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The Upanishads (/, /; singular: Sanskrit: उपनिषत्, IAST: Upaniṣat, IPA: [upəniʂət̪]; plural: Sanskrit: उपनिषदः) are a collection of texts in the Vedic Sanskrit language which contain the earliest emergence of some of the central religious concepts of Hinduism, some of which are shared with Buddhism and Jainism.[note 1][note 2] The Upanishads are considered by Hindus to contain revealed truths (Sruti) concerning the nature of ultimate reality (brahman) and describing the character and form of human salvation (moksha).
The Upanishads are sometimes referred to as Vedanta ("Last part of Veda") when interpreted in the context of Uttara Mimamsa. But according to the Brahmasutra, the Upanishads address a different subject matter (inquisition into Brahman), and the subject matter of the Vedas is inquisition into ritual action. Most interpretations of the Brahmasutra are clear that one does not have to master the Vedas first to study the Upanishads. Hence the Vedas and Upanishads are different, even though they share the same language (just like a book on history and a book on science may share the same language). To call them purely Vedanta would not be exactly right because they are really the source of both the Samkhya and later Vedanta philosophies.
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 have been passed down in oral tradition. They all predate the Common Era, possibly from the Pre-Buddhist period (6th century BCE)  down to the Maurya period. The remainder, known as the Muktika canon was mostly composed during medieval Hinduism, and new Upanishads continued being composed in the early modern and modern era, down to at least the 20th century.
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, among them, two influential monistic schools of Hinduism.[note 3][note 4][note 5]
With the translation of the Upanishads in the early 19th century they also started to attract attention from a western audience. Schopenhauer was deeply impressed by the Upanishads and called it "the production of the highest human wisdom". The 19th century transcendentalists noted the influence of Upanishads in the western philosophy.
- 1 Etymology
- 2 Development
- 3 Classification
- 4 Association with Vedas
- 5 Philosophy
- 6 Schools of Vedanta
- 7 Similarities with Platonic thought
- 8 Translations
- 9 Reception in the West
- 10 See also
- 11 Notes
- 12 References
- 13 Sources
- 14 Further reading
- 15 External links
The Sanskrit term Upaniṣad (u = at, pa = foot, nishat =sitting down) translates to "sitting at the foot/feet of", referring to the student sitting down near the teacher while receiving esoteric knowledge. Monier-Williams' Sanskrit Dictionary adds that, "According to native authorities Upanishad means 'setting to rest ignorance by revealing the knowledge of the supreme spirit.'" A gloss of the term Upanishad based on Shri Adi Shankara's commentary on the Kaṭha and Brihadaranyaka Upanishad equates it with Ātmavidyā, that is, "knowledge of the Self", or Brahmavidyā "knowledge of Brahma". Other dictionary meanings include "esoteric doctrine" and "secret doctrine". The term occurs in the name of the Jaiminiya Upanishad Brahmana, an early text of Vedanta, which is not counted as an Upanishad but as an Aranyaka.
The Upanishads have been attributed to several authors: Yajnavalkya and Uddalaka Aruni feature prominently in the early Upanishads. Other important writers include Shvetaketu, Shandilya, Aitareya, Pippalada and Sanatkumara. Important women discussants include Yajnavalkya's wife Maitreyi, and Gargi. Radhakrishnan considers authorship claims in the text to be unreliable, believing the supposed authors to be fictional characters. An example is Shvetaketu from Chāndogya Upaniṣad for whom there are no sources or books which mention him nor any other works attributed to him. According to Radhakrishnan most of the Upanishads were kept secret for centuries, only passed on to others orally in the form of Shloka, and that it is difficult to determine how much the current texts have changed from the original.
Scholars have disagreed about the exact dates of the composition of the Upanishads, but according to Olivelle a scholarly consensus can be established. The oldest Upanishads, the Brihadaranyaka, Jaiminiya Upanishad Brahmana and the Chandogya Upanishads, were composed during the pre-Buddhist era of India,[note 6] while the Taittiriya, Aitareya and Kausitaki, which show similarities to Buddhism, may have been composed after the 5th century BCE. The remainder of the mukhya Upanishads are dated to the last few centuries BCE.
