nyaya

Nyaya is one of the six orthodox schools of Indian philosophy and is primarily concerned with epistemology, logic, and debate. It holds that reliable knowledge, or pramana, is essential for valid inference about the world and for establishing truth. Nyaya is frequently studied together with Vaisheshika, forming the Nyaya–Vaisheshika tradition, which combines logical analysis with a theory of the world’s substances and properties.

Historically, the school is traditionally attributed to the sage Gautama and is developed through commentaries by later thinkers such as Vatsyayana and Udayana. In the medieval period, the Navya Nyaya movement, led by Gangesha Upadhyaya, introduced a more formal and technical approach to logic and language, influencing subsequent Indian philosophy and scholarship.

Core doctrines include a theory of pramanas, the means by which knowledge is obtained. The standard Nyaya list features perception (pratyaksa), inference (anumāna), comparison or analogy (upamāna), and verbal testimony (sabda); some lineages later add additional pramanas such as negative cognition (anupalabdhi). Nyaya also developed a detailed method of argumentation and a five-member syllogism: pratijña (proposition), hetu (reason), udāharaṇa (example), upanaya (application), and nigamana (conclusion). This framework is used to analyze valid inference, resolving epistemic challenges, and defending philosophical positions through logical debate.

Influence of Nyaya extends beyond its own tradition, affecting broader Hindu philosophy and interacting with Buddhist logicians. Today, Nyaya remains a core topic in the study of Indian philosophy, with the later Navya Nyaya representing a high point in its formal logic and linguistic analysis.