Understanding the Question: We are asked to identify the core factor that the Nyāya school of logic emphasizes for the correct understanding of a sentence's meaning.
Key Concepts and Approach: Comprehension of a sentence (Śābdabodha) requires several auxiliary conditions. While many schools agree on the need for syntax and logic, Nyāya places a heavy emphasis on the speaker's intent to resolve ambiguity.
Detailed Solution:
Step 1: Defining the Conditions. For a sentence to be meaningful, Nyāya posits four requirements: Ākāṅkṣā (Expectancy), Yogyatā (Consistency), Sannidhi (Proximity), and Tātparya (Intention).
Step 2: The role of Tātparya. Tātparya refers to the "speaker's intention." This is considered essential because many words have multiple meanings. For example, the word "Saindhava" can mean "salt" or "horse." Only the speaker's intention (Tātparya) tells the listener which one is correct in context.
Step 3: Comparing to other factors. Bhāvanā is a Mīmāṃsā concept; Sphoṭa belongs to the Grammarians; Anumāna (Inference) is a separate means of knowledge altogether.
Conclusion: According to Nyāya, Tātparya is the decisive factor in verbal comprehension.