The Brihadaranyaka Upanishad (, ) is one of the Principal Upanishads, associated with Shukla Yajurveda and is one of the first Upanishadic scriptures of Hinduism. A key scripture to various schools of Hinduism, the Brihadaranyaka Upanishad is tenth in the Muktikā or "canon of 108 Upanishads".

The Brihadaranyaka Upanishad is estimated to have been composed about 7th–6th century BCE. The Sanskrit text is preserved in two recensions, Mādhyandina and Kāṇva, and survives in medieval palm‑leaf manuscripts, the oldest of which date to the 12th century CE. Extant manuscripts are held in the National Archives of Nepal (via the Nepal–German Manuscript Preservation Project), the Sarasvati Bhavana Granthalaya in Varanasi, and later paper manuscripts in the Bhandarkar Oriental Research Institute in Pune. The Sanskrit language text is contained within the Shatapatha Brahmana, which is itself a part of the Shukla Yajur Veda. The Brihadaranyaka Upanishad is a treatise on Ātman (Self), includes passages on metaphysics, ethics, and a yearning for knowledge that influenced various Indian religions, ancient and medieval scholars, and attracted secondary works such as those by Adi Shankara and Madhvacharya.Brihadaranyaka Upanishad with Adi Shankara's commentary – Swami Madhavananada (Translator)Brihadaranyaka Upanisad with the commentary of Madhvacharya, Translated by Rai Bahadur Sriśa Chandra Vasu (1933); .

Chronology The chronology of Brihadaranyaka Upanishad, like other Upanishads, is uncertain and contested.Stephen Phillips (2009), Yoga, Karma, and Rebirth: A Brief History and Philosophy, Columbia University Press, , Chapter 1 The chronology is difficult to resolve because all opinions rest on scanty evidence, an analysis of archaism, style, and repetitions across texts, driven by assumptions about the likely evolution of ideas, and on presumptions about which philosophy might have influenced which other Indian philosophies. Patrick Olivelle states, "in spite of claims made by some, in reality, any dating of these documents (early Upanishads) that attempts a precision closer than a few centuries is as stable as a house of cards".

The chronology and authorship of the Brihadaranyaka Upanishad, along with Chandogya and Kaushitaki Upanishads, is further complicated because they are compiled anthologies of literature that must have existed as independent texts before they became part of these Upanishads.

The exact year and even the century of the Upanishad's composition is unknown. Scholars have offered different estimates ranging from 900 BCE to 600 BCE, all preceding Buddhism. Brihadaranyaka is one of the first Upanishads, along with Jaiminiya Upanishad and Chandogya Upanishads.Fujii, M. 1997, "On the Formation and Transmission of the Jaiminīya-Upaniṣad-Brāhmaṇa", Inside the Texts, Beyond the Texts: New Approaches to the Study of the Vedas, ed. M. Witzel, Harvard Oriental Series, Opera Minora, 2], Cambridge, 89–102 The Brihadaranyaka Upanishad was in all likelihood composed in the earlier part of 1st millennium BCE, in the 7th–6th century BCE, give or take a century or so, according to Patrick Olivelle. The text was likely a living document and some verses were edited over some time before the 6th century BCE.

Etymology and structure

Brihadaranyaka literally means "great wilderness or forest". The Brihadaranyaka Upanishad is credited to ancient sage Yajnavalkya, but was likely refined by a number of ancient Vedic scholars. The Upanishad forms the last part, that is the fourteenth kānda of Śatapatha Brāhmana of "Śhukla Yajurveda". The Brihadaranyaka Upanishad has six adhyayas (chapters) in total. There are two major recensions for the text – the Madhyandina and the Kanva recensions. It includes three sections: Madhu kānda (the 4th and 5th chapter of the fourteenth kānda of Satapatha Brahmana), Muni kānda (or Yajnavalkya Kanda, the 6th and 7th chapter of 14th kānda of Satapatha Brahmana) and Khila kānda (the 8th and 9th chapter of the fourteenth kānda of Satapatha Brahmana).

The first and second chapters of the Upanishad's Madhu kānda consists of six brahmanas each, with varying number of hymns per brahmana. The first chapter of the Upanishad's Yajnavalkya kānda consists of nine brahmanams, while the second has six brahmanas. The Khila kānda of the Upanishad has fifteen brahmanas in its first chapter, and five brahmanas in the second chapter.

Content First chapter The Brihadaranyaka Upanishad starts by stating one of the many Vedic theories of creation of the universe. It asserts that there was nothing before the universe began. Then, Prajapati created the universe from this nothingness as a sacrifice to themself, imbuing it with Prana (life force) to preserve it in the form of cosmic inert matter and individual psychic energy.Brihadaranyaka Upanishad, Chapter 1, Translator: S Madhavananda, pages 5–29 The Brihadaranyaka Upanishad asserts that the world is more than just matter and energy; it is also constituted by Atman or Brahman (Self, Consciousness, Invisible Principles, and Reality) as well as Knowledge.

