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Encyclopedia of India–China Cultural Contacts v1.c7.s7.t2: Hetuvidya

Encyclopedia of India–China Cultural Contacts v1.c7.s7.t2

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Hetuvidya

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Hetuvidya is a logic-centered theory of knowledge in ancient Indian philosophies of religion. Originally, it was formed out of some Indian philosophies of religions other than Buddhism, and later on, it was assimilated and transformed by Buddhism and became an important component of Buddhist thinking. Buddhist Hetuvidya, at a height of development, is a main representative of Indian logics and occupies an important position in the history of the development of ancient oriental philosophy.

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Birth of Hetuvidya

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The term “Hetuvidya” can be divided into “hetu”, which means knowledge or wisdom and combined, "vidya" refers to knowledge or wisdom acquired through inferred cause or basis. Therefore, Hetuvidya is a kind of logical reasoning that obtains knowledge by proving an argument on certain basis and studying principal components of the argumentation. Overall, Hetuvidya is a kind of logic, though it includes considerable contents of argumentation and general epistemology. Since Buddhism has quite consummate discussions on Hetuvidya, many people would like to refer Hetuvidya as Buddhist logic.

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Though not the earliest founder, Buddhism has the highest achievements in respect of ancient Indian Hetuvidya. It was originally derived from thoughts or schools of some Indian philosophies or religions rather than from Buddhism.

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[Figure: Hetuvidya: New Explorations; papers on Hetuvidya by Chinese scholars (front cover)]

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Its earliest form is associated with ancient Brahmin argumentation about sacrifice. Brahmanism has a very ancient origin in India, and at its early stage in particular, believed that “sacrifice is omnipotent”. Its sacrifice had various forms and very complicated procedures. In ancient India, religious doctrines and sacrificial procedures were passed on mainly through oral means and with time going, followers might remember and say differently and debate thus would occur. Objectively, this might make people strive to find out a fixed form of inference and corresponding logic rules. Ancient Hetuvidya is the earliest of such reference and logic rules.

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Its earliest form is also related to clashes among different thoughts or schools of thought that arose before or at the same time with Buddhism. These thoughts are numerous and quite complicated, and clashes between them gave rise to wide argumentation, creating a cultural and mental environment suitable for the formation of Indian Hetuvidya.

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The Nyaya School, as one of the six schools of Brahmin philosophy, was the first to satisfy such a demand and to make an important contribution to the establishment of Indian logic or Hetuvidya. The Nyaya Sutra, the earliest classic text for this school, was composed around 1ˢᵗ century CE by Gautama (or Gotama), and existing text, with later interpolations, was formed in about 3ʳᵈ to 4ᵗʰ centuries CE.

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[Figure: Lectures on Hetuvidya (*Nyāya praveśatāka śāstra* *Lectures*), Japan]

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Before or when the *Nyaya Sutra* was composed in India there were already certain scattered logic theories or concepts. For example, Bhadrabahu (about 433 to 375 BCE), a Jaina philosopher put forth some concepts or categories about the process of inference, involving the proposition, cause, example, conclusion and the like, but these concepts or categories all have a lesser influence than the *Nyaya Sutra* and a considerable part of them are only mentioned in some ancient documents, and their specific contents are not very clear. In contrast, the *Nyaya Sutra* is the first book in ancient India that proposed systematic logic theories and played an important role in the formation of Indian Hetuvidya.

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From the Nyaya Sutra and its commentaries, it can be seen that the logic proposed by ancient Nyaya mainly lies with “pramana”, which refers to means of right knowledge and usually was discussed by an ancient Indian philosophy. According to *Nyaya Sutras*, there are four means of attaining right knowledge: perception, inference, comparison and verbal testimony. The Nyaya's logic is mainly related to inference and its relevant theories can be divided into two parts. One is inferential theories about obtaining right knowledge and the other is analyses for the causation of fallacies or failure in the course of inference.

