Tiantai relates to other Buddhist traditions through a distinctive blend of integration and hierarchy, all oriented around the Lotus Sutra. Its system classifies the full range of Buddhist scriptures and doctrines into graded schemes, such as the “five periods” and “eight teachings,” and then places the Lotus Sutra at the apex as the most complete revelation of the Buddha’s enlightenment. Other teachings are not rejected outright; they are understood as provisional or expedient means (upāya), adapted to the capacities of different beings and historical circumstances. In this way, Tiantai acknowledges the validity of diverse paths while interpreting them as partial expressions that ultimately point toward the Lotus Sutra’s “perfect and sudden” teaching.

This classificatory vision shapes Tiantai’s relationship with major doctrinal schools. Madhyamaka’s emphasis on emptiness and Yogācāra’s analysis of consciousness are both taken up, yet they are reinterpreted within Tiantai’s own framework of the threefold truth and the comprehensive vision of “three thousand realms in one mind,” and thus regarded as incomplete on their own. Huayan’s grand vision of interpenetration and its devotion to the Avataṃsaka Sutra is respected as profound, yet Tiantai still asserts the Lotus Sutra as the final and highest teaching. In each case, other schools’ insights are absorbed and reframed, given a place within a broader Lotus-centered synthesis rather than standing as independent, ultimate authorities.

The relationship with practice-oriented traditions follows the same pattern of inclusive hierarchy. Pure Land devotion is accepted as a powerful expedient for beings of more limited capacity, and Tiantai masters sometimes combine Pure Land recitation with Tiantai contemplation, yet such practices are still seen as subordinate to the Lotus Sutra’s full revelation of universal Buddhahood. Chan/Zen, with its rhetoric of sudden awakening and suspicion of textual study, stands in a certain creative tension with Tiantai’s highly systematic and scriptural approach, even as both claim inspiration from the Lotus Sutra. Historically, Tiantai thus becomes a kind of doctrinal hub: its methods and classifications shape, challenge, and are reworked by other schools, while it continues to present itself as the overarching framework within which all Buddhist teachings can be understood and harmonized.