There are a great many statements and writings by Tiantai Zhiyi. The most distinctive having to do with the Lotus Sutra are Words and Phrases of the Lotus Sutra, written in 587 when he was fifty. The Profound Meaning of the Lotus Sutra, written in 593, and the ten-fascicle The Great Calming and Contemplation, written in 594. Together these books are known as “the three great works on the Lotus Sutra” or “the three great works of Tiantai.” But they were actually all dictated by Zhiyi and recorded by his disciple Guanding (561-632), and they include many of Guading’s revisions.

Words and Phrases of the Lotus Sutra is a commentary on the Lotus Sutra, with a kind of theory of interpretation. The Profound Meaning of the Lotus Sutra should be regarded as doctrine and doctrinal theory based on the teachings of the Lotus Sutra. The Great Calming and Contemplation, as a system of practice based largely on the Lotus Sutra, can be regarded as the Lotus Sutra’s theory of practice. These three treatises of Tiantai gave the Lotus Sutra a highly sophisticated and systematic structure of thought and philosophy.