The old school

Although as early as the commentators Prashastapada (5th century ce) and Uddyotakara (7th century ce) the authors of the Nyaya-Vaisheshika schools used each other’s doctrines and the fusion of the two schools was well on its way, the two schools continued to have different authors and lines of commentators. About the 10th century ce, however, there arose a number of texts that sought to combine the two philosophies more successfully. Well known among these syncretist texts are the following: Bhasarvajna’s Nyayasara (written c. 950; “The Essence of Nyaya”), Varadaraja’s Tarkikaraksha ( c. 1150; “In Defense of the Logician”), Vallabha’s Nyayalilavati (12th century; “The Charm of Nyaya”), Keshava Mishra’s Tarkabhasha ( c. 1275; “The Language of Reasoning”), Annam Bhatta’s Tarkasamgraha (c. 1623; “Compendium of Logic”), and Vishvanatha’s Bhashapariccheda (1634; “Determination of the Meaning of the Verses”).

Both the Nyaya-Vaisheshika schools are realistic with regard to things, properties, relations, and universals. Both schools are pluralistic (also with regard to individual selves) and theistic. Both schools admit external relations (the relation of inherence being only partly internal), atomistic cosmology, new production, and the concept of existence (satta) as the most comprehensive universal. Both schools regard knowledge as a quality of the self, and they subscribe to a correspondence theory regarding the nature of truth and a theory of pragmatism-cum-coherence regarding the test of truth. The points that divide the schools are rather unimportant: they concern, for example, their theories of number, and some doctrines in their physical and chemical theories.

Gautama’s sutras were commented upon about 400 ce by Vatsayana, who replied to the Buddhist doctrines, especially to some varieties of Shunyavada skepticism. Uddyotakara’s Varttika ( c. 635) was written after a period during which major Buddhist works, but no major Hindu work, on logic were written. Uddyotakara undertook to refute Nagarjuna and Dignaga. He criticized and refuted Dignaga’s theory of perception, the Buddhist denial of soul, and the anyapoha (exclusion of the other) theory of meaning. Positively, he introduced, for the first time, the doctrine of six modes of contact (samnikarsa) of the senses with their objects, which has remained a part of Nyaya-Vaisheshika epistemology. He divided inferences into those whose major premise (sadhya) is universally present, those in which one has to depend only upon the rule “Wherever there is absence of the major, there is absence of the middle (hetu),” and those in which both the positive and the negative rules are at one’s disposal. He rejected the sphota theory and argued that the meaning of a word is apprehended by hearing the last letter of the word together with recollection of the preceding ones. Vachaspati Mishra in the 9th century wrote his Tatparyatika (c. 840) on Uddyotakara’s Varttika and further strengthened the Nyaya viewpoint against the Buddhists. He divided perception into two kinds: the indeterminate, nonlinguistic, and nonjudgmental and the determinate and judgmental. In defining the invariable connection (vyapti) between the middle and the major premises, he introduced the concept of a vitiating condition (upadhi) and stressed that the required sort of connection, if an inference is to be valid, should be unconditional. He also proposed a modified version of the theory of the extrinsic validity of knowledge by holding that inferences as well as knowledges that are the last verifiers (phalajnana) are self-validating.

Prashastapada’s Vaisheshika commentary (c. 5th century) does not closely follow the sutras but is rather an independent explanation. Prashastapada added seven more qualities to Kanada’s list: heaviness (gurutva), fluidity (dravatva), viscidity (sneha), traces (samskara), virtue (dharma), vice (adharma), and sound. The last quality was regarded by Kanada merely as a mark of ether, whereas Prashastapada elevated it to a defining quality of the latter. He also made the Vaisheshika fully theistic by introducing doctrines of creation and dissolution.

The Nyaya-Vaisheshika general metaphysical standpoint allows for both particulars and universals, both change and permanence. There are ultimate differences as well as a hierarchy of universals, the highest universal being existence. Substance is defined as the substrate of qualities and in terms of what alone can be an inherent cause. A quality may be defined as what is neither substance nor action and yet is the substratum of universals (for universals are supposed to inhere only in substances, qualities, and actions). Universal is defined as that which is eternal and inheres in many. Ultimate particularities belong to eternal substances, such as atoms and souls, and these account for all differences among particulars that cannot be accounted for otherwise. Inherence (samavaya) is the relation that is maintained between a universal and its instances, a substance and its qualities or actions, a whole and its parts, and an eternal substance and its particularity. This relation is such that one of the relations cannot exist without the other (e.g., a whole cannot exist without the parts). Negation (abhava), the seventh category, is initially classified into difference (“A is not B”) and absence (“A is not in B”), absence being further divided into absence of a thing before its origin, its absence after its destruction, and its absence in places other than where it is present. For these schools, all that is is knowable and also nameable.

Knowledge is regarded as a distinguishing but not essential property of a self. It arises when the appropriate conditions are present. Consciousness is defined as a manifestation of object but is not itself self-manifesting; it is known by an act of inner perception (anuvyavasaya). Knowledge either is memory or is not; knowledge other than memory is either true or false; and knowledge that is not true is either doubt or error. In its theory of error, these philosophers maintained an uncompromising realism by holding that the object of error is still real but is only not here and now. True knowledge (prama) apprehends its object as it is; false knowledge apprehends the object as what it is not. True knowledge is either perception, inference, or knowledge derived from verbal testimony or comparison. Perception is defined as knowledge that arises from the contact of the senses with their objects, and it is viewed as either indeterminate and nonlinguistic or as determinate and judgmental. Both aspects of the definition of perception are viewed as valid—a point that is made against both the Buddhists and the grammarians. Furthermore, perception is either ordinary (laukika) or extraordinary (alaukika). The former takes place through any of the six modes of sense-object contact recognized in the system. The latter takes place when one perceives the proper object of one sense through another sense (“The cushion looks soft”) or when, on recognizing universal in a particular, one perceives all instances of the universal as its instances. Also extraordinary are the perceptions of the yogins, who are supposed to be free from the ordinary spatiotemporal limitations.

