RELATIONSHIP OF UPANISHADS WITH VEDIC LITERATURE
It is generally believed that the mantras, the Braahmanas and parts of the Aranyakas constitute the karma kaanda or the works section of the Vedas, the Upanishads are the jnaana kaanda or the knowledge section. In reality however, the mantras are ancient collections covering a wide range of topics including rituals, ethics, spirituality, cosmology and so on. The wwBraahmanas are theological treatises, largely dealing with Vedic ritual, and rubricating these mantras in the rituals expounded. Often appended to these Braahmanas are esoteric texts called the Aranyakas. And in these Aranyakas, are embedded the Upanishads. However, many Upanishads are stand alone texts which might not have been integral with the Aranyakas. While the subject of the karma kaanda is dharma, the subject of the jnaana kaanda is Brahman or reality. The Upanishads are also called the Vedaanta (Veda - scripture, anta - end of) or the end of the Veda i.e., the final purport of the Vedas. This is because of two reasons: They generally occur at the end of the Samhita-Braahmana-Aranyaka literature; and because they represent a culmination or the 'final view, or essence' (siddhanta) of the Vedic philosophy.
All extant Upanishads are traditional classified under one of the 4 Vedas. Sometimes, this classification is opposed to the correct ancient placement of the Upanishads in the Vedic cannon, and in the case of late Upanishads, such a classification often appears artificial. Appendix 1 groups the various ancient Upanishads under different Shakhas of the Vedas.

DEVELOPMENT OF THE UPANISHADIC DOCTRINE

The modern theory voiced in some quarters that the Upanishads represent the revolt of the critical minded kshatriya against the ritualistic brahmin, finds little support in the texts themselves. For not only do brahmin teachers outnumber kshatriya teachers in the Upanishads, it was only the brahmins who fully developed the teachings of the Upanishads as presented in the various schools of Vedaanta. A kshatriya teaching brahma vidhya or knowledge of reality to a brahmin, is no argument, since tradition allowed all the three top castes to learn Vedaanta and it is not unusual for a spiritually inclined kshatriya to possess higher knowledge of Brahman than the average brahmin. And again such cases are exceptions and not the norm.

Another modern assertion that the Upanishads are against the sacrificial religion of the Braahmanas is not wholly true. As noted before the Vedas are a whole spiritual package and each section - the hymns, the sacrifices, the philosophical discussions - have their validity and usefulness at a certain stage. The sacrificial religion served the religious needs of the masses and also helped in the purification of oneself. At the householder stage they're the main source of revenue for the brahmin. No orthodox thinker would object to that, which has so much social, spiritual and religious utility. So the Upanishads are not against the sacrifices per se, but only against their ultimate validity i.e., their ability or rather the lack of it, to effect liberation. While the sacrificial religion is to be practiced in the householder stage, when one moves to the forest dweller stage one is supposed to meditate on the symbolism and spiritual value of the sacrifices. During the samnyaasin stage one's life (worldly life with all its attachments) itself is said to be the sacrifice.

SIGNIFICANCE OF THE UPANISHADS

The Upanishads are truly the fount of all Indian philosophy. All the BrAhmanical schools derive their philosophies from the Upanishads and show an almost pathetic eagerness to find common ground between their doctrines and the Upanishads. Not only is Jainism with its duality of matter and Selves influenced by the Upanishads, even the Buddhist doctrines of annata, kshanikavaada, shunyavaada, vijnaanavaada and the two levels of reality are all derived from the Upanishads.

Numerous scholars have felt compelled down the ages to compose their own commentaries or sub-commentaries on the Upanishads. The commentaries of Shankaracharya are the most ancient available ones, and also the most popular. These are written from an Advaita Vedaanta perspective. The commentaries of Purnapraajna Anandatirtha (also called Madhvacharya) are written from a Dvaita Vedaanta perspective, whereas Rangaramanuja has written his commentaries from a Vishishtadvaita Vedaanta perspective. A partial list of these commentaries in Appendix B will give an idea of how prolific their commentarial tradition has been.

PHILOSOPHY OF THE UPANISHADS

The Upanishads do not represent systematic philosophy. They represent teachings of the sages who experienced or rather became reality (brahma vid brahmaiva bhavati - the knower of Brahman becomes Brahman). The purpose of the Upanishads is not mere intellectual satisfaction, but a practical solution to the ultimate problems of life. It is best expressed in the dialogue between Yama and Nachiketas in the Katha Upanishad. Nachiketas, a braahmana boy questions Yama (the God of Death) as to what happens to one's self after death. Does one exist or does he not, then? Yama tries to dissuade the boy from seeking an answer to a question, which even Gods find difficult to understand. Instead he offers a wide array of earthly comforts : long life, wealth, gold, elephants, horses, land, beautiful women etc. Nachiketas turns them down saying that all these are transient and only serve to wear out the senses of men. And when one has seen him i.e., Yama or death, how could anybody enjoy these things of sense? And having understood the transience of objects of sense and the implicit suffering contained in them, who would wish for a longer life?

As all phenomena are transient in nature worldly life ultimately leads to disappointment and suffering. Death puts an end to all our hopes and ridicules our achievements in life. To be born again is only to go through the same grind. So the end of suffering is not to be born at all and to become immortal. This according to the Upanishads can be achieved when we know the true nature of our Self (Atman).

The teaching of the Upanishads can be best understood under the following three categories :

1. the Self or essence of man - Atman
2. the Self or essence of the world - Brahman
3. the relation between Atman and Brahman

According to the Upanishads when knowledge of one's Self (Atman) is acquired, knowledge of the essence (Self) of the world (Brahman) as well as the relationship between Atman and Brahman is known.