The unified practice of Ch'an and Pure Land, known in Chinese as "Ch'an-ching I-chih," has a long history.
As early as the 4th century C.E., Master Hui-Yuan (334-416), considered to the be first Pure Land Ancestor, incorporated meditative discipline into Pure Land practice.
Tao-Hsin (580-651), the Fourth Ancestor of the Ch'an school, taught what he called the "[[Samadhi of [Oneness]]," utilizing the recitation of the Buddha's name to pacify the mind.
It should be noted that since this practice involved reciting the name of any Buddha (a practice dating back to the origins of Buddhism) it was not specifically designed to produce rebirth in the Realm of Bliss, but it did act as a bridge linking Ch'an and Nien-Fo practices.
Tao-Hsin taught that the Pure Mind is the Pure Buddha-Land.
The unified practice was also advocated by the Fifth Ch'an Ancestor Hung-Jen (601-674) who saw recitation as a good practice for beginners. Hung-Jen also advocated the visualization practices laid out in the Visualization Sutra.
Buddha recitation not concerned with rebirth was taught by a number of Hung-Jen's disciples including Fa-Chih (635-702), the Fourth Ancestor of the Ox-Head School of Ch'an.
It was also put forth by the Ching-Chung School which was descended from Chih-Hsien, one of the Fifth Ch'an Ancestor's 10 eminent disciples, in the early 8th century C.E.
Descendents of Chih-hsien who advocated the unified practice included Wu-Hsiang, a former Korean prince who made invocational Nien-Fo practice a key part of the Dharma Transmission Ceremony.
Although the practice was still not centered around Buddha Amitabha or rebirth in the Realm of Bliss, it marked the first time that Nien-Fo practice was explicitly adopted as part of a Ch'an school.
Subsequent schools which taught Nien-Fo as part of their training included the Pao-T'ang School, the Hsuan-Shih Nien-Fo Ch'an School and the Nan-Shan Nien-Fo Ch'an School.
Ancestor Tz'u-Min (679-748) is said to have been the first Pure Land Ancestor to advocate harmonizing Pure Land practice and Ch'an.
Tz'u-min developed his Pure Land faith after a pilgrimage to India, where he was inspired by stories centered around Buddha Amitabha and Bodhisattva Avalokitesvara.
The Ch'an Ancestor Pai-Chang Huai-Hai (720-814), who wrote the "20 Monastic Principles" which were the blueprint for Ch'an monastic practice, included "Recitation of the Name of Buddha Amitabha."
Pai-Chang stated, "In religious practice, take Buddha Recitation as a sure method." The practice of chanting Amitabha's name during a Ch'an monk's funeral was also put forth by Master Pai-Chang.
The T'ang Hui-Ch'an Persecution (845 C.E.) and the Huei-Ch'ang and Shih-Tsung Persecutions of the late Chou Dynasty (10th century C.E.) served to bring Ch'an and Pure Land even closer together.
These government crackdowns on Buddhist sects enervated the academically oriented Buddhist schools such as the T'ien-t'ai and Hua-yen sects. Correspondingly, the rise of Neo-Confucianism drew many speculative thinkers away from those schools.
But the Ch'an and Pure Land schools, marked by their emphasis on practice, their extreme degree of portability and their non-reliance on Imperial patronage, survived intact.
By this time, the Ch'an school had incorporated true Nien-Fo Amitabha practices into its training regimens, and the Pure Land school had incorporated more meditational elements into its own system.
The Ch'an monk and Pure Land practitioner Yung-Ming Yen-Shou (905-975) is said to have been the key figure in the synthesis of Ch'an and Pure Land during this period.
He taught that the Pure Land is the Realm of the Purified Mind.
The unified practices were taught in Vietnam by the Thao-Duong School, founded by the Chinese monk Ts'ao-Tang, who was taken to Vietnam as a prisoner of war in 1069 C.E.
Other eminent Chinese monks who promoted unified practice were Chu-Hung (1535-1615) and Han-Shan (1546-1623).
During the 17th century C.E., the monk Yin-Yuan Lung-Chi, known as Obaku in Japanese, brought the unified Ch'an/Pure Land practice to Japan.
His school is known as the Obaku Zen School, and survives to this day as a minor sect in the shadow of the much more influential Soto and Rinzai Zen sects.
The unified practice of Ch'an and Pure Land continues to this day, although it was de-emphasized in the major Japanese Zen schools.
The large Shin sect of Japanese Pure Land Buddhism discounts any efforts on one's own part to attain Enlightenment; superficially, Japanese "Other-Power" Pure Land Buddhism and "Self-Power" Zen Buddhism do not complement each other the way the Chinese Ch'an and Pure Land schools do.
However, there are recent movements which may yet be influential in returning Japanese Zen to its syncretic roots.
In the 1970s, the formation of the Zen Shin Sangha by Rev. Koshin Ogui in Cleveland, Ohio was one of the first instances of a Shin Buddhist priest in the United States combining Japanese Zen and Pure Land practices.
Similar movements have been reported in England, continental Europe and India.
As the esteemed Ch'an Master Hsu-Yun (1840-1959) put it, "All the Buddhas in every universe, past, present and future, preach the same Dharma. There is no difference between the methods advocated by Shakyamuni and Amitabha."