Four conditions must be satisfied in order that a combination of words may form a meaningful sentence: a word should generate an intention or expectancy for the words to follow (“Bring”—“What?”—“A jar”); there should be mutual fitness (“Sprinkle”—“With what?”—“Water, not fire”); there should be proximity in space and time; and the proper intention of the speaker must be ascertained, otherwise there would be equivocation.

Among theistic proofs offered in the system, the most important are the causal argument (“The world is produced by an agent, since it is an effect, as is a jar”); the argument from a world order to a lawgiver; and the moral argument from the law of karma to a moral governor. Besides adducing these and other arguments, Udayana in his Nyaya-kusumanjali stressed the point that the nonexistence of God could not be proved by means of valid knowledge.

The new school

The founder of the school of Navya-Nyaya (“New Nyaya”), with an exclusive emphasis on the pramanas, was Gangesha Upadhyaya (13th century), whose Tattvachintamani (“The Jewel of Thought on the Nature of Things”) is the basic text for all later developments. The logicians of this school were primarily interested in defining their terms and concepts and for this purpose developed an elaborate technical vocabulary and logical apparatus that came to be used by, other than philosophers, writers on law, poetics, aesthetics, and ritualistic liturgy. The school may broadly be divided into two subschools: the Mithila school, represented by Vardhamana (Gangesha’s son), Pakshadhara or Jayadeva (author of the Aloka gloss), and Shankara Mishra (author of Upaskara); and the Navadvipa school, whose chief representatives were Vasudeva Sarvabhauma (1450–1525), Raghunatha Shiromani (c. 1475–c. 1550), Mathuranatha Tarkavagisha (flourished c.1570), Jagadisha Tarkalankara (flourished c. 1625), and Gadadhara Bhattacharya (flourished c. 1650).

By means of a new technique of analyzing knowledge, judgmental knowledge can be analyzed into three kinds of epistemological entities in their interrelations: “qualifiers” (prakara); “qualificandum,” or that which must be qualified (visheshya); and “relatedness” (samsarga). There also are corresponding abstract entities: qualifierness, qualificandumness, and relatedness. The knowledge expressed by the judgment “This is a blue pot” may then be analyzed into the following form: “The knowledge that has a qualificandumness in what is denoted by ‘this’ is conditioned by a qualifierness in blue and also conditioned by another qualifierness in potness.”

A central concept in the Navya-Nyaya logical apparatus is that of “limiterness” (avacchedakata), which has many different uses. If a mountain possesses fire in one region and not in another, it can be said, in the Navya-Nyaya language, “The mountain, as limited by the region r, possesses fire, but as limited by the region r′ possesses the absence of fire.” The same mode of speech may be extended to limitations of time, property, and relation, particularly when one is in need of constructing a description that is intended to suit exactly some specific situation and none other.

Inference is defined by Vatsayana as the “posterior” knowledge of an object (e.g., fire) with the help of knowledge of its mark (e.g., smoke). For Navya-Nyaya, inference is definable as the knowledge caused by the knowledge that the minor term (paksha, “the hill”) “possesses” the middle term (hetu, “smoke”), which is recognized as “pervaded by” the major (sadhya, “fire”). The relation of invariable connection, or “pervasion,” between the middle (smoke) and the major (fire)—“Wherever there is smoke, there is fire”—is called vyapti.

The logicians developed the notion of negation to a great degree of sophistication. Apart from the efforts to specify a negation with references to its limiting counterpositive (pratiyogi), limiting relation, and limiting locus, they were constrained to discuss and debate such typical issues as the following: Is one to recognize, as a significant negation, the absence of a thing x so that the limiter of the counterpositive x is not x-ness but y-ness? In other words, can one say that a jar is absent as a cloth even in a locus in which it is present as a jar? Also, is the absence of an absence itself a new absence or something positive? Furthermore, is the absence of color in general nothing but the sum total of the absences of the particular colors, or is it a new kind of absence, a generic absence? Gangesha argued for the latter alternative, though he answers the first of the above three questions in the negative.

Though the philosophers of this school did not directly write on metaphysics, they nevertheless did tend to introduce many new kinds of abstract entities into their discourse. These entities are generally epistemological, though sometimes they are relational. Chief of these are entities called “qualifierness,” “qualificandumness,” and “limiterness.” Various relations were introduced, such as direct and indirect temporal relations, paryapti relation (in which a number of entities reside, in sets rather than in individual members of those sets), svarupa relation (which holds, for example, between an absence and its locus), and relation between a knowledge and its object.

Among the Navya-Nyaya philosophers, Raghunatha Shiromani in Padarthatattvanirupana undertook a bold revision of the traditional categorical scheme by (1) identifying “time,” “space,” and “ether” with God, (2) eliminating the category of mind by reducing it to matter, (3) denying atoms (paramanu) and dyadic (paired) combinations of them (dvyanuka), (4) eliminating “number,” “separateness,” “remoteness,” and “proximity” from the list of qualities, and (5) rejecting ultimate particularities (vishesha) on the grounds that it is more rational to suppose that the eternal substances are by nature distinct. He added some new categories, however, such as causal power (shakti) and the moment (kshana), and recognized that there are as many instances of the relation of inherence as there are cases of it (as contrasted with the older view that there is only one inherence that is itself present in all cases of inherence).