[Footnote ref 433]
The _Nyaya sutras_ begin with an enumeration of the sixteen subjects, viz. means of right knowledge (_prama@na_), object of right knowledge (_prameya_), doubt (_sa@ms'aya_), purpose (_prayojana_), illustrative instances (_d@r@s@tanta_), accepted conclusions (_siddhanta_), premisses (_avayava_), argumentation (_tarka_), ascertainment (_nir@naya_), debates (_vada_), disputations (_jalpa_), destructive criticisms (_vita@n@da_), fallacy (_hetvabhasa_), quibble (_chala_), refutations (_jati_), points of opponent's defeat (_nigrahasthana_), and hold that by a thorough knowledge of these the highest good (_nihs'reyasa_), is attained. In the second sutra it is said that salvation (_apavarga_) is attained by the successive disappearance of false knowledge (_mithyajnana_), defects (_do@sa_), endeavours (_prav@rtti_, birth (_janma_), and ultimately of sorrow. Then the means of proof are said to be of four kinds, perception (_pratyak@sa_), inference (_anumana_), analogy (_upamana_), and testimony (_s'abda_). Perception is defined as uncontradicted determinate knowledge unassociated with names proceeding out of sense contact with objects. Inference is of three kinds, from cause to effect (_purvavat_), effect to cause (_s'e@savat_), and inference from common characteristics (_samanyato d@r@s@ta_). Upamana is the knowing of anything by similarity with any well-known thing.
S'abda is defined as the testimony of reliable authority (apta) [Footnote ref 434]. Such a testimony may tell us about things which may be experienced and which are beyond experience. Objects of knowledge are said to be self (_atman_), body, senses, sense-objects, understanding (_buddhi_), mind (_manas_}, endeavour (prav@rtti), rebirths, enjoyment of pleasure and suffering of pain, sorrow and salvation. Desire, antipathy, effort (_prayatna_), pleasure, pain, and knowledge indicate the existence of the self. Body is that which upholds movement, the senses and the rise of pleasure and pain as arising out of the contact of sense with sense-objects [Footnote ref 435]; the five senses are derived from the five elements, such as prthivi, ap, tejas, vayu and akas'a; smell, taste, colour, touch, and sound are the qualities of the above five elements, and these are also the objects of the senses. The fact that many cognitions cannot occur at any one moment indicates the existence of mind (_manas_). Endeavour means what is done by speech, understanding, and body. Do@sas (attachment, antipathy, etc) are those which lead men to virtue and vice. Pain is that which causes suffering [Footnote ref 436]. Ultimate cessation from pain is called _apavarga_ [Footnote ref 437]. Doubt arises when through confusion of similar qualities or conflicting opinions etc., one wants to settle one of the two alternatives. That for attaining which, or for giving up which one sets himself to work is called _prayojana_.
Illustrative example (_d@r@s@tanta_) is that on which both the common man and the expert (_parik@saka_) hold the same opinion. Established texts or conclusions (_siddhanta_) are of four kinds, viz
(1) those which are accepted by all schools of thought called the _sarvatantrasiddhanta_;
(2) those which are held by one school or similar schools but opposed by others called the _pratitantrasiddhanta_;
(3) those which being accepted other conclusions will also naturally follow called _adhikara@nasiddhanta_;
(4) those of the opponent's views which are uncritically granted by a debater, who proceeds then to refute the consequences that follow and thereby show his own special skill and bring the opponent's intellect to disrepute (_abhyupagamasiddhanta_) [Footnote ref 438]. The premisses are five:
(1) _pratijna_ (the first enunciation of the thing to be proved);
(2) _hetu_ (the reason which establishes the conclusion on the strength of the similarity of the case in hand with known examples or negative instances);
(3) _udahara@na_ (positive or negative illustrative instances);
(4) _upanaya_ (corroboration by the instance);
(5) _nigamana_ (to reach the conclusion which has been proved). Then come the definitions of tarka, nir@naya, vada, jalpa, vita@n@da, the fallacies (hetvabhasa), chala, jati, and nigrahasthana, which have been enumerated in the first sutra.
