Explain Nyaya theory of inference
The Nyaya school of Indian philosophy developed a comprehensive theory of inference, known as Anumana, which forms one of the means of valid knowledge (Pramana) according to Nyaya epistemology.
Inference, in the Nyaya tradition, is a logical process through which one arrives at new knowledge by observing a relationship between two or more existing pieces of information. Here’s an explanation of the Nyaya theory of inference:
1. Components of Inference:
- Pratijna (Proposition): Inference begins with a proposition or statement that one seeks to establish as true. The pratijna asserts a connection between a subject (Sadhya) and a reason (Hetu).
- Hetu (Reason): The hetu is the middle term or reason that connects the subject with the predicate. It is a universal property that is observed to be present in the inferential subject.
- Udaharana (Example): The udaharana provides an example or instance of the hetu, demonstrating its presence in the inferential subject.
- Upanaya (Application): The upanaya is the application of the hetu to the inferential subject, establishing the connection between them.
- Nigamana (Conclusion): The nigamana is the conclusion drawn from the inference, affirming the truth of the proposition based on the presence of the hetu in the inferential subject.
2. Hetu and Hetvabhasa:
- The Nyaya tradition distinguishes between hetu (legitimate reason) and hetvabhasa (fallacious reason). A legitimate reason must satisfy certain conditions, including:
- Vyapti: The invariable concomitance between the hetu and the inferential subject.
- Satpratipaksa: The absence of the hetu in cases where the inferential subject is absent.
- Asiddha: The absence of counterexamples or exceptions to the hetu.
3. Types of Inference:
- Purvavat (Prior Inference): In prior inference, knowledge of the hetu precedes knowledge of the inferential subject. For example, knowing that there is fire (hetu) on a distant hill, one infers the presence of smoke (inferential subject) on the hill.
- Sheshavat (Subsequent Inference): In subsequent inference, knowledge of the inferential subject precedes knowledge of the hetu. For example, observing smoke (inferential subject) and inferring the presence of fire (hetu) based on past experience.
4. Role of Testimony and Perception:
- Nyaya acknowledges the role of testimony (Sabda) and perception (Pratyaksha) in supporting inference. Testimony provides information about the relationship between the hetu and the inferential subject, while perception provides direct knowledge of the hetu and its presence in the inferential subject.
5. Critiques and Challenges:
- Critics of the Nyaya theory of inference have raised various objections, including concerns about circularity in the justification of hetu, ambiguity in determining vyapti (universal concomitance), and the potential for subjectivity in identifying legitimate reasons.
- Nyaya philosophers have responded to these challenges by refining their theory, clarifying the conditions for valid inference, and engaging in dialectical debates with rival schools of thought.
In summary, the Nyaya theory of inference provides a systematic framework for reasoning and acquiring knowledge through logical inference. By delineating the components, conditions, and types of inference, Nyaya philosophers sought to establish a reliable method for ascertaining truth and understanding the nature of reality.