(B). Different divisions of Anumāna (in Nyāya-Vaiśeṣika Philosophy)

In Indian logic an anumāna is a combined deductive inductive reasoning consisting of at least three categorical propositions. In the Nyāya system, we find three different classifications of anumāna.

(i) According to the first classification, anumāna is of two kinds,-viz., (a) svārthānumāna and (b) parārthānumāna.

(ii) According to the second classification, anumāna is said to be of three kinds -viz., (a) pūrvavat, (b) śeṣavat and (c) sāmānyatodṛṣṭa. ^[1]

(iii) According to the third classification, anumāna is said to be of three kinds, viz., (a) kevalānvayi, (b) kevalavyatireki and (c) anvayavyatireki. ^[2]

(i) The first classification of anumāna:

Though the division of anumāna into svārtha and parārtha is not found in the Gautama’s Nyāyasūtra or Kaṇāda’s Vaiśeṣikasūtra, its history definitely goes back to Praśastapāda who has mentioned it in his commentary on Vaiśeṣikasūtra. ^[3] In the Nyāya-Vaiśeṣika system, Annambhaṭṭa, the author of Tarkasaṃgraha, divides anumāna into svārthānumāna and parārthānumāna. ^[4] This is a psychological classification which has in view the use or purpose, which an anumāna serves. An anumāna is called svārtha when it aims at the knowledge of an unperceived object on the part of a man who employs that anumāna. ^[5] In a svārthānumāna, the premises are known from our own experience. For example, a man infers the existence of fire in a kitchen (mahānasa), because he first perceives a mass of smoke in it and then he remembers that there is a universal relation between smoke and fire. Whenever he goes out and happens to see smoke coming out of hill, his previous memory of the concomitant relation between smoke and fire arises and then he comes to a conclusion that wherever there is smoke, there is fire. Thus, this is a psychological process of anumāna for one’s own sake.^[6]

Yet another anumāna is called parārthānumāna or inference for others. Parārthānumāna is the logical process in which we try to convince others of its truth by stating all the members of syllogism in a formal manner. In parārthānumāna, premises are discovered by one man and imparted to another through the medium of language. That is why there is a greater possibility of occurrence of fallacies in parārthānumāna than in svārthānumāna. Annambhaṭṭa opines that parārthānumāna is the syllogistic expression of a thing which a person employs after inferring for himself. It is for other’s sake. A parārthānumāna is illustrated when a man having inferred the existence of fire in a hill lays it down as a thesis and proves it as a conclusion following from the major and minor premises and their combination into a third premise.^[7] A parārthānumāna consists of five constituent propositions (pañcāvayava), viz., pratijñā, hetu, udāharaṇa, upanaya and nigamana. ^[8]

In the Tarkabhāṣā, Keśavamiśra has also mentioned two kinds of anumāna, viz., svārthānumāna and parārthānumāna. The former is that process by which one gets convinced in his own mind^[9] . For example, after ascertaining vyāpti between smoke and fire in the kitchen, etc. by the special perception. If one happens to go near a mountain and sees an unbroken line of smoke issuing from the mountain and reaching to the sky, he doubts the existence of fire there and immediately recollects the vyāpti, ‘where there is smoke, there is fire’, through the impression that gets aroused by the sight of smoke. Then he makes sure that such a (concomitant) smoke exists in the subject (pakṣa) before him and thereby concludes that there is fire (i.e.,mountain).This is called svārthānumāna.

Again when someone after inferring for himself fire from smoke, puts forth a five membered syllogism to carry conviction to another, that inference (i.e.,the one that occurs in the hearer’s mind) is called parārthānumāna (inference for others).^[10]

(ii) The second classification of anumāna:

In the Nyāya system, the second classification of anumāna is said to be of three kinds. Gautama, in his Nyāyasūtra, mentions these three kinds of anumāna, viz.,

1. pūrvavat, 
2. śeṣavat,
3. sāmānyatodṛṣṭa.