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*Abhidharmasamuccaya*, translated by Xuanzang

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The Nyaya thinks that a right form of inference or argument consists of five parts: proposition (*pratijna*), cause (*hetu*), illustration (*udaharana*), application (*upanaya*) and conclusion (*nigamana*). This is usually called as “Five-Part Syllogism”. According to the *Nyāya Sutra Bhāshya* by Vatsyayana (about 4ᵗʰ century CE), an application of this five-part syllogism can be as follows: Proposition: Sound is non-eternal. Cause: Because it is created. Illustration (positive): Whatever is created is non-eternal, as is a plate or dish. Application: So is sound, it is created. Conclusion: Therefore sound is non-eternal. Above is an example of positive illustration (*sadharma*) and below is an example of negative illustration (*vidharma*): Proposition: Sound is non-eternal. Cause: Because it is created. Illustration (negative): Whatever is not created is eternal, as is Atman. Application: Sound is not so and it is created. Conclusion: Therefore sound is non-eternal.

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In addition to five-part syllogism, the Nyaya also offers a detailed analysis of the causation of inference errors and argument failures, and expounds five logical errors, three quibbles, 24 futilities and 22 occasions for rebuke.

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There are five kinds of fallacy that may lead to failed inference, including the inconclusive, the contradictory, the controversial, the counter-questioned and the mistimed (for details please refer to *Nyaya Sutra* 1, 2, 4-9).

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Quibble is the opposition offered to a proposition by the assumption of an alternative meaning, including quibble in respect of a term, quibble in respect of a genus and quibble in respect of a metaphor (for details please refer to *Nyaya Sutra* 1, 2, 10-17).

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Futility consists in offering objections founded on mere similarity or dissimilarity. There are 24 kinds of futility as follows: (1) balancing the homogeneity, (2) balancing the heterogeneity, (3) balancing an addition, (4) balancing a subtraction, (5) balancing the questionable, (6) balancing the unquestionable, (7) balancing the alternative, (8) balancing the reciprocity, (9) balancing the co-presence, (10) balancing the mutual absence, (11) balancing the infinite regression, (12) balancing the counter-example, (13) balancing the non-produced, (14) balancing the doubt, (15) balancing the controversy, (16) balancing the non-reason, (17) balancing the presumption, (18) balancing the non-difference, (19) balancing the demonstration, (20) balancing the perception, (21) balancing the non-perception, (22) balancing the non-eternality, (23) balancing the eternality, and (24) balancing the effect (for details please refer to the *Nyaya Sutra* 5, 1, 1-43).

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The following are 22 occasions for rebuke, for which an argument or inference fails due to breaking rules: (1) hurting the proposition, (2) shifting the proposition, (3) opposing the proposition, (4) renouncing the proposition, (5) shifting the reason, (6) shifting the topic, (7) the meaningless,

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*Mahayanabhidharma-samuccaya-vyakhya, Fangshan Stone Classics*

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(8) the unintelligible, (9) the incoherent, (10) the inopportune, (11) saying too little, (12) saying too much, (13) repetition, (14) silence, (15) ignorance, (16) non-ingenuity, (17) evasion, (18) admission of an opinion, (19) overlooking the censurable, (20) censuring the non-censurable, (21) deviating from a tenet, and (22) the semblance of a reason (for details please refer to the *Nyaya Sutra* 5, 2, 1-25).

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The Nyaya laid a basis for the establishment of Indian Hetuvidya and put forth the basic form, theoretical framework or discussion. Later on, most issues discussed by quite developed Indian Hetuvidya that focussed on Buddhist logic were from the *Nyaya Sutra*. The difference is that Buddhism significantly pushed forward Indian logic and Buddhist Hetuvidya has more in-depth and scientific study in respect of inference and categorization of logic errors.

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Old Hetuvidya in Buddhism

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Logic theory proposed by Nyaya is quite systematic and had an important influence on the history of Indian philosophy and attracted many ancient Indian philosophers to pay attention to the problem of logic. Some were prominent Buddhist thinkers. In the course of the evolution of Buddhist Hetuvidya, Theravada and early Mahayana had less discussion on logic, while Yogacara (a school of Mahayana) paid more attention to this respect. Buddhist *Hetuvidya* texts were mostly composed by Yogacara thinkers, and of them, Dignaga (about 5ᵗʰ to 6ᵗʰ centuries CE) had prominent achievements in respect of Hetuvidya, and is often used to divide the history of Hetuvidya development and before him is “old Hetuvidya” and after him is “new Hetuvidya” and Dignaga is a leading character for new Hetuvidya.

