the desired connection'. Vācaspati in his refutation of this view says that the cause-effect relation cannot be determined as a separate relation. If causality means invariable immediate antecedence such that there being fire there is smoke and there being no fire there is no smoke, then it cannot be ascertained with perfect satisfaction, for there is no proof that in each case the smoke was caused by fire and not by an invisible demon. Unless it can be ascertained that there was no invisible element associated, it cannot be said that the smoke was immediately preceded by fire and fire alone. Again accepting for the sake of argument that causality can be determined, then also cause is known to precede the effect and therefore the perception of smoke can only lead us to infer the presence of fire at a preceding time and not contemporaneously with it. Moreover there are many cases where inference is possible, but there is no relation of cause and effect or of identity of essence (e.g. the sunrise of this morning by the sunrise of yesterday morning). In the case of identity of essence (tādātmya as in the case of the pine and the tree) also there cannot be any inference, for one thing has to be inferred by another, but if they are identical there cannot be any inference. The nature of concomitance therefore cannot be described in either of these ways. Some things (e.g. smoke) are naturally connected with some other things (e.g. fire) and when such is the case, though we may not know any further about the nature of this connection, we may infer the latter from the former and not vice versa, for fire is connected with smoke only under certain conditions (e.g. green wood). It may be argued that there may always be certain unknown conditions which may vitiate the validity of inference. To this Vācaspati's answer is that if even after observing a large number of cases and careful search such conditions (upādhi) cannot be discovered, we have to take it for granted that they do not exist and that there is a natural connection between the middle and the major. The later Buddhists introduced the method of Pañcakarani in order to determine effectively the causal relation. These five conditions determining the causal relation are (1) neither the cause nor the effect is perceived, (2) the cause is perceived, (3) in immediate succession the effect is perceived, (4) the cause disappears, (5) in

1 Kāryyakāraṇabhāvādvā svabhāvādva niyāmakāt avinābhāvaniyamo' darśanānna na darśanāt. Tātparyaṭīkā, p. 105.

immediate succession the effect disappears. But this method cannot guarantee the infallibility of the determination of cause and effect relation; and if by the assumption of a cause-effect relation no higher degree of certainty is available, it is better to accept a natural relation without limiting it to a cause-effect relation'.

In early Nyaya books three kinds of inference are described, namely pūrvavat, seṣavat, and samanyato-drsta. Pūrvavat is the inference of effects from causes, e.g. that of impending rain from heavy dark clouds; seṣavat is the inference of causes from effects, e.g. that of rain from the rise of water in the river; sāmānyatodrsta refers to the inference in all cases other than those of cause and effect, e.g. the inference of the sour taste of the tamarind from its form and colour. Nyāyamañjarī mentions another form of anumāna, namely pariseṣamāna (reductio ad absurdum), which consists in asserting anything (e.g. consciousness) of any other thing (e.g. ātman), because it was already definitely found out that consciousness was not produced in any other part of man. Since consciousness could not belong to anything else, it must belong to soul of necessity. In spite of these variant forms they are all however of one kind, namely that of the inference of the probandum (sādhya) by virtue of the unconditional and invariable concomitance of the hetu, called the vyāpti-niyama. In the new school of Nyaya (Navya-Nyāya) a formal distinction of three kinds of inference occupies an important place, namely anvayavyatireki, kevalānvayi, and kevalavyatireki. Anvayavyatireki is that inference where the vyāpti has been observed by a combination of a large number of instances of agreement in presence and agreement in absence, as in the case of the concomitance of smoke and fire (wherever there is smoke there is fire (anvaya), and where there is no fire, there is no smoke (vyatireka)). An inference could be for one's own self (svarthānumāna) or for the sake of convincing others (parārthānumāna). In the latter case, when it was necessary that an inference should be put explicitly in an unambiguous manner, five propositions (avayavas) were regarded as necessary, namely pratijña (e.g. the hill is fiery), hetu (since it has smoke), udāharaṇa (where there is smoke there is fire, as in the kitchen), upanaya (this hill has smoke), nigamana (therefore it has got 1 Vātsyāyaṇa's bhāṣya, Udyotakara's Vārttika and Tätparyyaṭīkā, 1. i. 5.

fire). Kevalanvayi is that type of inference, the vyāpti of which could not be based on any negative instance, as in the case "this object has a name, since it is an object of knowledge (idam, vácyam prameyatvāt)." Now no such case is known which is not an object of knowledge; we cannot therefore know of any case where there was no object of knowledge (prameyatva) and no name (vacyatva); the vyapti here has therefore to be based necessarily on cases of agreement-wherever there is prameyatva or an object of knowledge, there is vācyatva or name. The third form of kevalavyatireki is that where positive instances in agreement cannot be found, such as in the case of the inference that earth differs from other elements in possessing the specific quality of smell, since all that does not differ from other elements is not earth, such as water; here it is evident that there cannot be any positive instance of agreement and the concomitance has to be taken from negative instances. There is only one instance, which is exactly the proposition of our inference-earth differs from other elements, since it has the special qualities of earth. This inference could be of use only in those cases where we had to infer anything by reason of such special traits of it as was possessed by it and it alone.

Upamāna and Śabda.

