invoked are sometimes a priori, but for the most part they are inductive; and
in general the Nyayas emphasized sensory perception as the origin of knowl-
edge. None of the Indian schools distinguished between formal and empirical
validity. They always assumed that arguments should be substantively true,
unlike the Greeks, with their concern for the validity of inference apart from
its contents. Later logicians, led by the Buddhists, extensively classified the
modes of syllogistic argument;^41 but Indian logic remained closely tied to
arguments for particular epistemologies and ontologies. A concern for pure
technical logic emerged only with the Neo-Nyaya school around 1350.
Emerging from the inchoate competition of the Upanishadic sages, Nyaya
became the first real Hindu philosophical school, forming a meta-theory of
argument, useful across the factions. Not surprisingly, this was the first school
to make contact with the Buddhist side of the field. The Buddhist schools had
habitually formulated their arguments as ontological assertions; epistemology
seems to have remained implicit or at most uncritical assertion, and formal
logic was unknown. At the time Nyaya emerged on the Hindu side, the
Buddhists were entering a phase of intensified dispute, as Mahayana took the
offensive and Nagarjuna set out to destroy all rival ontologies. Nagarjuna used
no formal logic, but he was aware of the incipient Nyaya school logic, which
he attacked (Nakamura, 1980: 238–239, 287). Some of the impetus for for-
mulating the full Nyaya-sutras may have been in response to the Madhyami-
kas. Given that Nagarjuna, like many Buddhists, was a Brahman, it is possible
that Nyaya and Madhyamika both emerged in the vague borderland of Bud-
dhism and Hinduism, where a common pool of educated intelligentsia shared
early training by Brahman teachers while often moving on to the better
institutionalized and more advanced philosophy in the Buddhist networks.
Perhaps for this reason, in discussing the objects of knowledge the Nyaya-su-
tras (1.1.18–22) sound much like the Buddhist discussion of the chain of
causation from attachment, aversion and ignorance to worldly pain and trans-
migration, and finally to release.
Buddhist logic developed in symbiosis with the Nyaya school: first as
imitation, then as debate. The first explicit Buddhist logical writings were
manuals of debating tactics, including the five-member “syllogism,” produced
by the founders of Yogacara: Maitreyanatha, Asanga, and, with a little more
originality, the first Vasubandhu (Nakamura, 1980: 294; Dutt, 1962: 265;
Stcherbatsky, 1962: 1:28–29). Later on the Hinayana side Vasubandhu II
would incorporate more elaborate logic into the Abhidharma. The first great
individual name in Nyaya, Vatsyayana, was a contemporary of Vasubandhu
II and a target of his attacks. In the network (Figure 5.4) we also see a
connection between Vasubandhu II and Bhartrihari, whom Dignaga would in
turn both criticize and develop. Dignaga became the great Buddhist logician
External and Internal Politics: India • 229