This is a book about prayer. Writing about prayer, it has been said, is more difficult than prayer itself. Parodying Augustine’s struggle to describe time in Book 11 of the Confessions, D. Z. Phillips says, ‘I understand when I pray; I understand also when I hear another praying. What then is prayer? If no one asks me I know; if I wish to explain it to one that asketh, I know not.’1 Prayer is something done rather than written about. Yet even then, there is something fundamentally