Upanishad

The Upanishads (Devanagari: उपनिषद्, IAST: upaniṣad) are part of the Vedas and form the Hindu scriptures which primarily discuss philosophy, meditation, and the nature of God; they form the core spiritual thought of Vedantic Hinduism. Considered as mystic or spiritual contemplations of the Vedas, their putative end and essence, the Upanishads are known as Vedānta ("the end/culmination of the Vedas").

The Upanishads were composed over several centuries. The oldest, such as the Brhadaranyaka and Chandogya Upanishads, have been dated to around the eighth century BCE. The philosophical edifice of Indian religion viz., Hinduism, Jainism and Buddhism is built on the foundation laid by the Upanishads.

Etymology
The Sanskrit term  derives from upa- (near), ni- (down) and sad (to sit), i.e. referring to the  "sitting down near" a spiritual teacher (guru) in order to receive instruction in the Guru-shishya tradition. The term thus emphasizes the esoteric nature of the texts, not intended for public teaching, but restricted to the confidentiality of personal instruction.

A gloss of the term upaniṣad based on Shankara's commentary on the Kaṭha and Bṛhadāraṇyaka Upanishads equates it with Ātmavidyā, that is "knowledge of the Self", or Brahmavidyā "knowledge of Brahma".

Major Upanishads
Different Upanishads are affiliated with the four Vedas (Rigveda, Yajurveda, Samaveda and Atharvaveda). The Upanishads were transmitted orally by the Vedic schools sakhas. The longest and oldest Upanishad are the Brihadaranyaka and the Chandogya respectively.

The language of the Upanishads is Sanskrit, the oldest among them still classifying as late Vedic Sanskrit. The oldest Upanishads, the Brihadaranyaka and the Chandogya are composed in prose. These early texts may date back to the 8th-7th centuries BCE. Later followed a series of Upanishads composed in verse, such as the Īṣa, Māṇd.ukya, Katha, and Ṣvetāṣvatara Upanishads.

According to tradition, there were over two hundred Upanishads, but the philosopher and commentator Shankara only composed commentaries to eleven of them. The Upanishads commented on by Shankara are generally regarded as the oldest ones. The Muktika Upanishad lists 108 Upanishads. In 1656, at the order of Dara Shikoh, the Upanishads were translated from Sanskrit into Persian. From 1802 to 1804 Abraham-Hyacinthe Anquetil Du Perron published a Latin translation (2 vols.) from the Persian of the Oupnek'hat or Upanishada. It is a curious mixture of Latin, Greek, Persian, Arabic, and Sanskrit.

These philosophical and meditative tracts form the backbone of Hindu thought. Of the early Upanishads, the Aitareya and Kauoītāki belong to the Rig Veda, Kena and Chāndogya to the Samaveda, Īoa and Taittirīya and B'hadāra yaka to the Yajurveda, and Praṣna and Mu'd.aka to the Atharvaveda. In addition, the Mādukya, Katho, 'vetā'vatara are very important. Others also include Mahānārāya'a and Maitreyi Upanishads as key.

Place in the Hindu canon
Scholars of the Vedic books consider the four Vedas as poetic liturgy, collectively called mantra or samhitā-, adoration and supplication to the deities of vedic religion, in parts already melded with monist and henotheist notions, and an overarching order (Rta) that transcended even the gods.

The Brāhmana were a collection of ritual instructions, books detailing the priestly functions (which first were available to all men, and so concretized into strictly Brahmin privilege). These came after the Mantra.

Vedanta, is chiefly composed of Āranyakas and Upanishads. The Aranyakas ("of the forest") detail meditative yogic practices, contemplations of the mystic one and the manifold manifested principles. The Upanishad basically realized all the monist and universal mystical ideas that started in earlier Vedic hymns, and have exerted an influence unprecedented on the rest of Hindu and Indian philosophy. However, by adherents they are not considered philosophy alone, and form meditations and practical teachings for those advanced enough to benefit from their wisdom.

Contents
The Taittiriya Upanishad says this in the Ninth Chapter:

The Upanishads hold information on basic Hindu beliefs, including belief in a world soul, a universal spirit, Brahman, and an individual soul, Atman (Smith 10). A variety of lesser gods are seen as aspects of this one divine ground, Brahman (different from Brahma). Brahman is the ultimate, both transcendent and immanent, the absolute infinite existence, the sum total of all that ever is, was, or ever shall be. For Advaita (non-dual) philosophers Brahman is not a God in the monotheistic sense, as they do not ascribe to it any limiting characteristics, not even those of being and non-being, and this is reflected in the fact that in Sanskrit, the word Brahman has two genders (masculine, Brahmâ, the creator-god or Brahman, neuter, the Absolute). Dvaita philosophy holds that Brahman is ultimately a personal God, Vishnu, or Krishna (brahmano hi pratisthaham, I am the Foundation of Brahman Bhagavad Gita 14.27).

