„No folly is more costly than the folly of intolerant idealism.“

— Winston S. Churchill
„The most costly of all follies is to believe passionately in the palpably not true. It is the chief occupation of mankind.“
— H.L. Mencken
„Wickedness is always wickedness, but folly is not always folly.“
— Jane Austen
„Every man has his folly, but the greatest folly of all … is not to have one.“
— Nikos Kazantzakis