Upanishad

The Upanishads are a collection of ancient Indian philosophical texts forming the concluding part of the Vedas, known as Vedanta. The term Upanishad is from Sanskrit meaning “sitting down near” a teacher to receive esoteric instruction.

They present speculative and metaphysical ideas about the nature of reality, the self (atman), and the ultimate principle (Brahman). They treat the unity of Atman and Brahman, the problem of birth and death, and the path to liberation (moksha). They use dialogic and dialogue-like forms, parables, and debated questions, often focusing on meditation, discernment, and ethical living.

The texts are composed in Sanskrit over a broad period, roughly from the early first millennium BCE to the early centuries CE, with a core corpus of the ten principal Upanishads (Isavasya, Kena, Katha, Prasna, Mundaka, Mandukya, Aitareya, Taittiriya, Chandogya, Brihadaranyaka). Mandukya is brief and analyzes consciousness through the four states. The Mahavakyas include Tat Tvam Asi, Aham Brahmasmi, and Prajnanam Brahma.

Influence and reception: They underpin Vedanta schools; the non-dual Advaita Vedanta emphasizes unity of Atman and Brahman; others like Vishishtadvaita and Dvaita offer alternative interpretations. They shaped later Hindu thought, as well as Buddhist and Jain philosophical streams. They are considered shruti, revealed scripture in Hindu tradition.