Introduction (various types of Buddha-nature)

The Buddha-nature is the absolute nature of all beings existing in both ordinary people and the Buddha. The Buddha-nature is beyond all reasons; it is not to be brought under any forms of category. Therefore, the Buddha-nature may be called with various names. As defined above, the Buddha-nature may be individually named Buddhatā or Buddhagotra (fo-xing), Tathāgatagarbha (rulaicang), Dharmakāya (fashen), Selfnature (zixing), Real mind (zhenxin), Original mind (benxin), etc.^[1] Universally, the Buddha-nature is the absolute reality or “undifferentiated whole”, also known as tathatā (Thussness, zhenru), Dharmadhātu (fajie), Self-form (Shixiang), etc.^[2]

Epistemologically, the Buddha-nature has two characteristics: individuality and universality. Individually, the Buddha-nature called Tathāgatagarbha when it is still hidden and obscured by defilements in sentient beings, and Dharmakāya when it is completely uncovered from defilements and fully exposing in the Buddha. Universally, the Buddhanature called by various names such as Tathatā, Dharmadhātu, and so on, in order to refer to the absolute reality of all things.

The above concepts of the Buddha-nature can also be found in the Laṅkāvatārasūtra. The Sūtra sometimes uses the term Buddhatā to refer to the Buddha-nature.^[3] In other places, Buddha-nature is also known under the name Tathāgatagarbha, Ālayavijñāna, or Citta (Mind) when it is still enveloped with habit-energy (vāsanā);^[4] and under the name Dharmakāya, Tathāgata, or Buddha^[5] when referred to the enlightened-beings who have cleaned all habit-energy. Universally, the Laṅkāvatārasūtra maintains the view that the Tathāgatagarbha or Ālayavijñāna is the storage of the impure as well as the pure cause or mental seed, that it is both immanent and transcendental, both relative and absolute.^[6] In this case, Buddha-nature is regarded as the same as the concept of Mind-only (Cittamātra), which is the unique, absolute and immanent reality.