Purity in Buddhism

Purity (Pali: Vissudhi) is an important concept within much of Theravada and Mahayana Buddhism, although the implications of the resultant moral purification may be viewed differently in the varying traditions. The aim is to purify the personality of the Buddhist practitioner so that all moral and character defilements and defects (kleśas such as anger, ignorance and lust) are wiped away and nirvana can be obtained.

Theravada

Theravada Buddhism regards the path of self-purification as absolutely vital for reaching Nibbana. The main task of the Theravada Buddhist monk is to eradicate flaws in morality and character through meditation and moral cultivation, in alliance with the cultivation of insight or wisdom (Paññā), so that the purity of Nibbana can be achieved.

So important is this notion of purity in Theravada Buddhism that the famed Buddhist monk and commentator Buddhaghosa composed a central thesis on dhamma called The Path of Purification (Visuddhimagga).

Mahayana

Tathāgatagarbha

Controversially, according to the Mahayana Tathāgatagarbha sutras, the unsullied essence of a being—the "true self", or Buddha-nature—can become manifest once the temporary and superficial contaminants (kleśas) have been eradicated from its presence.

In the Śrīmālādevī Siṃhanāda Sūtra, there are two primary states of the Tathāgatagarbha. One is when it is covered with defilements and known as the "embryo of the Tathāgata" (Tathāgatagarbha). The other is when it becomes free from defilements, and is no more the "embryo", but the Tathāgata or Dharmakāya.

The Mahābherīharaka Sūtra elaborates that at the time one becomes a Tathāgata, one dwells in Nirvana and may be referred to as "permanent", "steadfast", "calm", "eternal" and "self" (ātman).