Upanishads

The Upanishads (ʊˈpʌnɪʃʌdz; उपनिषद् ˈʊpɐnɪʂɐd) are late Vedic and post-Vedic Sanskrit texts that "document the transition from the archaic ritualism of the Veda into new religious ideas and institutions" and the emergence of the central religious concepts of Hinduism. They are the most recent addition to the Vedas, the oldest scriptures of Hinduism, and deal with meditation, philosophy, consciousness, and ontological knowledge. Earlier parts of the Vedas dealt with mantras, benedictions, rituals, ceremonies, and sacrifices. While among the most important literature in the history of Indian religions and culture, the Upanishads document a wide variety of "rites, incarnations, and esoteric knowledge" departing from Vedic ritualism and interpreted in various ways in the later commentarial traditions. Of all Vedic literature, the Upanishads alone are widely known, and their diverse ideas, interpreted in various ways, informed later traditions of Hinduism. The central concern of all Upanishads is to discover the relations between ritual, cosmic realities (including gods), and the human body/person, postulating Ātman and Brahman as the "summit of the hierarchically arranged and interconnected universe," but various ideas about the relation between Atman and Brahman can be found. Around 108 Upanishads are known, of which the first dozen or so are the oldest and most important and are referred to as the principal or main (mukhya) Upanishads. The mukhya Upanishads are found mostly in the concluding part of the Brahmanas and Aranyakas and were, for centuries, memorized by each generation and passed down orally. The mukhya Upanishads predate the Common Era, but there is no scholarly consensus on their date, or even on which ones are pre- or post-Buddhist. The Brhadaranyaka is seen as particularly ancient by modern scholars. Of the remainder, 95 Upanishads are part of the Muktikā canon, composed from about the last centuries of 1st-millennium BCE through about 15th-century CE.