Indian logic: pramanas and anumana
Pramanas are the means of valid knowledge. Nyaya inference (anumana) rests on vyapti, the invariable relation between smoke (hetu) and fire (sadhya).
The six pramanas
| Pramana | What it gives | Example |
|---|---|---|
| Pratyaksha (perception) | Knowledge from contact of sense and object | Seeing a pot in front of you |
| Anumana (inference) | Knowledge through a sign, based on vyapti | Smoke on the hill, so fire on the hill |
| Upamana (comparison) | Knowing what a name refers to, through similarity | Told a gavaya looks like a cow, you recognise one in the forest |
| Shabda (verbal testimony) | Knowledge from the words of a reliable person or the Vedas | Learning a fact from a trustworthy expert |
| Arthapatti (postulation) | Assuming the fact that alone explains an apparent conflict | Devadatta is fat but does not eat by day, so he eats at night |
| Anupalabdhi (non-apprehension) | Direct knowledge of an absence | Knowing there is no pot on the floor |
Which school accepts how many
| School | Number | Pramanas accepted |
|---|---|---|
| Charvaka (Lokayata) | 1 | Pratyaksha only |
| Buddhist, Vaisheshika | 2 | Pratyaksha, anumana |
| Sankhya, Yoga | 3 | + shabda |
| Nyaya | 4 | + upamana |
| Prabhakara Mimamsa | 5 | + arthapatti |
| Bhatta Mimamsa, Advaita Vedanta | 6 | + anupalabdhi |
The five-membered anumana (panchavayava)
This is parartha anumana, inference stated for others. Svartha anumana, inference for oneself, needs no formal statement.
- 1The hill has fire.Pratijna (proposition)
- 2Because it has smoke.Hetu (reason)
- 3Whatever has smoke has fire, as in a kitchen.Udaharana (example with vyapti)
- 4The hill has smoke, which is always accompanied by fire.Upanaya (application)
- 5Therefore the hill has fire.Nigamana (conclusion)
Hetvabhasas: the five fallacies of inference (Nyaya)
| Hetvabhasa | Defect in the reason | Example |
|---|---|---|
| Savyabhichara (anaikantika) | Irregular: the reason goes with the sadhya and with its absence | The hill has fire because it is knowable |
| Viruddha | Contradictory: the reason proves the opposite | Sound is eternal because it is produced |
| Satpratipaksha | Counterbalanced: another reason proves the opposite | Sound is eternal because audible; sound is non-eternal because produced |
| Asiddha | Unproved: the reason or its locus is not established | The sky-lotus is fragrant because it is a lotus |
| Badhita | Contradicted by another pramana, such as perception | Fire is cold because it is a substance |
How NET asks this: match each pramana with its meaning or with the school that accepts it, put the five members of anumana in order, or name the hetvabhasa in an example.
Typical MCQ: “Which school accepts only perception as a pramana?” Charvaka (Lokayata). It rejects inference because vyapti can never be fully established.
Typical MCQ: “'Devadatta is fat but does not eat by day.' Which pramana yields 'he eats at night'?” Arthapatti (postulation): assuming the one fact that resolves the apparent conflict.
Schools add one pramana at each step: perception (Charvaka, 1) → inference (Buddhist, Vaisheshika, 2) → testimony (Sankhya, Yoga, 3) → comparison (Nyaya, 4) → postulation (Prabhakara, 5) → non-apprehension (Bhatta, Advaita, 6).