Upanishads (उपनिषदः)

Upanishads (Samskrit : उपनिषद्) are the concluding segments, available as a part of Aranyakas. Since they expound the various spiritual and dharmika siddhantas and tattvas that leads a sadhaka to the highest purpose of Moksha and because they are present at the end of the Vedas, they are also referred to as the Vedanta. They do not forbid the rituals or rites prescribed in the Karmakanda but expound that only through Jnana one can attain moksha.

The word Vedanta is a compound word made up of two Sanskrit words: ‘Veda’ and  ‘Anta’. The word ‘anta’ means an end. The Vedanta essentially refers to the philosophy pronounced in the Upanishads, the final parts of the Vedas.

परिचयः ॥ Introduction

The Vedas have been divided into four styles of texts – the Samhitas, the Aranyakas, the Brahmanas and the Upanishads. The subject matter of the whole Veda is divided into Karma-Kanda, Upasana-Kanda and Jnana-Kanda. The Karma-Kanda or Ritualistic section deals with various sacrifices and rituals. The Upasana-Kanda or Worship section deals with various kinds of worship or meditation. The Jnana-Kanda or Knowledge-Section deals with the highest knowledge of Nirguna Brahman. The Samhitas and the Brahmanas constitute Karma-Kanda; the Aranyakas constitute Upasana-Kanda; and the Upanishads constitute Jnana-KandaThe Upanishads along with the Bhagavadgita and Brahmasutras constitute the Prasthana Trayi (प्रस्थानत्रयी) and both the Gita and Brahmasutras are based again on the Upanishads. They are also the foundational sources for all Darshana shastras and including the Jain and Buddhist philosophies.

According to Dr. K. S. Narayanacharya, these are four different modes of expressing the same truths, each as a cross check against others so that misrepresentations are avoided, a method used and valid even today.

Most of the Upanishads are in forms of dialogues between a master and a disciple. In Upanishads, a seeker raises a topic and the enlightened guru satisfies the query aptly and convincingly. The central concepts found in the Upanishads involve the following aspects of Sanatana Dharma

• Brahman (Supreme Being, Ultimate Reality)
• Ātman (Self)
• Jiva (Embodiment of Atman)
• Unity of Brahman and Atman (Know that you are Ātman)
• Srshti (Origin of Creation)
• Jnana (Knowledge that Unity and Self are not separate)
• Avidya (Ignorance)
• Moksha (The Paramapurushartha)

The Upanishads speak about the identity of the Supreme Being, the Brahman, the individual Atman, their mutual relationship, the Universe (jagat) and man’s place in it. In short they deal with Jiva, Jagat and Jagadishwara and ultimately the path to mokṣa or mukti. Chronology and dating of Upanishads is not attempted in this article.

व्युत्पत्तिः ॥ Etymology

There are different versions about the meaning of Upanishad as given by many scholars. The term Upaniṣad term consists of उप (upa) and नि (ni) उपसर्ग-s (Upasargas or Prefixes) and सद् धातुः (Sad dhatu) followed by किव्प् प्रत्ययः (Kvip pratyaya as Suffix) used in the sense of विशरणगत्यवसादनेषु । Shri Adi Shankaracharya explains in his commentary on Taittriyopanishad about the meanings of Sad dhatu thus

• विशरण (नाशनम्) to destroy : They destroy the seeds of Avidya causing samsara in a Mumukshu (a sadhaka who wants to attain Moksha), hence this Vidya is called Upanishads

  अविद्यादेः संसारबीजस्य विशरणाद् विनाशनादित्यनेन अर्थयोगेन विद्या उपनिषदुच्यते । avidyādeḥ saṁsārabījasya viśaraṇād vināśanādityanena arthayogena vidyā upaniṣaducyate ।

• गति (प्रपणम् वा विद्यर्थकम्) to obtain or to know : That vidya which leads to or make the sadhaka obtain Brahma, is called Upanishad.

  परं ब्रह्म वा गमयतोति ब्रह्म गमयितृत्वेन योगाद् विद्योपनिषद् । paraṁ brahma vā gamayatoti brahma gamayitr̥tvena yogād vidyopaniṣad ।

• अवसादन (शिथिलर्थकम्) to loosen or to dissolve : Through which cycles of birth, aging etc painful process are loosened or dissolved (that is bondages of samsara are dissolved allowing the sadhaka to attain the Brahma)

  गर्भवासजन्मजराद्युपद्रववृन्दस्य लोकान्तरेपौनपुन्येन प्रवृत्तस्य अवसादपितृत्वेन उपनिषदित्युच्यते । garbhavāsajanmajarādyupadravavr̥ndasya lokāntarepaunapunyena pravr̥ttasya avasādapitr̥tvena upaniṣadityucyate ।

  His also defines the primary meaning of Upanishad as ब्रह्मविद्या (Brahmavidya। Knowledge of Brahma) and secondary meaning as ब्रह्मविद्याप्रतिपादकग्रन्थः (Brahmavidya pratipadaka granth । texts which teach Brahmavidya). Shankaracharya's commentaries of the Kaṭha and Brihadaranyaka Upanishad also support this explanation.

An alternative explanation of the word Upanishad is "to sit near" derived as follows

• नि (ni) उपसर्ग (Upasarga or Prefix) in front of सद् धातुः (Sad dhatu) also means 'to sit'.
• उप (upa) Upasarga is used to mean 'nearness or close to'.
• उपनिषद् term thus means "to sit near"

Thus Upanishad came to mean as ' to sit near the Guru (preceptor) to obtain the 'secret knowledge' or Brahmavidya (as per Shabdakalpadhruma : उपनिषद्यते प्राप्यते ब्रह्म-विद्या अनया इति)

Generally, Upanishads are synonymous with Rahasya (रहस्यम्) or secrecy. Upanishads themselves mention statements such as "इति उपनिषद् इति रहस्यम्" when discussing some important siddhantas. Probably such usages are given to prevent and caution against giving this knowledge to the undeserving.

