Part 4 - The Nyaya definitions of perception

The old school of the Nyaya defines perception in terms of sense-object contact (indriyartha-sannikarsa). According to it, perception is the valid knowledge produced by the contact of an object with a sense organ.' This means that perception as a form of valid knowledge is conditioned in its origin by the stimulation of the senses. This definition of perception follows from the etymological meaning of the word pratyaksa or perception. Pratyaksa derivatively means the functioning or operation of the sense organs, each in relation to its particular object (aksasyaksasya prativisayam vrttih pratyaksam). In relation to a particular object, the sense may function in two ways. It may function to bring about a contact of itself with the object. In this case, the result is a cognition of the object. Secondly, a sense organ may be operative to produce a cognition of some object. In this case the sense-function consists in sense-cognition, and the result is a judgment of the cognised object as something desirable or undesirable or neither." But even sense-cognition as a form of sense-function is conditioned by sense-object contact. It follows that the fact of sense-object contact is involved in the very meaning of the word pratyaksa, and is common to all perceptions. This common and essential character is made the basis of a definition of perception. For all the older Naiyayikas, perception is the valid cognition of an object, as distinguished from feeling and volition, and as conditioned by the contact of that object with a particular sense organ. The above definition of perception as knowledge due to 1 Nyaya-sutra, I. I. 4. 2 Nyaya-Bhasya, 1. 1. 3. 3 Ibid.

" sense-object contact is accepted by common sense and many philosophic systems. In the Vaisesika philosophy' perception is described as knowledge which is conditioned by the senses. The Sankhya-Yoga system also defines perception in terms of sense-stimulation. According to the Sankhya," perception is the direct cognition of an object by a sense when the two come in contact with each other. The Yoga system holds the same view while emphasising that perception is especially a cognition of the particularity of an object. For it, perception is a mental modification produced by sense impressions and mainly related to the specific characters entering into the nature of the individual object of perception." In the Mimamsa-sutra and the Bhatta school of Mimamsa, perception is defined as 'the cognition which is produced by the efficient contact of the senses with their objects." Varsaganya, a follower of the Mimamsa school, reduces perception just to the functioning of the sense organs." Although the old Naiyayikas are disposed to find fault with the definition of perception given in the other systems of philosophy, they do not dispute the fact of sense-object contact as constituting the essential nature of perception. Thus the Bhatta definition is attacked on the ground that it is not limited to valid perceptions but may apply also to doubt and error as forms of perception, in which there is sense-contact with some object. This means that a definition of perception as valid knowledge (prama) should explicitly mention that validity is an essentia! character of it. But the context makes it unnecessary for the Mimamsaka. Similarly, the Sankhya view is considered. by the Naiyayika to be inadequate, because it does not expressly state the fact of sense-object contact.' Such criticism, 1 Aksamaksam pratityotpadyate pratyaksam, Padarthadharina-samgraha, p. 94. 2 Vide Sankhya-sutra and Pravacanabhasya, 1. 89; Samkhyakarika, 5. 3 Vyasa-Bhasya on Yoga-sutra, 1. 7. 4 Satsamprayoge purusasyendriyanam buddhijanma tatpratyaksam, Mimamsa-sutra, I. I. 4. Vide also Sastradipika, p. 35; Slokavarttika. 4. 84. 5 'Srotradivrttiriti', Varsaganya quoted in Nyaya-varttika & Nyaya-varttika-tatparya-tika, 1. 1. 4. 6 Ibid. 7 Nyayamanjari, p. 109.

