Both in Udayana's Nyayavarttikatatparyaparisuddhi (NVTP) and in Ratnakirti's Isvarasadhanadusana (ISD), the following Sanskrit fragment of Prajñakaragupta's Pramanavarttikalamkara (PVA) is found:
yatkincid atmabhimatam vidhaya niruttaras tatra krtah parena/vastusvabhavair iti vacyam ittham tadottaram [ISD: tathottaram] syad vijayi samastah//
While Prajñakaragupta states this verse and Ratnakirti quotes it in the context of the refutation of Naiyayikas' proof of the existence of God (isvara), Udayana refers to it in the context of the refutation of the Buddhist view of unreality. The question arises: What is Udayana's intention in quoting the passage from PVA?
The key to the answer to this question is the word ‘svabhavavada’, which occurs in the passage of Jñanasrimitra's Vyapticarca (VC) or Ratnakirti's Vyaptinirnaya that is cited by Udayana in his NVTP immediately before the citation of the present verse of PVA. The word ‘svabhavavada’ in the very passage should be taken as signifying ‘to speak of the essence of a thing’ or ‘to explain about a thing in terms of its own essence’ rather than ‘naturalism’ as held by Carvakas. It is to be noted that in the given context the word ‘svabhavavada’ really means ‘to answer the question raised by an opponent, in terms of the essence of a thing, in a debate’ (vastusvabhavair uttaram vacyam).
In NVTP a Buddhist opponent explains the absence of a pot (ghatabhava), which is an unreal entity for him, resorting to this ‘svabhavavada’. In VC, however, Jñanasrimitra says that one can resort to the ‘svabhavavada’ only with reference to a real entity. In PVA, in addition, Prajñakaragupta says with irony that when a proponent is hard-pressed for an answer to the question raised by an opponent, the proponent should rely on the ‘svabhavavada’, which gives him victory.
Thus it is clear that Udayana quotes the verse of PVA together with the passage of VC with the intention of refuting the Buddhist view of an unreal entity, with irony and sarcasm.