Broken cisterns are idols, God-substitutes. They are the spiritual hot dogs we ingest on the way to God’s banquet. They dull and eventually kill our appetite for the deep and nourishing richness of his holy fare. Like the Turkish delight the witch gives to Edmund in C. S. Lewis’s The Lion, the Witch, and the Wardrobe, they are insatiably unsatisfying. The more we eat, the less we like what we eat, but the more we want to eat it. So Frederick Buechner defines gluttony as raiding the refrigerator to cure a case of spiritual malnutrition; and lust as the craving for salt of a man dying of thirst.