In the mukhya upanishads, there are many instances of रहस्यम् meaning secret or hidden knowledge especially in Atharvaveda upanishads. Kaushitaki Upanishad for example, contains detailed siddhantas of मनोज्ञानम् and तत्वज्ञानम् (Psychology and metaphysics). Apart from them they also contain मृतकज्ञानम् (siddhantas around death, travel of Atman etc), बालमृत्यु निवारणम् (preventing untimely childhood deaths) शत्रुविनाशार्थ रहस्यम् (secrets about the destruction of enemies) etc. Chandogya Upanishads gives the secrets about the origin of worlds, Jiva, Jagat, Om and their hidden meanings.

Classification of Upanishads

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 rest of them aid in explaining bhakti or jnana concepts and many are without bhashyas. Some scholars accept 12 Upanishads and some even consider 13 to be the principal Upanishads and some others accept 108 Upanishads.

Basis for Classification

Many modern and western indology thinkers have put forth their contemplations on the classification of Upanishads based on

1. the presence or absence of Shankaracharya's bhasyas (Ten for which bhashyas are available are Dasopanishads and the rest describing devatas. Vaishnava, Shaiva, Shakta, Saurya etc)
2. the ancientness of Upanishad based on association with Aranyakas and Brahmanas
3. the ancientness and modernness of the Upanishads based on description of deities and other aspects ( Given by Shri Chintamani Vinayak on Page 256 of Reference )
4. the shanti patha given in each of the Upanishads
5. the ancientness and modernness of the Upanishads having prose or metrical compositions (mostly given by Western Indologists like Dr. Daison)

दशोपनिषदः ॥ Dasopanishads

Muktikopanishad lists the following ten as principal Upanishads which have received attention from Shri Adi Shankaracharya in form of his bhasyas.

ईश-केन-कठ-प्रश्न-मुण्ड-माण्डूक्य-तित्तिरः । एेतरेयं च छान्दोग्यं बृहदारण्यकं तथा ॥ īśa-kēna-kaṭha-praśna-muṇḍa-māṇḍūkya-tittiraḥ । ēētarēyaṁ ca chāndōgyaṁ br̥hadāraṇyakaṁ tathā ॥

The 10 Mukhya Upanishad on which Adi Shankaracharya commented are:

1. ईशावाश्योपनिषद् ॥ Ishavasya Upanishad (Shukla Yajur Veda)
2. केनोपनिषद् ॥ Kena Upanishad (Sama Veda)
3. कठोपनिषद् ॥ Katha Upanishad (Yajur Veda)
4. प्रश्नोपनिषद् ॥ Prashna Upanishad (Atharva Veda)
5. मुण्डकोपनिषद् ॥ Mundaka Upanishad (Atharva Veda)
6. माण्डूक्योपनिषद् ॥ Mandukya Upanishad (Atharva Veda)
7. तैत्तियोपनिषद् ॥ Taittiriya Upanishad (Yajur Veda)
8. एेतरेयोपनिषद् ॥ Aitareya Upanishad (Rig Veda)
9. छान्दोग्योपनिषद्॥ Chhandogya Upanishad (Sama Veda)
10. बृहदारण्यकोपनिषद् Brhadaranyaka Upanishad (Yajur Veda)

Apart from these ten, कौषीतकि (Kaushitaki) श्वेताश्वतर (Shvetasvatara) and मैत्रायणीय (Maitrayaniya) Upanishads are regarded as ancient since the first two of these three found a mention by Shankaracharya in his Brahmasutra bhashyas along with dashopanishad bhashyas. However, there are no available commentaries on these given by him.

Upanishads as Part of Aranyakas

Many Upanishads are the final or exclusive portions of the Aranyakas or the Brahmanas. But these refer mainly to the dasha upanishads. It may be seen from the table below that some Upanishads not classified in dashopanishads are from Aranyakas. (Ex: Mahanarayaneeya Upanishad, Maitrayaniya Upanishad) while the Atharvana veda associated Upanishads do not have corresponding Brahmanas or Aranyakas as they are unavailable.

Upanishads as part of Aranyakas and Brahmanas

Veda		What part of Brahmana or Aranyaka constitutes Upanishad	Name of Upanishad
RigVeda		4th to 6th Adhyayas of 2nd Prapathaka of 2nd Aranyaka of Aitareya Aranyaka (Page 250 of Reference )	एेतरेयोपनिषद् ॥ Aitareya Upanishad
		3rd to 6th Adhyayas of Shankhyayana Aranyaka (Page 251 of Reference )	कौषीतकि उपनिषद् ॥ Kaushitaki Upanishad
Yajurveda	Krishna	7th to 9th Prapathakas of Taittriya Aranyaka (Page 251 of Reference )	तैत्तियोपनिषद् ॥ Taittiriya Upanishad
		10th Prapathaka of Taittriya Aranyaka (also considered as Khila khanda) (Page 251 of Reference )	महानारायणीय उपनिषद् ॥ Mahanarayaneeya Upanishad
		Kathasamhita or Kathavalli (Page 54 of Reference )	कठोपनिषद् ॥ Katha Upanishad
		Maitrayaniya Aranyaka (Page 251 of Reference )	मैत्रायणीय Maitrayaniya Upanishad
	Shukla	Last 6 Adhyayas of Shatapatha Brahmana (Page 56 of Reference )	Brhadaranyakopanishad
		40th Adhyaya of माध्यन्दिन-शतपथ-ब्राह्मणम् ॥ Madhyandina Shatapatabrahmana	ईशावाश्योपनिषद् ॥ Ishavasya Upanishad
Samaveda		10th Anuvaka of 4th Adhyaya of जैमिनीय ॥ Jaiminiya (Talavakara तलवकार) Brahmana (Page 253 of Reference )	केनोपनिषद् ॥ Kena Upanishad
		Last 10 Adhyayas of Chandogyabrahmana of Kauthuma Shakha (Page 55 of Reference )	छान्दोग्योपनिषद्॥ Chhandogya Upanishad
Adharvaveda		Associated with Pippalada brahmana (Page 54 of Reference )	प्रश्नोपनिषद् ॥ Prashna Upanishad
		Associated with Shaunaka samhita (Page 54 of Reference )	मुण्डकोपनिषद् ॥ Mundaka Upanishad
		Associated with Atharvaveda (Page 55 of Reference )	माण्डूक्योपनिषद् ॥ Mandukya Upanishad

Deity and Samkhya Based Classification

Pt. Shri. Chintamani Vinayak Vaidya has assigned the ancientness (प्राचीनता) or modernness (अर्वाचीनता) of Upanishads using the two factors

1. Siddhanta of Anatmarupa Brahma (a supreme power beyond and above deities)
2. Vishnu or Shiva deities are accepted as paradevata (supreme deity) and are praised
3. Principles of Samkhya Siddhanta (Prakriti, Purusha, Gunas-Satva, Rajas and Tamas)

It is proved beyond doubt that the ancient upanishads have described a Supreme Anatmarupa Brahma, above the vaidika deities, who has created regulated and maintained order of the creation. They are thus very ancient and include Aitareya, Isha, Taittriya, Brhadaranyaka, Chandogya, Prashna, Mundaka and Mandukya Upanishads.

