The Vedas are the oldest known literature of the world. Four vedic sumhitas in their numerous recensions along with their exegetic works, the brahmna, together are designated as the Veda. Mantra & Brahmna together are designated as the Veda.
Mantra here stands for the collections of hymns known as the Vedic samhitas, and brahmna for the voluminous exegetical works on the same.
The brahmna are clearly divided in two parts.
The first is purely exegetical and ritualistic. The second known as Aranyaka, is attached to each brahmna, in the form of an appendix and generally ends with its Upanishad. One of the reason, why the Upanishads are collectively known as vedanta, is their place at the end of the Vedic literature. This is also regarded as the chronological position of the Upanishads, in the Vedic literature.
Theoretically, every Upanishad, should be connected with the brahmna of some or other of the Vedic shakhas.
According to patanjali, rig Veda had 21 sakhas, the yajurveda 100, Samveda 1000, and the Atharvaveda had nine sakhas.
Thus in patanjali’s time ie in second century BC, as many as 1130 sakhas of the four vedic samhitas were extent, muktikopanishad accepts the no of sakhas as 1180, and categorically states that each of sakhas possesses an Upanishad of its own. Infact each sakha must have had it’s own brahmna, Arayanka and Upanishad. But the number of extant, Upanishads is only a little over 200. Of them only 13 are accepted to be the genuine vedic Upanishads.
The rest of the extant Upanishads are comparatively recent sectarian works, although the 108 Upanishads, enumerated in the muktikopanishad have been foisted on some or other of the Vedic samhitas. But the muktika tradition doesn’t appear to be either ancient or authentic.
According to it, the mantrika (Culika) Upanishad belongs to the Sukla-Yajurveda and the Garboupanishad to the krsnayurveda.
But Ramanuja has quoted either of them Atharvanic Upanishad.
In fact all the Upanishads,, other then the twelve or thirteen principal ones, are considered to belong to the Atharvaveda, although they have no real affinity with it.
Shankracharya, who probably flourished in the 18th century AD, wrote his commentary only on ten Upanishads, namely Isa, Aiteria, Katha, kena, Chandogya, Taitteriya, Prasna, Mandukya, Mundaka, & Brahdranyaka.
On Mandukya or karika by Gaudapada, the teacher of Sankara, has also come down to us.
Sankara has in addition, quoted in his brahmsutra-bhasya from two more Upanishads eg the kaustaki and the Svetasva tara.
In addition to these twelve, the maitrayani Upanishad too is believed to be a lost Brahmana of the Maitryani-samhita of the Krna yajurveda.
Most scholars Most scholars both indian & foreign accept these 23 as the authentic ancient Upanishads. The mahanarayayna Upanishad, too, has come down to us, along with the Taitteriya Upanishad, as part of the tettriya-brahmna; but it appears to have been interpolated at a later date. Still it is much older then the so-called Atharvanic Upanishas, and Witernitzvhas classified it with 13 principal ones. These 14, this, are connected with some or other of the Samhitas & Brahmnas. Of these 14 Upanishad scholars have tried to determine the date on the basis of interval as well as indirect evidence.
The subject matter and other features of four other Upanishads namely, Chagaleya, Arseya, Saunaka and Baskala compel us to classify them with the fourteen. First three are in prose and last is in the verse. They were discovered rather late, and hence escaped the attention of Deussen, Winternitz and other scholars, who dealt with this subject.
The German scholar has chronologically divided the entire gamut of the Upanishads into four classes.
I. Ancient prose Upanishads: 1. Brahadaranyaka 2. Chandogya 3. Tattiriya 4. Aitareya, 5. Kausitaki 6. Kena
The last is in mixed pros & verse, while the rest are only in prose. Their language and style are similar in simplicity and lucidity to those of the Brahmnas.
II. Ancient versical Upanisads: 7 Katha, 8. Isa, 9. Sveta-svatara, and 10. Mahanarayana.
III. Relatively less ancient prose Upanishads: 11. Prasna,
12. Maitri or Maltrayani and 13. Mandakya
IV. Atharvanic Upanisads expounding the following subjects:
1. Samnyasa, 2. Yoga, 3. Saivism,
4. Vaisnavism, 5. Sakrism, etc
This classiication is now regarded as defective, because it
ignores the ancient Mundaka and includes the later day Mahanarayana.
Winternitz agrees with the first group.
In the second group, he
includes, in addition, the Mundaka and the Prasna, in which the theories of Samkhya and Yoga are amalgamated. And in the third group of ancient Upanişads, he includes the Mandukya and the Maitrayan.
Macdonelll has also divided the Upanisads into four chronological groups.
In the most ancient group he lists chronologically:-
1. Brhadaranyaka, 2. Chandogva,
3. Taltirtya, 4. Aitareya and
5. KauSitaki,
because their prose style is after the Brahmanas. He places the kena, which is in mixed prose and verse, in the transition period. The Katha, the Isa, the Svetasvatara the Mundaka and the
Mahanarayana, are listed by him, in the last group of the ancient
Upanisads. They are all composed in impressive verse.
