Which school of ancient Indian philosophy is based on the technique of logical thinking (reasoning and proof)?

The Nyaya school of Indian philosophy is based on logic and the techniques of reasoning, debate and valid knowledge.

About Nyaya:

• "Nyaya" means "rule", "method" or "reasoning".
• Its basic text is the "Nyaya Sutra", attributed to the sage Gautama (also called Akshapada), composed perhaps between the 2nd century BCE and the 2nd century CE.
• Its main aim is to explain how we can gain true knowledge, and to show that liberation can be achieved through right knowledge.

The four means of valid knowledge (pramanas):

• "Pratyaksha": perception (direct knowledge through the senses).
• "Anumana": inference (reasoning from known facts to unknown conclusions).
• "Upamana": comparison (knowledge through similarity).
• "Shabda": verbal testimony (reliable words, such as the Vedas or the words of trustworthy persons).

The five-step syllogism:

Nyaya developed a method of logical argument with five steps:

• "Pratijna": the statement (for example, "the hill has fire").
• "Hetu": the reason ("because there is smoke").
• "Udaharana": the example ("wherever there is smoke, there is fire, as in a kitchen").
• "Upanaya": the application ("the hill has smoke").
• "Nigamana": the conclusion ("therefore, the hill has fire").

Other contributions:

• Nyaya thinkers developed rules for debate and discussed errors in reasoning (fallacies).
• They also argued for the existence of God (Ishvara) through logic.
• "Navya-Nyaya" (New Nyaya), developed by Gangesha Upadhyaya in Mithila in the 14th century in his "Tattvachintamani", was a highly technical system of logic.
• Later, Navadvipa (Nabadwip) in Bengal became a famous centre of Navya-Nyaya, with scholars such as Raghunatha Shiromani.

Nyaya and Vaisheshika:

Nyaya was later combined with the Vaisheshika school (which dealt with categories of reality and atoms) as "Nyaya-Vaisheshika".

The six orthodox schools:

Samkhya, Yoga, Nyaya, Vaisheshika, Purva Mimamsa and Vedanta.

Why not the other options?

• ✗Samkhya deals with the dualism of purusha and prakriti.
• ✗Yoga deals with meditation and the control of the mind.
• ✗Mimamsa deals with the interpretation of the Vedas and rituals.