In her novel Regeneration, Pat Barker writes of a doctor who 'knew only too well how often the early stages of change or cure may mimic deterioration. Cut a chrysalis open, and you will find a rotting caterpillar. What you will never find is that mythical creature, half caterpillar, half butterfly, a fit emblem of the human soul, for those whose cast of mind leads them to seek such emblems. No, the process of transformation consists almost entirely of decay.