[Chih-i’s] talent lies in the fact that he not only absorbed and incorporated different views and theories, but also went beyond all of his predecessors and contemporaries by formulating his own system of thought. Since his system is based on a complete evaluation and critique of all other available views of his time, it is thus endowed with the features of syncretism, comprehensiveness, and completeness, and a sense of harmony, flexibility, and perfection.
The Profound Meaning of the Lotus Sutra: Tien-tai Philosophy of Buddhism