Patrick Olivelle gives the following chronology, based on scholarly consensus:
- The Brhadaranyaka and the Chandogya are the two earliest Upanisads. They are edited texts, some of whose sources are much older than others. The two texts are pre-Buddhist; they may be placed in the 7th to 6th centuries BCE, give or take a century or so.
- The three other early prose Upanisads—Taittiriya, Aitareya, and Kausitaki come next; all are probably pre-Buddhist and can be assigned to the 6th to 5th centuries BCE.
- The Kena is the oldest of the verse Upanisads followed by probably the Katha, Isa, Svetasvatara, and Mundaka. All these Upanisads were composed probably in the last few centuries BCE.
- The two late prose Upanisads, the Prasna and the Mandukya, cannot be much older than the beginning of the common era.
The general area of the composition of the early Upanishads was northern India, the region bounded on the west by the Indus valley, on the east by lower Ganges river, on the north by the Himalayan foothills, and on the south by the Vindhya mountain range. There is confidence about the early Upanishads being the product of the geographical center of ancient Brahmanism, comprising the regions of Kuru-Panchala and Kosala-Videha together with the areas immediately to the south and west of these.
While significant attempts have been made recently to identify the exact locations of the individual Upanishads, the results are tentative. Witzel identifies the center of activity in the Brihadaranyaka Upanishad as the area of Videha, whose king, Janaka, features prominently in the Upanishad. Yajnavalkya is another individual who features prominently, almost as the personal theologian of Janaka. Brahmins of the central region of Kuru-Panchala rightly considered their land as the place of the best theological and literary activities, since this was the heartland of Brahmanism of the late Vedic period. The setting of the third and the fourth chapters of the Brihadaranyaka Upanishads were probably intended to show that Yajnavalkya of Videha defeated all the best theologians of the Kuru Panchala, thereby demonstrating the rise of Videha as a center of learning.
The Chandogya Upanishad was probably composed in a more Western than an Eastern location, possibly somewhere in the western region of the Kuru-Panchala country. The great Kuru-Panchala theologian Uddalaka Aruni who was vilified in the Brihadaranyaka features prominently in the Chandogya Upanishad. Compared to the Principal Upanishads, the new Upanishads recorded in the Muktikā belong to an entirely different region, probably southern India, and are considerably relatively recent.
There are more than 200 known Upanishads, one of which, Muktikā Upanishad, predates 1656 and contains a list of 108 canonical Upanishads, including itself as the last. These 108 texts span a historical period of about 2000 years, the earliest or mukhya ("primary") ones dating to the final centuries BCE., and the latest to the Mughal period. Various schools of Hinduism recognize the first 10, 11, 12 or 13 Upanishads as "principal" or Mukhya Upanishads. The remainder is further divided into Upanishads associated with Shaktism, Sannyasa (asceticism), Shaivism, Vaishnavism, Yoga, besides 21 Upanishads known as sāmānya ("common", or "general") which, while not part of the mukhya canon are still accepted as shruti by all schools of Vedanta. The newer Upanishads mentioned in the Muktikā probably originated in southern India. They are also categorized as "sectarian" since they reflect the emergence of the various Hindu sects in medieval Hinduism which sought to legitimize their texts by claiming for them the status of Śruti. The Upanishads of the Muktika canon are also all associated with a specific Brahmana and by extension with one of the four Veda.
The Mukhya Upanishads can themselves be stratified into periods. Of the early periods are the Brihadaranyaka, Jaiminiya Upanisadbrahmana and the Chandogya, the most important and the oldest, of which the two former are the older of the two, though some parts were composed after the Chandogya.[note 7]
The Aitareya, Kauṣītaki and Taittirīya Upanishads may date to as early as the mid 1st millennium BCE, while the remnant date from between roughly the 4th to 1st centuries BCE, roughly contemporary with the earliest portions of the Sanskrit epics. It is alleged that the Aitareya, Taittiriya, Kausitaki, Mundaka, Prasna, and Katha Upanishads show Buddha's influence, and must have been composed after the 5th century BCE, but it could just as easily have been the other way around. It is also alleged that in the first two centuries A.D., they were followed by the Kena, Mandukya and Isa Upanishads, but other scholars date these earlier. Not much is known about the authors except for those, like Yajnavalkayva and Uddalaka, mentioned in the texts. A few women discussants, such as Gargi and Maitreyi, the wife of Yajnavalkayva, also feature occasionally.