Only in the more recent upanishads one can see the older ones in praise of Vishnu as the Supreme Being followed by the more recent one's in praise of Shiva. In this group is classified Kathopanishad where Vishnu is the Supreme Being. Krishna Yajurveda Upanishads are famous for their Shiva and Rudra stutis (Rudra Prashna is a famous stuti) and in this way Shevetashvatara Upanishad which accepts Shiva as paradevata is more recent compared to Kathopanishad. In this series, Maitrayaniya Upanishad which accepts all the Trimurti's (Brahma Vishnu and Shiva) is more recent than the above two mentioned Upanishads.

Katha Upanishad (which has no principles of Samkhya) is ancient as against Shvetashvatara (which expounds principles of Samkhya and its preceptor Kapila Maharshi), further more recent is Maitrayaniya Upanishad where samkhya philosophy along with the description of the gunas is given in detail.

Shanti Patha Based Classification

Some upanishads are not related to any veda, while some are definitely associated with one or the other veda. Based on the Shanti patha that is given in the beginning of the Upanishads the following classification is proposed.(Page 288-289 of Reference )

108 Upanishads Classified Based on Shanti Patha of Each Veda

Veda	Shanti patha	Upanishads
Rigveda	Vangmemanasi...	Aitareya, Kaushitaki, Atmaprabodha, Nadabindu, Nirvana, Mudgala, Akshamalika, Tripura, Saubhagya, Bahvrucha Upanishads (10)
Krishna Yajurveda	Sahanavavatu...	Kathavalli (commonly referred to as Kathopanishad), Taittriya, Narayana, Brahma, Kaivalya, Shvetasvatara, Garbha, Amrtabindu, Amrtanada, Kalagnirudra, Kshurika, Sarvasara, Shukarahasya, Tejobindu, Dhyanabindu, Brahmavidya, Yogatattva, Dakshinamurty, Katha (different from Kathavalli), Skanda, Shareeraka, Varaha, Yogashikha, Ekakshara, Akshi, Avadhuta, Rudrahrdaya, Yogakundalini, Panchabrahma, Kalisantarana, Pranagnihotra, Sarasvatirahasya Upanishads (32)
Shukla Yajurveda	Purnamadah Purnamida ...	Ishavasya, Brhadaranya, Jabala, Subaala, Hamsa, Paramahamsa, Mantrikaniralamba, Tarasara, Trishikhi, Brahmanamandala, Brahmana, Advayataraka, Paingala, Bhikshuka, Turiyateeta, Adhyatma, Muktika, Shatyayani, Yajnavalkya Upanishads (19)
Samaveda	Apyayantu...	Kena, Chandogya, Aaruni, Maitrayani, Maitreyi, Vajrasuchi, Yoga, Chudamani, Vasudeva, Sanyasa, Avyakta, Savitri, Rudrakshajabala, Darshanajabali, Kundika, Mahopanishad Upanishads (16)
Adharvanaveda	Bhadramkarnebhi...	Prashna, Mundaka, Mandukya, Brhadjabala, Nrsimhatapini, Narada parivrajaka, Sitaa, Sharabha, Mahanarayana, Ramarahasya, Ramatapini, Shandilya, Paramahamsa parivrajaka, Annapurna, Surya, Atma, Parambrahma, Pashupata, Tripuratapini, Devi, Bhavana, Bhasmajabala, Ganapati, Mahavakya, Gopalatapini, Krishna, Hayagriva, Garuda, Dattatreya, Atharvashikha, Atharvashiro Upanishads (31)

Authorship

The authorship of most Upanishads is uncertain and unknown. The various philosophical theories in the early Upanishads have been attributed to famous seers such as Yajnavalkya, Uddalaka Aruni, Shvetaketu, Shandilya, Aitareya, Balaki, Pippalada and Sanatkumara. Women, such as Maitreyi and Gargi participated in the dialogues and are also credited in the early Upanishads.

There are exceptions to the anonymous tradition of the Upanishads and other Vedic literature. The Shvetashvatara Upanishad, for example, includes closing credits to Shvetashvatara, and he is considered the author of the Upanishad.

Upanishad vishaya

The main concept of Upanishads is the discussion about Paramatmatattva. There are two kinds of Vidyas : Para and Apara. Of these Paravidya is supreme and is called Brahmavidya. Upanishads present the detailed discussion about Paravidya. Aparavidya is primarily related to Karmas, hence called Karmavidya. The fruits of Karmavidya are perishable while the results of Brahmavidya are indestructable. Aparavidya may not lead one to Moksha (may lead to svarga and other worlds) but Paravidya always gives Moksha.

Some terms which are well explained in the Upanishads include, Prkriti, Purusha, Paramatma, Ishvara, Jivatma, Maya, Brahman, Avidya, Indriyas, etc. From the root cause Prkriti the world came into being. Paramatma is Nitya, Puratana, Shasvata (Eternal) devoid of the cycles of birth and death. The Sharira or body is subjected to death and birth but Atma residing in it continues to exist. Just like butter is evenly distributed in milk so also Paramatma is all-pervading in the world. Just like the sparks arise out of fire so also the beings take shape from the Paramatma. Such aspects which are explained in Upanishads have widely developed in the Darshana shastras.

Based on their content Upanishads can be divided into six categories.

1. Vedanta siddhanta
2. Yoga siddhanta
3. Samkhya siddhanta
4. Vaishnava siddhanta
5. Shaiva siddhanta
6. Shakta siddhanta

According to the beliefs, principles and nature of a particular sampradaya, Upanishads have been composed in later days.

