Nyāya Sūtras

Two authors share this text. Its root is the Nyāyasūtra, more than five hundred sūtras, terse aphorisms meant to be memorised and explained by a teacher, ascribed to Akṣapāda Gautama, the founder of Nyāya, the Indian school of logic and argument. Around and between them runs the Nyāya-bhāṣya, the oldest surviving commentary on them, written by Vātsyāyana in about the fifth century, and the commentary makes up most of the text. Nobody knows when Gautama lived: estimates for the sūtras run from several centuries before the common era to about 200 CE, and many scholars think the five books grew in layers. The first sūtra names sixteen topics whose correct knowledge leads to the highest good. The list starts with the means of knowledge and the things there are to know, and goes on through doubt and the example to the honest debate, the debate fought only to win, the quibble, and the point at which a debater can be declared beaten. The means of knowledge are four — perception, inference, comparison and reliable testimony — and a full proof has five steps, from the claim through the reason and an example to the conclusion. A skeptic argues that no means of knowledge can be established, since it can come neither before its object, nor after it, nor at the same time. The sūtras reply that his denial falls to the same argument, and that someone who rejects every means of knowledge has nothing left to deny with. Nāgārjuna, the second-century Buddhist philosopher, turns the same three-way argument against the logicians, and scholars still debate which of the two texts answers the other. Vātsyāyana claims that the whole inquiry is ānvīkṣikī, "investigation", which the Arthaśāstra, the old Indian manual of statecraft, had listed as the fourth of the four sciences, beside the Vedas, trade and government. Later Dignāga, a Buddhist logician, attacked Vātsyāyana's reasoning, and Uddyotakara wrote a further commentary, the Nyāyavārttika, to defend it. The text closes on a verse in which Vātsyāyana says that the Nyāya had revealed itself to the sage Akṣapāda, best of speakers, and that he has set out this commentary on it.