The sages of the Upanishad try to solve these mysteries and seek knowledge of a Reality beyond ordinary knowing. They also show a preoccupation with states of consciousness, and observed and analysed dreams as well as dreamless sleep.

Philosophy
Due to their mystical nature and intense philosophical bent that does away with all ritual and completely embraces principals of One Brahman and the inner Atman (Self), the Upanishads have a universal feel that has led to their explication in numerous manners, giving birth to the three schools of Vedanta.

The Upanishads are summed up in one phrase तत् त्वं असि "Tat Tvam Asi" (Thou Art That) by the Advaita Vedanta and they believe that in the end, the ultimate, formless, inconceivable Brahman is the same as our soul, Atman. We only have to realize it through discrimination and piercing through Maya.

A distinctive quotation that is indicative of the call to self-realization, one that inspired Somerset Maugham in titling a book he wrote on Christopher Isherwood, is as follows:

The Upanishads also contain the first and most definitive explications of aum as the divine word, the cosmic vibration that underlies all existence and contains multiple trinities of being and principles subsumed into its One Self. The Isha says of the Self (Verses 6, 7 & 8 of Isha Upanishad):

"Aum Shanti Shanti Shanti" This, too, is found first in the Upanishads, the call for tranquility, for divine stillness, for Peace everlasting.

Dara Shikoh, the Muslim sufi, and son of Mughal emperor Shah Jahan, translated the Upanishads in Persian in order to find in it elements of monotheism that might pave the way for a common mystical bond between Islam and Hinduism.

"Principal" Upanishads
The following is a list of the eleven "principal" (mukhya) Upanishads that were commented upon by Shankara, and that are accepted as shruti by all Hindus. They are listed with their associated Veda (Rigveda, Samaveda (SV), White Yajurveda , Black Yajurveda (KYV), Atharvaveda (AV)).


 * 1)  (ṚV)
 * 2)  (ŚYV)
 * 3) Isha Upanishad (ŚYV)
 * 4) Taittiriya Upanishad (KYV)
 * 5) (KYV)
 * 6) (SV)
 * 7) Kenopanishad (SV)
 * 8) (AV)
 * 9) (AV)
 * 10) (AV)

The and  Upanishads are sometimes added to extend the canon to 13. They are also the oldest Upanishads, likely all of them dating to before the Common Era. From linguistic evidence, the oldest among them are likely the Bṛhadāraṇyaka and Chāndogya Upanishads, belonging to the late Vedic Sanskrit period; the remaining ones are at the transition from Vedic to Classical Sanskrit.

Canon by Vedic Shakha
The older Upanishads are associated with Vedic Charanas (Shakhas or schools). The Aitareya Upanishad with the Shakala shakha, the Upanishad with the Bashakala shakha;  the  Upanishad with the Kauthuma shakha, the Kena Upanishad, and the Jaiminiya Upanishad Brahmana, with the Jaiminiya shakha; the  Upanishad with the Caraka-Katha shakha, the  and  with the Taittiriya shakha; the  Upanishad with the Maitrayani shakha; the  and  Upanishads with the Vajasaneyi Madhyandina shakha, and the  and  Upanishads with the Shaunaka shakha. Additionally, parts of earlier texts, of Brahmanas or passages of the Vedas themselves, are sometimes considered Upanishads.

The Muktika canon
The following is a list of the 108 canonical Upanishads of the Advaita school, according to the Muktika Upanishad (number 108), 1:30-39 (which does not list the associated Veda). In this canon,
 * 10 Upanishads are associated with the Rigveda and have the Shānti beginning .
 * 16 Upanishads are associated with the Samaveda and have the Shānti beginning .
 * 19 Upanishads are associated with the White Yajurveda and have the Shānti beginning .
 * 32 Upanishads are associated with the Black Yajurveda and have the Shānti beginning .
 * 31 Upanishads are associated with the Atharvaveda and have the Shānti beginning .

The first 10 are grouped as mukhya "principal", and are identical to those listed above. 21 are grouped as Sāmānya Vedānta "common Vedanta", 23 as Sannyāsa, 9 as Shākta, 13 as Vaishnava, 14 as Shaiva and 17 as Yoga Upanishads.