however, is vitiated by a sophistical sprit. It is true that Isvaraksna does not use just the phrase 'sense-object contact' in his definition (viz. prativisayadhyavasayo drstam). But this fcllows clearly when we collate the sutra and the commentaries on this point. It is therefore unnecessary to dwell at length on the Nyaya criticism of the above definitions of perception. It will suffice for our present purpose to say that the definition of perception as knowledge produced by sense-stimulation or sense-object contact is common to the Nyaya-Vaisesika, the Sankhya-Yoga and the Bhatta Mimamsa system of Indian philosophy. As we have already said, the same definition of perception is generally accepted in Western psychology and philosophy.' The modern school of the Nyaya takes exception to the old definition of perception in terms of sense-object contact. Gangesa, the father of modern Nyaya, opposes it on several grounds. First, it is objected by him that the definition is too wide, since it applies to inference and memory as forms of knowledge in which there is sense-object contact. The mind as an internal sense is operative and related to the object known through memory or inference. Secondly, the definition is too narrow in another sense. It precludes the possibility of God's omniscience which is a direct perception of all truth and reality. If there can be no perception without sense-object contact, we can hardly speak of the divine perception, since it is not a sensuous cognition in any sense. Further, we do not find that sense-contact, in one or other form, is common to all perceptions. Again, to define perception in terms of sensestimulation is to beg the question. What a sense-organ or its stimulation means is to be known from perception. As a matter of fact, we understand what perception is, long before we know what a sense is, and which of the senses is concerned in producing it. Hence to explain perception by sense-stimulation is to 1 Cf. Sir J. H. Parsons, An Introduction to the Theory of Perception, p. 3: "Sensory presentations, as we experience them, invariably evolve perception, however naive it may be, at the start: but there is no perception without sensory presentation."

explain the obscurum per obscurius.' In view of such defects in the old definition, the modern Naiyayikas propose to define perception as immediate knowledge. It is the character of immediacy (saksatkaritvam) that is common to all perceptions. The visual, auditory and other kinds of perception are alike connected with the feeling that something is immediately known by the subject or the knower.2 Another definition of perception, given by the modern Nyaya, is that it is knowledge which is not brought about by the instrumentality of any antecedent knowledge. This definition applies to all cases of perception, human or divine. At the same time it excludes all other kinds of knowledge, such as inference, comparison and testimony. Inference is due to the previous knowledge of a fixed relation between two things (vyaptijnana). In upamana or comparison the operative cause of knowledge (jnanakarana) is the knowledge of similarity between two things (sadrsyajnana.) Knowledge by testimony is brought about by the understanding of the meanings of words (padajnana). So also memory depends for its origin on some direct experience in the past (purvanubhava.) It is only in the case of perception that our knowledge is not caused by previous experience. It cannot be said that perception is entirely undetermined by previous experience. A determinate (savikalpaka) perception of an object, as having certain attributes and belonging to a class, is conditioned by the previous knowledge of those attributes as standing for a certain class of things. But even here our perception of the object is only conditioned but not caused by the previous knowledge (jnanajanya and not jnanakaranaka)." The present perception of the book before me does not arise out of my previous knowledge about books, although the character of that perception is determined by such antecedent knowledge. At least the perception is not the result of a conscious applicaTC., I, pp. 539-43- 2 Pratyaksasya saksatkaritvam laksanam, Tattvachintamani, ibid. ³ Jnanakaranakam jnanamiti tu vayam, Tattvachintamani, I, p. 552. • Op. cit., pp. 552-53.

