Buddhist logic

Buddhist logico-epistemology is a term used in Western scholarship to describe Buddhist systems of ' (epistemic tool, valid cognition) and ' (reasoning, logic).

While the term may refer to various Buddhist systems and views on reasoning and epistemology, it is most often used to refer to the work of the "Epistemological school" (Sanskrit: ), i.e. the school of Dignaga and Dharmakirti which developed from the 5th through 7th centuries and remained the main system of Buddhist reasoning until the decline of Buddhism in India.

The early Buddhist texts show that the historical Buddha was familiar with certain rules of reasoning used for debating purposes and made use of these against his opponents. He also seems to have held certain ideas about epistemology and reasoning, though he did not put forth a logico-epistemological system.

The Theravada '' Kathāvatthu'' contains some rules on debate and reasoning. The first Buddhist thinker to discuss logical and epistemic issues systematically was Vasubandhu in his ''Vāda-vidhi'' (''A Method for Argumentation''). A mature system of Buddhist logic and epistemology was founded by the Buddhist scholar Dignāga (–540 CE) in his ''magnum opus'', the '' Pramāṇa-samuccaya''.Alt URL
/ref> Dharmakirti further developed this system with several innovations in his ''Pramanavarttika'' ("Commentary on Valid Cognition"). His work was influential on all later Buddhist philosophical systems as well as on numerous Hindu thinkers. It also became the main source of epistemology and reasoning in Tibetan Buddhism.

Definition

Scholars such as H.N. Randle and Fyodor Shcherbatskoy (1930s) initially employed terms such as “Indian Logic” and “Buddhist Logic” to refer to the Indian tradition of inference ( anumāna), epistemology (pramana), and "science of causes" (''hetu-vidyā''). This tradition developed in the orthodox Hindu tradition known as Nyaya as well as in Buddhist philosophy. Logic in classical India, writes Bimal Krishna Matilal, is "the systematic study of informal inference-patterns, the rules of debate, the identification of sound inference vis-à-vis sophistical argument, and similar topics." As Matilal notes, this tradition developed out of systematic debate theory (''vadavidyā''):

Logic as the study of the form of correct arguments and inference patterns, developed in India from the methodology of philosophical debate. The art of conducting a philosophical debate was prevalent probably as early as the time of the Buddha and the Mahavira (Jina), but it became more systematic and methodical a few hundred years later.

"Indian Logic" is a different system than modern derivatives of classical logic (such as modern predicate calculus): ''anumāna''-theory, a system in its own right. "Indian Logic" was also influenced by the study of grammar, whereas Classical Logic—which principally informed modern Western Logic—was influenced by the study of mathematics.

A key difference between Western Logic and Indian Logic is that certain epistemological issues are included within Indian Logic, whereas in modern Western Logic they are deliberately excluded. Indian Logic includes general questions regarding the "nature of the derivation of knowledge," epistemology, from information supplied by evidence, evidence which in turn may be another item of knowledge. For this reason, other scholars use the term "logico-epistemology" to refer to this tradition, emphasizing the centrality of the epistemic project for Indian logical reasoning.
* According to Georges Dreyfus, while Western logic tends to be focused on formal validity and deduction:

The concern of Indian "logicians" is quite different. They intend to provide a critical and systematic analysis of the diverse means of correct cognition that we use practically in our quest for knowledge. In this task, they discuss the nature and types of pramana. Although Indian philosophers disagree on the types of cognition that can be considered valid, most recognize perception and inference as valid. Within this context, which is mostly epistemological and practically oriented, topics such as the nature and types of correct reasoning that pertain to logic in the large sense of the word are discussed.

Pramana

(Tib. ) is often translated as "valid cognition" or "instrument of knowledge" and refers to epistemic ways of knowing. Epistemological justification distinguishes Buddhist pramana from orthodox Hindu philosophy. All schools of Indian logic recognize various sets of "valid justifications for knowledge" or ''pramana''. Buddhist logico-epistemology was influenced by the Nyāya school's methodology, but where the Nyaya recognised a set of four pramanas—perception, inference, comparison, and testimony—the Buddhists (i.e. the school of Dignaga) only recognized two: perception and inference. For Dignaga, comparison and testimony are just special forms of inference.

