Tao Te Ching

“The Buddhist philosopher, Nagarjuna was probably the first to express a similar idea—reality is in itself a relative term which depend on the standpoint of an observer—and base his whole philosophy on it which led to the foundation of Mahayana, the Great Way, which became the main religion of China and was amalgamated with Taoism in the creation of Ch'an or Zen (the meditative school of Buddhism).”

— Anagarika​ (Lama) Govinda 1898 – 1985 CE
(Ernst Hoffmann)
Pioneer of Tibetan Buddhism to the West

from Inner Structure of the I Ching