The Upanishads

The Upanishads (Sanskrit: उपनिषद्) are Vedic Sanskrit texts of Hindu philosophy which supplied the basis of later Hindu philosophy. They are the most recent part of the Vedas, the oldest scriptures of Hinduism, and deal with meditation, philosophy, consciousness and ontological knowledge; earlier parts of the Vedas deal 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 the later traditions of Hinduism.

A page from Isa Upanishad

The Upanishads are commonly referred to as Vedānta. Vedanta has been interpreted as the "last chapters, parts of the Veda" and alternatively as "object, the highest purpose of the Veda". The aim of all Upanishads is to investigate the nature of Ātman (self), and "direct[ing] the enquirer toward it." Various ideas about the relation between Atman and Brahman can be found, and later commentators tried to harmonize this diversity. Along with the Bhagavad Gita and the Brahmasutra, the mukhya Upanishads (known collectively as the Prasthanatrayi) provide a foundation for the several later schools of Vedanta. According to Umesh Chandra Bhattacharya, the Upanishads were composed in the Mahajanapads of Magadha and Videha; i.e. modern day Bihar.

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.

Yajnavalkya at King Janaka's court

The various philosophical theories in the early Upanishads have been attributed to famous sages such as Yajnavalkya, Uddalaka Aruni, Shvetaketu, Shandilya, Aitareya, Balaki, Pippalada, and Sanatkumara. Women, such as Maitreyi and Gargi participate in the dialogues and are also credited in the early Upanishads. There are some exceptions to the anonymous tradition of the Upanishads. The Shvetashvatara Upanishad, for example, includes closing credits to sage Shvetashvatara, and he is considered the author of the Upanishad.

Some scholars have tried to analyse similarities between Hindu Upanishads and Buddhist literature to establish chronology for the Upanishads. Precise dates are impossible, and most scholars give only broad ranges encompassing various centuries. Gavin Flood states that "the Upanisads are not a homogeneous group of texts. Even the older texts were composed over a wide expanse of time from about 600 to 300 BCE." Stephen Phillips places the early or "principal" Upanishads in the 800 to 300 BCE range.