Belvalkar and Ranade have accepted tie following criteria for settling the dates of Upanisads.
1. Title. Some of the Upanisads receive their title from their first word.
2. Style, language and arrangement of subject matter
3. Use of similes, symbolism, illustrations and parables.The
older Upanisads are mixed with ritual and etymologies, given therein are imaginary.
4. The Vedic sacrificial gods, like Indra, Agni, etc. predominate in them.
5. Prose style, as Deussen has accepted.
6. Appearance of sacrifices (Yajnas), miracles and vratas, as
also by the announcement of reward (phalasrut) with the
words, “He who knoweth thus” (ya evam veda).
7. Mentioning the rivers, mountains, countries and settlements
(janapadas) by their names.
8. Quotations from each other and agreement in words.
9. Development of thought.
On the basis of the above criteria, Belvalkar and Ranade place
in the oldest class, 1. Chandogya, 2. Brhadaranyaka, 3. Katha, 4. Isa,
5. Aitareya, 6. Taittiriya, 7 Mundaka, 8. Kausitaki, 9. Kena,
and 10. Prasna.
In the second group they list, 11. Svetaśvatara,
12. Mandukya, and 13. Maitrayaniya. In the third group they list,
14. Baskala, 15. Chagaleya, 16. Arseya, and 17, Saunaka.
The basic criteria enunciated by Belvalker and Ranade are
vague. Therefore, conclusions based on them cannot be accepted as
final. They can, however, be helpful to a little extant in giving a tough estimate only. They themselves admit the limitations of their criteria, when they place the Isa in the oldest class, although it is in verse instead of prose.
For settling the relative dates of the Upanişads C. V. Vaidya has accepted two criteria, which appear to be more logical:
1. The most ancient Upanishads rise above the theory of physical gods, such as Indra, Varuna, etc. and teach the
existence of an impersonal, immanent, omnipresent brahman, who is not bound by time and space.
On the other hand, the later Upanishads progressively evolve personal and physical gods, like Brahma, Vishnu,
Shiva and others.
On
2. The Samkhya theories of Purusa and Prakrti and three
humours (gunas), namely, Sattva, Rajas and Tamas, have been progressively incorporated in the later Upanishads.
On these criteria Dr. Vaidya has settled the chronological
position of all the principal Upanishads. Accordingly, the Chandogya and the Bhadareyaka appear to be the oldest. They enunciate only the Ama and the Brahman. Next are placed the Isa, the Taittiriya and the Aitareya. In the third group are included the Prasna, the
Mundaka and the Mandukya. Then comes the Katha, which is the
first to mention Visnu. Rudra, the favourite god of the Krsna
Yajurveda, figures under the name, Mahesvara, in the Svetasvatara
This Upanishad should be dated after the Katha. The last among the
Principal Upanishads is the Maitrayani, in which the Puranic Trimarti,
namely, Brahma, Visnu and Mahesa, figure. Even on the second
criterion of Dr. Vaidya, the principal Upanishads appear in the same
chronological order. There is no reference to Samkhya theories in
the first three groups of Upanishads. The Katha and the Kena are the
first to mention the gunas. The date of Svetasvatara appears to be
after the last two, since it mentions the Ksara, Pradhana, Jneya,
Kapila Rsi and the Samkhya.
The Kaustaki contains verbatim
quotations from the old Upanishads and mentions the ten bhuta-matras
of the Samkhya. Hence it has to be placed with the last three. Last
in the order, comes the Maitrayani, which enunciates, in details, the
Sarmkhya theory of Prakrti and Purusa as also the three gunas.
Though a definite improvement on the earlier ones, the criteria
offered by C. V. Vaidya are still inadequate to lead us to a final conclusion. A post-Samkhya writer, too, can totally ignore the Samkhya
theories and the trio of gods, and can write in the idiom of the ancient
Upanisads, such as the Bhadaranayaka. In fact, the principles or
criteria laid down by all the scholars are helpful to some extent in
determining the relative chronology of the Upanisads. Their conclusions too in respect of some Upanishads agree. All have accepted the
Chandogya, the Brhadararnayaka, the Taittiriya and the Aitareya, as the
most ancient. None has placed in this catagory the Svetasvatara,
Maitrtyani, the Mahanarayana, the Baskala, the Chagaleya, the
Arseya and the Saunaka. All these should be put in the last group.
In agreement with Dr. Vaidya, I am in favour of including the
the indian society that the new rising sects presented their doctorines through newly composed Upanishads of their own for ready acceptance and tacked them on vedic sakha.
The practiced continued till the Mughal period or perhaps even afterwards.
The allopanishad was composed for the Mughal emperor Akbar, who reigned from 1526 to 1585 AD.
This Upanishad is not listed in muktikopanishad.
Therefore 208 Upanishads, listed therein were composed before the reign of Akbar.
But the muktika listed only what it calls the important ones, out of a large number known to it’s author. But we are not in a position to specify these others out of some 220 odd extant Upanishads.
The muktika is regarded to have been composed after Sankara, who flourished about 800 AD.