Special Points

Although all Upanishads proclaim that the goal of human life, embroiled in the flow of samsara, is to attain Jnana that leads to Moksha, the ultimate paramapurushartha, each of the upanishads have their own special features about their siddhantas as follows

1. Katha discusses the doubts about post death path of a Jiva
2. Shvetasvatara says Jagat and Paramatma are Maya
3. Brhadaranyaka gives the paths to higher worlds
4. Mundakopanishad stressed the fact that the whole Universe is nothing but Parabrahma
5. Isavasya defines that a Jnani is one who sees Self and Paramatma pervading the world.
6. Taittriyopanishad proclaims that Brahmajnana leads to Moksha.
7. Chandogyopanishad gives the outline of how janmas (births) happen and paths to reach Brahmaloka.
8. Prashnopanishad logically answers the questions regarding the nature of Atma.
9. Mandukya upanishad proclaims Atman to be Brahman
10. Aitareya upanishad establishes the characteristics of Brahma

Geography

The general area of the composition of the early Upanishads was northern India, the region bounded on the west by the upper Indus valley, on the east by lower Ganges region, 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.^[30] This region covers modern Bihar, Nepal, Uttar Pradesh, Uttarakhand, Himachal Pradesh, Haryana, eastern Rajasthan and northern Madhya Pradesh.^[6]

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.^[31]

The Chandogya Upanishad was probably composed in a more Western than an Eastern location in Indian subcontinent, possibly somewhere in the western region of the Kuru-Panchala country.^[32] 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.^[33] In fourth chapter of the Kaushitaki Upanishad, a location named Kashi (modern Varanasi) is mentioned.^[6]

Each of the principal Upanishads can be associated with one of the schools of exegesis of the four Vedas (shakhas).^[49] 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.^[50]

New Upanishads

There is no fixed list of the Upanishads as newer ones, beyond the Muktika anthology of 108 Upanishads, have continued to be discovered and composed.^[52] In 1908, for example, four previously unknown Upanishads were discovered in newly found manuscripts, and these were named Bashkala, Chhagaleya, Arsheya and Saunaka, by Friedrich Schrader,^[53] who attributed them to the first prose period of the Upanishads.^[54] The text of three, the Chhagaleya, Arsheya and Saunaka, were incomplete and inconsistent, likely poorly maintained or corrupted.^[54]

Ancient Upanishads have long enjoyed a revered position in Hindu traditions, and authors of numerous sectarian texts have tried to benefit from this reputation by naming their texts as Upanishads.^[55] These "new Upanishads" number in the hundreds, cover diverse range of topics from physiology^[24] to renunciation^[25] to sectarian theories.^[55] They were composed between the last centuries of the 1st millennium BCE through the early modern era (~1600 CE).^[55][25] While over two dozen of the minor Upanishads are dated to pre-3rd century CE,^[28][29] many of these new texts under the title of "Upanishads" originated in the first half of the 2nd millennium CE,^[55] they are not Vedic texts, and some do not deal with themes found in the Vedic Upanishads.^[58]

The main Shakta Upanishads, for example, 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. Sectarian texts such as these do not enjoy status as shruti and thus the authority of the new Upanishads as scripture is not accepted in Hinduism.^[59]

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.^[60] During the modern era, the ancient Upanishads that were embedded texts in the Vedas, were detached from the Brahmana and Aranyaka layers of Vedic text, compiled into separate texts and these were then gathered into anthologies of Upanishads.^[55] These lists associated each Upanishad with one of the four Vedas, many such lists exist, and these lists are inconsistent across India in terms of which Upanishads are included and how the newer Upanishads are assigned to the ancient Vedas. In south India, the collected list based on Muktika Upanishad,^{[note 5]} and published in Telugu language, became the most common by the 19th-century and this is a list of 108 Upanishads.^[55][26] In north India, a list of 52 Upanishads has been most common.^[55]

The Muktikā Upanishad's list of 108 Upanishads groups the first 13 as mukhya,^{[27][note 6]} 21 as Sāmānya Vedānta, 20 as Sannyāsa,^[28] 14 as Vaishnava, 12 as Shaiva, 8 as Shakta, and 20 as Yoga.^[29] The 108 Upanishads as recorded in the Muktikā are shown in the table below.^[60] The mukhya Upanishads are the most important and highlighted.

Veda-Upanishad association
Veda	Number[60]	Mukhya[27]	Sāmānya	Sannyāsa[28]	Śākta[30]	Vaiṣṇava[31]	Śaiva[32]	Yoga[29]
Ṛigveda	10	Aitareya, Kauśītāki	Ātmabodha, Mudgala	Nirvāṇa	Tripura, Saubhāgya-lakshmi, Bahvṛca	-	Akṣamālika	Nādabindu
Samaveda	16	Chāndogya, Kena	Vajrasūchi, Maha, Sāvitrī	Āruṇi, Maitreya, Brhat-Sannyāsa, Kuṇḍika (Laghu-Sannyāsa)	-	Vāsudeva, Avyakta	Rudrākṣa, Jābāli	Yogachūḍāmaṇi, Darśana
Krishna Yajurveda	32	Taittiriya, Katha, Śvetāśvatara, Maitrāyaṇi[note 7]	Sarvasāra, Śukarahasya, Skanda, Garbha, Śārīraka, Ekākṣara, Akṣi	Brahma, (Laghu, Brhad) Avadhūta, Kaṭhasruti	Sarasvatī-rahasya	Nārāyaṇa, Kali-Saṇṭāraṇa	Kaivalya, Kālāgnirudra, Dakṣiṇāmūrti, Rudrahṛdaya, Pañcabrahma	Amṛtabindu, Tejobindu, Amṛtanāda, Kṣurika, Dhyānabindu, Brahmavidyā, Yogatattva, Yogaśikhā, Yogakuṇḍalini, Varāha
Shukla Yajurveda	19	Bṛhadāraṇyaka, Īśa	Subala, Mantrika, Niralamba, Paingala, Adhyatma, Muktika	Jābāla, Paramahaṃsa, Bhikṣuka, Turīyātītavadhuta, Yājñavalkya, Śāṭyāyaniya	-	Tārasāra	-	Advayatāraka, Haṃsa, Triśikhi, Maṇḍalabrāhmaṇa
Atharvaveda	31	Muṇḍaka, Māṇḍūkya, Praśna	Ātmā, Sūrya, Prāṇāgnihotra[33]	Āśrama, Nārada-parivrājaka, Paramahaṃsa parivrājaka, Parabrahma	Sītā, Devī, Tripurātapini, Bhāvana	Nṛsiṃhatāpanī, Mahānārāyaṇa (Tripād vibhuti), Rāmarahasya, Rāmatāpaṇi, Gopālatāpani, Kṛṣṇa, Hayagrīva, Dattātreya, Gāruḍa	Atharvasiras,[34] Atharvaśikha, Bṛhajjābāla, Śarabha, Bhasma, Gaṇapati	Śāṇḍilya, Pāśupata, Mahāvākya
Total Upanishads	108	13[note 6]	21	19	8	14	13	20

