Few rules of law can so quickly strike terror into the hearts of lawyers as the Rule against Perpetuities. This rule, two centuries in development, is designed to prevent tying up property for too long a time. It can be stated in one sentence, but the great nineteenth-century master of the Rule, John Chipman Gray, required more than 400 scrupulously detailed pages to explain it. For deceptive subtleties and unexpected traps it has no equal. This book...