Buddhist logico-epistemology


Buddhist logico-epistemology is a term used in Western scholarship to describe Buddhist systems of and hetu-vidya.
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", 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 mature system of Buddhist logic and epistemology was founded by the Buddhist scholar Dignāga in his magnum opus, the Pramāṇa-samuccaya. Dharmakirti further developed this system with several innovations in his Pramanavarttika. 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 initially employed terms such as “Indian Logic” and “Buddhist Logic” to refer to the Indian tradition of inference, epistemology, and "science of causes". 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 :
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, but it became more systematic and methodical a few hundred years later.

"Indian Logic" is a different system than modern derivatives of classical logic : 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

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 only recognized two: perception and inference. For Dignaga, comparison and testimony are just special forms of inference.
Most Indic pramanavada accept "perception" and "inference", but for some schools of orthodox Hinduism the "received textual tradition" 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 pratyakṣa and anumāna. 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, during the Buddha's time, Indian views were divided into three major camps with regards to knowledge:
  • The Traditionalists who regarded knowledge as being derived from scriptural sources.
  • The Rationalists who only used reasoning or takka.
  • The "Experientialists" who held that besides reasoning, a kind of supra-normal yogic insight was able to bring about unique forms of knowledge.
The Buddha rejected the first view in several texts such as the Kalama sutta, arguing that a claim to scriptural authority 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. 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, 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. The Kalama sutta states that verification through one's own personal experience 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" 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 : "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. 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.
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. The early texts also mention that there was a set procedure 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 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
  • Those which cannot be asserted or denied categorically, which the Buddha further divided into:
  • *Those which after analysis 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.
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
  • 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 could be used in conventional everyday speech while at the same time not referring to anything that exists ultimately. 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 into two types with regards to their meaning: those which were intelligible, meaningful and those meaningless or incomprehensible. 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 were ultimately meaningless, because they could not be verified.
The Buddha, like his contemporaries, also made use of the "four corners" logical structure as a tool in argumentation. According to Jayatilleke, these "four forms of predication" can be rendered thus:
  1. S is P, e.g. atthi paro loko.
  2. S is not P, e.g. natthi paro loko.
  3. S is and is not P, e.g. atthi ca natthi ca paro loko.
  4. S neither is nor is not P, e.g. n'ev'atthi na natthi paro loko
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.