At the time of Chih-i, facing voluminous Buddhist scriptures and commentaries and diverse discourses, there was obviously an urgent need for a comprehensive guideline to swim through controversies in order to get a clear picture of what the real theme of the teaching of the Buddha is. Only when the real intention of the Buddha was grasped, the disputes over various Buddhist principles could be resolved. It was Chih-i who has come to the scene to fulfill this huge task. He has appropriately chosen the Lotus Sūtra to be the supreme doctrine, because of its reconcilable nature in incorporating all divisions of Buddhism, and because it equally addresses all sentient beings. The essence of T’ien-t’ai Buddhism is revealed through this text with Chih-i’s unique interpretations. When the concepts and principles in Indian Buddhism are reshaped, remolded, redefined, and re-categorized with Chinese epistemology in Chih-i’s system, they become distinctively Chinese, forming the main characteristics of Chinese Buddhism. Therefore, Chih-i is worthy to be called one of the greatest Buddhist masters in China, who contributed greatly to Chinese Buddhism which developed to full bloom in the T’ang Dynasty. (Preface xix-xxx)