Each of the principal Upanishads can be associated with one of the schools of exegesis of the four Vedas (shakhas). Many Shakhas are said to have existed, of which only a few remain. The new Upanishads often have little relation to the Vedic corpus and have not been cited or commented upon by any great Vedanta philosopher: their language differs from that of the classic Upanishads, being less subtle and more formalized. As a result, they are not difficult to comprehend for the modern reader.
|Rig Veda||Only one recension||Shakala||Aitareya|
|Sama Veda||Only one recension||Kauthuma||Chāndogya|
|Yajur Veda||Krishna Yajur Veda||Katha||Kaṭha|
|Taittiriya||Taittirīya and Śvetāśvatara|
|Shukla Yajur Veda||Vajasaneyi Madhyandina||Isha and Bṛhadāraṇyaka|
|Atharva||Two recension||Shaunaka||Māṇḍūkya and Muṇḍaka|
There is no fixed list of the Upanishads as newer ones have continued to be discovered and composed. On many occasions, when older Upanishads have not suited the founders of new sects, they have composed new ones of their own. 1908 marked the discovery of four new Upanishads, named Bashkala, Chhagaleya, Arsheya and Saunaka, by Friedrich Schrader, who attributed them to the first prose period of the Upanishads. The text of three, the Chhagaleya, Arsheya and Saunaka, was reportedly corrupt and neglected but possibly re-constructible with the help of their Perso-Latin translations. Other texts including Devadeva-rahasya and Subakshana have also ascribed as Upanishads. Several texts under the title of "Upanishads" originated right up to the first half of the 20th century, some of which did not deal with subjects of Vedic philosophy.
The main Shakta Upanishads mostly discuss doctrinal and interpretative differences between the two principal sects of a major Tantric form of Shaktism called Shri Vidya upasana. The many extant lists of authentic Shakta Upaniṣads vary, reflecting the sect of their compilers, so that they yield no evidence of their "location" in Tantric tradition, impeding correct interpretation. The Tantra content of these texts also weaken its identity as an Upaniṣad for non-Tantrikas and therefore, its status as shruti and thus its authority.
Association with Vedas
All Upanishads are associated with one of the four Vedas—Rigveda, Samaveda, Yajurveda (there are two primary versions or Samhitas of the Yajurveda: Shukla Yajurveda, Krishna Yajurveda), and Atharvaveda. The Muktikā Upanishad's list of 108 Upanishads groups the first 10 as mukhya, 21 as Sāmānya Vedānta, 23 as Sannyāsa, 14 as Vaishnava, 14 as Shaiva, 9 as Shakta and 17 as Yoga. The 108 Upanishads as recorded in the Muktikā are shown in the table below. The mukhya Upanishads are highlighted.
