Ñāṇadassana-visuddhi

ñāṇadassana-visuddhi is translated as "purification by knowledge and vision," "purification of knowledge and vision," etc. In the Pali tradition, ñāṇadassana-visuddhi is identified as the seventh of the seven stages of purification on the path to liberation, as presented in the Visuddhimagga.

This purity consists of the knowledge associated with the attainment of the four supramundane paths.

Buddhism: One Teacher, Many Traditions states:

Purification by knowledge and vision (ñāṇadassana visuddhi), according to Buddhaghosa, is knowledge of the four supramundane paths and thus is the only supramundane purification. Some moments of transition from purification by knowledge and vision of the way precede the breakthrough to the supramundane path as the mind “changes lineage” from being a mundane mind perceiving conditioned phenomena to a supramundane mind knowing nibbāna. The culmination of insight that occurs just before the first moment of the supramundane path focuses on the three characteristics. It is called insight leading to emergence because it leads to the supramundane path that emerges from conditioned phenomena by taking nibbāna, the unconditioned, as its object, and that emerges from mundane consciousness by eliminating some of the defilements.

This last moment of insight, called change of lineage consciousness, marks the transition from an ordinary being to an ariya. While it resembles the path by focusing on nibbāna, it is unlike the path because it cannot dispel the defilements that obscure seeing the four truths. The path consciousness that arises subsequent to the change of lineage consciousness performs four functions of: fully understanding dukkha; abandoning the origin of dukkha; realizing nibbāna; and cultivating the noble eightfold path.

Each path consciousness of stream-enterer and so forth performs these four functions, and when the corresponding level of defilements has been reduced or eradicated, that path consciousness is followed by the fruition consciousness. After the fruition consciousness, a reviewing knowledge (paccavekkhaṇañāṇa) arises. It looks back and reflects on the path, fruit, and nibbāna, and often on the defilements that have been abandoned and those that remain. There is a tremendous sense of satisfaction, relief, and joy at this time, and meditators continue to practice until they reach the fruit of arahantship. In this way the knowledge of the four supramundane paths is accomplished, and the final goal, nibbāna, is attained.

Sources

• Buswell, Robert E.; Lopez, Donald S. (2014), The Princeton Dictionary of Buddhism, Princeton University 
• Dalai Lama; Thubten Chodron (2014), Buddhism: One Teacher, Many Traditions, Wisdom Publications 
• Gethin, Rupert (1998), Foundations of Buddhism, Oxford University Press