Nyāya Sūtras 44.7

44.7

tathā coktaṃ ``tattvādhyavasāyasaṃrakṣaṇāthaṃ jalpavitaṇḍe bījaprarohasaṃrakṣaṇārthaṃ kaṇṭakaśākhāvaraṇavat'' iti/ yaś cāsau pramāṇaiḥ pratipakṣasyopālambhas tasya caitāni prayujyamānāni pratiṣedhavighātāt sahakārīṇi bhavanti/ tad evam aṅgībhūtanāṃ chalādīnām upādānaṃ jalpe, na svatantrāṇāṃ sādhanabhāvaḥ/ upālambhe tu svātantryam apy astīti// 2 //

And so it has been said: 'Disputation and cavil are for the purpose of preserving the determination of reality, like a fence of thorny branches for the purpose of preserving the sprout of a seed.' And as for that refutation of the counter-thesis by means of valid cognition, these [quibbles, etc.], when employed, become cooperative factors because they demolish the [opponent's] refutation. Thus, the inclusion of quibble and the rest in disputation is as auxiliary factors, not as independent means of proof. In refutation, however, there is even independence. || 2