The Brahmana 4 in the first chapter announces the non-dual monistic metaphysical premise that Atman and Brahman are identical Oneness. It asserts that because the universe came out of nothingness when the only principle existent was "I am He", the universe, after coming into existence, continues as Aham brahma asmi (I am Brahman).Brihadaranyaka Upanishad, Chapter 1, Translator: S Madhavananda, pages 92–118 In the last brahmana of the first chapter, the Upanishad explains that the Atman (Self) inspires by being self-evident (name identity), through empowering forms, and through action (work of a living being). The Self, states Brihadaranyaka, is the imperishable one that is invisible and concealed pervading all of reality.

Second chapter The Brihadaranyaka Upanishad starts the second chapter as a conversation between Ajatashatru and Balaki Gargya on theory of dreams, positing that human beings see dreams entirely unto themselves because mind draws, in itself, the powers of sensory organs, which it releases in the waking state. Brihadaranyaka in brahmana 3 asserts that the human mind can perceive and construct its own reality. Mind is a means, prone to flaws. It emphasizes the struggle to realize the true, unknowable nature of Atman-Brahman, described as "neti, neti" (not this, not this), beyond qualities or characteristics.

In the fourth brahmana of the Brihadaranyaka Upanishad, Yajnavalkya and his wife Maitreyi engage in a dialogue about love and spirituality. Yajnavalkya states that one doesn't connect with and love forms, nor does one connect or love mind, rather one connects with the Self, the Self of one's own and one's beloved. All love is for the sake of one's Self, and the Oneness one realizes in the Self of the beloved.Brihadaranyaka Upanishad, Chapter 2 Section IV, Translator: S Madhavananda, pages 347–377 He then asserts that this knowledge of the Self, the Self, and Brahman is what makes one immortal, and the connection is also immortal. All longing is the longing for the Self, as the Self represents the true, the immortal, the real, and infinite bliss.

The fifth brahmana introduces the Madhu theory, giving this section the name Madhu Khanda. The Madhu theory is one of the foundational principles of Vedanta schools of Hinduism, as well as other āstika schools of Indian philosophies. Madhu literally means "honey", or the composite fruit of numerous actions on the field of flowers. In this theory, notes Paul Deussen, the Brihadaranyaka Upanishad asserts that "Atman exists" (Self exists), that all organic beings (plants, animals, human beings and gods) are all beings are interconnected with each other and Brahman (Cosmic Self); it further asserts that inorganic nature (fire, air, earth, water, space) is the field where the beings act, and where their numerous actions create fruits that they separately and together experience. The Upanishad then states that everything is connected, beings affect each other, organic beings affect the inorganic nature, inorganic nature affects the organic beings, one is the "honey" (result, fruit, food) of the other, everyone and everything is mutually dependent, nourishing and nurturing each other, all stemming from one Brahman, resulting in blissful oneness.Brihadaranyaka Upanishad, Chapter 2 Section IV, Translator: S Madhavananda, pages 377–404 This theory appears in various early and middle Upanishads, and parallels Immanuel Kant's doctrine of "the affinity of phenomena" built on "the synthetic unity of apperception".Alan Jacobs (1999), The Principal Upanishads: The Essential Philosophical Foundation of Hinduism, Watkins,

The last brahmanam of the Upanishad's first section is a Vamsa (generational line of teachers) with the names of 57 Vedic scholars who are credited to have taught the Madhu Khanda from one generation to the next.

Third chapter The third chapter is a metaphysical dialogue between ten ancient sages, on the nature of Reality (Brahman), Atman (individual self), and Mukti (liberation). This metaphysical dialogue was held at the court of the King Janaka in Mithila during the occasion of the Bahudakshina Yajna organised by the king at his court. The Bahudakshina Yajna was organised by the King Kriti Janaka to find out the greatest scholar of Vedas called as Brahmistha among the participating Brahmin scholars at the court. Paul Deussen calls the presentation of ancient scholar Yajnavalkya in this chapter "not dissimilar to that of Socrates in the dialogues of Plato". Among other things, the chapter presents the theory of perceived empirical knowledge using the concepts of graha (sensory action) and atigraha (sense). It lists 8 combinations of graha and atigraha: breath and smell, speech and name (ideas), tongue and taste, eye and form, ear and sound, skin and touch, mind and desire, arms and work respectively. The sages debate the nature of death and whether any graha and atigraha prevails after one dies. After ruling out six of the sensory actions, they assert that one's ideas (name) and one's actions and work (karma) continue to have an impact on the universe even after one's physical death.

The fourth brahmana of the third chapter asserts, "it is your Self which is inside all", all Selfs are one, immanent and transcendent. The fifth brahmana states that profound knowledge requires one to give up showing off one's erudition, then to adopt childlike curiosity and simplicity, followed by becoming silent, meditating, and being observant (muni). This marks the beginning of the journey toward profound knowledge and understanding the Self of all things, where freedom from frustration and sorrow is found.

In the sixth and eighth brahmana, focus is on the concept of the imperishable (akshara). In these brahmanas, Gargi Vachaknavi and Yajñavalka engage in philosophical inquiries and debates, exploring the ultimate truth and the imperishable nature of reality. The discussions explore deep philosophical ideas, highlighting the importance of seeking spiritual wisdom and the quest to understand the timeless, unchanging reality that transcends the material world.