The Hua-yen School is original to China. Its philosophy is based on the Hua-yen ching (Skt. Avatamsaka Sutra) or Flower Garland Scripture, but it is also a product of the indigenous Chinese world view, in particular the world-affirming, all-inclusive thought of philosophical Taoism.
According to the Hua-yen School, in the second week after his enlightenment the Buddha entered the highest state of samadhi (enlightened concentration) and saw the entire universe as it really is, as an infinite harmonious totality of interdependently related phenomena. To communicate his enlightened perception the Buddha taught the Hua-yen ching, making this text, for the Hua-yen, the only unadulterated or undiluted expression of the absolute truth.
The Hua-yen School is an attempt to articulate, in philosophy, this absolute truth. One of the ways it does so is in its theory of the four universes, which are actually four different ways of perceiving or understanding the same one reality. The first is the universe of shih or phenomena, the universe of multiple discrete objects that we ordinarily perceive. The Hua-yen associates this view with the realistic philosophies of the schools of Hinayana Buddhism such as the Chu-she. The second is the universe of li or principle, which is the universe viewed solely in terms of the principle which transcends phenomena. This view is associated with the Fa-hsiang School and its Consciousness-Only teaching, and the San-lun School with its doctrine of emptiness. The third consists of the universe perceived as the interpenetration and identification of the first two universes of shih and li. This view is ascribed to the T'ien-t'ai School, with its doctrine that the principles of emptiness and the One Mind do not exist apart from phenomena. The fourth is the universe of the interpenetration of shih and shih, of phenomena and phenomena. This is the universe of the Hua-yen School, and it is the only universe which really exists, the others simply being incomplete interpretations of it. Once one understands that phenomena are neither expressions nor embodiments of principle, but are principle, and merely the One Mind or emptiness known by another name, then there is no more need to speak of principle.
The Hua-yen calls this universe the fa-chiai yuan-ch’i, or the universe of interdependent existence, because the existence of every thing within it is interdependent with the existence of all other things, in all places and in all times. To explain this one text uses the example of a barn and its constituent parts to represent, respectively, the totality of existence and the individual phenomena within it. Just as one cannot remove a part of the barn without altering the identity of the whole barn (for clearly the original barn does not remain when the part is removed), so, likewise, no phenomena can be removed from the totality without changing the identity of that totality. The existence of the whole universe then, and all things within it, is dependent upon the existence of each and every one of the individual phenomena which make it up. There are thus an infinite number of interdependency relations indissolubly connecting and uniting every thing in the universe. The existence and identities of all things are therefore said to interpenetrate, forming an organic, harmonious whole, a doctrine which the Hua-yen summarises in its saying, “One in One, All in All, One in All, All in One.” The practical realisation of this philosophy in life, is enlightenment, that is the acceptance, and ultimately the love, of all things as necessary and integral to the whole, no matter how insignificant or repellent some parts of the whole may at first appear.
In terms of the history of Buddhist thought one way of understanding Hua-yen philosophy is as a positive re-interpretation of the cardinal Buddhist doctrines of Dependent Origination (Skt. pratitya-samutpada) and emptiness. The Hua-yen School viewed itself as in harmony with, and inclusive of, other Buddhist schools in that it accepted their teachings as expedient, but also as separate from them, in that only its philosophy was free from partiality and presented the absolute truth.
The Hua-yen ching was first translated in 418-20, and then again between 695-9. At the beginning of the sixth century the text began to be studied by the Ti-lun, a scholastic sect based on the Dasabhumika Sutra Sastra. One of the Ti-lun’s claims was that the ten separate bhumis or stages of the Bodhisattva path were all interdependent and identical. This doctrine of interdependency and identity, which was to become the central motif of Hua-yen philosophy, passed into the Hua-yen tradition when the members of the Ti-lun sect were attracted to the teachings of the first Hua-yen patriarch, Tu-shun (557-640). Tu-shun was a monk, meditation master, and miracle worker, who took his inspiration from the Hua-yen ching. He attracted popular as well as imperial support, the Emperor Wen of the Sui Dynasty giving him both a title and a monthly allowance. Tu-shun’s successor was Chih-yen (602-668), a monk and able scholar well versed in the doctrines of the She-lun and Ti-lun scholastic sects. Chih-yen applied his knowledge to the interpretation of the Hua-yen ching,and formulated many of the basic doctrines of the School.
