Ramanuja's Summary of the Advaitin's Position - 1

[S. Sriram]

>
> Can you find me a single Upanishhadic statement that
> *discredits* abheda? There are several that discredit
> bheda (e.g. B.U. 4.4.19, 2.4.14, 4.5.15).
>

The essence of this argument has been addressed numerous times over
the last 1,000 years notably in texts such as the
Satadusani - Satabhusani & Paramartha Bhusanam.

A short explanation of your question is:

  Your Q:
  name one upanisadic statement that *disproves* or *discredits*
  abheda similar to the statements that discredit bheda i.e. not those that
  simply favor bheda.

  Short Explanation:
  The premise that: because there are no such statements, abheda is the
  proper interpretation requires that some statements are more valid
  than others, this requirement is legitimized by the
  principle of 'apaccheda nyaya'. Ramanuja's ghataka sruti implies that
  both statements are valid following the principle  known as utsaragA
  pavAda nyAya which denotes that the negative text will have to be
  interpreted in accordance with the affirmative text.

  Long(er) explanation:
  http://www.ramanuja.org/sv/bhakti/archives/jul99/0120.html
  http://www.ramanuja.org/sv/bhakti/archives/jul99/0119.html

  Source books (English):
  SMS Chari Advaita v Visistadvaita Pgs 79,80

BTW: There's an experimental collaborative study site setup, specifically
for the study of the Vedanta-Sutras at sripedia.org - It currently only
houses Ramanuja's commentary, Sankara's commentary is being prepared
at http://texts01.archive.org/dp

Thanks
Srinivasan Sriram