|Ṛigveda||Aitareya||Kauśītāki, Ātmabodha, Mudgala||Nirvāṇa||Tripura, Saubhāgya, Bahvṛca||-||Akṣamālika (Mālika)||Nādabindu|
|Samaveda||Chāndogya, Kena||Vajrasūchi, Mahad, Sāvitrī||Āruṇeya, Maitrāyaṇi, Maitreyi, Sannyāsa, Kuṇḍika||-||Vāsudeva, Avyakta||Rudrākṣa, Jābāla||Yogachūḍāmaṇi, Darśana|
|Krishna Yajurveda||Taittirīya, Kaṭha||Sarvasāra, Śukarahasya, Skanda (Tripāḍvibhūṭi), Śārīraka, Ekākṣara, Akṣi, Prāṇāgnihotra||Brahma, Śvetāśvatara, Garbha, Tejobindu, Avadhūta, Kaṭharudra, Varāha||Sarasvatīrahasya||Nārāyaṇa (Mahānārāyaṇa), Kali-Saṇṭāraṇa (Kali)||Śvetāśvatara, Kaivalya, Kālāgnirudra, Dakṣiṇāmūrti, Rudrahṛdaya, Pañcabrahma||Amṛtabindu, Amṛtanāda, Kṣurika, Dhyānabindu, Brahmavidyā, Yogatattva, Yogaśikhā, Yogakuṇḍalini|
|Shukla Yajurveda||Bṛhadāraṇyaka, Īśa||Subāla, Mantrikā, Nirālamba, Paiṅgala, Adhyātmā, Muktikā||Jābāla, Paramahaṃsa, Advayatāraka, Bhikṣu, Turīyātīta, Yājñavalkya, Śāṭyāyani||-||Tārasāra||-||Haṃsa, Triśikhi, Maṇḍalabrāhmaṇa|
|Atharvaveda||Muṇḍaka, Māṇḍūkya, Praśna||Sūrya, Ātmā||Parivrāt (Nāradaparivrājaka), Paramahaṃsaparivrājaka, Parabrahma||Sītā, Annapūrṇa, Devī, Tripurātapani, Bhāvana||Nṛsiṃhatāpanī, Mahānārāyaṇa (Tripādvibhuti), Rāmarahasya, Rāmatāpaṇi, Gopālatāpani, Kṛṣṇa, Hayagrīva, Dattātreya, Gāruḍa||Śira, Atharvaśikha, Bṛhajjābāla, Śarabha, Bhasma, Gaṇapati||Śāṇḍilya, Pāśupata, Mahāvākya|
The Upanishadic age was characterized by a pluralism of worldviews. While some Upanishads have been deemed 'monistic', others, including the Katha Upanishad, are dualistic. The Maitri is one of the Upanishads that inclines more toward dualism, thus grounding classical Samkhya and Yoga, in contrast to the non-dualistic Upanishads eventuating in Vedanta. They contain a plurality of ideas,[note 8] which only by the later Vedanta-schools were tried to reconcile.
Sarvepalli Radhakrishnan notes that the Upanishads are primarily presented as conversations between two persons or animals rather than expository statements of philosophy or ideology. He contends that the frog's metaphorical speech the Mandukya Upanishad (manduka means frog in Sanskrit) is a common source of confusion.
Scholars agree that the earliest formulation of the Karma doctrine occurs in the Brihadaranyaka Upanishad, which is the earliest of the Upanishads.
Development of thought
While the hymns of the Vedas emphasize rituals and the Brahmanas serve as a liturgical manual for those Vedic rituals, the spirit of the Upanishads is inherently opposed to ritual. The older Upanishads launch attacks of increasing intensity on the ritual. Anyone who worships a divinity other than the Self is called a domestic animal of the gods in the Brihadaranyaka Upanishad. The Chāndogya Upanishad parodies those who indulge in the acts of sacrifice by comparing them with a procession of dogs chanting Om! Let's eat. Om! Let's drink.
The Kaushitaki Upanishad asserts that "external rituals such as Agnihotram offered in the morning and in the evening, must be replaced with inner Agnihotram, the ritual of introspection", and that "not rituals, but knowledge should be one's pursuit". The Mundaka Upanishad declares how man has been called upon, promised benefits for, scared unto and misled into performing sacrifices, oblations and pious works. Mundaka thereafter asserts this is foolish and frail, by those who encourage it and those who follow it, because it makes no difference to man's current life and after-life, it is like blind men leading the blind, it is a mark of conceit and vain knowledge, ignorant inertia like that of children, a futile useless practice. The Maitri Upanishad states,
The performance of all the sacrifices, described in the Maitrayana-Brahmana, is to lead up in the end to a knowledge of Brahman, to prepare a man for meditation. Therefore, let such man, after he has laid those fires, meditate on the Self, to become complete and perfect.
The opposition to the ritual is not explicit all the time. On several occasions the Upanishads extend the task of the Aranyakas by making the ritual allegorical and giving it a philosophical meaning. For example, the Brihadaranyaka interprets the practice of horse-sacrifice or ashvamedha allegorically. It states that the over-lordship of the earth may be acquired by sacrificing a horse. It then goes on to say that spiritual autonomy can only be achieved by renouncing the universe which is conceived in the image of a horse.
