Nyaya

Five Hetvābhāsas — Fallacies of Reason

Nyaya Epistemology & Fallacy Analysis

हिन्दी English

In the Nyaya school of logic, a sound argument relies on a valid reason (Hetu). When a reason appears valid on the surface but is fundamentally defective, it is called a Hetvabhasa (literally 'fallacy of the reason' or 'pseudo-reason'). Nyaya categorizes these logical fallacies into five distinct types based on how the reason fails to establish the proposition (Sadhya).

Occurs when the reason (Hetu) is not exclusively tied to the target property (Sadhya), but leads to variable, irregular, or contradictory conclusions.

  • Sadharana (Too Common): The reason leads to both the presence and absence of the Sadhya.
  • Asadharana (Too Uncommon): The reason exists only in the subject and nowhere else, offering no comparison.
  • Anupasamhari (Inconclusive): The subject encompasses everything, making comparison or verification impossible.

Classical example

The mountain has fire because it is knowable. (Fallacy: 'Knowability' exists in both fiery and non-fiery things like lakes, so it cannot prove fire.)

Modern fallacy

False Cause / Hasty Generalization

Modern example

Claiming: 'This new smartphone app will make you productive because it runs on a computer.' (Fallacy: Running on a computer is too common—video games and social media feeds also run on computers, so software platform alone does not establish productivity.)

Occurs when the reason offered to prove the target property actually proves the exact opposite of that property.

  • Directly disproves the Sadhya it attempts to establish.

Classical example

Sound is eternal because it is produced. (Fallacy: Anything that is 'produced' is by definition impermanent, so the reason directly disproves eternality.)

Modern fallacy

Contradiction / Self-Defeating Argument

Modern example

In an economic debate: 'Implementing this strict price ceiling will reduce consumer hardship because it forces companies to stop producing the product altogether.' (Fallacy: Forcing companies to halt production increases scarcity and hardship, proving the opposite of consumer relief.)

Occurs when an argument's reason is met with an equally strong counter-reason that establishes the exact opposite conclusion, leaving the argument stymied in net uncertainty.

  • Symmetrical counterbalance between two conflicting inferences.

Classical example

Arguer A: 'Sound is eternal because it is audible.' Arguer B: 'Sound is non-eternal because it is a product, like a pot.' (Fallacy: Both inferences carry equal weight, neutralizing each other.)

Modern fallacy

Equivocation / False Balance / Unresolved Counter-Argument

Modern example

In a corporate policy debate: Executive A claims, 'We should adopt remote work because employee survey scores will rise.' Executive B responds, 'We should mandate office returns because collaborative serendipity will rise.' (Fallacy: Both arguments use unweighted single metrics that counterbalance each other without addressing overall business productivity or retention.)

Occurs when the reason (Hetu) relies on a premise that is unproven, non-existent, or false, rendering the argument ungrounded.

  • Ashrayasiddha: The subject (Paksha) itself does not exist (e.g., 'The sky-flower is fragrant because...').
  • Svarupasiddha: The reason does not actually exist in the subject.
  • Vyapyatvasiddha: The universal concomitance (invariable connection) between Hetu and Sadhya is unproven.

Classical example

The sky-lotus is fragrant because it is a lotus, like a lake-lotus. (Fallacy: A 'sky-lotus' does not exist in reality.)

Modern fallacy

Begging the Question (Petitio Principii) / False Premise

Modern example

In a technology policy debate: 'We must regulate the telepathic energy emitted by 6G towers because telepathic emissions disrupt sleep cycles.' (Fallacy: The subject 'telepathic energy emitted by 6G towers' is a non-existent, unproven premise.)

Occurs when the conclusion established by the inference (Hetu) is directly contradicted and overruled by a stronger, immediate form of valid knowledge—such as direct perception (Pratyaksha).

  • Direct sensory sublation.

Classical example

Fire is cold because it is a substance, like water. (Fallacy: Direct touch immediately proves that fire is hot, so logical inference cannot override direct sensory evidence.)

Modern fallacy

Empirical Refutation / Denial of Direct Evidence

Modern example

In an urban planning debate: 'This newly built highway intersection has zero vehicle traffic congestion because our computer model predicted smooth flow.' (Fallacy: Live camera feeds showing a 5-mile bumper-to-bumper gridlock directly sublate and invalidate the computer model's inference.)

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