Within the Tendai tradition, enlightenment is understood first and foremost through the doctrine of original enlightenment (hongaku). All beings, and indeed all phenomena, are regarded as inherently endowed with Buddha-nature and thus fundamentally already enlightened. Enlightenment is not conceived as something imported from outside or newly produced, but as the uncovering or recognition of a reality that has been present from the very beginning. Delusion and enlightenment are not two separate substances; delusion is seen as a misperception of an already enlightened mind. From this perspective, the ordinary and the awakened are not divided by an unbridgeable gulf, but differ in how reality is apprehended.

At the same time, Tendai does not dismiss the importance of practice, and here the distinction between original enlightenment (hongaku) and acquired enlightenment (shikaku) becomes significant. Practice—embracing precepts, meditation, wisdom, and ritual—serves to actualize and reveal the pre-existing enlightened nature, rather than to fabricate it. This gives Tendai a characteristic balance: enlightenment is both the ground that has always been present and the goal that must be realized. The path may appear gradual, unfolding through cultivation and deepening insight, yet what is realized is the “sudden” recognition that one’s mind has never been other than Buddha-mind.

Tendai also frames enlightenment in terms of non-duality and the profound interrelation of all things. Enlightenment is the realization that samsara and nirvana, defilement and purity, are not ultimately two separate realms but different expressions of the same underlying reality. Ordinary mind and Buddha-mind are thus understood as non-dual, and this non-duality extends to the perception of interconnectedness and emptiness in all phenomena. The doctrine that each moment of consciousness contains all possible states of existence underscores that enlightenment is not confined to some distant realm or future time, but can be realized in any present moment.

Because Buddha-nature is held to be universal, enlightenment is regarded as accessible to all beings, regardless of their present condition. There is no fixed, permanent division between Buddhas and ordinary beings; rather, every being stands within the sphere of possible Buddhahood. Tendai’s synthesis of original and acquired enlightenment, of sudden insight and gradual cultivation, allows it to embrace a wide range of practices while maintaining a single, overarching vision: enlightenment is both the ever-present nature of mind and the lived realization of that nature in the midst of this very world.