By Zuio Hisao Inagaki.
Compared with the Indo-Tibetan tradition of Buddhism, esoteric Buddhism attained a fuller development in China and Japan. Kukai's "genuine esotericism"claims that it is based on the direct exposition of the mystic truth by the cosmic Buddha, Mahavairocana. The essence of his teaching is to be found in the Sokushinjobutsugi. This short but pregnant work is a harmonious fusion of esoteric symbolism and Mahayana philosophy, explaining in highly-symbolic terms the possibility of becoming a Buddha with the present human body.
Some 300 years later, this abstruse esotericism was brought to the level of general Shingon followers by Kakuban. The Three Mystic Practices which Kukai asserted would reveal the Three Bodies of Buddha were condensed into one - the Oral Mystic Practice of calling Amida's Name. When young, while pursuing the Way, Kakuban met a nembutsu sage on Mt. Koya who led him to aspire for the Pure Land through the Nembutsu. Kakuban later systematized the Shingon Nembutsu. This form of Nembutsu, it should be noted, is radically different from the nembutsu in Pure Land Buddhism, as promulgated by Honen and others, but may suggest a possible approach for those who cannot follow either the authentic Shingon way or the more popular nembutsu practice.