Most Indic ''pramanavada'' accept "perception" (Sanskrit: ) and "inference" (Sanskrit: ), but for some schools of orthodox Hinduism the "received textual tradition" (Sanskrit: ) is an epistemological category equal to perception and inference. The Buddhist logical tradition of Dignaga and Dharmakirti accept scriptural tradition ''only'' if it accords with and . This view is thus in line with the Buddha's injunction in the '' Kalama Sutta'' not to accept anything on mere tradition or scripture.

Early Buddhist background

Epistemology

The time of the Gautama Buddha was a lively intellectual culture with many differing philosophical theories. KN Jayatilleke, in his "Early Buddhist Theory of Knowledge", uses the Pali Nikayas to glean the possible epistemological views of the historical Buddha and those of his contemporaries. According to his analysis of the ''Saṅgārava-sutta'' ( AN 3.60), during the Buddha's time, Indian views were divided into three major camps with regards to knowledge:Jayatilleke, K. N. ''Early Buddhist Theory of Knowledge'', London, 1963

*The Traditionalists (''anussavika'') who regarded knowledge as being derived from scriptural sources (the Brahmins who upheld the Vedas).
*The Rationalists (''takki vimamsi'') who only used reasoning or ''takka'' (the skeptics and materialists).
*The "Experientialists" who held that besides reasoning, a kind of supra-normal yogic insight was able to bring about unique forms of knowledge (the Jains, the middle and late Upanishadic sages).

The Buddha rejected the first view in several texts such as the '' Kalama sutta'', arguing that a claim to scriptural authority (''sadda'') was not a source of knowledge, as was claimed by the later Hindu Mimamsa school. The Buddha also seems to have criticized those who used reason (''takka''). According to Jayatilleke, in the Pali Nikayas, this term refers "primarily to denote the reasoning that was employed to construct and defend metaphysical theories and perhaps meant the reasoning of sophists and dialecticians only in a secondary sense". The Buddha rejected metaphysical speculations, and put aside certain questions which he named the unanswerables (''avyakatas''), including questions about the soul and if the universe is eternal or not.

The Buddha's epistemological view has been a subject of debate among modern scholars. Some such as David Kalupahana, have seen him first and foremost as an empiricist because of his teaching that knowledge required verification through the six sense fields ( ayatanas). The '' Kalama sutta'' states that verification through one's own personal experience (and the experiences of the wise) is an important means of knowledge.

However, the Buddha's view of truth was also based on the soteriological and therapeutic concern of ending suffering. In the ''"Discourse to Prince Abhaya"'' (MN.I.392–4) the Buddha states that a belief should only be accepted if it leads to wholesome consequences. This has led scholars such as Mrs Rhys Davids and Vallée-Poussin to see the Buddha's view as a form of Pragmatism. This sense of truth as what is useful is also shown by the Buddha's parable of the arrow.

K. N. Jayatilleke sees Buddha's epistemological view as a kind of empiricism which also includes a particular view of causation (dependent origination): "inductive inferences in Buddhism are based on a theory of causation. These inferences are made on the data of perception. What is considered to constitute knowledge are direct inferences made on the basis of such perceptions." Jayatilleke argues the Buddhas statements in the Nikayas tacitly imply an adherence to some form of correspondence theory, this is most explicit in the ''Apannaka Sutta'' ( MN 60). He also notes that Coherentism is also taken as a criterion for truth in the Nikayas, which contains many instances of the Buddha debating opponents by showing how they have contradicted themselves. He also notes that the Buddha seems to have held that utility and truth go hand in hand, and therefore something which is true is also useful (and vice versa, something false is not useful for ending suffering).

Echoing this view, Christian Coseru writes:

canonical sources make quite clear that several distinct factors play a crucial role in the acquisition of knowledge. These are variously identified with the testimony of sense experience, introspective or intuitive experience, inferences drawn from these two types of experience, and some form of coherentism, which demands that truth claims remain consistent across the entire corpus of doctrine. Thus, to the extent that Buddhists employ reason, they do so primarily in order further to advance the empirical investigation of phenomena.