(a) Pūrvavat:

A pūrvavat anumāna is that knowledge in which we infer the unperceived effect from a perceived cause. In this anumāna, the liṅga is related to sādhya as its cause and is therefore, antecedent to it. For example, “a future rainfall is inferred from the rising clouds.”^[11] Vātsyāyana gives two sets of interpretation of the term, pūrvavat. According to the first, pūrvavat anumāna is that in which the effect is inferred from the cause, e.g., when we see clouds rising, we infer that there will be rain.^[12] According to the second interpretation, reason and effect belong to two different places. If the effect is already known or it does not exist, there can be no scope for anumāna. According to Vātsyāyana, it is a type of anumāna in which out of two things, one that is not perceived is inferred from the perception of the other on the basis of a former perception of both of these things taken together.

Jayanta interprets these three divisions of anumāna in another way, i.e., taking vat in pūrvavat etc. as the remainder of the suffix vati and holding that it is the universal concomitance between the reason and the consequence which is responsible for the establishment of one by another. According to him, vat is the remainder of the suffix vati and interprets pūrvavat likewise. Whenever we discover the universal relation of concomitance holding between the reason and the consequence on the basis of our previous perception of the same homogenous reason with the same homogenous consequence, then it is called pūrvavat. As for instance, in a kitchen, we find that smoke and fire co-exist. Therefore, when we see smoke in hill, we infer fire. According to Jayanta, the particular reason which is perceived along with its details establishes fire which is similar to the fire experienced before and that is why an act of anumāna is similar to that of perception.^[13]

(b) Śeṣavat:

A śeṣavat anumāna is that in which we infer an unperceived cause from a perceived effect. Here, the middle term is related as an effect to the major term. e.g., when we see that the water of the river is not as usual but is swollen and swifter, we infer that there has been rain. According to Vātsyāyana, a śeṣavat anumāna is that in which the knowledge of cause is derived from the perception of its effects, e.g., one seeing a river swollen infers that there was rain.^[14]

Jayanta refers to the inference of cause from its effect and quotes the same example that Vātsyāyana gives to illustrate the process. He, however, comes to the conclusion that it is not really the cause (rain), but the up-country which has heavy shower of rain, which is inferred from the abnormal swelling of the river; or a particular country may be the subject of anumāna instead of the river, holding that this country is in contact with another country which has heavy shower, because it has a river with a swollen stream.^[15] As in the case of pūrvavat, Jayanta gives an alternative interpretation of śeṣavat also and holds vat as the reminder of the suffix vati propounding that the conclusion in this anumāna is arrived at through the method of elimination.

(c) Sāmānyatodṛṣṭa:

A sāmānyatodṛṣṭa is the anumāna of an unperceived object from the mark which is perceived. It is based on the non causal relation. In sāmānyatodṛṣṭa anumāna, the vyāpti or the universal relation between the major and middle terms does not depend on a causal relation.^[16] For example, we infer the existence of the soul substance from the qualities of cognition, pleasure, pain, desire, volition which must inhere in a substance. These qualities are similar to other qualities. Therefore, they must be inherent in a substance. This substance is called soul.

According to Vātsyāyana, sāmānyatodṛṣṭa anumāna is the knowledge of one thing derived from perception of another things with which it is commonly seen, e.g., one seeing a beast possessing horns, infers that it possesses also a tail, or one seeing smoke on a hill infers that there is fire on it.^[17]

According to Jayanta, when we infer the consequent from the antecedent which is neither a cause nor an effect, then it is called sāmānyatodṛṣṭa. For example, the taste of a ‘kapittha’ (wood apple) is inferred from its colour. Colour and taste inhere in ‘kapittha’ and they are not causally related to each other. Jayanta holds that when an imperceptible object is inferred on the basis of concomitance between the universal, the antecedent (reason) and the universal of the consequent, it is called sāmānyatodṛṣṭa anumāna. ^[18]

(iii) The third classification of anumāna:

In the Nyāya system, the third classification of anumāna is divided into three types. Uddyotokara is the first logician who recognizes kevalānvayi, kevalavyatireki and anvayavyatireki as the varieties of inference.^[19] He rejects pūrvavat as an inference from a cause to an effect, and śeṣavat as an inference from an effect to a cause. He defines sāmānyatodṛṣṭa as an anumāna which is based on uniformity of co-existence as distinct from uniformity of causation. In addition to rejecting pūrvavat, śeṣavat etc, Uddyotakara expounds these three new types of anumāna. This division is based upon the different methods of establishing vyāpti. Now we shall discuss them elaborately:

