This excerpt from Science and Philosophy in the Indian Buddhist Classics, Vol. 4: Philosophical Topics, the new book by His Holiness the Dalai Lama (and edited by Thupten Jinpa) — reviewed in the Summer 2023 issue of Buddhadharma: The Practitioner’s Guide — is provided courtesy of the publisher, Wisdom Publications. We thank Wisdom for sharing this with Buddhadharma‘s readers, and we thank our readers for supporting dharma publishers.
What is known as the “science of reasoning” is included among the five greater sciences mentioned in early Buddhist sources. Within this branch of science, the main points that need to be understood are: the object known, the epistemic instruments that are the valid cognitions that know it, inference as a means of realizing it, and ways in which the mind knows its object. The logico-epistemological (pramāṇa) tradition is a discipline of knowledge that has flourished in India since ancient times. Many renowned thinkers in India, both Buddhist and non-Buddhist, engaged in extensive analyses and established their own positions on several of the key issues of epistemology: how valid cognition ascertaining its object arises on the basis of inferential reasoning; what specific qualifications are necessary for valid inference of this kind; what sort of relation obtains between the thesis proved and the evidence that proves it; presentations of the objects of knowledge; how the mind knows reality; how language and thought engage with reality; and what specific types of cognition exist among the categories of mind knowing reality.
According to some contemporary historians, among the first treatises on science in India was the medical text Compendium of Caraka (Carakasṃhitā) compiled by Caraka (ca. 100 CE). The third chapter of this text includes a presentation of twenty-four categories of logic, within which are found the Vaiśeṣika system’s six categories of logic. In general the most renowned non-Buddhist text about reasoning is the Nyāya Sūtra, the primary logical treatise composed by Akṣapāda Gautama—the definitive teacher of the Nyāya tradition. This text delineates sixteen categories of logic: valid means of knowing, objects of valid knowledge, doubt, purpose, example, tenet, components of inference, reasoning, ascertainment, debate, presentation, refutation only, fallacious inference, deceit, futile rejoinder, and defeat. Since each of these sixteen categories of logic is refuted in Nāgārjuna’s treatise Finely Woven, it is evident that these assertions of the Nyāya have been in existence from ancient times up to the present day. Based on the Nyāya Sūtra, the Naiyāyika posit four types of valid cognition — perception, inference, testimony, and comparative analogy — and they assert that a correct proof statement has five limbs. The non-Buddhist Sāṅkhya system is said to rely on such texts as the Īśvarakṛṣṇa Tantra, Sixty Tantras, Seventy Golden Ones, Thirty Scriptural Traditions, Fifty Defining Characteristics, and so on. The Īśvarakṛṣṇa Tantra, also called the Verses of Sāṅkhya, says:
Because perception, inference, and trustworthy testimony encompass all types of valid cognition, three types of valid cognition are accepted. Objects known are established by means of valid knowing.
Texts such as the one cited above give extensive presentations on the enumeration of valid cognition, its essential nature, the object of each type of valid cognition, how valid cognition establishes its object, and so on. The Sāṅkhya Sūtra explains: “The realization of the meaning of the pervasion through having realized earlier the relation between the evidence and the evidence-possessor is the inference, and the understanding of such a meaning by the person is the consciousness that possesses the inference.” This shows the way in which the evidential reason comes to be established, and how, on that basis, inferential cognition comes to arise. The Vaiśeṣika system’s main treatise is considered to be Kaṇāda’s Vaiśeṣika Sūtra. It presents extensive proofs establishing sound to be a quality of space, using reasons of contradiction and of inherence, where cause, effect, and relation are synonymous. There are a variety of ideas as to when the Nyāya Sūtra and the Vaiśeṣika Sūtra were composed. However, since many of the treatises in an Indian language were written down during the second century, it seems that both of those treatises were written down around that time.
The Mīmāṃsā system’s main treatise is considered to be Jaimini’s Mīmāṃsā Sūtra, based on which a hugely important later thinker, Kumārila Bhaṭṭa (seventh century CE), composed his Exposition of Verses on Mīmāṃsā.  In this text he developed an extensive presentation of epistemology according to the Mīmāṃsā tradition. As for the Nirgrantha, now widely known as Jaina, epistemology is presented in the Explanation of the Ten Auspicious Observances (Daśavaikālikaniryukti) composed by Bhadrabāhu (fourth century BCE), and in later works such as Entering into Reasoning authored by the great master Siddhasena Divākara (seventh century CE).
