Lord of the Rings