"Tat" as Indefinite Pronoun

[Brendan S. Gillon]

No one, I think, would be inclined to render a sentence such as
`tat pa"syaami' as `I see something'; nonetheless, there are
situations where the third person pronoun has the force of the
English indefinite pronoun. This becomes most evident when there
is no plausible grammaticalized antecedent within the sentence or
preceding sentences to serve as an antecedent. I am interested in
trying to pin down the grammatical environment for such usages
and would be pleased to receive examples, along with references
and a translation.
 
Related to this usage, I believe, are occurrences of `tat' in
compounds where it has no apparent sense. Such compounds include:
"tat-utpatti", "taad-aatmya" , "tad-atipaata", "tat-kara",
"tat-kriya", "taj-j~na", "tad-dhana", "tat-para-tva",
"tan-maatra", and "tad-vidya".
 
Related to the same usage, I believe, are cases where the
third person pronoun is an alternative to the relative pronoun,
as exemplified by the sentences, as illustrated by these
sentences taken from Dharmakiirti's Pramaa.navaartika and from
Kar.nakagomin's commentary to it (there is between the sentences
cited):
 
Example 1: Gnoli Edition: p. 20, line 20
na hi tasmin ni.spanne ani.spanna.h bhinna-hetuka.h vaa tat-svabhaava,h
yukta.h.
 
For, when something has arisen, it cannot be the nature of either
that which has not arisen or that whose causes are different.
 
Note: "tasmin" is the antecedent of "tat" and "tat-svabhaava"
      is a bahuvrihi compound.
 
 
Example 2: Sankrtyayana's Edition: p. 48, line 4 of commentary
yasmin anumiiyamaane kaarya-antaram api tat-vi"se.sa.nam ni"scitam
bhavati.
 
When something is being inferred, another effect too is
ascertained as a quality of it.
 
Note: "yasmin" is the antecedent of "tat" and "tat-vi"se.sa.nam"
      is a bahuvrihi compound.
 
 
Indeed, it seems to me that Kar.nakagomin's sentence could have
easily have read:
 
tat-anumaane kaarya-antaram api tat-vi"se.sa.nam ni"scitam bhavati.
 
This opinion was confirmed to me by Kamaleswara Bhattacharya.
 
 
Examples and opinions pertaining to such cases would be greatly
appreciated.