In the Indian tradition almost all branches of knowledge like vyākaraṇaṃ, mīmāṃsā have some insight on epistemology, but nyāya is discipline, where it is dealt with extensively. That is why Nyāya is considered as pramāṇa śāstraṃ, the study related to knowledge source. Pramā is nothing but the logically legitimate knowledge and the source of that is pramānaṃ. Legitimate knowledge brings out a thing used daily as it actually is. It can be identified as valid knowledge when it corresponds to the actual nature of the object. One can also know that it is valid when the object stated is obtained successfully. This correspondence between the knowledge or pramā and nature of object leads to the successful utilization thereof.
Pratyakha- anumāna- upamāna- śabdāḥ pramāṇāni.
Concepts of Different Indian Schools for Inference of Knowledge
Each school of Indian thought has its own theory of the means to obtain correct knowledge.
pratyakṣamēkaṃ cārvākāḥ kaṇādasugatau punaḥ |
anumānanca taccātha sāṃkhyāḥ śabdanca tē api || nyāyaikadēśinōpyēvaṃ upamānaṃ ca kēcana | arthāpatyā sahaitāni catvāryāha prabhākarāḥ || abhāva ṣaṣṭhānyētāni bhāṭṭā vēdāntinastathā |sambhavaitihyayuktāni tāni paurāṇikā jaguḥ||
|School||Theory 1||Theory 2||Theory 3||Theory 4||Theory 5||Theory 6||Theory 7||Theory 8|
|Vaiśeṣika & Buddhists||-||Inference/Anumānaṃ||-||-||-||-||-||-|
|Bhāṭṭas & Vedāntins||-||Inference/Anumānaṃ||Comparison/Upamānaṃ||Verbal testimony/Ṣabdaḥ||Presumption/Arthāpattiḥ||Non-existence/Abhāvaḥ||-||-|
Classification of Pramāṇāni
According to Nyāya tradition, there are four pramāṇāni namely:
- Pratyakhaṃ - It is called as the source of perceptual cognition.
- Anumānaṃ - It is called as the source of inferential cognition.
- Upamānaṃ - It is the source of analogical cognition.
- Śabdāḥ - It is the source of verbal cognition.
इन्द्रियार्थसन्निकर्षोत्पन्नं ज्ञानं अव्यपदेश्यं अव्यभिचारि व्यवसायात्मकं प्रत्यक्षम्।
Indriyārthasannikarṣōtpannaṃ jñānaṃ avyapadēṣyaṃ avyabhicāri vyavasāyātmakaṃ pratyakshaṃ.
According to Nyāya tradition, there are six sense organs or indriyāṇi. All these organs have a different type of relationships with different objects. For example, an eye can see a pot with a different relation and know its color with a different relation. To know the pot the eye or cakṣurindriya has a relation called samyōgaḥ with the pot. To know the pot’s color it has samyutasamavāyaḥ as a relation.
Here in the sūtraṃ we have three adjectives to the word pratyakshaṃ.
- Avyapadēṣyaṃ - It means non-verbal cognition.
- Avyabhicāri - It means non-illusion.
- Vyavasāyātmakaṃ - It means the undoubted cognition.
So the true cognition occurs because of a special relation between sense organs and its object. We can conclude it as a pratyakhaṃ or perceptual cognition when it is not a verbal cognition, illusion and doubtful.
अथ तत्पूर्वकं त्रिविधं अनुमानं पूर्ववत्शेषवत्सामान्यतोदृष्टं च।
Tha tatpūrvakaṃ trividhaṃ anumānaṃ pūrvavat- śēṣavat- sāmānyatōdṛṣṭaṃ ca.
The instrument or the process which produces the inferential cognition is called as anumānaṃ. For example we can infer that there is fire on the mountain if we see smoke on it.
Types of Anumānaṃ
According to the above sūtraṃ, anumānaṃ is of three types:
- Pūrvavat - Inferring an effect by knowing the cause. Here pūrva means cause. Like we can forecast rain by seeing the clouds height and color. The clouds become heavier and black in color when it is going to rain. So here we are inferring the effect i.e., rain by knowing the cause i.e., particular height and color of the clouds. The statement for this is, 'The clouds may rain because its lower than usual and black in color.'
- Śēṣavat - Inferring a cause by knowing an effect. Here śēṣa means effect. Like we can know that the place has fire by seeing smoke in it because smoke is the effect of fire. So here we are inferring cause i.e., fire by knowing the effect i.e., smoke. The statement for this is, 'The place has fire, because of the smoke that we can see.'
- Sāmānyatōdṛṣṭaṃ - It can be simply explained as 'commonly seen'. It is the knowledge of one thing derived from the perception of another thing with which it is commonly seen. The statement for this is, 'on seeing rain, one infers that there are clouds'.
Anumānaṃ as per Nyāya Tradition
The Nyāya tradition explains this process in detail as follows:
- Step 1: Acquiring the knowledge that 'Smoke and fire are having an invariable relationship'. This requires the knowledge of their co-existence at many places and not having any contradiction of the above statement. This is called vyāpti jñānaṃ. This is not always consciously known by the pramātā.
- Step 2: Seeing the smoke on the mountain and knowing that the mountain possesses the smoke.
- Step 3: Remembering the invariable relationship between smoke and the fire.  According to this logic, one will automatically remind you the other. Like if we see a tigers tail, we can affirm the presence of the tiger. Here, as the person knows this invariable relationship between smoke and fire, by seeing smoke he would remind fire.
- Step 4: Conforming that such a smoke with such a relationship exists on the mountain. The difference between the second step and fourth one is that in the primary stage he would just know smoke, but in the later stage, he could definitely know that the smoke possesses an invariable relationship with fire.
- Step 5: Concluding that the mountain possesses fire. This is called anumitiḥ.
प्रसिद्धसाधर्म्यात्साध्यसाधनं उपमानम् ।
Prasidhdhasādharmyāt sādhyasādhanaṃ upamānaṃ।
An analogical cognition is a cognition of the relationship between a word and its meaning. The instrument of that is the knowledge of similarity. To explain this concept in detail, when a person dose not know the meaning of the word 'gavaya' then,
- Step 1: He knows from a forester that "gavaya is similar to cow".
- Step 2: He goes to the forest and sees an animal similar to cow and remembers the sentence of the forester.
- Step 3: Then an analogical cognition or upamitiḥ arises such as "This is the referent of the word gavaya".
Here if the man did not knew from the forester that the "gavaya is similar to cow", even though seeing gavaya in the forest he could not come to the conclusion that "This is the reference of the word gavaya".
सः द्विविधः दृष्टादृष्टार्थत्वात्।
Saḥ dvividhaḥ dṛṣṭādṛṣṭārthatvāt।
The cognition derived from a set of words uttered by a reliable person is called śābdabōdhaḥ and its is called śabdaḥ.
Types of Śabdaḥ
This is divided into two types as follows:
- Dṛṣṭārthaḥ - It is the source for the cognition which deals with all the worldly subjects, like the instructions given by a doctor as a treatment.
- Adṛśṭārthaḥ - It is the source for the cognition which deals with all the supernatural subjects, like the instructions given by the Veda to attain the heaven or svargaḥ.
- 'ēka sambandhi jñānaṃ apara sambandhi smārakaṃ'
- Here this refers to the animal.