Upanishads
उपनिषद्
The secret teachings of the Vedas — 108 Upanishads revealing the nature of Brahman, Atman, and Moksha. The culmination of Vedic wisdom and the foundation of all Vedanta philosophy.
108+
Total Upanishads
10
Mukhya (Principal)
4
Mahavakyas
4
Associated Vedas
The Four Mahavakyas
The Great Sayings — one from each Veda — declaring the identity of Atman and Brahman
प्रज्ञानं ब्रह्म
Prajñānaṃ Brahma
"Consciousness is Brahman"
From the Aitareya Upanishad of the Rigveda. Declares that the pure consciousness (prajnana) which is the innermost essence of all beings is identical with Brahman, the ultimate reality.
अहं ब्रह्मास्मि
Ahaṃ Brahmāsmi
"I am Brahman"
Spoken by sage Yajnavalkya in the Brihadaranyaka Upanishad. The direct recognition that the individual self (Atman) is not different from the ultimate reality (Brahman).
तत् त्वम् असि
Tat Tvam Asi
"That Thou Art"
Repeated nine times by sage Uddalaka Aruni to his son Shvetaketu in the Chandogya Upanishad. Declares that the individual self (tvam) is identical with Brahman (tat).
अयम् आत्मा ब्रह्म
Ayam Ātmā Brahma
"This Self is Brahman"
From the shortest of the principal Upanishads, the Mandukya. Identifies the Atman experienced in all four states of consciousness (waking, dreaming, deep sleep, turiya) with Brahman itself.
The Ten Mukhya Upanishads
The principal Upanishads commented upon by Shankaracharya — the foundation of Advaita Vedanta
Isha
ईश
The shortest principal Upanishad — 18 mantras on the Lord pervading all things.
Kena
केन
Inquires into the source of mind, speech, sight, and breath — "by whom" is all this known?
Katha
कठ
Nachiketa learns the secret of death and immortality from Yama himself.
Prashna
प्रश्न
Six questions to sage Pippalada on life, creation, prana, sleep, and the syllable OM.
Mundaka
मुण्डक
Distinguishes para (higher) and apara (lower) knowledge; the two birds on the tree.
Mandukya
माण्डूक्य
Only 12 mantras — contains the Mahavakya "Ayam Atma Brahma"; analysis of OM and four states.
Taittiriya
तैत्तिरीय
The five koshas (sheaths) of existence; the nature of Brahman as Ananda (bliss).
Aitareya
ऐतरेय
Contains the Mahavakya "Prajnanam Brahma"; cosmogony and the nature of consciousness.
Chandogya
छान्दोग्य
Largest of the principal Upanishads. Contains "Tat Tvam Asi" and the story of Uddalaka and Shvetaketu.
Brihadaranyaka
बृहदारण्यक
Contains "Aham Brahmasmi". The dialogues of Yajnavalkya — deepest philosophical Upanishad.
Rigveda
ऋग्वेद~10 UpanishadsThe oldest Veda — hymns to the Devas. Upanishads of the Rigveda explore consciousness (chit) and the divine ground of all existence.
Samaveda
सामवेद~16 UpanishadsThe Veda of chants and melodies. Its Upanishads, especially Chandogya, contain some of the most profound dialogues on Brahman-Atman identity.
Krishna Yajurveda
कृष्ण यजुर्वेद~32 UpanishadsThe dark Yajurveda — associated with Taittiriya Samhita. The Katha Upanishad, with its dialogue with Death, belongs here.
Shukla Yajurveda
शुक्ल यजुर्वेद~19 UpanishadsThe bright Yajurveda — associated with Vajasaneyi Samhita. Contains the Isha and Brihadaranyaka Upanishads.
Atharvaveda
अथर्ववेद~31 UpanishadsThe Veda of Atharvan — contains the Mandukya, Mundaka, and Prashna Upanishads, including the mahavakya "Ayam Atma Brahma".
About the Upanishads
The Upanishads (उपनिषद्, "sitting near") are the concluding portions of the Vedas — the Vedanta ("end of the Vedas"). Composed between roughly 800 BCE and 200 BCE, they represent the most profound metaphysical inquiry in the Vedic tradition, moving from external ritual to internal wisdom.
The word Upanishad is derived from upa (near), ni (down), and shad (to sit) — indicating the practice of sitting near a teacher to receive secret knowledge. The 108 Upanishads span all four Vedas, though only 10–13 are considered "Mukhya" (principal).
The central teaching is the identity of Atman (individual self) with Brahman (universal consciousness). This non-dual insight, expressed in the four Mahavakyas, forms the philosophical foundation of Advaita Vedanta as systematized by Shankaracharya in the 8th century CE.
The Upanishads were studied through the Prasthanatrayi — three foundational texts: the Upanishads (Shruti), the Brahma Sutras (Nyaya), and the Bhagavad Gita (Smriti) — each commented upon by all major Vedanta sub-schools.