Imagine an allegory; a large-scale, coherent and world-building allegory, something like The Faerie Queene. You got it, in your mind? Good. Have your knight, Virtue, ride in. Have him slay the dragons, Error, Sin and Doubt, and rescue the beautiful Lady Truth, good, good. But--next on the road he encounters the Monster Allegoria herself. After long fight he destroys this monster.