Did Vaishnava Aachaaryas Prove Vishnu to be the Supreme God using only the Vaidic texts?

Question

I read in an answer, that Shripaada Ramanujacharya and his disciples proved the Supremacy of Shri Vishnu using the Vedas, Upanishads, Smritis, Puraanas and other texts. Also, Shripaada Ramanujacharya says in his Brahma Sutra Bhaashya, that the Veda declares Naaraayana to be Brahman. My question is:

• Does only the main Vedic literature (Veda Samhitas, Braahmanas and Upanishads) provide sufficient proof for Vishnu being the ultimate Eeshwara? Can this be done without the involvement of any other Shaastras, such as the Shaiva and Vaishnava aagamas, Ithihaasas or Puraanas?
• How do Vaishnava Aachaaryas, like Shripaada Ramanujacharya or Shripaada Madhvacharya, prove the Supremacy of Vishnu, even when the Vedas say in certain places, that "there is no one mightier than Rudra"?
• I have also heard of a grammatical trick used by Sri Vaishnavas, through which one can use certain names of Shiva to refer to Naaraayana. How is this done and is this interpretation valid as per other Shaastras, such as the Smritis?

Hope to get a proper answer.

Answer 1

There are several words in the Vedas that are used to mean different things in different contexts. However if you look at the word "Narayana", it is always found to be consistently used to only refer to Sriyahpati and nothing else.

Even today (1000 years after Ramanujacharya) if you pick up a Sanskrit Dictionary and look at the size of the entry for the word "Narayana", you will find a very small number of entries when compared to other terms like Sat, Brahman, Shambhu, Agni, etc.

Therefore when interpreting Upanishad verses which follow this pattern:

• A is X
• B is X
• C is X
• D is X
• Narayana is X

then one has to interpret that X is Narayana only (as Narayana is the most specific entity whereas A, B, C, D can refer to more than one thing). This principle of Mimamsa interpretation is called chAga-pashu nyAya.

Vedanta Desika establishes this in his Tattvamuktakalapa and SarvarthaSiddhi texts. I have given details about the relevant verse here.

The specific example given by Vedanta Desika in above link: Consider the following upanishad sentences:

• In the beginning only Sat existed, one without a second.
• In the beginning only Brahman existed.
• In the beginning only Narayana existed, neither Brahma nor Isa.

Vedanta Desika says that in such places, one has no choice but to accept that Narayana existed at the beginning and Sat and Brahman are referring to Narayana.

Grammatical tricks are not necessary given the above.