In similar fashion, Vedic gods such as the Agni, Aditya, Indra, Rudra, Visnu, Brahma and others become equated in the Upanishads to the supreme, immortal and incorporeal Brahman-Atman of the Upanishads, god becomes synonymous with Self, and is declared to be everywhere, inmost being of each human being and within every living creature. The one reality or ekam sat of the Vedas becomes the ekam eva advitiyam or "the one and only and sans a second" in the Upanishads. Brahman-Atman and Self-realization develops, in the Upanishad, as the means to moksha (liberation, freedom in this life or after-life).
Brahman and Atman
Two words that are of paramount importance in grasping the Upanishads are Brahman and Atman. The Brahman is the ultimate reality and the Atman is individual self. Differing opinions exist amongst scholars regarding the etymology of these words. Brahman probably comes from the root brh, which means "The Biggest ~ The Greatest ~ The ALL." Brahman is "the infinite Spirit Source and fabric and core and destiny of all existence, both manifested and unmanifested and the formless infinite substratum and from whom the universe has grown". Brahman is the ultimate, both transcendent and immanent, the absolute infinite existence, the sum total of all that ever is, was, or shall be. The word Atman means the immortal perfect Spirit of any living creature, all beings, including animals and trees. Ātman is a central idea in all the Upanishads, and "Know your Ātman" their thematic focus. These texts state that the inmost core of every person is not the body, nor the mind, nor the ego, but Atman – "Soul" or "Self". Atman is the spiritual essence in all creatures, their real innermost essential being. It is eternal, it is the essence, it is ageless. Atman is that which one is at the deepest level of one's existence.
Atman is the predominantly discussed topic in the Upanishads, but they express two distinct, somewhat divergent themes. Some state that Brahman (Highest Reality, Universal Principle, Being-Consciousness-Bliss) is identical with Atman, while others state Atman is part of Brahman but not identical. This ancient debate flowered into various dual, non-dual theories in Hinduism. The Brahmasutra by Badarayana (~ 100 BCE) synthesized and unified these somewhat conflicting theories, stating that Atman and Brahman are different in some respects particularly during the state of ignorance, but at the deepest level and in the state of Self-realization, Atman and Brahman are identical, non-different.
The Upanishads also contain the first and most definitive explications of the divine syllable Aum, the cosmic vibration that underlies all existence. The mantra Aum Shānti Shānti Shānti, translated as "the soundless sound, peace, peace, peace", is often found in the Upanishads. The path of bhakti or "Devotion to God" is foreshadowed in Upanishadic literature, and was later realized by texts such as the Bhagavad Gita.
Two different types of the non-dual Brahman-Atman are presented in the Upanishads, according to Mahadevan. The one in which the non-dual Brahman-Atman is the all inclusive ground of the universe and another in which empirical, changing universe is a form of Maya, often translated as "illusion".
The Upanishads describe the universe, and the human experience, as an interplay of Purusha (the eternal, unchanging principles, consciousness) and Prakṛti (the temporary, changing material world, nature). The former manifests itself as Ātman (Soul, Self), and the latter as Māyā. The Upanishads refer to the knowledge of Atman as "true knowledge" (Vidya), and the knowledge of Maya as "not true knowledge" (Avidya, Nescience, lack of awareness, lack of true knowledge).
Hendrick Vroom explains, "the term Maya [in the Upanishads] has been translated as 'illusion,' but then it does not concern normal illusion. Here 'illusion' does not mean that the world is not real and simply a figment of the human imagination. Maya means that the world is not as it seems; the world that one experiences is misleading as far as its true nature is concerned." According to Wendy Doniger, "to say that the universe is an illusion (māyā) is not to say that it is unreal; it is to say, instead, that it is not what it seems to be, that it is something constantly being made. Māyā not only deceives people about the things they think they know; more basically, it limits their knowledge."
In the Upanishads, Māyā is the perceived changing reality and it co-exists with Brahman which is the hidden true reality. Maya, or "illusion", is an important idea in the Upanishads, because the texts assert that in the human pursuit of blissful and liberating Self-knowledge, it is Maya which obscures, confuses and distracts an individual.
