The religious urge in man is not a mere passing phase in the history of his spiritual development, but the ultimate source of all his ethical thought and all his concepts of morality; not the outcome of primitive credulity which a more "enlightened" age could outgrow, but the only answer to a real, basic need of man at all times and in all environments. In another word, it is an instinct.
When students scoff at the idea of a magical relation between a picture and what it represents, ask them to take a photograph of their mother and cut out the eyes.