The second book deals with the refutations of objections against the means of right knowledge (pramana). In refutation of certain objections against the possibility of the happening of doubt, which held that doubt could not happen, since there was always a difference between the two things regarding which doubt arose, it is held that doubt arises when the special differentiating characteristics between the two things are not noted. Certain objectors, probably the Buddhists, are supposed to object to the validity of the prama@na in general and particularly of perceptions on the ground that if they were generated before the sense-object contact, they could not be due to the latter, and if they are produced after the sense-object contact, they could not establish the nature of the objects, and if the two happened together then there would be no notion of succession in our cognitions. To this the Nyaya reply is that if there were no means of right knowledge, then there would be no means of knowledge by means of which the objector would refute all means of right knowledge; if the objector presumes to have any means of valid knowledge then he cannot say that there are no means of valid knowledge at all. Just as from the diverse kinds of sounds of different musical instruments, one can infer the previous existence of those different kinds of musical instruments, so from our knowledge of objects we can infer the previous existence of those objects of knowledge [Footnote ref 439].
The same things (e.g. the senses, etc.) which are regarded as instruments of right knowledge with reference to the right cognition of other things may themselves be the objects of rightknowledge. There are no hard and fast limits that those which are instruments of knowledge should always be treated as mere instruments, for they themselves may be objects of right knowledge. The means of right knowledge (prama@na) do not require other sets of means for revealing them, for they like the light of a lamp in revealing the objects of right knowledge reveal themselves as well.
Coming to the question of the correctness of the definition of perception, it is held that the definition includes the contact of the soul with the mind [Footnote ref 440]. Then it is said that though we perceive only parts of things, yet since there is a whole, the perception of the part will naturally refer to the whole. Since we can pull and draw things wholes exist, and the whole is not merely the parts collected together, for were it so one could say that we perceived the ultimate parts or the atoms [Footnote ref 441]. Some objectors hold that since there may be a plurality of causes it is wrong to infer particular causes from particular effects. To this the Nyaya answer is that there is always such a difference in the specific nature of each effect that if properly observed each particular effect will lead us to a correct inference of its own particular cause [Footnote ref 442]. In refuting those who object to the existence of time on the ground of relativity, it is said that if the present time did not exist, then no perception of it would have been possible. The past and future also exist, for otherwise we should not have perceived things as being done in the past or as going to be done in the future. The validity of analogy (upamana) as a means of knowledge and the validity of the Vedas is then proved. The four prama@nas of perception, inference, analogy, and scripture are quite sufficient and it is needless to accept arthapatti (implication), aitihya (tradition), sambhava (when a thing is understood in terms of higher measure the lower measure contained in it is also understood--if we know that there is a bushel of corn anywhere we understand that the same contains eight gallons of corn as well) and abhava (non-existence) as separate prama@nas for the tradition is included in verbal testimony and arthapatti, sambhava and abhava are included within inference.
The validity of these as prama@nas is recognized, but they are said to be included in the four prama@nas mentioned before. The theory of the eternity of sound is then refuted and the non-eternity proved in great detail. The meaning of words is said to refer to class-notions (_jati_), individuals (_vyakti_), and the specific position of the limbs (_ak@rti_), by which the class notion is manifested. Class (_jati_} is defined as that which produces the notion of sameness (_samanaprasavatmika jati@h_).
The third book begins with the proofs for the existence of the self or atman. It is said that each of the senses is associated with its own specific object, but there must exist some other entity in us which gathered together the different sense-cognitions and produced the perception of the total object as distinguished from the separate sense-perceptions. If there were no self then there would be no sin in injuring the bodies of men: again if there were no permanent self, no one would be able to recognize things as having seen them before; the two images produced by the eyes in visual perception could not also have been united together as one visual perception of the things [Footnote ref 443]; moreover if there were no permanent cognizer then by the sight of a sour fruit one could not be reminded of its sour taste. If consciousness belonged to the senses only, then there would be no recognition, for the experience of one could not be recognized by another. If it is said that the unity of sensations could as well be effected by manas (mind), then the manas would serve the same purpose as self and it would only be a quarrel over a name, for this entity the knower would require some instrument by which it would co-ordinate the sensations and cognize; unless manas is admitted as a separate instrument of the soul, then though the sense perceptions could be explained as being the work of thesenses, yet imagining, thinking, etc., could not be explained. Another argument for the admission of soul is this, that infants show signs of pleasure and pain in quite early stages of infancy and this could not be due to anything but similar experiences in previous lives. Moreover every creature is born with some desires, and no one is seen to be born without desires. All attachments and desires are due to previous experiences, and therefore it is argued that desires in infants are due to their experience in previous existences.
