The Tiantai school (天台宗, pinyin: Tiāntái zōng) is a Chinese school of Mahâyâna Buddhism that emerged in the lifetime, whose interpretation of the sutras and speculative elaborations exerted great influence on the development of Buddhism in China, Japan, and Korea.
The Sui monk Zhiyi (538-597) is considered the main author of this doctrine, which the school's tradition traces back to Nāgārjuna, some of whose concepts inspired Zhiyi and his two predecessors, Huiwen and Huisi.
Zhiyi himself seems to have read a lot but left few writings, and it is mainly through his disciples that we know his thought. The Tiantai school regards the Lotus Sūtra as the completed expression of the Buddha's teaching. It takes its name from the mountain in Zhejiang on which the famous monk spent most of his life.
According to the official genealogy, the first nine masters were Nāgārjuna (simplified Chinese: 龙树; traditional Chinese: 龍樹; pinyin: lóng shù), Huìwén (慧文), Huìsī (慧思) (515-577? ), Zhìyǐ (智顗) (538-597), Guàndǐng (灌頂/灌顶) (561-632), Zhìwēi (智威) (？-680), Huìwēi 慧威, Xuánlǎng 玄朗 (673-754), Zhànrán 湛然（711-782)
Context of appearance
The Sui and Tang dynasties were a time of flourishing for Chinese Buddhism during which schools multiplied. The Chinese now had at their disposal a very large number of canonical texts (sutras) from different schools and periods of Indian Buddhism, brought by monks from India or Central Asia; they themselves went in search of "authentic" sources in India, like the famous Xuanzang.
An important translation activity started in the second century and continued until the end of the Tang. These translations were done in teams composed of Chinese and foreign monks, the most famous of whom was Kumarajiva (鳩摩羅什, jiūmóluóshí), active in the early fifth century; the translations in which he participated have become references.
More familiar with Indian texts, the Chinese began to interpret them in their own way, incorporating concepts from their own culture, Taoist for example. Apocryphal sutras were written, especially on subjects important to the local culture, such as filial piety.
Chinese sutras or translations into Chinese were later spread to Japan, Korea and Vietnam from the second century onwards.
It was therefore necessary to explain the contradictions between the different texts. A widespread idea, which found its canonical justification in certain passages, was that the Buddha had not revealed his true dharma from the beginning, but had adapted the teaching to the public and to its level of wisdom, an idea which found a resonance in the Confucian conception of teaching.
The various schools agreed that the Hinayana teaching was less advanced than the Mahayana; most considered that Buddha-nature existed in everyone; nevertheless, they did not agree on the reference sūtras and did not have the same interpretation of the nature of the phenomena of existence.
The Tiantai school, for whom the Lotus Sutra contained the supreme revelation of Buddhism, offered a doctrine in harmony with Chinese thought and particularly eclectic and syncretistic, an ideal matrix for all local variants of Buddhism; this was one of the reasons for its success.
Evolution
In China
Tiantai's doctrine, which had brought him rapid fame, making him the dominant school under the Sui, was by the end of the dynasty sufficiently complete to leave little room for further development. By the Tang, the school was already losing vitality, especially after the death of Guanding, when half of his disciples joined other schools.
The geographical location of Mount Tiantai, far from the capitals where the wealthy and cultured classes who constituted its main audience lived, was a handicap for this mainly exegetical and intellectual trend. The last master to exert a notable influence was Zhanran, less in thought than in ritual, relying in part on the Sūtra Avatamsaka.
The school faded away following the persecutions of the ninth century for nearly a hundred years, then reappeared under the Wuyue kingdom thanks to the support of its ruler, who brought from the Koryŏ kingdom the texts destroyed during the troubles of the preceding decades.
It was thus able under the Song to resume the rivalry struggle begun in the sixth century against the chán school, with which it moreover maintained cousinly relations through the intermediary of masters who were fellow students, defectors and influences. It was also under the Song that a monk named Tiantai founded the White Lotus School, which became famous for its Taoist deviations.
Tiantai faded away almost completely from the Yuan period onwards, although it did not disappear completely, as there are still monks who claim to follow it. It nevertheless remained a major doctrinal reference along with Huayan, another exegetical and speculative branch.
In Japan
Saichō, better known by the posthumous name of Dengyo Daishi (伝教大師 767-822), imported it into Japan in the ninth century, where under the name Tendai it supplanted the Nara schools that had preceded it thanks to the support of the imperial family.
Developing in parallel with Shingon, it integrated tantric elements absent from the Chinese school. In the thirteenth century, the monk Nichiren, an original personality with an eventful life, reaffirmed the pre-eminence of the Lotus Sūtra by deepening the main works of Zhiyi annotated by Zhanran and founded the Hokke-shū ("lotus school") school at the origin of the Buddhism that bears his name.
Other famous monks came out of the Tendai school to create their own movements: Honen and Shinran for amidism and Dogen for sōtō Zen.
The Cheontae (en) school is the Korean form of the Tiantai school.
Philosophy
The tradition of the school lends to Huiwen, its first Chinese master, the initial revelation obtained by reading in Nagarjuna's Treatise of the Middle Way: "That which is produced by causes is identical to emptiness... this is the meaning of the middle way".
He is said to have transmitted this revelation to the second master, Huisi, from whom Zhiyi received it. However, contemporary historians consider the latter to be the true author of the Tiantai doctrine, which the sixth master, Zhiqi, would have helped to clarify.
Zhiyi groups the teachings of the various Mahayana nikayas and sutras into five eras and eight types of instruction suitable for different levels of wisdom. He makes use of a concept widely developed in the Lotus Sutra, that of "expedient means" (upaya), methods that may be unorthodox (recourse to magic, etc.) but are sometimes better adapted to the level of the practitioner and therefore more effective in guiding him or her along the path.
No Buddhist writing is therefore rejected, but they do not all situate themselves at the same level: the Hinayâna sutras are generally further from the absolute truth, the best expression of it being found in the Sūtra of the Lotus, the definitive version of the Buddha's teaching.
This view is based on the way the text records his vow to save all beings: 'From the beginning I resolved...'. This formula is interpreted by Tiantai thinkers as an explicit statement of his intention to develop his revelation gradually.
Tiantai rejects the pure idealism of certain Indian schools, such as the Nalanda school where Xuanzang studied, which see the phenomena of the world as purely the production of the mind.
For the Tiantai masters, who reject the duality of matter and spirit, the world of transient phenomena is indeed a reality, but conditioned and impermanent, whose essential emptiness must be understood, the middle way being the path that allows one to apprehend these two aspects simultaneously and to reach the supreme truth.
Tiantai therefore advocates "threefold contemplation" (Yixinsanguan 一心三觀):
All phenomena have a transient reality (contemplation of illusion guanjia 觀假)
The essence of all phenomena is emptiness (contemplation of emptiness guankong 觀空)
Everything is absolutely empty and transiently real at the same time (contemplation of the middle way guanzhong 觀中)
It is by returning to the middle way that the bodhisattva can show enlightened compassion appropriate to the situation.
This threefold contemplation, combined with a representation of 3,000 different worlds, results in the "contemplation of the 3,000" (yiniansanqian 一念三千, jp: Ichinen Sanzen, "three thousand worlds in a moment of life" defined by:
"Ten worlds (or states of life)" and their mutual inclusion, combining the "Ten factors (or modalities of life)", in the "Three levels of existence (or realms of existence)" (10x10x10x3), is the principle enunciated by the great master Tiantai (Tendai Chih-I or Zhiyi) that serves as the basis of Nichiren's Buddhism.
