syād etat yadi bhavatāṃ jñānāpekṣayā parataḥprāmāṇyaṃ sādhyate, tadāsmākam api siddhasādhyatā
It might be objected: "If you are trying to prove the extrinsic validity [of cognition] with respect to cognition itself, then for us too this would be proving what is [already] proven."