Part 15 - Sautrāntika theory of Inference

^[1]

According to the Sautrāntika doctrine of Buddhism as described by Dharmakīrtti and Dharmmottara which is probably the only account of systematic Buddhist logic that is now available to us in Sanskrit, inference (anumāna) is divided into two classes, called svārthānumāna (inferential knowledge attained by a person arguing in his own mind or judgments), and parārthānumāna (inference through the help of articulated propositions for convincing others in a debate). The validity of inference depended, like the validity of perception, on copying the actually existing facts of the external world. Inference copied external realities as much as perception did; just as the validity of the immediate perception of blue depends upon its similarity to the external blue thing perceived, so the validity of the inference of a blue thing also, so far as it is knowledge, depends upon its resemblance to the external fact thus inferred (sārūpyavaśāddhi tannīlapratītirūpam sidhyati).

The reason by which an inference is made should be such that it may be present only in those cases where the thing to be inferred exists, and absent in every case where it does not exist. It is only when the reason is tested by both these joint conditions that an unfailing connection (pratibandha) between the reason and the thing to be inferred can be established. It is not enough that the reason should be present in all cases where the thing to be inferred exists and absent where it does not exist, but it is necessary that it should be present only in the above case. This law (niyama) is essential for establishing the unfailing condition necessary for inference^[2]. This unfailing natural connection (svabhāvapratibatidha) is found in two types of cases.

The first is that where the nature of the reason is contained in the thing to be inferred as a part of its nature, i.e. where the reason stands for a species of which the thing to be inferred is a genus; thus a stupid person living in a place full of tall pines may come to think that pines are called trees because they are tall and it may be useful to point out to him that even a small pine plant is a tree because it is pine; the quality of pineness forms a part of the essence of treeness, for the former being a species is contained in the latter as a genus; the nature of the species being identical with the nature of the genus, one could infer the latter from the former but not vice versa ; this is called the unfailing natural connection of identity of nature (tādātmya).

The second is that where the cause is inferred from the effect which stands as the reason of the former. Thus from the smoke the fire which has produced it may be inferred. The ground of these inferences is that reason is naturally indissolubly connected with the thing to be inferred, and unless this is the case, no inference is warrantable.

This natural indissoluble connection (svabhāvapratibandha\ be it of the nature of identity of essence of the species in the genus or inseparable connection of the effect with the cause, is the ground of all inference^[3]. The svabhāvapratibandha determines the inseparability of connection (avinābhāvaniyama) and the inference is made not through a series of premisses but directly by the liṅga (reason) which has the inseparable connection^[4].

The second type of inference known as parārthānumāna agrees with svārthānumāna in all essential characteristics; the main difference between the two is this, that in the case of parārthānumāna, the inferential process has to be put verbally in premisses.

Pandit Ratnākaraśānti, probably of the ninth or the tenth century A.D., wrote a paper named Antarvyāptisamarthana in which he tried to show that the concomitance is not between those cases which possess the liṅga or reason with the cases which possess the sādhya (probandum) but between that which has the characteristics of the liṅga with that which has the characteristics of the sādhya (probandum); or in other words the concomitance is not between the places containing the smoke such as kitchen, etc., and the places containing fire but between that which has the characteristic of the liṅga, viz. the smoke, and that which has the characteristic of the sādhya, viz. the fire. This view of the nature of concomitance is known as inner concomitance (antarvyāpti), whereas the former, viz. the concomitance between the thing possessing liṅga and that possessing sādhya, is known as outer concomitance (bahirvyāpti) and generally accepted by the Nyāya school of thought. This antarvyāpti doctrine of concomitance is indeed a later Buddhist doctrine.

It may not be out of place here to remark that evidences of some form of Buddhist logic probably go back at least as early as the Kathāvatthu (200 B.C.). Thus Aung on the evidence of the Yamaka points out that Buddhist logic at the time of Aśoka “was conversant with the distribution of terms” and the process of conversion.

He further points out that the logical premisses such as

• the udāharaṇa (Yo yo aggimā so so dhūmavā —whatever is fiery is smoky),
• the upanayana (ayam pabbato dhūmavā —this hill is smoky)
• and the niggama (tasmādayam aggimā —therefore that is fiery)

were also known.

(Aung further sums up the method of the arguments which are found in the Kathāvatthu as follows:

“Adherent.           Is A B? (ṭhāpana).
Opponent.            Yes.
Adherent.             Is C D ? (pāpanā).
Opponent.            No.
Adherent.             But if A be B then (you should have said) C is D.
                            That B can be affirmed of A but D of C is false.
                            Hence your first answer is refuted.”)

The antecedent of the hypothetical major premiss is termed thāpanā, because the opponent’s position, A is B, is conditionally established for the purpose of refutation.

The consequent of the hypothetical major premiss is termed pāpanā because it is got from the antecedent. And the conclusion is termed ropaṇa because the regulation is placed on the opponent.

Next:

“If D be derived of C.
Then B should have been derived of A.
But you affirmed B of A.
(therefore) That B can be affirmed of A but not of D or C is wrong.”

This is the patiloma, inverse or indirect method, as contrasted with the former or direct method, anuloma. In both methods the consequent is derived.

But if we reverse the hypothetical major in the latter method we get

If A is B C is D.
But A is B.
Therefore C is D.

By this indirect method the opponent’s second answer is reestablished^[5].”

Footnotes and references:

[1]:

As the Pramāṇasamuccaya of Diñnāga is not available in Sanskrit, we can hardly know anything of developed Buddhist logic except what can be got from the Nyāyabinduṭīkā of Dharmmottara.

[2]:

tasmāt niyamavatorevānvayavyatirekayoḥ prayogaḥ karttavyaḥ yena pratibandho gamyeta sādhanyasa sādhyena. Nyāyabinduṭīkā, p. 24.

[3]:

na hi yo yatra svabhāvena na pratibaddhah sa tarn apratibaddhaviṣayamavaśya-meva na vyabhicaratīti nāsti tayoravyabhicāraniyamah. Nyāyabinduṭīkā, p. 29.

[4]:

The inseparable connection determining inference is only possible when the liñga satisfies the three following conditions, viz. (1) paksasattva (existence of the liñga in the paksa—the thing about which something is inferred); (2) sapaksasattva (existence of the liñga in those cases where the sādhya or probandum existed), and (3) vipaksāsattva (its non-existence in all those places where the sādhya did not exist). The Buddhists admitted three propositions in a syllogism, e.g. The hill has fire, because it has smoke, like a kitchen but unlike a lake.

[5]:

See introduction to the translation of Kathāvatthu (.Points of Controversy) by Mrs Rhys Davids.