Several theories that constitute the basis of knowledge only, such as knowledge only theory (including “Three Natures” and “the middle way of knowledge only”); Knowledge theory; The theory of seed and knowledge transformation; The doctrine of cultivation, which aims to remove the seeds of habit, has a huge gap with early Buddhism and early Mahayana, which ignore the ontological priority of the soul, but shows an essential affinity with the epistemology of the Upanishads.
Therefore, they must be formed by the thought of the Upanishads absorbed by the Mahayana Yoga school.
The penetration of Upanishads into Mahayana Buddhism is mainly through Zen.
The yoga practice school combines the “knowledge” theory from the Upanishads with the original “emptiness” theory of Mahayana, takes “emptiness” as the purpose of “knowledge only”, and breaks the attachment of the Upanishads to the true mind as an existing entity.
However, influenced more and more deeply by the tradition of Upanishads, idealism gradually transformed from “emptiness” to “being” in the future development, so as to converge with Upanishads and Vedanta’s thoughts—— Wu XueGuo: Research on the thought of Upanishads, Volume 5..