Philosophy

Main article: Vedanta

The Upanishadic age was characterized by a pluralism of worldviews. While some Upanishads have been deemed 'monistic', others, including the Katha Upanishad, are dualistic.^[74] The Maitri is one of the Upanishads that inclines more toward dualism, thus grounding classical Samkhya and Yoga schools of Hinduism, in contrast to the non-dualistic Upanishads at the foundation of its Vedanta school.^[75] They contain a plurality of ideas.^{[76][note 8]}

The Upanishads include sections on philosophical theories that have been at the foundation of Indian traditions. For example, the Chandogya Upanishad includes one of the earliest known declaration of Ahimsa (non-violence) as an ethical precept.^[39][40] Discussion of other ethical premises such as Damah (temperance, self-restraint), Satya (truthfulness), Dāna (charity), Ārjava (non-hypocrisy), Daya (compassion) and others are found in the oldest Upanishads and many later Upanishads.^[41][42] Similarly, the Karma doctrine is presented in the Brihadaranyaka Upanishad, which is the oldest Upanishad.^[43]

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.^[86] 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.^[86]

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".^[44] The Mundaka Upanishad declares how man has been called upon, promised benefits for, scared unto and misled into performing sacrifices, oblations and pious works.^[45] 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.^[45][46] The Maitri Upanishad states,^[47]

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,^[91] meditate on the Self, to become complete and perfect.

— Maitri Upanishad^[92][93]

The opposition to the ritual is not explicit in the oldest Upanishads. On 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.^[86]

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.^[48][49][50] 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.^[86] Brahman-Atman and Self-realization develops, in the Upanishad, as the means to moksha (liberation, freedom in this life or after-life).^[50][51][52]

Brahman and Atman

Main articles: Ātman (Hinduism) and Brahman

Two concepts that are of paramount importance in the Upanishads are Brahman and Atman.^[101] The Brahman is the ultimate reality and the Atman is individual self (soul).^[53][54] Brahman is the material, efficient, formal and final cause of all that exists.^[55][56][57] It is the pervasive, genderless, infinite, eternal truth and bliss which does not change, yet is the cause of all changes.^[53][58] Brahman is "the infinite source, fabric, core and destiny of all existence, both manifested and unmanifested, the formless infinite substratum and from which the universe has grown". Brahman in Hinduism, states Paul Deussen, as the "creative principle which lies realized in the whole world".^[59]

The word Atman means the inner self, the soul, the immortal spirit in an individual, and all living beings including animals and trees.^[60][54] Ātman is a central idea in all the Upanishads, and "Know your Ātman" their thematic focus.^[61] 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".^[62] Atman is the spiritual essence in all creatures, their real innermost essential being.^[63][64] It is eternal, 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.^[65][66] 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.^[65]

The idea put forth by the Upanishadic seers that Atman and Brahman are One and the same is one of the greatest contributions made to the thought of the world.^{[116][117][118][119]}

Illusion

Main article: Maya (illusion)

Two different types of the non-dual Brahman-Atman are presented in the Upanishads, according to Mahadevan.^[120] 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).^[67] 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).^[68]

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."^[69] 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."^[70]

In the Upanishads, Māyā is the perceived changing reality and it co-exists with Brahman which is the hidden true reality.^[71][72] 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.^[73][74]

Schools of Vedanta

Main article: Vedanta

The Upanishads form one of the three main sources for all schools of Vedanta, together with the Bhagavad Gita and the Brahmasutras.^[129] 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.^[130] The schools of Vedanta are named after the relation they see between atman and Brahman:^[131]

• According to Advaita Vedanta, there is no difference.^[131]
• 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.^[132] The philosopher Adi Sankara has provided commentaries on 11 mukhya Upanishads.^[133]

Advaita Vedanta

Advaita literally means non-duality, and it is a monistic system of thought.^[134] 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.^[134] Gaudapada was the first person to expound the basic principles of the Advaita philosophy in a commentary on the conflicting statements of the Upanishads.^[135] Gaudapada's Advaita ideas were further developed by Shankara.^[136][137] King states that Gaudapada's main work, Māṇḍukya Kārikā, is infused with philosophical terminology of Buddhism, and uses Buddhist arguments and analogies.^[138] King also suggests that there are clear differences between Shankara's writings and the Brahmasutra,^[136][137] and many ideas of Shankara are at odds with those in the Upanishads.^[139] Radhakrishnan, on the other hand, suggests that Shankara's views of Advaita were straightforward developments of the Upanishads and the Brahmasutra,^[140] and many ideas of Shankara derive from the Upanishads.^[75]

Shankara in his discussions of the Advaita Vedanta philosophy referred to the early Upanishads to explain the key difference between Hinduism and Buddhism, stating that Hinduism asserts "Atman (Soul, Self) exists", while Buddhism asserts that there is "no Soul, no Self".^[76][77][78]

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)^[145]
• "Aham brahmāsmi" - "I am Brahman" (Brihadaranyaka Upanishad)^[146]
• "Tat tvam asi" - "That Thou art" (Chandogya Upanishad)^[147]
• "Ayamātmā brahma" - "This Atman is Brahman" (Mandukya Upanishad)^[148]

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.^{[149][note 9]}

Dvaita

The Dvaita school was founded by Madhvacharya.^[150] Dvaita is regarded as the best philosophic exposition of theism.^[151] Madhva, much like Adi Shankara claims for Advaita, states that his theistic Dvaita Vedanta is grounded in the Upanishads.^[79]

Vishishtadvaita

The third school of Vedanta is the Vishishtadvaita, which was founded by Ramanuja. Ramanuja strenuously refuted Shankara's works.^[153] Visistadvaita is a synthetic philosophy bridging the monistic Advaita and theistic Dvaita systems of Vedanta.^[151] Ramanuja, just as Madhva claims for Dvaita sub-school, states that Vishishtadvaita is grounded in the Upanishads.^[79]

References

43.     ↑ Ayyangar, TRS (1953). Saiva Upanisads. Jain Publishing Co. (Reprint 2007). pp. 194–196. ISBN 978-0895819819.

