During the development of Pure Land Buddhism in Japan , two approaches to Amida Buddha appeared. The first one – adopted by the Jodo sect – has it that Amida Tathagata is a Sambhogakaya Buddha. Sambhogakaya, often translated as Body of Enjoyment, is one of the three bodies of a Buddha, the other two being the Nirmanakaya or Created Body and the Dharmakaya or Truth Body. The Sambhogakaya is made out of pure light and possesses all the wondrous, splendid and transcendental characteristics of an Enlightened One. The Nirmanakaya is the ephemeral body of a Buddha while the Dharmakaya, being the Body of the Ultimate Reality, is formless and shared by all the Buddhas. In Jodo Shinshu, another approach to Amida appeared, centred on the comments made by Master Shinran. This approach, informs us that the Tathagata of Unhindered Light and Eternal Life, has a much longer lifespan than that mentioned in the Sutras. Actually, it is declared, that Amida Buddha is the Eternal Buddha who attained Supreme Enlightenment in the remotest past.
Accepting the Teachings of Master Shinran, we also accept Amida Tathagata as the Eternal Buddha. The very concept of the Eternal Buddha appears in the Lotus Sutra and more specifically in Chapter 26. There, Shakyamuni expounds that His body is just an ephemeral appearance of the Buddha in this world as well as that He attained Enlightenment innumerable aeons ago. In Jodo Shinshu, it is believed that Buddha Shakyamuni was an incarnation of Amida Buddha, in order to liberate all beings from samsara. Thus, since Shakyamuni Buddha is accepted as an emanation of Amida and Shakyamuni in the Lotus Sutra makes it clear that He is a temporal form of the Eternal Buddha; the direct result is a verification of the commentaries made by Master Shinran.
In Tendai and Nichiren Buddhism, this belief is considered a heresy since the place of the Eternal Buddha for them, is attributed solely to Shakyamuni while Amida Buddha is considered just one of His numerous emanations. In order to defend Jodo Shinshu here, we must firstly clarify that the belief of Amida being the Eternal Buddha, is not a Shin Buddhist innovation. Tibetan Buddhists addressed and still address to Amida during prayer, calling him the Supreme Dharmakaya. Additionally, soon after the appearance of Jodo Shinshu, many priests of the Shingon sect accepted that Amida and Dainichi Nyorai are both aspects of the Dharmakaya. Secondly, if we accept that Shakyamuni was an emanation of Amida Buddha, then we verify the very teachings of the Lotus Sutra where it is clearly stated that Gautama Buddha was a temporal form of the Eternal Buddha who - for Shin Buddhists - is none other than Amida Tathagata.
In the previous argument, an important question arises:
Why do we believe that formless Dharmakaya may have a name and form like that of Amida or Dainichi?
In Jodo Shinshu, there is a unique teaching to explain this. Master Shinran taught that Amida Nyorai as the Eternal Buddha, manifests in two ways. The first one is Dharmakaya as Emptiness which is formless and the other one is Dharmakaya as Compassion, which receives form and leads us to salvation. Thus, Amida Tathagata is the very compassionate activity of the Dharmakaya, which was revealed through the life and accomplishments of Dharmakara Bosatsu and His unsurpassed Vows. Thanks to these Vows and most notably the Primal Vow, all ordinary beings that place their faith in Amida Buddha and utter His Sacred Name, can attain Buddhahood. Namu Amida Butsu!
