In order to have a better understanding of the nature of Buddha, one has to study the Trikaya doctrine in Buddhism. According to the Buddhist doctrine, the Buddhas have three bodies (Trikaya) or three aspects of personality.

    35.1   The Form Body (Rupakaya)

    The Form Body (Rupakaya) or the Manifestation Body (Nirmanakaya) or Transformation Body or Response Body.

    After a Buddha has attained Enlightenment, he is the living embodiment of wisdom, compassion, happiness and freedom. In the history made known to us, there was only one Buddha, Shakyamuni. This was his physical body (i.e. Form Body) who was born among men, attained Enlightenment, preached the Dharma and entered Nirvana.

    In the Buddhist scripture, it is said that during the three months after the Nirvana, Shakyamuni Buddha was engaged in preaching the Abhidharma, the Earth Store Sutra, etc. to his mother in the Tusita Heaven. He created some Nimmita-Buddha (or Laksana Buddha) as exact replicas of himself. This mind-formed body of Buddhas (i.e. Manomayakaya) is regarded as the Nirmana-kaya, which cannot be distinguished from the Buddha's voice, words and even the rays of light that emitted forth from his body. The created Buddha could be detected only by the gods of the higher realms of existence, and not by ordinary gods or men. The Manifestation Body (i.e. Nirmana-kaya) of the Buddha is the purely transcendental nature of the Form Body (i.e. Rupakaya). The Manifestation Body of the Buddha is possessed of a beautiful Rupakaya adorned with thirty-two marks.

    The Manifestation Body is transformed in response to the conditions of the sentient beings. Therefore it is sometimes known as the Transformation Body or the Response Body.

    35.2   Reward Body/Enjoyment Body (Sambhoga-kaya)

    The formation of Sambhoga-kaya of a Buddha is based on his blessings and wisdom, as a reward of his vigorous cultivation in Buddhahood. In various stages of the Bodhisattva's career, a Bodhisattva attains a transcendental body by means of which he continues to appear in the various realms of phenomenal existence.

    There are two kinds of Sambhoga-kaya:

    1. Svasambhoga - it is perceived by the Buddhas in other world systems, considered as the body or aspect through which the Buddha enjoys himself in certifying the Dharma.

    2. Parasambhoga - it is perceived by Bodhisattvas and considered as the body or aspect through which the Buddha preaches the Dharma, leading others to the realization of the truth, and enjoys the company of Bodhisattvas.

    This is a selfless, pure, spiritual enjoyment, not to be confused with sensual pleasure. Though not a human, historical person, Sambhogakaya is also considered as a being with a transcendental nature.

    There are different Buddhas in different world-systems, which are formed in different ways by different minds. One of the best known popular system of classification is known as the Five Dhyani-Buddhas, i.e. a group of five "families" over each of which a particular Buddha presided. They are the wisdom-Buddha in Vajradhatu, (1) Vairocana, (2) Aksobhya, (3) Ratnasambhava, (4) Amitabha and (5) Amoghasiddhi.

    35.3   Dharma Body (Dharmakaya)

    This is referred to as the Truth Body of the Buddha, which is the embodiment of the principle of Enlightenment. The Dharma or the truth is not confined to the verbal teachings which are recorded in the Buddhist scriptures, but in general, also the real and essential nature of Buddhas.

    Shakyamuni said, "The Tathagata was Dharma-kaya, as well as Dharmabhuta (i.e. the one who has become Truth)". He also said, "He who sees the Dharma sees the Tathagata; he who sees the Tathagata sees the Dharma".

    In other words, the Buddha is equal to Dharma, and all Buddhas are one and the same, being no different from one another in the Dharma-kaya, because the reality of Truth is one.

    The reality, being not only wisdom, but also compassion for the purpose of preaching the Dharma to all beings assume innumerable forms. These forms, of which Shakyamuni is the one best known to us, are all identical in nature, and hence they are wholly transcendental.

    The Buddha is possessed of a Dharmakaya purified in every way and glorified by the Ten Paramitas, full of splendour and virtue, incomparable and fully enlightened.

    In the Shakyamuni's lifetime, both the Form Body and the Dharma Body were united in him. However, after his Nirvana, the distinction became more pronounced. His Form Body was dead and enshrined in the form of relics in stupas, but his Dharma Body being the collection of his Dharma is eternally present.

    In Buddhist doctrine, Vairocana represents the Dharmakaya, Rocana (or Locana) represents the Sambhogakaya and Shakyamuni represents the Nirmanakaya. Vairocana is generally recognised as the spiritual or essential body of Buddha, and pervading everything like light. The esoteric school interprets it by the sun, or its light. Vairocana is the chief of the Five Dhyani Buddhas, occupying the centre position, known as the Great Sun Tathagatha.