---
type: Concept
bundle: nyaya-vaisheshika
bundle_version: 0.9.0
id: hetvabhasa
title: Hetvābhāsa
iast: Hetvābhāsa
devanagari: हेत्वाभास
description: 'The taxonomy of pseudo-reasons, marks that look probative but fail (classically fivefold: savyabhicāra, viruddha, satpratipakṣa, asiddha, bādhita); the Nyāya theory of inferential error; NOT the list of Western informal fallacies, NOT rhetorical foul play, NOT logical invalidity in the formal sense.'
darshana:
- Nyāya
text_source: Nyāya Sūtra 1.2.4-9
tags:
- hetvabhasa
- fallacy
- pseudo-reason
- nyaya
- inference
not:
- term: the Western list of informal fallacies (ad hominem, straw man, etc.)
  why: 'Informal fallacies catalogue bad moves in argument and persuasion. Hetvābhāsa is a precise typology of how a mark fails its probative conditions: deviating from the target, contradicting it, being countered by an equal opposing reason, being itself unestablished, or being overridden by a stronger pramāṇa. It is a theory of failed inference, not of rhetorical misconduct.'
  instead: 'Map the five heads to defects in the mark itself: savyabhicāra (the mark strays into cases lacking the target), viruddha (it proves the opposite), satpratipakṣa (an equal counter-reason stands), asiddha (the mark is unproved), bādhita (perception or a stronger source refutes the conclusion).'
- term: cheating or bad faith in debate
  why: The deceptive, victory-seeking moves of debate are catalogued separately as chala, jāti, and nigrahasthāna. Hetvābhāsa concerns marks that fail on the merits even when advanced sincerely; a careful honest reasoner can still commit one.
- term: formal invalidity (an invalid argument form)
  why: A hetvābhāsa can occur in an argument whose surface form looks fine; the failure is epistemic, in the mark's real relation to subject and target, not in a truth-functional schema. Formal validity is neither necessary nor sufficient for a Nyāya inference to be sound.
related:
- /concepts/hetu.md
- /concepts/vyapti.md
- /concepts/anumana.md
- /concepts/nigrahasthana.md
timestamp: '2026-07-02'
okf_version: '0.2'
license: CC BY-SA 4.0
---

# Hetvābhāsa -- हेत्वाभास

**Not:** informal fallacies, debate cheating, formal invalidity

## What It Actually Means

Hetvābhāsa, 'the semblance of a reason', is Nyāya's account of how inference goes wrong at the mark. The standard five: savyabhicāra (anaikāntika), the straying reason, present also where the target is absent, so it proves nothing determinately; viruddha, the contradictory reason, which actually establishes the opposite of the thesis; satpratipakṣa (prakaraṇasama), the counterbalanced reason, met by an equally good reason for the contrary; asiddha, the unestablished reason, whose own presence in the subject is not secured; and bādhita (kālātyayāpadiṣṭa), the stultified reason, whose conclusion is already refuted by perception or a stronger source. Each names a specific way a mark fails its conditions rather than a category of rhetorical bad behaviour. This is why importing the Western catalogue of informal fallacies misses the target: hetvābhāsa is a diagnostics of inference, keyed to the trairūpya, not a list of debating sins.

## Audience Metaphor

A metal detector that beeps at bottle caps, stays silent over buried coins, or is drowned out by a second detector beeping the opposite, is not committing rude behaviour; it is failing at detection in five diagnosable ways. Hetvābhāsa is the repair manual for the detector, a fault tree for marks, not an etiquette guide for the operators.

## Citations

1. Nyāya Sūtra 1.2.4-9 (the five hetvābhāsas) -- see [references/nyaya-sutra.md](../references/nyaya-sutra.md)
2. Annambhaṭṭa, Tarkasaṃgraha, the standard fivefold classification -- see [references/tarkasamgraha.md](../references/tarkasamgraha.md)
3. Jayanta Bhaṭṭa, Nyāyamañjarī -- see [references/nyayamanjari.md](../references/nyayamanjari.md)
