Threefold truth

The threefold truth is the central teaching of the Tiantai school, formulated by Zhiyi in the sixth century. Every phenomenon, he taught, can be seen in three ways: as empty, since it has no fixed nature and arises only in dependence on conditions; as provisionally real, since it nonetheless appears, functions and can be named; and as the middle, which is both of these at once and neither alone.

Zhiyi drew the teaching from a verse of Nāgārjuna, which identifies dependent origination with emptiness, with provisional designation and with the middle way. Where Madhyamaka speaks of two truths, conventional and ultimate, Zhiyi insists that the three are perfectly integrated: each includes the others, so that to see any one fully is to see all three. The teaching rules out both a nihilism that clings to emptiness and a realism that clings to things.

From it follows the Tiantai doctrine that a single moment of thought contains the whole of reality, and the practice of seeing ordinary experience, even the passions, as the very place where the threefold truth is realized.