PHI-DSC-202 (Logic II): Unit 2: Hetvabhasa (Fallacies of Inference)
Contact Hours: 60 | Full Marks: 100 (ESE=70/CCA=30)
Table of Contents
- Hetvabhasa: Definition and Types
- Asiddha (Unproved Hetu)
- Badhita (Contradicted Hetu)
- Satpratipaksa (Inferentially Contradicted Hetu)
- Viruddha (Contradictory Hetu)
- Savyabhichara (Irregular Hetu)
Hetvabhasa: Definition and Types
**Hetvabhasa** literally means 'hetu that appears as a reason but is not a valid reason'. It refers to a fallacious middle term (Hetu) that fails to satisfy the necessary conditions for a valid inference (**Anumāna**). These are mistakes related to the application of **Vyāpti** and the **Pakşatā**.
The Five Types of Hetvabhasa (Nyaya Classification)
The Nyaya system recognizes five standard fallacies, collectively known as *pañcahetvābhāsa*.
Asiddha (Unproved Hetu)
**Asiddha** means 'unproved' or 'non-existent'. This fallacy occurs when the existence of the Hetu (middle term) in the Pakşa (minor term) is not established or is conditional.
- Failure: Failure to prove the minor premise (The hill has smoke).
- Example: "The hill is fiery, because it is *a cloud of steam*." (The Hetu, 'cloud of steam,' is not actually a form of the Sādhya, 'fire,' and its existence as a cause of fire is unproved).
- Sub-types: *Āśrayāsiddha* (Pakşa itself is unproved), *Svarūpāsiddha* (Hetu is unproved in the Pakşa), *Vyāpyatvāsiddha* (Vyāpti is based on a condition - *Upādhi*).
Badhita (Contradicted Hetu)
**Badhita** means 'sublated' or 'contradicted'. This fallacy occurs when the absence of the Sādhya (major term) in the Pakşa (minor term) is conclusively proved by another source of knowledge (Pramāna), such as perception or a sacred text.
- Failure: The conclusion (Sādhya in Pakşa) is contradicted by another stronger piece of evidence.
- Example: "Fire is cold, because it is a substance." (The conclusion that fire is cold is directly contradicted by **perception**, which proves fire is hot).
Satpratipaksa (Inferentially Contradicted Hetu)
**Satpratipaksa** means 'opposed by an equally strong Hetu'. This occurs when the proposed Hetu is counter-balanced by another Hetu that proves the exact opposite conclusion.
- Failure: The inference is contradicted by a counter-inference that is equally strong.
- Example:
- **Inference A:** Sound is eternal, because it is audible. (Hetu: audibility; Sādhya: eternality)
- **Counter-Inference B:** Sound is non-eternal, because it is produced by effort. (Hetu: produced by effort; Sādhya: non-eternality)
Since the two Hetus lead to contradictory conclusions and are equally potent, both inferences are flawed.
Viruddha (Contradictory Hetu)
**Viruddha** means 'contradictory'. This occurs when the Hetu (middle term) is not merely non-concomitant with the Sādhya (major term), but is actually established to be invariably concomitant with the **absence** of the Sādhya.
- Failure: The Hetu leads to a conclusion opposite to the one intended.
- Example: "Sound is eternal, because it is produced." (The Hetu, 'produced,' is invariably connected with **non-eternality**, thus proving the opposite of the Sādhya, 'eternal').
Savyabhichara (Irregular Hetu)
**Savyabhichara** means 'erratic' or 'inconstant'. This occurs when the Hetu (middle term) is not exclusively related to the Sādhya (major term), meaning the Hetu exists in places where the Sādhya is both present and absent. The Vyāpti is violated.
- Failure: Failure of the Vyāpti (invariable concomitance).
- Example: "The hill has fire, because it is knowable." (The Hetu, 'knowable,' is too wide. Knowability exists everywhere, in things with fire and things without fire - it is **too general**).
Exam Tip: Nyaya Fallacy Distinction
The core distinction often tested is between **Viruddha** and **Savyabhichara**. In **Viruddha**, the Hetu proves the *opposite* conclusion. In **Savyabhichara**, the Hetu proves *nothing* because it is too ambiguous or general.
Key Takeaway for Unit 2:
Master the definition of **Hetvabhasa** and be prepared to provide a unique, clear **example** for each of the five types. The fallacies are based on the failure of one or more of the five conditions (Rūpa) of a valid Hetu.