Schools of Vedanta
The Upanishads form one of the three main sources for all schools of Vedanta, together with the Bhagavad Gita and the Brahmasutras. Due to the wide variety of philosophical teachings contained in the Upanishads, various interpretations could be grounded on the Upanishads. The schools of Vedānta seek to answer questions about the relation between atman and Brahman, and the relation between Brahman and the world. The schools of Vedanta are named after the relation they see between atman and Brahman:
- According to Advaita Vedanta, there is no difference.
- According to Vishishtadvaita the jīvātman is a part of Brahman, and hence is similar, but not identical.
- According to Dvaita, all individual souls (jīvātmans) and matter as eternal and mutually separate entities.
Other schools of Vedanta include Nimbarka's Dvaitadvaita, Vallabha's Suddhadvaita and Chaitanya's Acintya Bhedabheda. The philosopher Adi Sankara has provided commentaries on 11 mukhya Upanishads.
Advaita literally means non-duality, and it is a monistic system of thought. It deals with the non-dual nature of Brahman and Atman. Advaita is considered the most influential sub-school of the Vedanta school of Hindu philosophy, though whether it represents the mainstream Hindu position has been debated.
Gaudapada was the first person to expound the basic principles of the Advaita philosophy in a commentary on the conflicting statements of the Upanishads. His main work is infused with philosophical terminology of Buddhism, and uses Buddhist arguments and analogies. Gaudapada took over the Buddhist doctrines that ultimate reality is pure consciousness (vijñapti-mātra) Gaudapada "wove [both doctrines] into a philosophy of the Mandukaya Upanisad, which was further developed by Shankara". At the same time, Gaudapada emphatically rejected the epistemic idealism of the Buddhists, arguing that there was a difference between objects seen in dreams and real objects in the world, although both were ultimately unreal. He also rejected the pluralism and momentariness of consciousnesses, which were core doctrines of the Vijnanavada school, and their techniques for achieving liberation. Gaudapada also took over the Buddhist concept of "ajāta" from Nagarjuna's Madhyamaka philosophy, which uses the term "anutpāda".[note 9]
Gaudapada's ideas were further developed by Shankara.[note 10] There are clear differences between Shankara's writings and the Brahmasutra, and many ideas of Shankara are at odds with those in the Upanishads. The Upanishads contain four sentences, the Mahāvākyas (Great Sayings), which were used by Shankara to establish the identity of Atman and Brahman as scriptural truth:
- "Prajñānam brahma" - "Consciousness is Brahman" (Aitareya Upanishad)
- "Aham brahmāsmi" - "I am Brahman" (Brihadaranyaka Upanishad)
- "Tat tvam asi" - "That Thou art" (Chandogya Upanishad)
- "Ayamātmā brahma" - "This Atman is Brahman" (Mandukya Upanishad)
Although there are a wide variety of philosophical positions propounded in the Upanishads, commentators since Adi Shankara have usually followed him in seeing idealist monism as the dominant force.[note 11]
The Dvaita school was founded by Madhvacharya. Born in 1138 near Udupi, Dvaita is regarded as the best philosophic exposition of theism. Sharma points out that Dvaita, a term commonly used to designate Madhava's system of philosophy, translates as "dualism" in English. The Western understanding of dualism equates to two independent and mutually irreducible substances. The Indian equivalent of that definition would be Samkya Dvaita. Madhva's Dvaita differs from the Western definition of dualism in that while he agrees to two mutually irreducible substances that constitute reality, he regards only one – God, as being independent.
The third school of Vedanta is the Vishishtadvaita, which was founded by Ramanuja. Traditional dates of his birth and death are given as 1017 and 1137, though a shorter life span somewhere between these two dates has been suggested. Ramanuja strenuously refuted Shankara's works. Visistadvaita is a synthetic philosophy that tries to reconcile the extremes of the monistic and theistic systems of Vedanta. It is called Sri-Vaisanavism in its religious aspect. Chari claims that it has been misunderstood by its followers as well as its critics, because jiva is a substance as well as an attribute and call this system "qualified non-dualism" or the adjectival monism. While the Dvaita insists on the difference between the Brahman and the Jiva, Visistadvaita states that God is their inner-Self as well as the transcendent.
