Nyaya

Nyaya begins from a practical problem: two philosophers disagree, and there has to be a way to settle it other than shouting. The Nyaya Sutra, attributed to Gautama Akshapada, answers with a formal structure for debate built around sixteen categories, covering everything from the topic under dispute to the fallacies that disqualify a move. Its best known device is the five membered syllogism: state the thesis, there is fire on the hill, give the reason, because there is smoke, offer an accepted example, as in a kitchen, apply the reason to the present case, and this hill has smoke of that kind, then draw the conclusion, therefore there is fire on the hill. Every step is checkable by an opponent.

Behind the method sits a theory of knowledge. Nyaya recognizes four independent sources, perception, inference, comparison and testimony, and works out exactly when each can be trusted. Nyaya used that apparatus for large claims: a creator god exists, the self is a substance distinct from the body, the Veda counts as reliable testimony, and each claim faced determined opponents ready to attack the reasoning behind it.

By the eleventh century Nyaya's logic had absorbed Vaisheshika's inventory of the world's basic categories, producing a combined Nyaya-Vaisheshika system. In the thirteenth or fourteenth century the philosopher Gangesha rebuilt the logical core in his Tattvachintamani, the Jewel of Thought, founding what later scholars call Navya-Nyaya, the New Logic, whose precise technical definitions were adopted even by the Buddhist logicians Nyaya had argued against for centuries.

Among the classical schools of Indian philosophy, Nyaya stands out for treating God's existence as a thesis to be proven by the same inferential method it used for everything else, rather than as a premise taken on faith or scripture alone. The clearest statement is Udayana's eleventh century Nyayakusumanjali, the Handful of Flowers of Logic, which gathers and formalizes arguments earlier Naiyayikas had offered piecemeal. The core move treats the world itself as an effect: mountains, oceans and bodies are complex, composite things, and every composite thing Nyaya's epistemology recognizes as an effect requires an intelligent agent to arrange its parts, the way a pot requires a potter. Since the world is vastly more intricate than any pot, its maker must possess correspondingly vast knowledge and power, which Nyaya identifies with Ishvara, God, understood here as an efficient cause who shapes eternal atoms into the world rather than as a creator who brings matter into being from nothing.

The argument met determined opposition on Nyaya's own philosophical terms. Mimamsa philosophers, defenders of Vedic ritual as self-sufficient and requiring no divine author, denied that the world needs a maker at all, treating the analogy to a pot as an illegitimate leap from a small, observed class of effects to the cosmos as a whole. Buddhist logicians, who accepted much of Nyaya's formal apparatus while rejecting a creator, attacked the same analogy from the opposite direction, arguing that pots have observed makers while the world's supposed maker is never observed at all. Nyaya's theologians spent centuries refining the argument against exactly these objections, which is why the debate is remembered as a genuine philosophical contest rather than a doctrine merely asserted.