Upanishads

The Upanishads (Sanskrit: Upaniṣad; IPA: [ʊpən̪ɪʂəd̪]) are a collection of texts that contain some of the central philosophical concepts of Hinduism, some of which are shared with Buddhism and Jainism. The Upanishads are considered by Hindus to contain utterances (śruti) concerning the nature of ultimate reality (brahman) and describing the character of and path to human salvation (mokṣa or mukti).

The Upanishads are commonly referred to as Vedānta, variously interpreted to mean either the "last chapters, parts of the Veda" or "the object, the highest purpose of the Veda". The concepts of Brahman (Ultimate Reality) and Ātman (Soul, Self) are central ideas in all the Upanishads, and "Know your Ātman" their thematic focus. The Upanishads are the foundation of Hindu philosophical thought and its diverse traditions. Of the Vedic corpus, they alone are widely known, and the central ideas of the Upanishads are at the spiritual core of Hindus.

More than 200 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 early Upanishads all predate the Common Era, some in all likelihood pre-Buddhist (6th century BCE), down to the Maurya period. Of the remainder, some 95 Upanishads are part of the Muktika canon, composed from about the last centuries of 1st-millennium BCE through about 15th-century CE. New Upanishads, beyond the 108 in the Muktika canon, continued to being composed through the early modern and modern era, though often dealing with subjects which are unconnected to the Vedas.

Muktikā

The Muktikā (Sanskrit: "deliverance") refers to the canon of 108 Upaniṣads found in Telugu language version of Muktika Upanishad. The date of composition of each is unknown, with the oldest probably from about 800 BCE and the youngest probably composed after the 15th-century CE. The Principal Upanishads were composed in the 1st millennium BCE, most Yoga Upanishads composed probably from the 100 BCE to 300 CE period, and seven of the Sannyasa Upanishads composed before the 3rd century CE.

The Canon

The canon is part of a dialogue between Rama and Hanuman. Rama proposes to teach Vedanta, saying "Even by reading one verse of them [any Upanishad] with devotion, one gets the status of union with me, hard to get even by sages." Hanuman enquires about the different kinds of "liberation" (Mukti, hence the name of the Upanishad), to which Rama answers that "the only real type [of liberation] is Kaivalya".

The list of 108 Upanishads is introduced in verses 26-29:

Some scholars list ten as principal – the Mukhya Upanishads, while most consider twelve or thirteen as principal, most important Upanishads (highlighted).