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Basically, old Buddist Hetuvidya absorbed the logic from Nyaya and other schools and did not have many innovations. *Hetuvidya* in the works written by famous Buddhist commentators such as Hagarjuna, Maitreya, Asanga and Vasubandhu, is basically “old Hetuvidya”.

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A considerable number of Buddhist texts include contents of old Hetuvidya, including among others, *Upaya-Kausalya-hṛdaya śastra, Yogacarabhumi-sastra* (volume XV), *Prakaranaryavaca-sastra* (volume XI), *Mahayanabhidhar-ma-samuccaya-vyakhya* (volume XVI), and *Tarka sastra*.

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The *Upaya-Kausalya-hṛdaya śastra* discussed a number of Hetuvidya questions, for example, discussion about “four means of knowledge” (perception, comparison, example, sutra), and discussion about improper “cause” or “example” that might lead to contradictory or failed inference, and many of such contents were similar to the Nyaya.

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The *Yogacarabhumi-sastra* also mentioned Hetuvidya, with most such discussions in the

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‘*Index to the Yogacharabhumisastra: Chinese- Sanskrit- Tibetan*’, (front cover)

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volume XV, suggesting that “valid knowledge can be obtained through the following eight means: (1) proposition, (2) cause, (3) example, (4) similarity, (5) dissimilarity, (6) perception, (7) inference, and (8) valid cognition. Here, the first five correspond to Hetuvidya, and the latter three are main categories of “pramana”. Volume XV explains each of them in details.

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“Proposition” corresponds to that of Hetuvidya’s five-part syllogism and is mainly intended to establish a proposition or a basic idea. According to the *Yogacarabhumi-sastra*, “a proposition is either *for asserting one’s own idea or refuting, defeating or agreeing with an idea of others*”.

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According to *Yogacarabhumi-sastra*, “cause”, similar with that of the Nyaya, “is to explain the proposition on the basis of similarity, dissimilarity, perception and inference and to obtain valid knowledge”.

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"Example" equivalent to the "illustration" of Hetuvidya, as explained in the *Yogacarabhumi-* *sastra*, “is also to explain the proposition, by using examples to make for easy understanding”.

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“Similarity” refers to similar points between things. According to the *Yogacarabhumi-sastra*, “It is to use similar means to prove the proposition. There are five kinds of similarity ie similar in state, similar in bhava-svabhava, similar in application, similar in means and similar in cause and effect”. This is relevant to “positive illustration” (sadharma) of the Nyaya’s five-part syllogism.

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“Dissimilarity” means no similar point between things. According to *Yogacarabhumi-sastra*, “It is

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‘Great Commentary on the Nyayapravesa’

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to use dissimilar means to prove the proposition. The same with above categories, there are five kinds of dissimilarity”. This is relevant to “negative illustration” (*vidharma*) of the Nyaya’s five-part syllogism.

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“Perception” is knowledge obtained through senses, and Indian philosophies all recognise this “pramana”. According to the *Yogacarabhumi-sastra*, “perception has three kinds, the one is not invisible, the second is not having thought or being obliged to think, and the third is not deranged”, and the *Nyaya Sutra* also mentions “perception”, but with a description somewhat different from that of the *Yogacarabhumi-sastra*.

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“Inference” actually is a major component of Hetuvidya, and the *Yogacarabhumi-sastra* divides it into a number of categories, “inference means thinking and identifying all possibilities that have been thought or should be thought, and has five types: inference from appearance, inference from the corporeal, inference from action, inference from recognised law, and inference from cause and effect.” The *Nyaya Sutra* also mentions “inference”, but with a description very different from that of the *Yogacarabhumi-sastra*.

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“Valid cognition” is to obtain knowledge through teachings or theories of the wise or holy man, and according to the *Yogacarabhumi-sastra*, “valid cognition refers to teachings of the omniscient or what he hears or follows, and it also has three categories, the one is no violation of holy scriptures, the second is no defilement, and the third is no breaking of recognised law.” The *Nyaya Sutra* also mentions “valid cognition”, but with a description not identical with that of *Yogacarabhumi-sastra*.