tion of antecedent knowledge to a present case. The Buddhist definition of perception as knowledge which is directly produced by the object alone, excludes all the conscious and unconscious conditions of knowledge from perception except the object. The modern Nyaya, however, excludes all the conscious conditions of knowledge from the definition of perception above given. For it, perception is not entirely undetermined by previous experience. But even if it be determined by previous experience, it is not consciously brought about by that experience. Hence perception has been defined as the knowledge which is not brought about by the instrumentality of any antecedent knowledge. In the syncretist school of the Nyaya, attempts have been made to reconcile the older definition of perception with the modern. Among the ancient Naiyayikas, Udayana, Vardhamana and others have suggested that the definition of perception, as given in the Nyaya-sutra in terms of sense-object contact, applies only to ordinary human perception (laukikamatravisayatvat).' The science of logic is concerned with the conditions or grounds of valid knowledge. It is not interested in the eternal and unconditioned knowledge of the divine being. Hence the sutra gives a definition of such perception as is due to certain specific causes (pramana). In view of this it has been suggested by some syncretist logicians that for normal human perception the definition is that it is knowledge produced by sense-object contact. But when we take perception in a wider sense so as to cover ordinary and extraordinary human perceptions as well as the eternal perception of the divine being, we should define it as immediate (aparoksa) knowledge, or as knowledge which is not brought about by antecedent knowledge (jnanakaranaka)." Kesavamisra in his Tarkabhasa goes further and takes the old and modern definitions of perception to mean 1 Vide Udayana's Kusumanjali and Vardhamana's Prakasa, 4-5, 2 Aparoksapramavyaptam pratyaksam vivaksayamindriyajanya pramasadhakatamam PP. 57-59. anyatha laukikapratyaksamatrapratyaksam, Tarkikaraksa and Sarasamgraha,

the same thing. According to him, perception is the source of valid immediate knowledge and immediate knowledge is that which is brought about by sense-object contact.' Hence for knowledge there is no distinction between what is immediate and what is sensed. Rather immediate knowledge is just the product of sense-stimulation. Of the two definitions of perception given above, that proposed by the modern Nyaya seems to be more acceptable. That perception is generally conditioned by sense-stimulation or sense-object contact is true as a matter of fact. Still this fact does not constitute the essential or the universal character of all perceptions. There are cases of knowledge which are undoubtedly perceptual in character and yet not brought about by sense-object contact. Instances to the point are to be found not only in the intuition of seers and God's omniscience, but in such abnormal perceptions as illusion, hallucination, dream, delirium and the like. In these cases we have perceptions of objects that are not in actual contact with our senses. No doubt they are all cases of wrong knowledge, but that they are actual perceptions we cannot dispute. When we have such experiences or when afterwards we recollect them, we feel that we did perceive certain things which we should not have so perceived. These then are significant experiences which show that perceptual knowledge is not essentially a matter of senseobject contact. Similarly, any ordinary valid perception is found on analysis to contain elements which are not sensations in any sense. When we perceive an orange from a distance, we have a sensation of its colour but not of its smell, taste and touch. Still we perceive all these qualities as constituents of the total percept.2 Hence it may legitimately be said that 1 Saksatkaripramakaranam pratyaksam, saksatkarini ca prama saivocyate yendriyaja, Tarkabhasa, p. 5. 2 Cf. L. S. Stebbing, Logic in Practice, p. 13: "It is true that such judgments ('That is a cow,' 'Here is a pen') go beyond what is directly given to sense, but it does not follow that they are reached by inference. Certainly such judgments may be erroneous. None of these is completely trustworthy, but they are all we have." 17 (O.P. 103)

sense-stimulation is not the essence of perception. Wherein that essence lies we may also find in the light of the above instances. They serve to show that we feel sure to perceive anything that is directly presented to us. It does not matter much whether the direct presentation, which we call perception, is right or wrong, is by way of sense or not. Hence we may say that to perceive a thing is to know it immediately. The modern Nyaya hits upon a truth when it defines perception as immediate knowledge, although it recognises the fact that perception is generally conditioned by sense-object contact. The Prabhakara Mimamnsa and the Advaita Vedanta are at one with the modern Nyaya in recognising this truth about the essential nature of perception. This is also admitted by Hobhouse when he says that the common and essential character of simple ideas of sensation and reflection lies, not in their dependence on any sense organ, or any special kind of physiological stimulus, but in their immediate presence to consciousness. Hence while admitting that apprehension, in the sense of sensation or perception, is conditioned by both the sense organ and its stimulation, he defines it as the knowledge of what is immediately present to consciousness.' 1 Hobhouse, The Theory of Knowledge, Pt. I, Ch. I. Dr. Stebbing seems to endorse the definition of perception as immediate knowledge when she observes that in perceptual judgments we merely record what we take to be directly given. Vide op. cit., p. 13.