The third Hua-yen patriarch, Chih-yen’s pupil Fa-tsang (643-712), is generally regarded as the School’s true founder and greatest teacher. In his many written works he elaborated, refined, and systematised, Hua-yen philosophy, as well as being an active preacher of its doctrines. The School also gained the patronage of Empress Wu Tse-t’ien (r. 683-705), who found in these doctrines sanction for her position as China’s first female ruler. Confucianism did not allow women to rule, while by distinction the Hua-yen claim that the Buddha-nature was equally present in women and men, could be taken as affirming, at least in this one very important respect, the equality of the sexes. The relationship between Fa-tsang’s and Empress Wu was therefore very good. He lectured at the imperial palace on more than one occasion, and she honoured him with various titles.
When Empress Wu abdicated to her son in 705, he maintained her patronage of the Hua-yen. The School continued to thrive under its fourth patriarch, Ch’eng-kuan (738-839?), who held the post of Imperial Master under six successive emperors. Like Chih-yen and Fa-tsang before him, Ch’eng-kuan was an able scholar, and knowledgeable in the doctrines of the other schools of Chinese Buddhism. In particular he studied the Ch'an School, which was then emerging as the dominant religious force of the period, and drew attention to the commonalities between it and the Hua-yen. This bringing together of the Hua-yen and Ch'an Schools was continued by the fifth and last patriarch, Tsung-mi (780-841), who was a Ch'an monk before he became a Hua-yen master. His work served to ensure at least the doctrinal survival of the Hua-yen beyond the great persecution of 845, for it was within the Ch'an tradition that the School’s teachings were preserved.
D.T. Suzuki, the eminent writer on Zen (Ch'an) Buddhism, has remarked that while the Ch'an School represents the practical culmination of Buddhism's development in China, the philosophy of the Hua-yen School stands as its theoretical culmination: thus we have the Chinese saying "Ch'an for practice, Hua-yen for philosophy". Moreover, because Hua-yen doctrines were absorbed by the Ch'an, the Hua-yen continues to exert its influence today as, essentially, the adopted philosophy of the Ch'an School. Hua-yen thought also had a significant influence on Neo-Confucian metaphysics.
Perhaps partly due to the complexity of its thought, the Hua-yen did resort to symbols to illustrate the universe which its philosophy described. The primary symbol used was the Sun or Illumination Buddha, Vairocana (also Mahavairocana), who as the universal Buddha is identified with the totality of existence. A fifteen metre stone statue of Vairocana, carved during the time of the third Hua-yen patriarch Fa-tsang, survives at the Lung-men cave complex near Lo-yang in Honan Province, while another, sixteen metres high and made of bronze, is at the Todaiji temple in Japan.
From the Hua-yen ching the Hua-yen School drew theimage of Indra’s Net. Here the universe is pictured as net with an infinite number of loops, and on every loop of the net is hung a single jewel, symbolising individual phenomena. Each jewel reflects and contains the light from the totality of all the other the jewels, both collectively and individually, thus illustrating the interdependent existence of the universe, and the Hua-yen saying, "One in One, All in All, One in All, All in One."
The fifth Hua-yen patriarch Tsung-mi symbolised the pure and impure aspects of universal Consciousness by an empty circle and a black circle respectively. Progress toward enlightenment is illustrated by the black circle gradually becoming empty, while the fall into ignorance is shown by the empty circle becoming increasingly black.
The Hua-yen School was for a long time associated with a complex of monasteries in the Wu-t’ai Mountains in northern Shansi Province. Welch, writing just before the Cultural Revolution, noted that a few Hua-yen monasteries remained in north China, and it is perhaps to those in the Wu-t’ai Mountains that he is referring. He also mentions that there were, at the time, a lot of Hua-yen temples in Beijing (Welch 1967: 398; 507). In Japan the main centre is the Todaiji Temple at Nara, the capital city of Nara Prefecture in southern Honshu Island.