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The *Prakaranaryavaca-sastra*, in the Volume 11, basically has the same discussion with the Volume 15 of *Yogacarabhumi-sastra*.

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The *Mahayanabhidhar-ma-samuccaya-vyakhy* has a detailed discussion of Hetuvidya in the Volume 16, suggesting “there are eight types, that is, proposition, cause, illustration, application, conclusion, perception, inference, and valid cognition”, but these eight are different from those mentioned in the Yogacarabhumi-sastra, since “application” and “conclusion” replace “similarity” and “dissimilarity” in the *Yogacarabhumi-sastra*.

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As for “application”, the *Mahayanabhidhar-ma-samuccaya-vyakhy* explains it “as extending the proposed maxim to remaining cases and making the proposition applicable and correct under other circumstances”.

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The *Mahayanabhidhar-ma-samuccaya-vyakhy* explains “conclusion” as “consummate, complete and having a final result in respect of the proposition”.

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As for the other six types, the *Mahayanabhidhar-ma-samuccaya-vyakhya* basically is not different from the *Yogacarabhumi-sastra*, and some names are different, but contents are the same.

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In the *Mahayanabhidhar-ma-samuccaya-vyakhy*, the first five types are a kind of syllogism, and below is an illustration: Proposition: Things are without self Cause: Because an aggregate can be supposed. Example: As apply the present to the past. Application: If reputed, the proposition is non-permanent. Conclusion: So five aggregates are non-eternal and without self.

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Closer to the contents of the *Nyaya Sutra* is *Tarka Sastra*, another text of old Buddhist Hetuvidya, which discusses Hetuvidya under “three classes”, and its occasions for rebukes are extremely similar to those in the *Nyaya Sutra* and its discussion about syllogism and dispute errors basically are the same with relevant discussions in the *Nyaya Sutra*.

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The *Tarka sastra* introduces a “five-part” syllogism in respect of occasions for rebuke ie “proposition, cause, example, application, and conclusion”, and uses the following example to illustration this: Proposition: Sound is non-eternal. Cause: Because it is created.

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Example: Whatever is created is non-eternal, as earthenware is.

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Application: So is sound.

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Conclusion: Thus sound is non-eternal.

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The five-part syllogism in the *Tarka sastra*, though different in name, is completely the same with that in the *Nyaya Sutra* and both have used the virtually same examples.

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As for erroneous dispute, the *Tarka sastra* says under “Occasions for Rebuke”, “there are 22 occasions for rebuke”, which are consistent with those in the *Nyaya Sutra*, also including: (1) hurting the proposition, (2) shifting the proposition, (3) opposing the proposition, (4) renouncing the proposition, (5) shifting the reason, (6) shifting the topic, (7) the meaningless, (8) the unintelligible, (9) the incoherent, (10) the inopportune, (11) saying too little, (12) saying too much, (13) repetition, (14) silence, (15) ignorance, (16) non-ingenuity, (17) evasion, (18) admission of an opinion, (19) overlooking the censurable, (20) censuring the non-censurable, (21) deviating from a tenet, and (22) the semblance of a reason.

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Overall, old Buddhist Hetuvidya, with logic reasoning assimilated from the Nyaya, is different from the Nyaya but not much and enough to separate both in a strict sense,

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Old Buddhist *Hetuvidya* and *Nyaya* all have some aspects that are not complete or rigorous. For instance, “five-part” syllogism obviously has repetitions and after removing the first two or the latter two, the remaining three parts still can accomplish the inference. Old *Hetuvidya* in the main is a kind of analogous or inductive inference and a conclusion from such inference sometimes is not necessarily correct. Moreover, in spite of considerable studies on “hetu”, old Hetuvidya still lacks adequate exploration as to how to decide a “hetu” is right or not and so, its theories of logics are not rigorous. Besides, its “occasions for rebuke” include contradictory or fallacious contents as well as contents that violate specific rules of dispute and some of contents are not within the strict scope of logic reasoning. These defects arose mainly because old Hetuvidya or the Nyaya proposed their theories in the process of debate and these theories are for the need of argumentation rather than for pure logic reasoning.