The third pramāṇa, (which is admitted by Nyāya and not by Vaiseṣika, is upamāna, and consists in associating a thing unknown before with its name by virtue of its similarity with some other known thing. Thus a man of the city who has never seen a wild ox (gavaya) goes to the forest, asks a forester"what is gavaya?" and the forester replies—“oh, you do not know it, it is just like a cow"; after hearing this from the forester he travels on, and on seeing a gavaya and finding it to be similar to a cow he forms the opinion that this is a gavaya. This knowing an hitherto unknown thing by virtue of its similarity to a known thing is called upamana. If some forester had pointed out a gavaya to a man of the city and had told him that it was called a gavaya, then also the man would have known the animal by the name gavaya, but then this would have been due to testimony (śabda-pramāņa). The knowledge is said to be generated by the upamāna process when the association of the unknown animal with its name is made by the observer

on the strength of the experience of the similarity of the unknown animal to a known one. The naiyāyikas are thorough realists, and as such they do not regard the observation of similarity as being due to any subjective process of the mind. Similarity is indeed perceived by the visual sense but yet the association of the name in accordance with the perception of similarity and the instruction received is a separate act and is called upamana1.

Śabda-pramāṇa or testimony is the right knowledge which we derive from the utterances of infallible and absolutely truthful persons. All knowledge derived from the Vedas is valid, for the Vedas were uttered by Isvara himself. The Vedas give us right knowledge not of itself, but because they came out as the utterances of the infallible Isvara. The Vaiseṣikas did not admit sabda as a separate pramāṇa, but they sought to establish the validity of testimony (śabda) on the strength of inference (anumiti) on the ground of its being the utterance of an infallible person. But as I have said before, this explanation is hardly corroborated by the Vaiseṣika sūtras, which tacitly admit the validity of the scriptures on its own authority. But anyhow this was how Vaisesṣika was interpreted in later times.

Negation in Nyāya-Vaiśeṣika.

The problem of negation or non-existence (abhāva) is of great interest in Indian philosophy. In this section we can describe its nature only from the point of view of perceptibility. Kumārila

1 See Nyāyamañjarī on upamāna. The oldest Nyaya view was that the instruction given by the forester by virtue of which the association of the name “wild ox" to the strange animal was possible was itself "upamana." When Prasastapāda held that upamāna should be treated as a case of testimony (aptavacana), he had probably this interpretation in view. But Udyotakara and Vācaspati hold that it was not by the instruction alone of the forester that the association of the name "wild ox" was made, but there was the perception of similarity, and the memory of the instruction of the forester too. So it is the perception of similarity with the other two factors as accessories that lead us to this association called upamāna. What Vātsyāyaṇa meant is not very clear, but Dinnaga supposes that according to him the result of upamana was the knowledge of similarity or the knowledge of a thing having similarity. Vācaspati of course holds that he has correctly interpreted Vätsyāyaṇa's intention. It is however definite that upamana means the associating of a name to a new object (samākhyāsambandhapratipattirupamānärthaḥ, Vātsyāyaṇa). Jayanta points out that it is the preception of similarity which directly leads to the association of the name and hence the instruction of the forester cannot be regarded as the direct cause and consequently it cannot be classed under testimony (śabda). See Prasastapāda and Nyāyakandalī, pp. 220-22, Vātsyāyaṇa, Udyotakara, Vācaspati and Jayanta on Upamāna.

2 See Kumārila's treatment of abhäva in the Ślokavārttika, pp. 473–492.

and his followers, whose philosophy we shall deal with in the next chapter, hold that negation (abhāva) appears as an intuition (mānam) with reference to the object negated where there are no means of ordinary cognition (pramāņa) leading to prove the existence (satparicchedakam) of that thing. They held that the notion "it is not existent" cannot be due to perception, for there is no contact here with sense and object. It is true indeed that when we turn our eyes (e.g. in the case of the perception of the nonexistence of a jug) to the ground, we see both the ground and the non-existence of a jug, and when we shut them we can see neither the jug nor the ground, and therefore it could be urged that if we called the ground visually perceptible, we could say the same with regard to the non-existence of the jug. But even then since in the case of the perception of the jug there is sensecontact, which is absent in the other case, we could never say that both are grasped by perception. We see the ground and remember the jug (which is absent) and thus in the mind rises. the notion of non-existence which has no reference at all to visual perception. A man may be sitting in a place where there were no tigers, but he might not then be aware of their non-existence at the time, since he did not think of them, but when later on he is asked in the evening if there were any tigers at the place where he was sitting in the morning, he then thinks and becomes aware of the non-existence of tigers there in the morning, even without perceiving the place and without any operation of the memory of the non-existence of tigers. There is no question of there being any inference in the rise of our notion of non-existence, for it is not preceded by any notion of concomitance of any kind, and neither the ground nor the non-perception of the jug could be regarded as a reason (linga), for the non-perception of the jug is related to the jug and not to the negation of the jug, and no concomitance is known between the non-perception of the jug and its non-existence, and when the question of the concomitance of non-perception with non-existence is brought in, the same difficulty about the notion of non-existence (abhava) which was sought to be explained will recur again. Negation is therefore to be admitted as cognized by a separate and independent process of knowledge. Nyaya however says that the perception of non-existence (e.g. there is no jug here) is a unitary perception of one whole, just as any perception of positive existence (e.g.