Debate and analysis

The Early Buddhist Texts show that during this period many different kinds of philosophers often engaged in public debates (''vivada''). The early texts also mention that there was a set procedure (''patipada'') for these debates and that if someone does not abide by it they are unsuitable to be debated. There also seems to have been at least a basic conception of valid and invalid reasoning, including, according to Jayatilleke, fallacies (''hetvabhasah'') such as '' petitio principii''. Various fallacies were further covered under what were called ''nigrahasthana'' or "reasons for censure" by which one could lose the debate. Other ''nigrahasthanas'' included ''arthantaram'' or "shifting the topic", and not giving a coherent reply.

According to Jayatilleke, ' pure reasoning' or 'a priori' reasoning is rejected by the Buddha as a source of knowledge. While reason could be useful in deliberation, it could not establish truth on its own.

In contrast to his opponents, the Buddha termed himself a defender of 'analysis' or vibhajjavada'''. He held that after proper rational analysis, assertions could be classified in the following way:

*Those assertions which can be asserted or denied categorically (''ekamsika'')
*Those which cannot be asserted or denied categorically (''anekamsika''), which the Buddha further divided into:
**Those which after analysis (''vibhajja-'') could be known to be true or false.
**Those like the ''avyakata''-theses, which could not be thus known.

This view of analysis differed from that of the Jains, which held that all views were ''anekamsika'' and also were relative, that is, they were true or false depending on the standpoint one viewed it from ('' anekantavada'').

The early texts also mention that the Buddha held there to be "four kinds of explanations of questions."

* a question which ought to be explained categorically
* a question which ought to be answered with a counter question
* a question which ought to be set aside (''thapaniya'')
* a question which ought to be explained analytically

The Buddha also made use of various terms which reveal some of his views on meaning and language. For example, he held that many concepts or designations (''paññatti'') could be used in conventional everyday speech while at the same time not referring to anything that exists ultimately (such as the pronouns like "I" and "Me"). Richard Hayes likewise points to the ''Potthapada sutta'' as an example of the Early Buddhist tendency towards a nominalist perspective on language and meaning in contrast to the Brahmanical view which tended to see language as reflecting real existents.

The Buddha also divided statements (''bhasitam'') into two types with regards to their meaning: those which were intelligible, meaningful (''sappatihirakatam'') and those meaningless or incomprehensible (''appatihirakatam''). According to Jayatilleke, "in the Nikayas it is considered meaningless to make a statement unless the speaker could attach a verifiable content to each of its terms." This is why the Buddha held that statements about the existence of a self or soul ('' atman'') were ultimately meaningless, because they could not be verified.

The Buddha, like his contemporaries, also made use of the "four corners" ('' catuṣkoṭi'') logical structure as a tool in argumentation. According to Jayatilleke, these "four forms of predication" can be rendered thus:
#S is P, e.g. ''atthi paro loko'' (there is a next world).
#S is not P, e.g. ''natthi paro loko'' (there is no next world).
#S is and is not P, e.g. ''atthi ca natthi ca paro loko'' (there is and is no next world).
#S neither is nor is not P, e.g. ''n'ev'atthi na natthi paro loko'' (there neither is nor is there no next world)

The Buddha in the Nikayas seems to regard these as "'the four possible positions or logical alternatives that a proposition can take". Jayatilleke notes that the last two are clearly non- Aristotelian in nature. The Buddhists in the Nikayas use this logical structure to analyze the truth of statements and classify them. When all four were denied regarding a statement or question, it was held to be meaningless and thus set aside or rejected (but ''not negated'').

Two levels of Truth

The early texts mention two modes of discourse used by the Buddha. Jayatilleke writes:

when he is speaking about things or persons we should not presume that he is speaking about entities or substances; to this extent his meaning is to be inferred (''neyyattha-''). But when he is pointing out the misleading implications of speech or using language without these implications, his meaning is plain and direct and nothing is to be inferred (''nitattha-''). This is a valid distinction which certainly holds good for the Nikäyas at least, in the light of the above-statement.

The later commentarial and Abhidharma literature began to use this distinction as an epistemic one. They spoke of two levels of truth, the conventional (''samutti)'', and the absolute (''paramattha''). This theory of double truth became very influential in later Buddhist epistemic discourse.

