Correct Answer - Option 4 :
Anavaya vyatireki
Gautama, the propounder of the Nyaya system defines anumana as a ‘knowledge which is preceded by perception.
According to the classification of inference, the inference is divided into three types. They are — kevalanvayi, kevalavyatireki, and anvayavyatireki inferences. It is based on the nature of vyapti.
1) Kevalanvayi inference:
- When vyapti between the middle and the major term is derived from uniform agreement in presence alone, it is called Kevalanvayi inference. In this inference, the hetu has affirmative concomitance with sadhya only.
- For example, All knowable objects are nameable; The pot is a knowable object; Therefore the pot is nameable.
2) Kevalavyatireki inference:
- When vyapti between middle and the major is derived from uniform agreement in absence alone, it is called kevalavyatireki inference. In this inference, hetu is only negatively related to the sadhya.
- For example, What is not different from other elements has no smell; The earth has smell; Therefore the earth is different from other elements.
3) Anvayavyatireki inference :
- When the middle term in an inference is both positively and negatively related to the major term, it is called anvaya-vyatireki inference.
- In it, there is a vyapti or universal relation between the hetu and the sadhya in respect of both their presence and absence.
- For example,
- a) All smoky objects are fiery; The hill is smoky; Therefore the hill is fiery.
- b) No non-fiery object is smoky; The hill is smoky; Therefore the hill is not non-fiery; That is, the hill is fiery.
Kevalanvayi inference corresponds to Mill’s Method of Agreement, Kevalavyatireki inference corresponds to his Method of Difference and Anvayavyatireki inference corresponds to his Joint Method of Agreement and Difference or the Method of Double Agreement.
Thus, option 4 is the correct answer.