(a) Kevalānvayi:

An anumāna is called kevalānvayi, when it is based on a middle term which is only positively related to the major term. The terms agree only in presence; there is no negative instance of their agreement in absence.^[20] For example, “all knowable things are nameable; the jar is nameable, because it is knowable;” The reason is that knowability exists in all nameable objects. There are no knowable objects which are not nameable. The reason is not counter positive entity of the negation of the predicate.^[21] In kevalānvayi inference (anumāna), the reason exists in the subject and similar instances and is devoid of dissimilar instances.

For example:

Sound is non-eternal.
Because it is produced.

In kevalānvayi anumāna the middle term is positively related to the major term.

(b) Kevalavyatireki:

In kevalavyatireki anumāna, the reason has negative invariable concomitance with the absence of the predicate. In this anumāna, the middle term is negatively related to the major term. It depends upon a negative invariable concomitance or uniform relation between the absence of the reason with the absence of the predicate, which is established by the method of agreement in absence. As for example, “Earth differs from the other elements, because it has odour.” Or, “What is not different from the other elements has no odour.” In this anumāna, the reason ‘odour’ is the uncommon attribute of the subject Earth. It is co-extensive with the subject; there is no similar instance in which it may exist. Therefore, it is called kevalavyatireki. ^[22] In kevalavyatireki inference (anumāna) the reason is the counter positive entity of the absence which pervades the absence of the predicate.^[23]

(c) Anvayavyatireki:

An anumāna is called anvayavyatireki, when its middle term is both positively and negatively related to the major term.^[24] Anvayavyatireki is an inference (anumāna) in which the reason exists in the subject and similar instances, but does not exist in dissimilar instances. For example, “sound is non-eternal, because it is perceptible through our sense organ, being possessed of a higher genus and a lower genus.”^[25] In anvayavyatireki anumāna, the vyāpti has been observed by a combination of a large number of instances of agreement in presence and agreement in absence. As for example, yatra dhūmaḥ, tatra vahniḥ; as in the mahānasa. There is a universal affirmative relation of the reason with the predicate as well as a universal negative relation between them in an anvayavyatireki inference (anumāna). The former is known by the method of agreement in presence and the later by the method of agreement in absence.^[26] In this anumāna, the reason is present in similar instances and absent from dissimilar instances,^[27] e.g., (1) “All smoky objects are fiery; the hill is smoky; therefore, the hill is fiery.” (2) “No non-fiery objects are smoky; the hill is smoky; therefore, the hill is fiery.” ‘Smoke exists in similar instances’, e.g., a kitchen. With such positive arguments it is called anvaya anumāna. And if the same is proved through negative example or dissimilar instances, e.g., a lake, in which fire does not exist, then it is called anvayavyatireki anumāna.

Jayanta does not accept this kind of division of anumāna. But Vācaspati Miśra, Gaṅgeśa and Viśvanātha followed the division set forth by Uddyotakara. Annambhaṭṭa and Keśavamiśra refer to kevalānvayi, kevalavyatireki and anvayavyatireki as the types of liṅga (reason) and not as a division of anumāna.

In the Vaiśeṣika system, Praśastapāda divides svārthānumāna into two kinds, viz., dṛṣṭa anumāna and sāmānyatodṛṣṭa anumāna. An anumāna is called dṛṣṭa, in which the character of the familiar instances and the character that is inferred possesses specific unity pertaining to the same species. For example, we perceived a dewlap in a cow in a town. Then we perceived a dewlap in an animal in a forest. From this, we infer it to be a cow. This is called dṛṣṭa anumāna. There is an absolute identity in the genus of the animal perceived in the past and the animal perceived at present. The genus of cow (gotva) inferred in the individual perceived in the forest was already perceived in the cow in a town. Therefore, it is called dṛṣṭa anumāna.

