Sri Aurobindo translates Aitareya Upanishad, Chapter 3: “Who is this Spirit that we may adore Him? and which of all these is the Spirit? By whom one seeth or by whom one heareth or by whom one smelleth all kinds of perfume or by whom one uttereth clearness of speech or by whom one knoweth the sweet and bitter. This which is the heart, is mind also. Concept and will and analysis and wisdom and intellect and vision and continuity of purpose and feeling and understanding, pain and memory and volition and operation (Or, application) of thought and vitality and desire and passion, all these, yea all, are but names of the Eternal Wisdom. This creating Brahma; this ruling Indra, this Prajapati, Father of his peoples; all these Gods and these five elemental substances, even earth, air, ether, water and the shining principles; and these great creatures and those small; and seeds of either sort; and things egg-born and things sweat-born and things born of the womb and plants that sprout; and horses and cattle and men and elephants; yea, whatsoever thing here breatheth and all that moveth and everything that hath wings and whatso moveth not; by Wisdom all these are guided and have their firm abiding in Wisdom. For Wisdom is the eye of the world. Wisdom is the sure foundation, Wisdom is Brahman Eternal. By the strength of the wise and seeing Self, the sage having soared up from this world, mounted (Or, ascended) into this other world of Paradise; and there having possessed desire, put death behind him, yea, he put death behind him.”
The focus of chapter 3 is to remind the reader of the conscious awareness, behind the operations of mind and senses, behind the operations of the universal forces, and behind the operations of the evolutionary process of the manifestation, and to equate this conscious awareness with Brahman Eternal. This represents an expansive description of the concise formulation “All This is the Brahman,” which, taken together with “One without a Second” represents the Upanishadic view of existence.
The term “Wisdom” in this text is a translation of the term prajnana. The sense of this word is what we would call “consciousness”. It comes from the root term jnana, which means knowledge and is related to the term vijnana, which is the term used for an all-embracing and detailed knowledge which acts as the intermediary between the undifferentiated Oneness and the world of Multiplicity in all of its complexity and inter-relationships.
The Upanishad describes the experience of the sage who discovers the Self within and thereby overcomes the force of desire and puts the concept of death behind him. This is a common theme in the Upanishads describing the shift in standpoint from the individual egoistic view to the divine status of Oneness with the Transcendent and the Universal aspects of Brahman. Such a sage gains the all-encompassing conscious awareness of the Brahman and shares, thereby, in the immortality of the Brahman.
Sri Aurobindo, The Upanishads, Aitareya Upanishad, pp.285-294