Synopsis The eleventh-century classic, Nyayavarttikatatparyaparisuddhi, forms the fourth tier of that quartet of commentaries, Nyayacaturgranthika, which has been regarded for more than nine hundred years as the central corpus of ancient Nyaya.  Apart from analyzing nearly every line of Vacaspati's Tatparyatika, this vast yet tersely written gloss adds fresh philosophical insights engaging in debates with Buddhist stalwarts like Jnanasrimitra and with philosophers like Srivatsa.  This is the first critically edited complete publication of the work eagerly awaited by traditional as well as modern scholars of Nyaya in India and abroad.