India · c. 2nd c. BCE – 18th c. CE
Nyāya–Vaiśeṣika
The world is made of real, knowable categories—substances, qualities, actions, universals—and disciplined reasoning can prove what perception alone cannot, including a creator God.
How can we reason correctly about what is real?
Vaiśeṣika began as a natural philosophy that sorted everything into categories and atoms, while Nyāya grew out of the rules of public debate. Over the first millennium CE they merged into one realist system, sharpened by long controversy with Buddhists who denied substances, universals and lasting selves.
Knowledge comes through four means—perception, inference, comparison and testimony—and an inference is sound when the reason is invariably linked (vyāpti) with what it proves, as smoke with fire. Since we really do perceive pots and cows as wholes sharing common features, the world contains real wholes, universals and enduring selves, and the ordered composition of things points to an intelligent maker.
- Four means of knowledge: perception, inference, comparison, testimony.
- Everything falls under a few real categories (padārthas).
- Material things are composed of indivisible atoms.
It gave Indian thought its shared technical logic, and Gaṅgeśa’s Navya-Nyāya (‘new logic’) built a precise language that scholars of every school had to master.
Thinkers
c. 2nd c. BCE – 2nd c. CE (traditional author)Akṣapāda GautamaTraditional author of the Nyāya Sūtrac. 2nd c. BCE? (dates uncertain)KaṇādaFounder of Vaiśeṣika, India’s classic atomismfl. 14th c., MithilāGaṅgeśa UpādhyāyaFounder of Navya-Nyāya, the ‘new logic’Key texts
Where it came from
Reacted againstCārvāka / Lokāyata materialismNyāya’s careful theory of invariable concomitance (vyāpti) answered the Cārvāka objection that inference can never be justified.Reacted against
Buddhist epistemology (Pramāṇa school)Later Naiyāyikas such as Uddyotakara and Udayana defended real selves, universals and God against Dignāga and Dharmakīrti.
What it led to
Opposed byBuddhist epistemology (Pramāṇa school)Dignāga criticised Nyāya’s four means of knowledge and its realist universals, cutting the list to perception and inference.