本文皆旨在分析與重構在《梵書》、《梵經》、《薄伽梵歌》及《奧義書》中所展示的有關梵天的「本體神學」或「實有神學」之本質，其要點如下： （1）「本體神學」或「實有神學」這個概念常與海德格連在一起，而它其實是出於康德。從字面上說，「本體神學」或「實有神學」一詞是指「上帝之實在性」或「實有的神學」。康德把「超驗神學」分為「本體神學」（實有神學）與「宇宙論神學」。根據康德之見，「超驗神學」之目標是推論或論証最高實有之存在，稱之為「宇宙論神學」，或者只藉概念之研究，以求認識此種實有之存在，並稱之為「本體神學」（實有神學）。對海德格來說，自希臘哲學以來，形上學明顯地是針對本體論（實有論）與神學，於是，形上學其實是「本體神學」（實有神學）。 （2）《梵經》解釋《奧義書》有關梵天、世界，及個體自我與梵天之間的關係之教，把梵天視作自在與永恆，並作為宇宙因。梵天賦予存在界能力，讓存在界藉之而演化。《梵經》一方面表明梵天與個體自我有差異，因為個體自我是有限的，而梵天則是無限。但在另一方面，個體自我與梵天有相同之處，因為個體自我是梵天的一部份。 （3）《薄伽梵歌》是藉黑天與般度家族的王子阿周那之間的對話，闡述生命的意義，時間背景是在古盧之野的摩訶婆羅多大戰前夕。黑天向阿周那描述如何藉著獲得完美知識而達至完美或最高的境地，這是一個自我實現的過程。當他完全超脫假我之時，便不受物性之制約。 （4）《奧義書》將梵天定義為「真實、知識與無限」，有時又將梵天稱作“Sacchidā nanda”，這是由「實有」、「意識」及「福樂」所組成。梵天是不變、無限、內在與超越的實在體，祂是一切物質、能量、時間、空間、及在宇宙內外任何事物之根基。梵天又分別被不同的《奧義書》視為具人格、非人格或超越人格。《奧義書》的開悟者深信解脫者的靈魂能實現梵我合一之境。 （5）最後，撰者指出將婆羅門教的「本體神學」（實有神學）視為「萬有在神論」，比將之視為「泛神論」較為適宜，其原因在於印度的泛神只被視為梵天的不同之表現形式，而所謂「一切即一」或「一切是梵」，其意義即指不同途徑皆能達至一梵。婆羅門教的本體神學認為萬有皆具梵之本質，世界是梵之身體，同時，梵與世界之間是互為關係的。

The task of this paper is to analyze and to reconstruct the ontotheological characteristics of the conception of Brahman exposed in the Brahmanas, the Brahma Sutra, the Bhagavad Gita as well as in the Upanishads respectively, and its key concepts are as follows: (1) The term "ontotheology" which is often associated with Heidegger was actually coined by Immanuel Kant. Verbally speaking, the term ontotheology means the ontology of God or the theology of being. Kant divided transcendental theology into ontotheology and cosmotheology. According to him, transcendental theology aims either at inferring the existence of the Supreme Being, and it is called cosmotheology; or it endeavours to cognize the existence of such a being, through mere conceptions, and is then termed ontotheology. For Martin Heidegger, Western metaphysics since the beginning with the Greeks has eminently been both ontology and theology, and for this reason, metaphysics is for him onto-theology. (2) The Brahma Sutra inteprets the Upanishads teachings about Brahman, the world and the relation of the individual soul to Brahman. The Sutra admits uncreated and eternal Brahman as the Cause of the whole universe. It is Brahman that confers the power through the exercise of which the evolution takes place. The Sutra exposes the view that the jiva is different but also not different from Brahman. Although Badarayana looks upon the different between Brahman and the individual soul as ultimate, the Sutra maintains that the jiva is not different from Brahman at the same time, since jiva is a part of Brahman. (3) The Bhagavad Gita presents a dialogue between Krishna and the Pandava hero Prince Arjuna on the meaning of life before the great Mahabharata battle on the holy field of Kurukshetra. Krishna describes for Arjuna that one can achieve the highest perfectional stage simply by attaining the perfection of knowledge. That is the process of self-realization. When he is completely free from false ego, he becomes nonattached to all material things. (4) The Upanishads define Brahman as “satyam jnanam anantam brahman”, i.e. as “truth, knowledge and infinity” or “Sacchidānanda” which is combined from sat-chit-ānanda, meaning “being-consciousness-bliss”. Brahman is the unchanging, infinite, immanent, and transcendent reality which is the Divine Ground of all matter, energy, time, space, being, and everything in as well as beyond this universe. The nature of Brahman is described as transpersonal, personal and impersonal by different Upanishads. The seers who inspired the composition of the Upanisads asserted that the liberated soul (jivanmukta) has realized his identity with Brahman as his true self. (5) Finally, the ontotheology of Brahmanism is panentheism rather pantheism on the ground that the Hindu pantheon of gods is said to be only higher manifestations of Brahman, and the phrase "ekam sat" (all is one), or “all is Brahman” explains the Hindu view that all paths lead to the one Brahman, though many religions call him different things. Brahmanism recognizes that everything shares God's being (or becoming) and God and the world, which is God's body, are interdependent.