Tendai Buddhism receives from Tiantai a very particular way of speaking about emptiness, one that refuses to isolate it from the rest of reality. Emptiness is treated as one aspect within a triadic structure known as the Three Truths: emptiness, provisional or conventional existence, and the middle. Emptiness here means that all phenomena lack any fixed, independent self‑nature and arise only in dependence on causes and conditions. At the same time, these very empty phenomena still appear, function, and bear karmic consequences, which is described as their provisional existence. The “middle” is not a third thing standing apart, but the non‑dual integration of emptiness and provisional existence, the insight that things are at once empty and functionally real.

Within this framework, emptiness is not reified as a kind of metaphysical nothingness, nor is it allowed to negate the world of daily experience. Instead, it serves as a contemplative lens through which the ordinary world is seen as inseparable from the realm of awakening. This is expressed in Tendai doctrines such as the non‑duality of samsara and nirvana, where defiled and pure are understood as “two but not two.” Because all dharmas are empty and interdependent, one moment of mind is said to encompass all realms and possibilities, which supports the view that the deluded mind is not ultimately separate from Buddhahood.

Tendai also reads the Lotus Sutra as a scriptural expression of this understanding of emptiness. The many teachings and vehicles presented by the Buddha are regarded as provisional, adapted to the needs and capacities of beings, while their underlying ground is the emptiness of all fixed views and rigid distinctions. Emptiness thus becomes the basis for the doctrine of the one vehicle, where diverse paths are gathered into a single, all‑embracing way. This same vision underlies the teaching of original enlightenment, which holds that all beings and all phenomena, in their true suchness, are already expressions of Buddha‑nature.

In practice, Tendai cultivates this view through meditative disciplines that contemplate emptiness, provisional existence, and the middle as inseparable aspects of each experience. The world is not something to be fled but the very field in which the non‑dual nature of reality is realized. Emptiness loosens clinging and undermines absolutist views, while the recognition of provisional functioning affirms that ethical action, ritual, and meditation all matter. In this way, the doctrine of emptiness becomes both a philosophical key and a lived method for seeing this very world as the Buddha’s domain.