Ennin

His journey to Tang China (838–847) and his subsequent writings profoundly influenced Japanese Buddhism.

• Name — Ennin (圓仁) • Other Names — Jikaku Daishi (慈覺大師) • Born — 793 or 794 CE • Birthplace — Mibu, Tochigi Prefecture, Japan • Died — 24 February 864 • Religion — Buddhism • School — Tendai school • Lineage — Sammon lineage • Title — Third zasu, head of the Tendai Order • Predecessor — Enchō (円澄) • Successor — An'e (安慧)

He was born into the Mibu (壬生) family in Shimotsuke Province (present-day Tochigi Prefecture), Japan and entered the Buddhist priesthood at Enryaku-ji on Mt. Hiei (Hieizan) near Kyoto at the age of 15. Studying under Saichō, the founder of Japanese Tendai Buddhism, Ennin excelled in his studies, particularly in the Lotus Sutra and Tiantai meditation practices. After Saichō’s death, Ennin sought to deepen his understanding of Buddhism by traveling to Tang China.

In 838, Ennin was in the party which accompanied Fujiwara no Tsunetsugu's diplomatic mission to the Tang dynasty Imperial court. The trip to China marked the beginning of a set of tribulations and adventures which he documented in his journal. The journal describes an account of the workings of the government of China, which saw strong and able administrative control of the state and its provinces, even at a time of a supposed decline of the Tang dynasty. His writings also expanded on religious matters and commerce. He stayed in Xi'an for five years. Initially, he studied under two masters and then spent some time at Wutaishan (五臺山; Japanese: Godaisan), a mountain range famous for its numerous Buddhist temples in Shanxi Province in China. Here, he learned "Five tone nembutsu" among other practices. Later he went to Chang'an (Japanese: Chōan), then the capital of China, where he was ordained into both mandala rituals: the Mahāvairocana-sūtra and the Vajraśekhara-sūtra, along with initiation and training in the Susiddhikara Sūtra tantra. He also wrote of his travels by ship while sailing along the Grand Canal of China. Ennin was in China when the anti-Buddhist Emperor Wuzong of Tang took the throne in 840, and he lived through the Great Anti-Buddhist Persecution of 842–846. As a result of the persecution, he was deported from China, returning to Japan in 847.

Upon returning to Japan in 847, Ennin brought back numerous Buddhist texts, maṇḍalas, and ritual implements. In 854, he became the third abbot of the Tendai sect at Enryaku-ji, where he built buildings to store the sutras and religious instruments he brought back from China. He played a pivotal role in the esotericization of Tendai Buddhism, reconciling the Lotus Sutra’s teachings with the practices of Chinese Esoteric Buddhism. Ennin introduced numerous rituals which became central to Tendai practice such as the Lotus Repentance Rite (Hokke Senbō). He had a significant influence on Tendai Pure Land practice due to his introduction of two Pure Land rites that became central to the tradition's exoteric praxis: the “constantly walking” meditation on Amida (J: jōgyō zammai) and the "continuous nembutsu" chant (fudan nembutsu). While his chief contribution is seen as the strengthening of Tendai esotericism, the Pure Land recitation practices that he introduced also helped to lay a foundation for the independent Pure Land movements of the subsequent Kamakura period (1185–1333). Ennin also established Sōji-in, a center for esoteric rituals, and built the Prabhūtaratna Stūpa to enshrine the Lotus Sutra. Ennin also founded the temple of Ryushakuji at Yamadera. His dedication to expanding the monastic complex and its courses of study assured the Tendai school a unique prominence in Japan. Ennin's efforts laid the foundation for Taimitsu (Tendai Esotericism), which was further developed by later monks like Enchin and Annen. In 866, Emperor Seiwa posthumously awarded him the title Jikaku Daishi, recognizing his contributions to Japanese Buddhism. Ennin's synthesis of exoteric and esoteric teachings, along with his emphasis on the Lotus Sutra, solidified Tendai Buddhism's influence in Japan. His writings and rituals continue to be studied and practiced, making him one of the most important figures in Japanese Buddhist history.

Ennin was a prolific writer, producing over one hundred works. Some of his most important works are two commentaries on the Vajraśekhara Sūtra and Susiddhikara Sūtra. His diary of travels in China, Nittō Guhō Junrei Kōki, was translated into English by Professor Edwin O. Reischauer under the title Ennin's Diary: The Record of a Pilgrimage to China in Search of the Law. Sometimes ranked among the best travelogues in world literature, it is a key source of information on life in Tang China and Silla Korea and offers a rare glimpse of the Silla personality Chang Pogo.

• Illustration — Letter A in Siddham script Ennin played a crucial role in developing the Esoteric Buddhist tradition within Japanese Tendai Buddhism, known as Taimitsu (台密). Drawing from his experiences studying in Tang China, Ennin sought to expand and refine the Esoteric teachings that Saichō had introduced but left incomplete. Central to Ennin's Esoteric metaphysics was his theory that the syllable "A", as the foundational vowel in the Sanskrit alphabet, represented the ultimate reality that is unborn and undying. This reality is equated with the inner enlightenment of the cosmic Buddha Mahāvairocana (Jp. Dainichi, 大日), the central figure in East Asian Esoteric Buddhism. Ennin identified the syllable "A" as the scriptural essence of key Esoteric texts such as the Vajraśekhara-sūtra and the Mahāvairocana-sūtra. In his commentary on the Vajraśekhara-sūtra, he declared that the syllable "A" unified the sutra's diverse meanings. Citing the Mahāvairocana, Ennin maintained that the Esoteric teachings in their entirety are encapsulated by the syllable "A." He asserted that this syllable is the source of all phenomena, and in response to differing conditions, it manifests either as the enlightened realm symbolized by Esoteric mandalas or as the realm of delusion experienced by ordinary beings. This framework echoes Saichō's doctrine of "Suchness according with conditions," in which ultimate reality manifests itself in response to changing circumstances. Ennin further linked the "A" syllable to the differentiated expressions of truth symbolized by the various sounds and characters in Buddhist mantras. He claimed that the single syllable "A" expands into all syllables, reflecting the principle that Suchness manifests in accordance with conditions. In the question-and-answer section of his commentary, Ennin affirmed that the Buddha's enlightened realm—depicted in the vajra realm mandala—is established through the conditioned arising of the dharma-realm, which itself embodies dharma-nature. Here, Ennin emphasized that the syllable "A" manifests in accordance with conditions to produce the phenomenal world. He further maintained that this understanding aligned with the Tendai doctrine of the Buddha-nature of insentient beings (cf. Zhanran), reinforcing the idea that all things participate in the ultimate reality of Suchness according with conditions.

The authorities additionally record the headings Shi Yuanren, Huafang dashi, Cijiao dashi, Yuanren and Jikaku Daishi. His recorded language was Japanese. His recorded confession was Tendai.