Similarities with Platonic thought
Several scholars have recognised parallels between the philosophy of Pythagoras and Plato and that of the Upanishads, including their ideas on sources of knowledge, concept of justice and path to salvation, and Plato's allegory of the cave. Platonic psychology with its divisions of reason, spirit and appetite, also bears resemblance to the three gunas in the Indian philosophy of Samkhya.[note 12]
Based on these common features some scholars, most notably E.J. Urwick and M.L. West, have argued that the Ancient Greek philosophy was influenced by, and borrowed some core concepts from, the Upanishads. Various mechanisms for such a transmission of knowledge have been conjectured including Pythagoras traveling as far as India; Indian philosophers visiting Athens and meeting Socrates; Plato encountering the ideas when in exile in Syracuse; or, intermediated through Persia.
However other scholars, such as Arthur Berriedale Keith, J. Burnet and A.R. Wadia, believe that the two systems developed independently. They note that there is no historical evidence of the philosophers of the two schools meeting, and point out significant differences in the stage of development, orientation and goals of the two philosophical systems. Wadia writes that Plato's metaphysics were rooted in this life and his primary aim was to develop an ideal state. In contrast, Upanishadic focus was the individual, the self (atman, soul), self-knowledge, and the means of an individual's moksha (freedom, liberation in this life or after-life).
The Upanishads have been translated into various languages including Persian, Italian, Urdu, French, Latin, German, English, Dutch, Polish, Japanese, Spanish and Russian. The Moghul Emperor Akbar's reign (1556–1586) saw the first translations of the Upanishads into Persian, and his great-grandson, Dara Shikoh, produced a collection called Sirr-e-Akbar (The Greatest Mysteries) in 1657, with the help of Sanskrit Pandits of Varanasi. Its introduction stated that the Upanishads constitute the Qur'an's "Kitab al-maknun" or hidden book. But Akbar's and Sikoh's translations remained unnoticed in the Western world until 1775.
Abraham Hyacinthe Anquetil-Duperron, a French Orientalist who had lived in India between 1755 and 1761, received a manuscript of the Upanishads in 1775 from M. Gentil, and translated it into French and Latin, publishing the Latin translation in two volumes in 1802–1804 as Oupneck'hat. The French translation was never published.
The first English translation of the Aitareya Upanishad was made by Colebrooke, in 1805 and the first English translation of the Kena Upanishad was made by Rammohun Roy in 1816. Colebrooke was aware of 170 Upanishads. Sadhale's catalog from 1985, the Upaniṣad-vākya-mahā-kośa lists 223 Upanishads.
The first German translation appeared in 1832 and Roer's English version appeared in 1853. However, Max Mueller's 1879 and 1884 editions were the first systematic English treatment to include the 12 Principal Upanishads. After this, the Upanishads were rapidly translated into Dutch, Polish, Japanese and Russian.
Reception in the West
The German philosopher Arthur Schopenhauer read the Latin translation and praised the Upanishads in his main work, The World as Will and Representation (1819), as well as in his Parerga and Paralipomena (1851). He found his own philosophy was in accord with the Upanishads, which taught that the individual is a manifestation of the one basis of reality. For Schopenhauer, that fundamentally real underlying unity is what we know in ourselves as "will". Schopenhauer used to keep a copy of the Latin Oupnekhet by his side and commented,
It has been the solace of my life, it will be the solace of my death.
Another German philosopher, Friedrich Wilhelm Joseph Schelling, praised the mystical and spiritual aspects of the Upanishads. Schelling and other philosophers associated with German idealism were dissatisfied with Christianity as propagated by churches. They were fascinated with the Vedas and the Upanishads. In the United States, the group known as the Transcendentalists were influenced by the German idealists. These Americans, such as Emerson and Thoreau, were not satisfied with traditional Christian mythology and therefore embraced Schelling's interpretation of Kant's Transcendental idealism, as well as his celebration of the romantic, exotic, mystical aspect of the Upanishads. As a result of the influence of these writers, the Upanishads gained renown in Western countries.