47.     ↑ Mahadevan 1956, p. 56.

48.     ↑ Ranade 1926, p. 61.

49.     ↑ Joshi 1994, pp. 90–92.

51.     ↑ Lal 1992, p. 4090.

53.     ↑ Singh 2002, pp. 3–4.

67.     1 2 The Yoga Upanishads TR Srinivasa Ayyangar (Translator), SS Sastri (Editor), Adyar Library

68.     ↑ AM Sastri, The Śākta Upaniṣads, with the commentary of Śrī Upaniṣad-Brahma-Yogin, Adyar Library, OCLC 7475481

69.     ↑ AM Sastri, The Vaishnava-upanishads: with the commentary of Sri Upanishad-brahma-yogin, Adyar Library, OCLC 83901261

70.     ↑ AM Sastri, The Śaiva-Upanishads with the commentary of Sri Upanishad-Brahma-Yogin, Adyar Library, OCLC 863321204

83.     ↑ PV Kane, Samanya Dharma, History of Dharmasastra, Vol. 2, Part 1, page 5

86.     1 2 3 4 Mahadevan 1956, p. 57.

97.     ↑ RC Mishra (2013), Moksha and the Hindu Worldview, Psychology & Developing Societies, Vol. 25, No. 1, pages 21-42

99.     1 2 3 Jayatilleke 1963, p. 32.

100.  ↑ Jayatilleke 1963, pp. 36-39.

101.  ↑ Mahadevan 1956, p. 59.

104.  ↑ PT Raju (2006), Idealistic Thought of India, Routledge, ISBN 978-1406732627, page 426 and Conclusion chapter part XII

110.  ↑ PT Raju (1985), Structural Depths of Indian Thought, State University of New York Press, ISBN 978-0887061394, pages 35-36

120.  ↑ Mahadevan 1956, p. 62.

121.  ↑ Paul Deussen, The Philosophy of the Upanishads, p. 161, at Google Books, pages 161, 240-254

122.  ↑ Ben-Ami Scharfstein (1998), A Comparative History of World Philosophy: From the Upanishads to Kant, State University of New York Press, ISBN 978-0791436844, page 376

123.  ↑ H.M. Vroom (1996), No Other Gods, Wm. B. Eerdmans Publishing, ISBN 978-0802840974, page 57

124.  ↑ Wendy Doniger O'Flaherty (1986), Dreams, Illusion, and Other Realities, University of Chicago Press, ISBN 978-0226618555, page 119

125.  ↑ Archibald Edward Gough (2001), The Philosophy of the Upanishads and Ancient Indian Metaphysics, Routledge, ISBN 978-0415245227, pages 47-48

126.  ↑ Teun Goudriaan (2008), Maya: Divine And Human, Motilal Banarsidass, ISBN 978-8120823891, pages 1-17

127.  ↑ KN Aiyar (Translator, 1914), Sarvasara Upanishad, in Thirty Minor Upanishads, page 17, OCLC 6347863

128.  ↑ Adi Shankara, Commentary on Taittiriya Upanishad at Google Books, SS Sastri (Translator), Harvard University Archives, pages 191-198

129.  ↑ Radhakrishnan 1956, p. 272.

130.  ↑ Raju 1992, p. 176-177.

131.  1 2 Raju 1992, p. 177.

132.  ↑ Ranade 1926, pp. 179–182.

133.  ↑ Mahadevan 1956, p. 63.

134.  1 2 Encyclopædia Britannica.

145.  ↑ Panikkar 2001, p. 669.

146.  ↑ Panikkar 2001, pp. 725–727.

147.  ↑ Panikkar 2001, pp. 747–750.

148.  ↑ Panikkar 2001, pp. 697–701.

149.  1 2 Olivelle 1998.

150.  ↑ Raghavendrachar 1956, p. 322.

151.  1 2 Chari 1956, p. 305.

152.  1 2 Stafford Betty (2010), Dvaita, Advaita, and Viśiṣṭādvaita: Contrasting Views of Mokṣa, Asian Philosophy, Vol. 20, No. 2, pages 215-224, doi:10.1080/09552367.2010.484955

153.  ↑ Klostermaier 2007, pp. 361–363.

154.  1 2 Chousalkar, pp. 130-134.

155.  1 2 Wadia 1956, p. 64-65.

156.  ↑ Collins 2000, pp. 197–198.

157.  ↑ Urwick 1920.

158.  ↑ Keith 2007, pp. 602-603.

159.  1 2 WD Strappini, The Upanishads, p. 258, at Google Books, The Month and Catholic Review, Vol. 23, Issue 42

160.  ↑ RC Mishra (2013), Moksha and the Hindu Worldview, Psychology & Developing Societies, Vol. 25, No. 1, pages 21-42; Chousalkar, Ashok (1986), Social and Political Implications of Concepts Of Justice And Dharma, pages 130-134

172.  ↑ Sadhale 1987.

173.  ↑ Hume, Robert Ernest (1921), The Thirteen Principal Upanishads, Oxford University Press

174.  ↑ Deussen, Bedekar & Palsule (tr.) 1997.

175.  ↑ Radhakrishnan, Sarvapalli (1953), The Principal Upanishads, New Delhi: HarperCollins Publishers (1994 Reprint), ISBN 81-7223-124-5

176.  ↑ Olivelle 1992.

177.  ↑ Schopenhauer & Payne 2000, p. 395.

178.  ↑ Schopenhauer & Payne 2000, p. 397.

179.  1 2 Singh 1999, p. 456-461.

180.  ↑ Versluis 1993, pp. 69, 76, 95. 106–110.