''Kathāvatthu''

The Theravada '' Kathāvatthu'' (''Points of Controversy'') is a Pali Buddhist text which discusses the proper method for critical discussions on doctrine. Its date is debated by scholars but it might date to the time of Ashoka (C. 240 BC). Western scholarship by St. Schayer and following him A. K. Warder, have argued that there is an "anticipations of propositional logic" in the text. However, according to Jonardon Ganeri "the leading concern of the text is with issues of ''balance'' and ''fairness'' in the conduct of a dialogue and it recommends a strategy of argumentation which guarantees that both parties to a point of controversy have their arguments properly weighed and considered."Ganeri, Jonardon. Argumentation, dialogue and the "Kathāvatthu", Journal of Indian Philosophy August 2001, Volume 29, Issue 4, pp. 485–493

In the ''Kathāvatthu'', a proper reasoned dialogue (''vadayutti'') is structured as follows: there is a point of contention – whether A is B; this is divided into several 'openings' (''atthamukha''):

#Is A B?
#Is A not B?
#Is A B everywhere?
#Is A B always?
#Is A B in everything?
#Is A not B everywhere?
#Is A not B always?
#Is A not B in everything?

These help clarify the attitude of someone towards their thesis in the proceeding argumentative process. Jonardon Ganeri outlines the process thus:

Each such ‘opening’ now proceeds as an independent dialogue, and each is divided into five stages: the way forward (anuloma), the way back (patikamma), the refutation (niggaha), the application (upanayana) and the conclusion (niggamana). In the way forward, the proponent solicits from the respondent the endorsement of a thesis and then tries to argue against it. On the way back, the respondent turns the tables, soliciting from the proponent the endorsement of the counter-thesis, and then trying argue against it. In the refutation, the respondent, continuing, seeks to refute the argument that the proponent had advanced against the thesis. The application and conclusion repeat and reaffirm that the proponent’s argument against the respondent’s thesis is unsound, while the respondent’s argument against the proponent’s counter-thesis is sound.

''Milindapanha''

Another Buddhist text which depicts the standards for rational debate among Buddhists is the '' Milindapanha'' (''"Questions of Menander"'', 1st century BCE) which is a dialogue between the Buddhist monk Nagasena and an Indo-Greek King. In describing the art of debate and dialogue, Nagasena states:

When scholars talk a matter over one with another, then is there a winding up, an unravelling, one or other is convicted of error, and he then acknowledges his mistake; distinctions are drawn, and contra-distinctions; and yet thereby they are not angered.

The various elements outlined here make up the standard procedure of Buddhist debate theory. There is an 'unravelling' or explication (''nibbethanam'') of one's thesis and stances and then there is also a 'winding up' ending in the censure (''niggaho'') of one side based on premises he has accepted and the rejoinders of his opponent.

Abhidharma views

The Buddhist Abhidharma schools developed a classification of four types of reasoning which became widely used in Buddhist thought. The Mahayana philosopher Asanga in his ''Abhidharma-samuccaya'', outlines these four reasons (''yukti'') that one may use to inquire about the nature of things. According to Cristian Coseru these are:

#The principle of dependence (apeksāyukti), which takes into account the fact that conditioned things necessarily arise in dependence upon conditions: it is a principle of reason, for instance, that sprouts depend on seeds.
#The principle of causal efficacy (kāryakāranayukti), which accounts for the difference between things in terms of the different causal conditions for their apprehension: it is a principle of reason, thus, that, in dependence upon form, a faculty of vision, and visual awareness, one has visual rather than, say, auditory or tactile experiences.
#The realization of evidence from experience (sāksātkriyāsādhanayukti). We realize the presence of water from moisture and of fire from smoke.
#The principle of natural reasoning, or the principle of reality (dharmatāyukti), which concerns the phenomenal character of things as perceived (for instance, the wetness and fluidity of water).

According to Coseru "what we have here are examples of natural reasoning or of reasoning from experience, rather than attempts to use deliberative modes of reasoning for the purpose of justifying a given thesis or arguing for its conditions of satisfaction."

Nyaya influences

The Nyāya Sūtras of Gotama (6th century BC – 2nd century CE) is the founding text of the Nyaya school. The text systematically lays out logical rules for argumentation in the form of a five-step schema and also sets forth a theory of epistemology. According to Jonardon Ganeri, the Nyaya sutra brought about a transformation in Indian thinking about logic. First, it began a shift away from interest in argumentation and debate towards the formal properties of sound inference. Secondly, the Nyaya sutra led a shift to rule-governed forms of logical thinking.

