KUKAI, the founder of Japanese esoteric Buddhism, was born in Zentsuji on the island of Shikoku to an aristocratic family. His uncle, a tutor to the crown prince, also became his teacher. As a young man, he dropped his studies of Confucius and career at court to study Buddhism, then very much a minority perspective. He was only 23 when he produced his first book, in which he argued for the superiority of Buddhism over Confucianism and Taoism. Over the next few years he studied widely in the several different schools of Buddhist thought then available in Japan, all of which were headquartered at Nara, near the imperial capital at Kyoto.
In 804 he traveled to Changan, then the capital of China, and became the last student of Hui-Guo (746–805), the leader of the Shingon or esoteric school of Buddhism. When he returned to Japan he was an accomplished exponent of the esoteric tradition. He established himself in two centers, one on Mount Koya south of Kyoto and the other in Kyoto at the Toji temple. He would teach at these two places for the rest of his life and establish Dhingon as a major school of Japanese Buddhism.
In contrast to most Buddhists of his day who suggested that enlightenment took many lifetimes, Kukai argued that it was possible to achieve in a single lifetime. He also argued that the body, which most who sought enlightenment considered an obstacle, was in fact the vessel for its realization. He argued that the Buddha nature is present in all things, including all human beings. To understand the essential and innate unity of all things, Kukai proposed that students engage in meditative disciplines. Meditative insight would bring clarity to what was otherwise a seemingly unbelievable idea. Kukai also argued for the dissolving of the secular and sacred. He argued for a form of natural mysticism in which the Buddha was incarnate in the world of nature and by extension in the world of art and music. He believed that even words could have the power of revelation.
In his book The Meanings of Sound, Word, and Reality, Kukai argued for the correlation of words and reality. Some words correspond to the reality of the Buddha nature. These True Words are termed mantras, and chanting a mantra articulates the Buddha nature for as long as the sound persists. He also believed that the overcoming of the ordinary consciousness and the Buddha nature was in fact most difficult for most people. People could overcome the separation through the practice of meditation, the chanting of mantras, and the use of mystical hand gestures called mudras.
Kukai died at Mt. Koyo in 835. In later generations he came to be worshipped almost as a god and many came to believe that he had never died. He is now generally called Kobo Daishi or Great Master of the Extensive Teachings. Shingon Buddhism now exists in a variety of separate schools in Japan who have, over the centuries, developed a wide variety of esoteric methods to achieve communion with the Buddha nature.
Kukai: Major Works. Translated by Yoshito Hakeda.
New York: Columbia University Press, 1972.
Yamasaki, Taiko. Shingon: Japanese Esoteric Buddhism.
Boston: Shambhala, 1988.