If in the representation of perception illusion does at moments distort reality, then in the representation of the abstract error can reign for thousands of years, impose its iron yoke on whole nations, stifle the noblest impulses of mankind; through its slaves and dupes it can enchain even the man it cannot deceive. It is the enemy against which the wisest minds of all times have kept up an unequal struggle, and only what these have won from it has become the property of mankind.
- Arthur Schopenhauer