Nyāya and Buddhist Epistemology

The influence of Nyāya on Buddhist epistemology is profound, especially in the development of the four major pramāṇa (valid means of knowledge). Below is a breakdown of how Buddhist thinkers integrated and adapted Nyāya concepts in their philosophical systems:

Nyāya and Buddhist Logic

Another significant area of influence was in the domain of logic. Nyāya's formal system of inference (anumāna) directly impacted Buddhist logic, especially in the works of scholars like Dharmakīrti. Nyāya's focus on hetu (reasoning or cause) and the structure of valid arguments was adopted and modified by Buddhists in their development of logical proofs ( pramāṇa) to support doctrines like impermanence and non-self.

In the Pramāṇavārttika, Dharmakīrti reinterpreted Nyāya’s logical tools to fit within Buddhist metaphysical views. For example, Nyāya’s approach to inference was used to argue against essentialist doctrines by showing that all phenomena are dependent on causes and conditions (dependent origination), rather than existing inherently ( svabhāva). In Mādhyamika philosophy, Nāgārjuna and Śāntideva also employed logic and dialectical reasoning, heavily influenced by Nyāya, to argue against Nyāya’s own concept of an unchanging self.

Nyāya and Buddhist Debate Practices

The formal practice of debate (''yukti'') in Buddhist scholasticism, especially within monastic institutions, reflects the influence of Nyāya. The rigorous techniques of formal reasoning and logical debate in Nyāya were adopted by Buddhists to engage in systematic argumentation, not only with other philosophical schools but also within their own traditions.

Buddhist monastic institutions, particularly in India, followed a debate structure built on Nyāya’s epistemological principles, emphasizing the importance of valid reasoning and evidence in defending doctrinal views. These debates often centered around the ''validity of pramāṇas'' and the nature of reality (impermanence and non-self versus permanence and self). In Tibet and East Asia, these debates became central to the scholastic tradition and helped refine Buddhist thought over centuries.

Nyāya Influence in Later Buddhist Traditions

The impact of Nyāya was not confined to early Indian Buddhist thinkers but continued to shape later Buddhist traditions. For example, Tibetan Buddhism developed sophisticated methods of debate and logic that were heavily influenced by Indian Nyāya. In the Gelug school, the ''Pramāṇa'' texts of Dharmakīrti became a central part of the curriculum, alongside Nyāya texts.

In addition, Zen Buddhism and Chan Buddhism also exhibited traces of logical techniques influenced by the early scholastics of India, where rational discourse was used to sharpen the practitioner's understanding of emptiness (''śūnyatā'') and impermanence.

Further Developments and Synthesis

In addition to Dharmakīrti and Nāgārjuna, Buddhist thinkers like Vasubandhu and Śāntideva also utilized Nyāya-derived logic in their writings. Vasubandhu's work in the Abhidharma tradition integrated Nyāya’s inference and perception frameworks to argue for emptiness and the illusion of permanence in all things.

Moreover, Tibetan Buddhist scholars like Chandrakirti and Jamyang Zhépa further developed these ideas, showing that the dialogue between Nyāya and Buddhism was not a one-way flow but rather an ongoing intellectual exchange that continued across centuries and geographical regions.

B.K. Matilal outlines the five steps or limbs of the Nyaya method of reasoning as follows:

#There is fire on the hill. hesis#For there is smoke. eason#(Wherever there is smoke, there is fire), as in the kitchen. xample#This is such a case (smoke on the hill).
#Therefore, it is so, i.e., there is fire on the hill.

Later Buddhist thinkers like Vasubandhu would see several of these steps as redundant and would affirm that only the first two or three were necessary.

The Naiyayikas (the Nyaya scholars) also accepted four valid means (''pramaṇa'') of obtaining valid knowledge (''pramana'') - perception (''pratyakṣa''), inference (''anumāna''), comparison ('' upamāna'') and word/testimony of reliable sources (''śabda'').

The systematic discussions of the Nyaya school influenced the Medieval Buddhist philosophers who developed their own theories of inferential reasoning and epistemic warrant (pramana). The Nyaya became one of the main opponents of the Buddhists.

