“Morality has many charms. What could be more captivating than a vision of everlasting justice? Yet visions of justice are as immutable as styles in shoes. What morality demands shifts across the generations and may change more than once within a single human lifetime. Not so long ago morality required spreading civilization by extending imperial power. Today, morality condemns empire in all its forms. These judgements are irreconcilably opposed. But they provide the same satisfaction to those who pronounce them – a gratifying sense of virtue.”