181.  ↑ Eliot 1963.

182.  ↑ Schrödinger 1992, p. 129.

183.  ↑ Easwaran 2007, p. 9.

184.  ↑ Juan Mascaró, The Upanishads, Penguin Classics, ISBN 978-0140441635, page 7, 146, cover

185.  1 2 Paul Deussen, The Philosophy of the Upanishads University of Kiel, T&T Clark, pages 150-179

Sources

• Brodd, Jefferey (2003), World Religions, Winona, MN: Saint Mary's Press, ISBN 978-0-88489-725-5
• Brooks, Douglas Renfrew (1990), The Secret of the Three Cities: An Introduction to Hindu Shakta Tantrism, The University of Chicago Press
• Brown, Rev. George William (1922), Missionary review of the world, Volume 45, Funk & Wagnalls
• Causality: The Central Philosophy of Buddhism, The University Press of Hawaii, 1975, ISBN 0-8248-0298-5
• Deussen, Paul; Bedekar, V.M. (tr.); Palsule (tr.), G.B. (1997). Sixty Upanishads of the Veda, Volume 2. Motilal Banarsidass. ISBN 978-81-208-1467-7.
• Deussen, P.; Geden, A. (2010), The Philosophy of the Upanishads, Cosimo, ISBN 978-1-61640-239-6
• Chari, P. N. Srinivasa (1956), Sarvepalli Radhakrishnan, ed., History of Philosophy Eastern and Western
• Chousalkar, Ashok (1986), Social and Political Implications of Concepts Of Justice And Dharma, Mittal Publications
• Chowdhry, Tarapada (1956), Sarvepalli Radhakrishnan, ed., History of Philosophy Eastern and Western, George Allen and Unwin Limited, p. 46
• Collins, Randall (2000), The Sociology of Philosophies: A Global Theory of Intellectual Change, Harvard University Press, ISBN 0-674-00187-7
• Coningham (2013), "The earliest Buddhist shrine: excavating the birthplace of the Buddha, Lumbini (Nepal)", Antiquity, 87 (338): 1104–1123
• Cornille, Catherine (1992), The Guru in Indian Catholicism: Ambiguity Or Opportunity of Inculturation, Wm. B. Eerdmans Publishing, ISBN 978-0-8028-0566-9
• Cousins, L. S. (1996), The dating of the historical Buddha: a review article, 3 (6(1)), Journal of the Royal Asiatic Society, pp. 57–63
• Deussen, Paul (1908), The philosophy of the Upanishads, Alfred Shenington Geden, T. & T. Clark, ISBN 0-7661-5470-X
• A.G.Krishna Warrier (translator), Muktika Upanishad, The Theosophical Publishing House, Chennai, retrieved 10 August 2010
• Easwaran, Eknath (2007), The Upanishads, Nilgiri Press, ISBN 978-1-58638-021-2
• Eliot, T. S. (1963), Collected Poems, 1909-1962, New York: Harcourt, Brace & World, ISBN 0-15-118978-1
• Encyclopædia Britannica, Advaita, retrieved 10 August 2010
• Farquhar, John Nicol (1920), An outline of the religious literature of India, H. Milford, Oxford university press, ISBN 81-208-2086-X
• Fields, Gregory P (2001), Religious Therapeutics: Body and Health in Yoga, Āyurveda, and Tantra, SUNY Press, ISBN 0-7914-4916-5
• Flood, Gavin D. (1996), An Introduction to Hinduism, Cambridge University Press, ISBN 978-0521438780
• Glucklich, Ariel (2008), The Strides of Vishnu: Hindu Culture in Historical Perspective, Oxford University Press, ISBN 0-19-531405-0
• Heehs, Peter (2002), Indian religions: a historical reader of spiritual expression and experience, NYU Press, ISBN 978-0-8147-3650-0
• Holdrege, Barbara A. (1995), Veda and Torah, Albany: SUNY Press, ISBN 0-7914-1639-9
• Jayatilleke, K.N. (1963), Early Buddhist Theory of Knowledge (PDF) (1st ed.), London: George Allen & Unwin Ltd.
• Joshi, Kireet (1994), The Veda and Indian culture: an introductory essay, Motilal Banarsidass Publ., ISBN 978-81-208-0889-8
• Kalupahana (1975), Causality: The Central Philosophy of Buddhism, The University Press of Hawaii, ISBN 0-8248-0298-5
• Coningham (2013), "The earliest Buddhist shrine: excavating the birthplace of the Buddha, Lumbini (Nepal)", Antiquity, 87 (338): 1104–1123
• Keith, Arthur Berriedale (2007). The Religion and Philosophy of the Veda and Upanishads. Motilal Banarsidass Publishers. ISBN 978-81-208-0644-3.
• King, Richard (1999), Indian philosophy: an introduction to Hindu and Buddhist thought, Edinburgh University Press, ISBN 0-87840-756-1
• King, Richard; Ācārya, Gauḍapāda (1995), Early Advaita Vedānta and Buddhism: the Mahāyāna context of the Gauḍapādīya-kārikā, SUNY Press, ISBN 978-0-7914-2513-8
• Klostermaier, Klaus K. (2007), A survey of Hinduism, SUNY Press, ISBN 0-585-04507-0
• Lanman, Charles R (1897), The Outlook, Volume 56, Outlook Co.
• Lal, Mohan (1992), Encyclopaedia of Indian Literature: sasay to zorgot, Sahitya Akademi, ISBN 978-81-260-1221-3
• Müller, Friedrich Max (1900), The Upanishads Sacred books of the East The Upanishads, Friedrich Max Müller, Oxford University Press
• Macdonell, Arthur Anthony (2004), A practical Sanskrit dictionary with transliteration, accentuation, and etymological analysis throughout, Motilal Banarsidass, ISBN 978-81-208-2000-5
• Mahadevan, T. M. P (1956), Sarvepalli Radhakrishnan, ed., History of Philosophy Eastern and Western, George Allen & Unwin Ltd
• Mohammada, Malika (2007), The foundations of the composite culture in India, Aakar Books, ISBN 978-81-89833-18-3
• Monier-Williams, A Sanskrit-English Dictionary, ISBN 0-8426-0286-0, retrieved 10 August 2010
• Mueller, Friedrich Max (1859), A history of ancient Sanskrit literature so far as it illustrates the primitive religion of the Brahmans, Williams & Norgate
• Muller, F. Max (1899), The science of language founded on lectures delivered at the royal institution in 1861 AND 1863, ISBN 0-404-11441-5
• Nakamura, Hajime (2004), A history of early Vedānta philosophy, Volume 2, Trevor Leggett, Motilal Banarsidass Publ.
• Narain, A. K (2003), Narain, A. K, ed., The Date of the Historical Śākyamuni Buddha', B. R. Publishing Corporation, New Delhi, ISBN 81-7646-353-1
• Olivelle, Patrick (1992). The Samnyasa Upanisads. Oxford University Press. ISBN 978-0195070453.
• Olivelle, Patrick (1998), Upaniṣads, Oxford University Press, ISBN 978-0192835765
• Panikkar, Raimundo (2001), The Vedic experience: Mantramañjarī : an anthology of the Vedas for modern man and contemporary celebration, Motilal Banarsidass, ISBN 978-81-208-1280-2
• Parmeshwaranand, Swami (2000), Encyclopaedic Dictionary of Upanisads, Sarup & Sons, ISBN 978-81-7625-148-8
• Phillips, Stephen H. (1995), Classical Indian metaphysics: refutations of realism and the emergence of "new logic", Open Court Publishing, ISBN 978-81-208-1489-9, retrieved 2010-10-24
• Samuel, Geoffrey (2010), The Origins of Yoga and Tantra. Indic Religions to the Thirteenth Century, Cambridge University Press
• Radhakrishnan, Sarvepalli (1956), Sarvepalli Radhakrishnan, ed., History of Philosophy Eastern and Western, George Allen & Unwin Ltd
• Raghavendrachar, Vidvan H. N (1956), Sarvepalli Radhakrishnan, ed., History of Philosophy Eastern and Western
• Ranade, R. D. (1926), A constructive survey of Upanishadic philosophy, Bharatiya Vidya Bhavan
• Rinehart, Robin (2004), Robin Rinehart, ed., Contemporary Hinduism: ritual, culture, and practice, ABC-CLIO, ISBN 978-1-57607-905-8
• Sadhale, S. Gajanan Shambhu (1987), Sri Garibdass Oriental Series (44), Delhi: Sri Satguru Publications
• Schayer, Stanislaw (1925), Die Bedeutung des Wortes Upanisad, 3, Rocznik Orientalistyczny
• Schopenhauer, Arthur; Payne, E. F.J (2000), E. F. J. Payne, ed., Parerga and paralipomena: short philosophical essays, Volume 2 of Parerga and Paralipomena, E. F. J. Payne, Oxford University Press, ISBN 978-0-19-924221-4
• Schrödinger, Erwin (1992), What is life?, Cambridge University Press, ISBN 978-0-521-42708-1
• Schrader, Friedrich Otto; Adyar Library (1908), A descriptive catalogue of the Sanskrit manuscripts in the Adyar Library, Oriental Pub. Co
• Sen, Sris Chandra (1937), "Vedic literature and Upanishads", The Mystic Philosophy of the Upanishads, General Printers & Publishers
• Sharma, B. N. Krishnamurti (2000), A history of the Dvaita school of Vedānta and its literature: from the earliest beginnings to our own times, Motilal Banarsidass Publishers, ISBN 978-81-208-1575-9
• Sharma, Shubhra (1985), Life in the Upanishads, Abhinav Publications, ISBN 978-81-7017-202-4
• Singh, N.K (2002), Encyclopaedia of Hinduism, Anmol Publications PVT. LTD, ISBN 978-81-7488-168-7
• Singh, Nagendra Kr (2000), Ambedkar on religion, Anmol Publications, ISBN 978-81-261-0503-8
• Slater, Thomas Ebenezer (1897), Studies in the Upanishads ATLA monograph preservation program, Christian Literature Society for India
• Smith, Huston (1995), The Illustrated World’s Religions: A Guide to Our Wisdom Traditions, New York: Labyrinth Publishing, ISBN 0-06-067453-9
• Sri Aurbindo Kapali Sastr Institute of Vedic Culture, SAKSIVC: Vedic Literature: Upanishads: 108 Upanishads:, www.vedah.com, retrieved 10 August 2010
• Tripathy, Preeti (2010), Indian religions: tradition, history and culture, Axis Publications, ISBN 978-93-80376-17-2
• Urwick, Edward Johns (1920), The message of Plato: a re-interpretati
• Raju, P. T. (1992), The Philosophical Traditions of India, Delhi: Motilal Banarsidass Publishers Private Limited

