Is it fair to call Nāgārjuna or Śrīharṣa a sceptic at all?
In English books on Indian philosophy two names are regularly filed under "scepticism": Nāgārjuna, the Buddhist founder of Madhyamaka, and Śrīharṣa, the twelfth-century Advaitin whose Khaṇḍanakhaṇḍakhādya (roughly "The Sweets of Refutation") takes apart the Nyāya definitions of valid cognition one after another.
I have read Śrīharṣa for many years, and I am uneasy with the label. He is merciless with definitions. Give him a definition of pramā, valid cognition, and he will find a case it includes that it should not, or excludes that it should. But he is not doubting for the sake of tranquillity, nor saying that nothing can be known. He is an Advaitin. He holds that consciousness is self-established, and his demolition of categories clears the ground for that. He also argues, as I understand him, that debate can proceed on agreed rules without either side first committing to the other's theory of knowledge.
Nāgārjuna is a different case, and others here know him better than I do. But he too has a positive teaching, the middle way of emptiness, and a soteriological purpose.
So my question is not whether these thinkers are good or bad, but whether "sceptic" helps us understand them or distorts them. If it distorts, what word should we use? "Dialectician"? "Critic"? Or should we keep the label and widen it, the way Sextus seems to use it, for those who keep inquiring?