A passage from This Is Your Brain on Metaphors
"What are we to make of the brain processing literal and metaphorical versions of a concept in the same brain region? Or that our neural circuitry doesn’t cleanly differentiate between the real and the symbolic? What are the consequences of the fact that evolution is a tinkerer and not an inventor, and has duct-taped metaphors and symbols to whichever pre-existing brain areas provided the closest fit?"
(via 'The Loom')