Nyāya-Vaiśeṣika

The Nyāya school of philosophy developed out of the ancient Indian tradition of debate; its name, often translated as ‘logic’, relates to its original and primary concern with the method (nyāya) of proof. The fully fledged classical school presents its interests in a list of sixteen categories of debate, of which the first two are central: the means of valid cognition (perception, inference, analogy and verbal testimony) and the soteriologically relevant objects of valid cognition (self, body, senses, sense objects, cognition, and so on). The latter reflect an early philosophy of nature added to an original eristic-dialectic tradition. On the whole, classical Nyāya adopts, affirms and further develops, next to its epistemology and logic, the ontology of Vaiśeṣika. The soteriological relevance of the school is grounded in the claim that adequate knowledge of the sixteen categories, aided by contemplation, yogic exercises and philosophical debate, leads to release from rebirth. Vaiśeṣika, on the other hand, is a philosophy of nature most concerned with the comprehensive enumeration and identification of all distinct and irreducible world constituents, aiming to provide a real basis for all cognitive and linguistic acts. This endeavour for distinction (viśeṣa) may well account for the school’s name. Into the atomistic and mechanistic worldview of Vaiśeṣika a soteriology and orthodox ethics are fitted, but not without tensions; still later the notion of a supreme god, whose function is at first mainly regulative but later expanded to the creation of the world, is introduced. In the classical period the Vaiśeṣika philosophy of nature, including the highly developed doctrine of causality, is cast into a rigorous system of six, later seven, categories (substance, quality, motion, universal, particularity, inherence, nonexistence). Nyāya epistemology increasingly influences that of Vaiśeṣika.

The interaction and mutual influences between Nyāya and Vaiśeṣika finally led to the formation of what may be styled a syncretistic school, called Nyāya-Vaiśeṣika in modern scholarly publications. This step, facilitated by the common religious affiliation to Śaivism, occurs with Udayana (eleventh century), who commented on texts of both schools. Subsequently, numerous syncretistic manuals attained high popularity. Udayana also inaugurated the period of Navya-Nyāya, ‘New Logic’, which developed and refined sophisticated methods of philosophical analysis.