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New Hetuvidya in Buddhism

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The important reform made by Dignaga signalled the formation of the new Buddhist Hetuvidya, with major figures including Dignaga, Samkarasvamin, Dharmapala, Silabhadra, Jayasena and Dharmakirti and Dignaga, Samkarasvamin and Dharmakirti had the greatest influence.

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Dignaga had written many works, but many of them were no longer available, and extant texts are mainly Chinese and Tibetan translations eg *Nyaya-mukha*, *Upadayaprajnaptiprakarana*, *Praj~naapaaramitaa-pi.n.daartha-sa.mgraha*, *Pramāṇa-samuccaya*, *Alambana-parikṣa* and *Hastavalaprakarana*. And among them, *Nyaya-mukha* and *Pramāṇa-samuccaya* are the most important.

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Samkarasvami, a disciple of Dignaga, mainly composed the commentary on Dignaga’s Nyayamukha ie the *Nyāyapravea*.

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Dharmakirti is a quite accomplished thinker of new *Hetuvidya* and has many writings, including the so called “Seven works on Hetuvidya” ie *Pramanavarttika*, *Pramanaviniscaya*, *Nyayabindu*,

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[Figure: *Nyayamukha: A Study (Yin Ming Zheng Li Men Lun Yanjiu)*; front cover]

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*Hetubindu*, *Sambandha parikṣa*, *Santanantara-siddhi* and *Vada-nyay*, all extant in Tibetan and some in Sanskrit as well as some modern Chinese translations. Of them, Nyayabindu and Pramanavarttika have the greater influence.

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As for Dharmapala, Silabhadra and Jayasena, their thoughts about Hetuvidya are scattered in Yogacara works, including their won.

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New Hetuvidya is an improvement of the old Hetuvidya, since its syllogism is improved, and it is more accurate when deciding whether a “hetu” is right or not.

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In old Hetuvidya, Buddhism usually adopted a five-part syllogism and some Buddhist texts, when talking about Hetuvidya, mentioned “three-part syllogism”, for instance, the *Mula-madhyamaka-karika* mentioned “proposition-cause-comparison”, but its examples also contained “application”, and it is not a sure form of three-part syllogism. “*Yogacarabhumi-sastra*” refers to “Founding Communion”, “Debating on the Causal” and “Allusion”. To sum up, three-part syllogism in old *Hetuvidya* is neither a regular nor a perfect reference. On the basis of these shortcomings, new *Hetuvidya* explicitly removed “application” and “conclusion”, made “three parts” a quite regular form of syllogism and further improved and made some contents more reasonable or scientific. Dignaga and Samkarasvamin all gave three-part examples in their works.

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An example in *Nyaya-mukha* by Dignaga is as below: Proposition: Sound is non-eternal. Cause: Because it is made. Positive example (Sadharma): Whatever is made is non-eternal, as a bottle. Negative example (Vidharma): Whatever is eternal is not made, such as void.

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While, an example in Samkarasvamin’s *Nyāyapravea* can be summarised as follows: Proposition: Sound is non-eternal. Cause: Because it is created. Positive example (Sadharma): Whatever is created is non-eternal, such as a bottle. Negative example (Vidharma)” Whatever is eternal is not created, such as emptiness.

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In *Nyāyapravea*, when talking about the three constituents of valid source of knowledge, Samkarasvamin suggested “using proposition-cause-comparison to make people understand”, “....can be proved when explaining to others..., and only with these three, can a proposition be proved”.

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The most important difference between new and old *Hetuvidya* lies with their analysis of “hetu”, since whether a “hetu” is correct or not directly relates to the success of the inference. Old Hetuvidya made much exploration in respect of “hetu”, for instance, it proposed “fallacious cause”, but, it failed to show what hetu is correct and to discuss it in a clear and detailed manner. In this respect, new Hetuvidya made much improvement or reformation, and many of its theories of “hetu” were contained in “trairupya”. The term “trairupya” had been mentioned in old *Hetuvidya*, for example, volume I of *Mula-madhyamaka-karika* but without a clear explanation. It is neo-Hetuvidya thinkers that discussed “trairupya” in a complete and clear manner.