Isha Kena Katha Prashna Mundaka Mandukya Taittiriya Aitareya Chandogya Brihadaranyaka Brahma Kaivalya Jabala Shvetashvatara Hamsa Aruneya Garbha Narayana Paramahamsa Amritabindu Amritanada Atharvashiras Atharvashikha Maitrayaniya Kaushitaki Brihajjabala Nrisimha Tapaniya Kalagni Rudra Maitreya Subala Kshurika Mantrika Sarvasara Niralamba Shukarahasya Vajrasuchi Tejobindu Nadabindu Dhyanabindu Brahmavidya Yogatattva Atmabodha Naradaparivrajaka Trishikhi-brahmana Sita Yogachudamani Nirvana Mandala-brahmana Dakshinamurti Sharabha Skanda Mahanarayana Advayataraka Rama Rahasya Ramatapaniya Vasudeva Mudgala Shandilya Paingala Bhikshuka Maha Sariraka Yogashikha Turiyatita Sannyasa Paramahamsaparivrajaka Akshamalika Avyakta Ekakshara Annapurna Surya Akshi Adhyatma Kundika Savitri Atma Pashupatabrahma Parabrahma Avadhuta Tripuratapini Devi Tripura Kathashruti Bhavana Rudrahridaya Yoga-Kundalini Bhasma Rudraksha Ganapati Darshana Tarasara Mahavakya Pancabrahma Pranagnihotra Gopala-Tapani Krishna Yajnavalkya Varaha Shatyayaniya Hayagriva Dattatreya Garuda Kali-Santarana Jabali Saubhagyalakshmi Sarasvati-rahasya Bahvricha Muktikā