The Upanishads and Nyaya – Vaiseshika Pluralism:-
These realistic schools propose that there are multiple souls which are co-eternal with the God. They list many reasons for the existence of God, and being realists Nyaya claims, object and (its) qualities are different, not same, like the idealists think. Nyaya have developed sixteen categories and stresses much on the syllogism to arrive in the correct knowledge. Nyaya philosophy is systematically expounded in the Nyaya-sutra of Rishi Gotama. Vatsayana, Udyotakara, Vacaspati Misra and Udayana are the major writers and commentators on this sutra and other Nyaya related treatises. Nyaya and Vaiseshika systems are considered as the sister philosophical sects in Indian philosophy. Differences between these systems are meager and so, they do not invite different treatments.
As one may expect, seeds of Nyaya-Vaiseshika system is in the Upanishadic teaching. Monism and dualism, of course, failed to satisfy the thinking minds of that period. What they see, when they looked around in the experiential world, is a full-fledged pluralism. While monism states that there is a single substratum lies behind these pluralist phenomena, and the pluralism is an imposed aspect on this single substratum, many scholars did not agree with it, because to know the existence of this single ultimate substratum, special intuitive knowledge is needed. From the experimental or phenomenal point of view, such a single substratum cannot be proved as existing realistically, but only theoretically. (To realize this single substratum one has to transcend the realm of phenomenal existence, which is not an easy task for commoners). Hence many scholars came forward basing their experiments with the natural world. They confined their inquiry in the phenomenal plane, leaving aside the ultimate place of reality. The emergence of pluralist schools of Vaiseshika and Nyaya is here. Of these Vaiseshika is more ancient school than Nyaya.
Matter is composed of eternal atoms and we cannot destroy them, as per Rishi Kanada, the founder of Vaiseshika System. Though Upanishadic teaching is fundamentally monistic and, transcendentally idealistic, the pluralistic and realistic speculations are also commented upon in them; (or we may say that certain Upanishadic passages can be interpreted as supportive to pluralism). However, in the Upanishads, these comments are supposed to be from the phenomenal truth’s point of view; not from the ultimate truth’s point of view. From the ultimate truth’s standpoint, Brahman is one without a second; there is no plurality. But from the phenomenal point of view, pluralism is sustainable and it is not in contradiction with the absolute idealism of Upanishadic teaching.
Thus Mundaka Upanishad says: –
“That thing, that is such is true: As from a fire fully ablaze, fly off sparks in their thousands that are akin to the fire, similarly O good-looking one, from the Imperishable originates different kinds of creatures and into It again they merge.”
Here the creation and dissolution is from and into the same thing, the Imperishable (Brahman). As long as this creation, sustenance and dissolution, have a relative and dependent (on Brahman) outlook, as stated in the Upanishad text, we may take it in the ‘real’ sense, which clearly matches to the Nyaya – Vaiseshika school’s philosophy.
There are many hymns in various Upanishads that support the Karma Marga of Purva Mimamsa Philosophy, as given in next section. All such statements also supports pluralism of Nyaya-Vaiseshika, because rituals are performed in the real world. In addition to this, the Vedas are replete with pluralistic ideas, which also paved way for the formation of pluralistic philosophies.
The Upanishads and Purva Mimamsa Philosophy:-
Though Upanishads fall in Jnana-Marga tradition, which gives more importance to knowledge over the ritual performance, there are many passages in various Upanishads extolling the importance of Karma or rituals, in realization. Yet, it is very much evident that the Upanishads considers ‘Jnana’ as superior to anything else to realize the ultimate reality, Brahman.
Mundaka Upanishad points to the importance of rituals.
“That thing that is such is true. The Karmas that the wise discovered in the mantras are accomplished variously, where the three Vedic duties get united. You perform them forever with the desire for the true results. This is your path leading to the fruits of karma acquired by yourselves…… When the fire begins set ablaze, the flame shoots up, one should offer the oblations into that part that is in between the right and the left.”.
Mundaka Upanishad further says that, if agnihotra sacrifice is not performed properly, then the future seven worlds of the non-performer will be destroyed. Agnihotra rite is said to be of that much importance.
“It (agnihotra) destroys the seven worlds of that man whose agnihotra sacrifice is without Darsa and Paunamasa rites, devoid of caturmasya, bereft of Agrayana, unblest with guests, goes unperformed, is unaccomplished by Vaisvadeva rite, and is performed perfunctorily.”
Upanishad further says that performer of all prescribed sacrifices will get into the place of the lord.
“These oblations turn into the rays of the sun and taking him up they lead him, who performs the rites in these shining flames at the proper time, to where the single lord of the gods presides over all…… Saying ‘come, come’, uttering pleasing sounds such as, ‘this is your well-earned, virtuous path which leads to heaven’, and offering him adoration, the scintillating oblations carry the sacrifice along the rays of the sun.”
Ritual performance, trademark of the Purva Mimamsa tradition, was prevalent in India from the dawn of Indian civilization. Anyone reading the Rigveda, may understand it amply. By the period of the Upanishads, the importance of ritualistic tradition dented considerably, though did not vanish fully.
 A detailed account of these reason are furnished in Kishor Kumar Chakrabarti’s ‘Classical Indian philosophy of Mind: the Nyaya dualist tradition’.
 Though we say, Rishi Kanad is the founder of Vaiseshika system, that means that he gave a systematic structure for the, then prevalent, pluralistic ideas. Pluralism must have been existed even before Rishi Kanada.
 Mundaka Upanishad II.i.1
 Peculiar enough, this Upanishad also contains passages that denounce the ritual performance.
 Mundaka Upanishad. I.ii.1-2
Mundaka Upanishad. I.ii.3
 Mundaka Upanishad. I.ii.5-6
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