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“Trairupya” refers to “three conditions” that have to be met to be a valid source of knowledge. And these three conditions are: *pakṣa, sapakṣa and vipakṣa*.

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*Pakṣa* means that it should be present in the case or object under consideration, the ‘subject-locus’. Take an example from the *Nyāyapravea*, the cause’s attribute must be present in “sound” (as the object). Such an attribute can be present in many things, but “sound” must have it.

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*Sapakṣa* means that it should be present in a ‘similar case’ (*sadharma*) or a homologue. For example, the attribute should be present in a similar case (sadharma), that is, “bottle”.

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*Vipakṣa* means that it should not be present in any ‘dissimilar case’ (*vidharma*) or heterologue. For example, as a dissimilar case (*vidharma*), “emptiness” should not have the cause’s attribute.

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Hetucakra is the most prominent innovation made by neo-*Hetuvidya* thinkers, and it was based on and was a further improvement of “*trairupya*”.

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Hetucakra was used by neo-*Hetuvidya* thinkers to decide whether a cause is right or not. A “cause” that satisfies *pakṣa* has nine possibilities with sapakṣa and vipakṣa: (1) + sapakṣa, + vipakṣa, (2) + sapakṣa, – vipakṣa, (3) + sapakṣa, ± vipakṣa, (4) – sapakṣa, + vipakṣa, (5) – sapakṣa, – vipakṣa, (6) – sapakṣa, ± vipakṣa, (7) ± sapakṣa, + vipakṣa, (8) ± sapakṣa, – vipakṣa, and (9) ± sapakṣa, ± vipakṣa

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(*Note: + = all, ± = some, – = none*)

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A compilation of Hetuvidya in Nyaya Theory

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Dignaga and others were of the opinion, above (2) and (8) all satisfy the latter two conditions of “trairupya”, and therefore, are valid cause, and the remaining seven are fallacious cause, since they do not satisfy the latter two conditions.

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Under new Hetuvidya, errors (faults or occasions for rebuke) were organized, replenished and closely connected with “trairupya”, and were divided into *paksābhāsa, hetvābhasa* and *drstantābhāsa*. Samkarasvamin, in *Nyāyapravea*, gave a most systematic list of 33 errors, including nine *paksābhāsa* ie pratyaksa-viruddh, anumana-viruddha, svasastra-viruddha, loka-viruddha, svavaccana-viruddha, aprasiddha-visesan, aprasiddha–visesya, aprasiddhobhaya, and prasiddha – sambandha, 14 “hetvābhasa” that include ubhayasiddha, anyatar-siddha, samdigdhadhsiddha, asrayadsidddha, sadharana-anaikantik, asadhāraṇa-anaikantika, sapaksa-eka-desa-vrtti-vipaksa-vyapin-anaikantika, vipaksaikadesa-vrtti-sapaksa-vyapaka—anaikantik, apaksa-vipaksalkadesa-vrtti, viruddhavyabhicarin, dharma-svarupa-viruddha, dharma-visesa-viruddha, dharmi-svarupa-viruddha and dharmi-visesa-viruddha. Ten *drstantabhasa* include sadhana-dharmasiddha, adhya-dharma-asiddha, ubhyaya-asiddhah, ananvaya, viparitanvaya, sadhya-avyavrtta, sadhanavyavrtta, ubhayavyavrtta, avyavrtta and viparita-vyatireka

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In addition to logic reasoning new Hetuvidya, the same with Hetuvidya, also has epistemology-related discussion. In *Nyāyapravea*, Samkarasvamin put forth the so-called “eight approaches to two kinds of benefit” (or eight propositions in two kinds of making aware). These eight approaches are: sadhana, dūaa, sadhanabhasa, dusanabhasa, pratyaka, anumana, pratyaksabhasa and anumanabhasa. “Two benefits” refer to enlightening self and others and in fact indicate the comprehensive role to be played by the new *Hetuvidya*. Clearly, these theories are more systematic and improved than those in old Hetuvidya.