 * 1) Isha Upanishad, (ŚYV, Mukhya) "The Inner Ruler"
 * 2) Kenopanishad (SV, Mukhya) "Who moves the world?"
 * 3) Katha Upanishad (KYV, Mukhya) "Death as Teacher"
 * 4) Prashnopanishad, (AV, Mukhya) "The Breath of Life"
 * 5) Mundaka Upanishad (AV, Mukhya) "Two modes of Knowing"
 * 6) (AV, Mukhya) "Consciousness and its phases"
 * 7) Taittiriya Upanishad (KYV, Mukhya) "From Food to Joy"
 * 8) Aitareya Upanishad, (ṚV Mukhya) "The Microcosm of Man"
 * 9) Chandogya (SV, Mukhya) "Song and Sacrifice"
 * 10) (ŚYV, Mukhya)
 * 11) (KYV, Sannyasa)
 * 12) (KYV, Shaiva)
 * 13) (ŚYV, Sannyasa)
 * 14) Shvetashvatara Upanishad (KYV, Sannyasa) "The Faces of God"
 * 15) (ŚYV, Yoga)
 * 16) (SV, Sannyasa)
 * 17) (KYV, Sannyasa)
 * 18) (KYV, Vaishnava)
 * 19) (ŚYV, Sannyasa)
 * 20) (KYV, Yoga)
 * 21) (KYV, Yoga)
 * 22) (AV, Shaiva)
 * 23)  (AV, Shaiva)
 * 24) Maitrayaniya Upanishad (SV, Sannyasa)
 * 25) (ṚV, Samanya)
 * 26) (AV, Shaiva)
 * 27) (AV, Vaishnava)
 * 28) (KYV, Shaiva)
 * 29) (SV, Sannyasa)
 * 30) (ŚYV, Samanya)
 * 31) (KYV, Yoga)
 * 32) (ŚYV, Samanya)
 * 33) (KYV, Samanya)
 * 34) (ŚYV, Samanya)
 * 35) (KYV, Samanya)
 * 36) (SV, Samanya)
 * 37) (KYV, Sannyasa)
 * 38) (ṚV, Yoga)
 * 39) (KYV, Yoga)
 * 40) (KYV, Yoga)
 * 41) (KYV, Yoga)
 * 42) (ṚV, Samanya)
 * 43)  (AV, Sannyasa)
 * 44) (ŚYV, Yoga)
 * 45) (AV, Shakta)
 * 46) (SV, Yoga)
 * 47) (ṚV, Sannyasa)
 * 48) (ŚYV, Yoga)
 * 49) (KYV, Shaiva)
 * 50) (AV, Shaiva)
 * 51)  (KYV, Samanya)
 * 52) (AV, Vaishnava)
 * 53) (ŚYV, Sannyasa)
 * 54) (AV, Vaishnava)
 * 55) (AV, Vaishnava)
 * 56) (SV, Vaishnava)
 * 57) (ṚV, Samanya)
 * 58) (AV, Yoga)
 * 59) (ŚYV, Samanya)
 * 60) (ŚYV, Sannyasa)
 * 61) (SV, Samanya)
 * 62) (KYV, Samanya)
 * 63) (KYV Yoga)
 * 64) (ŚYV, Sannyasa)
 * 65) (SV, Sannyasa)
 * 66) (AV, Sannyasa)
 * 67)   (ṚV, Shaiva)
 * 68) (SV, Vaishnava)
 * 69) (KYV, Samanya)
 * 70) (AV, Shakta)
 * 71) (AV, Samanya)
 * 72) (KYV, Samanya)
 * 73) (ŚYV, Samanya)
 * 74) (SV, Sannyasa)
 * 75) (SV, Samanya)
 * 76) (AV, Samanya)
 * 77) (AV, Yoga)
 * 78) (AV, Sannyasa)
 * 79) (KYV, Sannyasa)
 * 80) (AV, Shakta)
 * 81) (AV, Shakta)
 * 82) (ṚV, Shakta)
 * 83) (KYV, Sannyasa)
 * 84) (AV, Shakta)
 * 85) (KYV, Shaiva)
 * 86) (KYV, Yoga)
 * 87) (AV, Shaiva)
 * 88) (SV, Shaiva)
 * 89) (AV, Shaiva)
 * 90) (SV, Yoga)
 * 91) (ŚYV, Vaishnava)
 * 92) (AV, Yoga)
 * 93) (KYV, Shaiva)
 * 94) (KYV, Samanya)
 * 95) (AV, Vaishnava)
 * 96) (AV, Vaishnava)
 * 97) (ŚYV, Sannyasa)
 * 98) (KYV, Sannyasa)
 * 99) (ŚYV, Sannyasa)
 * 100) (AV, Vaishnava)
 * 101) (AV, Vaishnava)
 * 102) (AV, Vaishnava)
 * 103) Kali-Santarana Upanishad (KYV, Vaishnava)
 * 104)  (SV, Shaiva)
 * 105) (ṚV, Shakta)
 * 106) (KYV, Shakta)
 * 107) (ṚV, Shakta)
 * 108) (ŚYV, Samanya)

Criticism
The Upanishads were denounced by Lala Hardayal, a Hindu Nationalist, as "full of absurd conceits, quaint fancies and chaotic speculations". He also was critical of Hindu religious figures for allegedly dogmatizing the texts without "learning that they are worthless".

Dalit activist Bhimrao Ambedkar, contended that the Upanishads were the "true source of Hindu philosophy", but questioned whether the philosophy had any influence on Hinduism as a social and political system. According to his analysis, philosophy of Upanishads "turned out to be most ineffective and inconsequential piece of speculation with no effect on the moral and social order of the Hindus."