The body is made up of the k@siti element. The visual sense is material and so also are all other senses [Footnote ref 444]. Incidentally the view held by some that the skin is the only organ of sensation is also refuted. The earth possesses four qualities, water three, fire two, air one, and ether one, but the sense of smell, taste, eye, and touch which are made respectively by the four elements of earth, etc., can only grasp the distinctive features of the elements of which they are made. Thus though the organ of smell is made by earth which contains four qualities, it can only grasp the distinctive quality of earth, viz. smell.
Against the Sa@mkhya distinction of _buddhi_ (cognition) and _cit_ (pure intelligence) it is said that there is no difference between the _buddhi_ and _cit_. We do not find in our consciousness two elements of a phenomenal and a non-phenomenal consciousness, but only one, by whichever name it may be called. The Sa@mkhya epistemology that the anta@hkara@na assumes diverse forms in cognitive acts is also denied, and these are explained on the supposition of contacts of manas with the senses, atman and external objects. The Buddhist objection against the Sa@mkhya explanation that the anta@hkara@nas catch reflection from the external world just as a crystal does from the coloured objects that may lie near it, that there were really momentary productions of crystals and no permanent crystal catching different reflections at different times is refuted by Nyaya; for it says that it cannot be said that all creations are momentary, but it can only be agreed to in those cases where momentariness was actually experienced. In the case of the transformation of milk into curd there is no coming in of new qualities and disappearance of old ones, butthe old milk is destroyed and the curd originates anew. The contact of manas with soul (_atman_) takes place within the body and not in that part of atman which is outside the body; knowledge belongs to the self and not to the senses or the object for even when they are destroyed knowledge remains. New cognitions destroy the old ones. No two recollections can be simultaneous. Desire and antipathy also belong to the soul. None of these can belong either to the body or to the mind (manas). Manas cannot be conscious for it is dependent upon self. Again if it was conscious then the actions done by it would have to be borne by the self and one cannot reap the fruits of the actions of another. The causes of recollection on the part of self are given as follows: (1) attention, (2) context, (3) repetition, (4) sign,
(5) association, (6) likeness, (7) association of the possessor and the possessed or master and servant, or things which are generally seen to follow each other, (8) separation (as of husband and wife), (9) simpler employment, (10) opposition,
(11) excess, (12) that from which anything can be got, (13) cover and covered, (14) pleasure and pain causing memory of that which caused them, (15) fear, (16) entreaty, (17) action such as that of the chariot reminding the charioteer, (18) affection,
(19) merit and demerit [Footnote ref 445]. It is said that knowledge does not belong to body, and then the question of the production of the body as due to ad@r@s@ta is described. Salvation (_apavarga_) is effected by the manas being permanently separated from the soul (atman) through the destruction of karma.
In the fourth book in course of the examination of do@sa (defects), it is said that moha (ignorance), is at the root of all other defects such as raga (attachment) and dve@sa (antipathy). As against the Buddhist view that a thing could be produced by destruction, it is said that destruction is only a stage in the process of origination. Is'vara is regarded as the cause of the production of effects of deeds performed by men's efforts, for man is not always found to attain success according to his efforts. A reference is made to the doctrine of those who say that all things have come into being by no-cause (_animitta_), for then no-cause would be the cause, which is impossible.
The doctrine of some that all things are eternal is next refuted on the ground that we always see things produced and destroyed.
The doctrine of the nihilistic Buddhists (s'unyavadin Bauddhas) that all things are what they are by virtue of their relations to other things, and that of other Buddhists who hold that there are merely the qualities and parts but no substances or wholes, are then refuted. The fruits of karmas are regarded as being like the fruits of trees which take some time before they can ripen. Even though there may be pleasures here and there, birth means sorrow for men, for even the man who enjoys pleasure is tormented by many sorrows, and sometimes one mistakes pains for pleasures. As there is no sorrow in the man who is in deep dreamless sleep, so there is no affliction (_kles'a_) in the man who attains apavarga (salvation) [Footnote ref 446]. When once this state is attained all efforts (_prav@rtti_) cease for ever, for though efforts were beginningless with us they were all due to attachment, antipathy, etc. Then there are short discussions regarding the way in which egoism (_aha@mkara_) ceases with the knowledge of the true causes of defects (_do@sa_); about the nature of whole and parts and about the nature of atoms (_a@nus_) which cannot further be divided. A discussion is then introduced against the doctrine of the Vijnanavadins that nothing can be regarded as having any reality when separated from thoughts. Incidentally Yoga is mentioned as leading to right knowledge.
The whole of the fifth book which seems to be a later addition is devoted to the enumeration of different kinds of refutations (_nigrahasthana_) and futilities (_jati_).