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After Dignaga and Samkarasvamin, Dharmakirti further pushed forward new Hetuvidya. According to texts such as the *Nyayabindu*, Dharmakirti had ideas on the form of inference, the judgment of valid cause and inferential errors that were different from or not even mentioned by Dignaga and others.

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As for the form of inference, Dharmakirti had a unique understanding of “three-part” syllogism, and thought that “example” could be combined into “cause”, since the meaning or role of an example could be included into “cause”. Therefore, “example” actually does not necessarily become a separate part. However, Dharmakirti thought that it was not necessary to remove “example” or “three-part” syllogism and instead, the sequence of the “three parts” could be rearranged with “example” in the first and “proposition” in third. It would be “example-cause-proposition” and such a form of inference, in fact, is similar to “three-part” syllogism, and is something of deductive reasoning and is more rational or scientific.

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As for “valid cause”, Dharmakirti advanced on the basis of “trairupya”. He suggested, there could be three kinds of valid cause that satisfied “three conditions” ie unattainable, of self-nature and causal. “Unattainable cause” means, when inferring the non-presence of an object, the cause can be not finding this object under relevant conditions, for instance, the signs (sound, body, etc.) of the presence of someone are not found in a certain place, and this being a cause, it can be inferred that this person is not present; “cause of self nature” means inferring the genus of an object from its attributes, for instance, an object can move and make a sound by itself (with attributes of animal or belonging to a kind of animal), it could be inferred as animal; “causal cause” means inferring the cause from the effect for an cause-and-effect object. For instance, from the rising of water, it can be inferred that it rains in the upper reaches of the river. As for “inferential errors”, Dharmakirti also put forth some novel ideas and he had a different opinion on *Asadharaṇa-anaikantika* and *Viruddhavyabhicarin*, the two hetvābhasa proposed by some *Hetuvidya* thinkers (Dignaga and others).

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*Asadharaṇa-anaikantika* means that a cause is not present in similar and dissimilar cases and thus cannot establish whether the proposition is right. For instance, suppose the proposition is “sound is non-eternal”, the cause is “can be heard”, a similar case is “bottle”, and a dissimilar case is “emptiness”. “Bottle” and “emptiness” all cannot be heard and so, the cause cannot prove that the proposition is right. This actually is the fifth circumstance under the Hetucakra.

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*Viruddhavyabhicarin* means that in the course of an argument, both sides put forth their own propositions, and “causes” all satisfy “three conditions”, but conclusions (or propositions) are totally opposite (or contrary), and so, which side is right cannot be established. For instance, one side proposes: sound is non-eternal, because it is created, as a bottle, and another proposes: sound is eternal, because it can be heard, as an attribute of sound. For each side, their proposition seems to be right but it cannot prove the other’s fallacy.

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For Dharmakirti, above two hetvābhasa in fact were not possible to arise, and so, should be removed.

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With above thoughts of *Dharmakirti*, new *Hetuvidya* became more sound and rational. After him, there were also a number of *Hetuvidya* scholars, who usually inherited new *Hetuvidya* thoughts from Dignaga, Dharmakirti and others and pushed Buddhist Hetuvidya to a height of ancient Indian logic, and greatly enriched the pool of ancient Indian philosophy.

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Dissemination and Influence in China

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Indian *Hetuvidya* was brought into China together with other Buddhist thoughts, and had an important influence on ancient Chinese thoughts. In particular, when Yogacara School arose in the Tang Dynasty, since *Hetuvidya* had been much discussed in Yogacara texts, some Yogacara thinkers, while disseminating Yogacara, also worked vigorously to spread Hetuvidya theories. Moreover, Tibetans have translated and kept many valuable Hetuvidya texts, some of which are no longer available in India and both Chinese and Tibetans have played an important role in facilitating the study and development of Hetuvidya.

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In modern China, scholars have attached significant importance to Hetuvidya, since it is a major representative of Indian logic and an important branch of Buddhism. Some Hetuvidya scholars have published many articles and works on Hetuvidya and universities also offer courses on Hetuvidya.

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