As for the Buddhist systems, the logico-epistemological textual tradition is considered to have flourished since the time of the renowned master Dignāga in the fifth century CE. However, one may discern that that there were some earlier highly advanced logical analyses relating to epistemology from what is found in Nāgārjuna’s Refutation of Objections and Finely Woven (second century CE). Moreover, many Mahāyāna sūtras contain presentations of the four forms of rationality, notably the four forms of rationality found in the Unraveling the Intention Sūtra, especially its presentation of the rationality of inferential proof. In addition, the Points of Discussion (Kathāvatthu) attributed to Moggaliputta Tissa, which was compiled as part of the third Buddhist council during the period of Emperor Aśoka and included within the Abhidhamma Piṭaka of the Theravāda tradition, contains many detailed doctrinal debates. A paraphrase of this text is available in English these days as part of the translation of the Pali canon. Included within the Abhidhamma Piṭaka of the Sarvāstivāda tradition, the Compendium of Consciousness (Vijñānakāya), attributed to Devakṣema/Devaśarman, contains many arguments that relate to proving the selflessness of the person. Similarly, Asaṅga presents various types of inference, along with examples illustrating them, in his monumental Levels of Yogācāra; within that work, his Śrāvaka Levels presents the four forms of rationality. Also, in the chapter “Examining the Dialectic” in his Compendium of Abhidharma, he explains that a proof statement has five limbs and that valid cognition is categorized into three types: perception, inference, and testimony. In particular, Vasubandhu is said to have composed treatises expressly pertaining to the discipline of epistemology, such as Practice of Debate, Heart of Debate, and so on.
Among the Buddhist thinkers, Dignāga carefully investigates the categories of logic presented in the Nyāya Sūtra and proposes eight categories within his own system of epistemology: (1) correct perception and (2) correct inference, both of which enable oneself to ascertain the object of knowledge; also (3) fallacious perception and (4) fallacious inference, which are for identifying distortions in each of the previous two; then (5) correct proof statement or inference for the sake of others and (6) correct refutation, both of which, after having ascertained the object of knowledge oneself, are for the sake of bringing others to that realization; also (7) fallacious proof statement and (8) fallacious refutation, which are for identifying distortions in the previous two. These eight categories of logic are delineated by Dignāga in the following treatises (some of which are no longer extant): Investigation of the Universal (Sāmānyalakṣaṇaparikṣā), Investigation of the Nyāya System (Nyāyaparīkṣā), Investigation of the Vaiśeṣika System (Vaiśeṣikaparīkṣā), Investigation of the Sāṅkhya System (Sāṅkhyaparīkṣā), Investigation of the Object, Investigation of the Three Times, Entering into Valid Reasoning, Classification of the Winds, Introduction to Logic (Hetumukha), Introduction to Entering into Valid Reasoning, and Drum of a Wheel of Reasons. In particular, he composed the six-chapter work Compendium of Valid Cognition, also known as the Sūtra on Valid Cognition, in the form of both a root text in verse as well as an autocommentary; it is a foundational treatise for the entire discipline of Buddhist epistemology.
After Dignāga some highly skilled proponents of non-Buddhist epistemology appeared, in particular the Vaiśeṣika master Praśastapāda (sixth century CE), the Nyāya master Uddyotakara (sixth century), the Mīmāṃsā master Kumārila (seventh century), and the Jaina master Mallavādin (eighth century). These four composed treatises to refute many of the points stated by Dignāga concerning epistemology and logic and to prove that the presentations of their own pramāṇa traditions were correct. Thus the level of discourse in philosophy and epistemology in India was raised considerably.
Dignāga’s immediate disciple Īśvarasena appears to have composed a commentary on Compendium of Valid Cognition that unfortunately is no longer extant. Īśvarasena’s student was Dharmakīrti (seventh century), who is the most highly renowned master in the history of Indian epistemology. To provide detailed explanations of the meaning of Dignāga’s Compendium of Valid Cognition and its autocommentary, this master composed seven treatises on valid cognition. He wrote three primary treatises, likened to the body, that present fully the eight categories of logic: Exposition of Valid Cognition, the lengthiest version; Ascertainment of Valid Cognition, the medium-length version; and Drop of Reasoning, the shortest version.