Again, a sāmānyatodṛṣṭa anumāna is defined as that in which the perceived character and the inferred character have generic unity. As for instance, when seeing that the actions of a farmer, a merchant etc. lead to same results, we infer that such actions of the four castes as sacrifice etc., must lead to same results, then the result that is inferred, viz., the attainment of heaven, which is non secular, is of a species totally different from the former result, which is secular. This kind of anumāna is called sāmānyatodṛṣṭa anumāna. ^[28]

Footnotes and references:

[1]:

Nyāyasūtra, i. 1. 5

[2]:

trividhamiti, anvayi, vyatireki, anvayavyatireki ceti. Nyāyavārttika, 1. 1. 5

[3]:

Vide Bijalwan, C.D., Indian Theory of Knowledge, p. 142

[4]:

taccānumānam dvividham, svārtham parārtham ceti. Tarkasaṃgraha, p. 9

[5]:

svārthaṃ svānumitihetuḥ. Ibid., p. 27

[6]:

tathā hi svayameva bhūyo … tadetatsvar̄thānumānam. Ibid.

[7]:

Ibid., pp. 46–49

[8]:

pratijñāhetudāharaṇopanayanigamanāni pañcāvayavaḥ. Ibid.,p. 29

[9]:

svārthaṃ svapratipattihetuḥ. Tarkabhāṣā, 40, p. 70

[10]:

yattu kaścit svayam…tad yathā parvato agnimān. dhūmavatvāt…tenaitad parārthānumānam. Ibid., 41, p. 71

[11]:

pūrvavaditi yatra kāraṇena kāryamutpadyate yathā meghonnatyā bhaviṣyati bṛṣṭiriti. Nyāyabhāṣya, i. 1. 5

[12]:

Ibid.

[13]:

Vide Bijalwan, C.D., Indian Theory of Knowledge, pp. 138,139

[14]:

tad yatra kāryena kāraṇamanumīyate pūrvodakaviparītamudakaṃ nadyāḥ pūrṇatvaṃ śīghratvaṃ ca dṛṣṭvā srotaso’numīyate bhutā dṛṣṭiriti. Nyāyabhāṣya, i. 1. 5

[15]:

iyam vācoyuktiḥ kāryena kāraṇam anumīyate iti paramārthastu dharmo dharmavatvena dharmavānanumīyate iti sthitiḥ. Nyāyamañjarī, I. 118

[16]:

sāmānyatodṛṣṭam kāryakāraṇa bhinnaliṅgakam. Nyāyasūtravṛtti, i. 1. 5

[17]:

sāmānyatodṛṣṭam nāmo yatrāapratyakṣe…..sthānāṃ ca ātmeti. Nyāyabhāṣya, i. 1. 5

[18]:

Vide Bijalwan, C.D., Indian Theory of Knowledge, pp. 140,141

[19]:

trividhamiti, anvayi, vyatireki, anvayavyatireki ceti. Nyāyavārttika, 1. 1. 5
Cf: traividhyamanumānasya kevalānvayibhedataḥ /
dvaividhyantu bhaved vyāptenvayavyatirekataḥ // Bhāṣāpariccheda, kārikā 142

[20]:

yatra sādhyavyatireko na kutrāpyasti sa kevalānvayi. Tarkāmṛta, ch-II

[21]:

asadvipakṣam atvantābhāvapratiyogīsādhyakam. Siddhāntamuktāvalī on kārikā 142-143, p. 542

[22]:

asatpakṣaḥ kevalavyatireki. Ibid.

[23]:

sādhyabhāvavyāpakibhutābhāvapratiyogītvam. Ibid.

[24]:

yatra sādhyam sādhyabhāvāśca anyatra prasiddhaḥ so’nvayavyatireki. Tarkāmṛta, ch-II

[25]:

Nyāyavārttika, i. 1. 5

[26]:

gṛhītānvayavyatirekisādhyakam anvayavyatireki. Tattvacintāmaṇidīdhiti, p. 796

[27]:

satsapakṣavipakṣo’nvayavyatireki. Siddhāntamuktāvalī on kārikā 143, p. 542

[28]:

dṛṣṭaṃ prasiddhasādhyayoratyantājātyābhede’numānam. prasiddhasādhyayor atyantājātibhede liṅgānumeyadharmasāmanyānuvṛṭṭito’numānam sāmānyatodṛṣṭam. Praśastapāda Bhāṣya, pp. 507-508