Vaiśeṣika Influences

While the direct influence of the Vaiśeṣika school on Buddhism was limited compared to that of the Nyāya school, certain concepts from Vaiśeṣika philosophy did inform or prompt responses within Buddhist thought, particularly in the context of Atomism, metaphysics, and conceptual classification. The influence was often indirect, occurring through shared intellectual debates and through the later fusion of Nyāya and Vaiśeṣika into a combined tradition.

Historical Context

The Vaiśeṣika school, traditionally attributed to the sage Kaṇāda, emerged around the 2nd century BCE and developed a detailed realist metaphysical system centered on the analysis of substances, qualities, motion, and universals.Potter, Karl H. (ed.), ''Encyclopedia of Indian Philosophies, Vol. II: Indian Metaphysics and Epistemology: The Tradition of Nyāya-Vaiśeṣika up to Gaṅgeśa'', Princeton University Press, 1977, pp. 18–22. While Buddhist traditions primarily emphasized ethical practice, meditation, and liberation from suffering, by the time of the Abhidharma scholastic period, Buddhist scholars began to systematize their own metaphysical and epistemological positions, sometimes in response to or dialogue with non-Buddhist systems like Vaiśeṣika.Dhammajoti, K.L., ''Sarvāstivāda Abhidharma'', Centre of Buddhist Studies, University of Hong Kong, 2007, pp. 127–131.

Atomism and Ontological Categories

Vaiśeṣika philosophy is considered one of the earliest proponents of atomism in Indian thought.Chakrabarti, Arindam, ''The Nyāya-Vaiśeṣika Theory of Universals: A Linguistic Analysis'', Springer, 1992, pp. 45–49. According to this view, all material objects are composed of indivisible, eternal atoms (''paramāṇu'') of four elements: earth, water, fire, and air. These atoms combine through conjunction (''saṃyoga'') and inherence (''Samavāya'') to form complex, perceivable objects.

Buddhist schools, particularly the Sarvāstivāda and later Theravāda Abhidhamma and Yogācāra traditions, developed their own theories of atomism and constituent elements ('' dharmas''). These Buddhist atoms, however, were fundamentally momentary and non-substantial, existing only in a single instant before giving rise to a successor. While structurally similar in positing basic building blocks of reality, Buddhist atomism served a different function: not to establish a permanent material substratum, but to support doctrines of impermanence (''anitya'') and dependent origination.

Some scholars suggest that the development of Buddhist atomism may have been in part a philosophical response to the atomistic realism of Vaiśeṣika, offering a counter-theory that maintained empirical rigor without conceding to metaphysical permanence.

Epistemology and Debate Culture

Vaiśeṣika epistemology, though not as developed as Nyāya’s, accepted perception (''Pratyakṣa'') and inference ('' anumāna'') as valid means of knowledge ('' Pramāṇa''). Over time, Vaiśeṣika and Nyāya merged into a unified system, often referred to as the ''Nyāya-Vaiśeṣika'' school, particularly from the post- Uddyotakara period (c. 5th century CE onward). This synthesis brought Vaiśeṣika metaphysics into the sphere of logical and epistemological debate.

Buddhist logicians, especially Dignāga and Dharmakīrti, engaged deeply with Nyāya-Vaiśeṣika thinkers, critiquing their views on perception, inference, and universals. While these critiques were often aimed at Nyāya formulations, many of the underlying metaphysical positions—such as the reality of substances or inherence—were drawn from Vaiśeṣika doctrines.

This interaction spurred Buddhist thinkers to clarify and refine their own positions on cognition, objecthood, and conceptual construction (''vikalpa''). For example, Dharmakīrti’s theory of Apoha (exclusion) as the basis of conceptual cognition can be read as a direct challenge to both Vaiśeṣika's realist universals ('' Sāmānya'') and their role in perception.

Shared Frameworks and Divergences

There are also conceptual parallels that may reflect shared cultural and intellectual frameworks rather than direct influence. For instance, both Vaiśeṣika and Buddhist Abhidharma employ classificatory taxonomies to understand reality. Vaiśeṣika lists six or seven categories of being (''Padārtha

HOME


Content is Copyleft
Website design, code, and AI is Copyrighted (c) 2014-2017 by Stephen Payne


Consider donating to Wikimedia



As an Amazon Associate I earn from qualifying purchases