One of the great English-language poets of the 20th century, T. S. Eliot, inspired by his reading of the Upanishads, based the final portion of his famous poem The Waste Land (1922) upon one of its verses. Erwin Schrödinger, the great quantum physicist said,
The multiplicity is only apparent. This is the doctrine of the Upanishads. And not of the Upanishads only. The mystical experience of the union with God regularly leads to this view, unless strong prejudices stand in the West.
Eknath Easwaran, in translating the Upanishads, articulates how they
...form snapshots of towering peaks of consciousness taken at various times by different observers and dispatched with just the barest kind of explanation.
Juan Mascaró states that the Upanishads represents for the Hindu approximately what the New Testament represents for the Christian, and that the message of the Upanishads can be summarized in the words, "the kingdom of God is within you".
Paul Deussen in his review of the Upanishads, states that the texts emphasize Brahman-Atman as something that can experienced, but not defined. This view of the soul and self are similar, states Deussen, to those found in the dialogues of Plato and elsewhere. The Upanishads insisted on oneness of soul, excluded all plurality, and therefore, all proximity in space, all succession in time, all interdependence as cause and effect, and all opposition as subject and object. Max Muller, in his review of the Upanishads, summarizes the lack of systematic philosophy and the central theme in the Upanishads as follows,
There is not what could be called a philosophical system in these Upanishads. They are, in the true sense of the word, guesses at truth, frequently contradicting each other, yet all tending in one direction. The key-note of the old Upanishads is "know thyself," but with a much deeper meaning than that of the γνῶθι σεαυτόν of the Delphic Oracle. The "know thyself" of the Upanishads means, know thy true self, that which underlines thine Ego, and find it and know it in the highest, the eternal Self, the One without a second, which underlies the whole world.
- These include rebirth, karma, moksha, ascetic techniques and renunciation.
- The Upanishadic, Buddhist and Jain renunciation traditions form parallel traditions, which share some common concepts and interests. While Kuru-Panchala, at the central Ganges Plain, formed the center of the early Upanishadic tradition, Kosala-Magadha at the central Ganges Plain formed the center of the other shramanic traditions
- Advaita Vedanta, summarized by Shankara (788–820), advances a non-dualistic (a-dvaita) interpretation of the Upanishads."
- "These Upanishadic ideas are developed into Advaita monism. Brahman's unity comes to be taken to mean that appearances of individualities.
- "The doctrine of advaita (non dualism) has is origin in the Upanishads."
- The date of the Buddha's birth and death are uncertain: most early 20th-century historians dated his lifetime as c. 563 BCE to 483 BCE, but more recent opinion dates his death to between 486 and 483 BCE or, according to some, between 411 and 400 BCE., but recent archaeological excavations in Lumbini, the birthplace of the Buddha, published in 2013 in Antiquity journal showed through radiocarbon analysis that he lived in 6th century BCE
- These are believed to pre-date Gautam Buddha (c. 500 BCE)
- Oliville: "In this Introduction I have avoided speaking of 'the philosophy of the upanishads', a common feature of most introductions to their translations. These documents were composed over several centuries and in various regions, and it is futile to try to discover a single doctrine or philosophy in them."
- According to Radhakrishnan, Gaudapada lived in a time when Buddhism was widely prevalent in India, and he was at times conscious of the similarity between his system to some phases of Buddhist thought.
- Radhakrishnan believed that Shankara's views of Advaita are straightforward developments of the Upanishads and the Brahmasutra and he offered no innovations to these,
- It has become traditional to view the Upanishads through the lens of Shankara's Advaita interpretation. This imposes the philosophical revolution of about 700 C.E. upon a very different situation 1,000 to 1,500 years earlier. Shankara picked out monist and idealist themes from a much wider philosophical lineup. According to Collins, the breakdown of the Vedic cults is more obscured by retrospective ideology than any other period in Indian history. It is commonly assumed that the dominant philosophy now became an idealist monism, the identification of atman (self) and Brahman (Spirit), and that this mysticism was believed to provide a way to transcend rebirths on the wheel of karma. This is far from an accurate picture of what we read in the Upanishads. 
- For instances of Platonic pluralism in the early Upanishads see Randall.
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