He also wrote four secondary treatises, likened to the limbs of the body, that present only some portion of the eight categories, expanding upon them: Drop of Reasons, Investigation of Relations, Proof of Other Mind streams, and Reasoning for Debate. Among these, Drop of Reasons presents in particular the defining characteristics of reasons for something hard to know, expanding upon the “Inference for Oneself ” chapter of Exposition of Valid Cognition. The root text and commentary of Investigation of Relations expands on the demonstration of the thesis-evidence relation found in the “Inference for Oneself ” chapter. This text in particular explains how the relation between thesis and evidence is posited conventionally and is not ultimately existent. Proof of Other Mindstreams gives a clear response to the question that arises in the “Perception” chapter when explaining forms and so on to be mere cognition only: “If what appears to the disputant is in the nature of their own mind, then how can it be feasible for the proof statement’s locus of presentation, a person of a different continuum, to exist?” The text shows how there can be a person who is a different continuum from the disputant even though there are no forms and so on that are different substances from the consciousness that brings about the appearance. Reasoning for Debate expands upon the “Inference for Others” chapter and in particular explains: the proof statement, definitions of the proponent and the opponent showing how to train in the path of proof statements, how to engage in debate, refutation that is the essence of debate, the presentation of consequential reasoning, the categories of futile rejoinder (jāti) that deviate from it, and so on.
Thus Dharmakīrti’s seven treatises in general, and in particular his most renowned work Exposition of Valid Cognition, present Dignāga’s tradition of logic and epistemology in a systematic way. In particular, he elucidates the points that Dignāga did not state clearly, or, if stated, that he did not explain in detail. For example, although Dignāga sets forth the definition of evidence to be “that which is qualified by the three modes,” he does not give much explanation about its instances — effect evidence, nature evidence, and evidence consisting in nonperception — nor does he explain in depth the rationale by which the presence of the three modes within correct evidence is ascertained. Similarly, while Dignāga states that in any correct inferential reasoning there must be an invariable relation of unaccompanied nonoccurrence (avinābhāvaniyama) between the evidence and the thesis, Dharmakīrti determines this type of relation to consist of two kinds — causal relation and intrinsic relation — so he gives lengthy explanations about how the categories of correct evidence have a definitive enumeration as three — effect, nature, and nonperception — and other such difficult points of epistemology. Moreover, he refutes the extensive criticisms of Dignāga’s epistemological views in general, especially about his proof of the exclusion of other to be the linguistic referent (or word meaning), put forward by the non-Buddhist masters Praśastapāda, Uddyotakara, Kumārila, and Mallavādin. Thus he proves Dignāga’s own system to be correct and further raises the level of Buddhist epistemology considerably.
Devendrabuddhi (seventh century) wrote a commentary on the final three chapters of Exposition of Valid Cognition. His disciple Śākyabuddhi (or Śākyamati; seventh century) wrote his Commentary on the Exposition of Valid Cognition. His other disciple Vinītadeva, as well as a lineage that followed, including Prajñākaragupta, Dharmottara, Mahāmati, Jamāri, and Mokṣākaragupta, also wrote commentaries on the seven treatises of Dharmakīrti. Then in the eighth century Śāntarakṣita wrote his highly renowned text on valid cognition, Compendium of Reality, and his disciple Kamalaśīla wrote his Commentary on the Difficult Points in the Compendium of Reality. These two texts present responses to each of the criticisms leveled by certain non-Buddhist logicians against not only Dignāga’s position but also certain points made by Dharmakīrti pertaining to epistemology, and they give detailed refutations of objections to their presentation of the exclusion of other in the “Investigating Word Meaning” chapter in particular. In addition [to the above masters], Śaṅkarānanda (eleventh century), also known as Mahāmati, composed an explanation of the auto commentary on the first chapter of Exposition of Valid Cognition, as well as the treatises Proof of Relation and Proof of Exclusion. And Jitāri (eleventh century) wrote several treatises on epistemology, such as A Beginner’s Primer on Logic, Distinguishing the Systems of the Blessed One, Ascertainment of Dharma and Dharmin, and Presenting the Principles of Inferential Evidence. From the fact that these texts are included in the Pramāṇa section of the Tengyur one can discern how so many works on logic and epistemology came to be composed [in India].
The purpose for giving such detailed explanations about epistemology, as presented by both Buddhist and non-Buddhist Indian masters from one generation to the next, is to demonstrate the following: how the attainment of human goals is dependent on valid cognition; how all the varieties of suffering, which people do not want, come from not knowing correctly the nature of reality; and how once one has gained correct valid cognition, one will be able to accomplish one’s aims in reliance on it. Seeing the importance of these understandings, [the masters] offered their extensive presentations on epistemology. Accordingly, Dharmakīrti’s Ascertainment of Valid Cognition says: “Since correct understanding is a necessary precursor for obtaining what is beneficial and abandoning what is harmful, this text has been composed for the purpose of teaching those who lack this expertise.” Likewise, Dharmakīrti’s Drop of Reasoning says: “Since the accomplishment of every being’s goal is preceded by correct understanding, this text has been taught.”
From Science and Philosophy in the Indian Buddhist Classics, Vol. 4: Philosophical Topics by His Holiness the Dalai Lama and edited by Thupten Jinpa © 2023 Wisdom Publications, www.wisdomexperience.org
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