Indian Epistemology: Part 1

Validity - from the Nyaya (न्याय) perspective

This post builds on the framework explored in a previous post: Navigating Indian Philosophy

Among the six orthodox (āstika) schools of Hindu philosophy, the Nyaya school is credited with forging the epistemological foundation that has come to serve as a common framework across the different traditions. In Sanskrit, the word Nyaya (न्याय) roughly translates to “judgment” or “rules” - aptly reflecting the school’s realist approach and rigorous methodologies. While the fabric of Nyaya philosophy is vast - and intertwines with the neighboring Vaisheshika school - there is a central conviction: personal liberation is obtained through knowledge of our underlying reality; and it is therefore imperative to distinguish and pursue valid knowledge.

Nyaya practitioners trace the origin of the school to The Vedas themselves - citing ancient passages that suggest a principal focus on ontological speculation. One particularly famous excerpt from The Rigveda (the oldest of the four Vedas) is known as the Nasadiya Sukta - or the Hymn of Creation:

“Then even non-existence was not there, nor existence,
There was no air then, nor the space beyond it.
What covered it? Where was it? In whose keeping?
Was there then cosmic fluid, in depths unfathomed?”

Rigveda 10.129.6 (trans. A. L. Basham)

The latter part of the Vedic Period (~500 BC onwards) saw an explosion of logical and epistemological inquiries, which served as precursors to the formal schools that later developed. Aksapada Gautama is credited with producing the first rigorous curation of the various strains of discursive thinking. In his Nyaya Sutras, Gautama is exacting in his delineations; covering a set of logical, methodological, and philosophical topics that span five books - each subdivided into two discrete sections. There is ongoing debate on when the Nyaya Sutras were written; the prevailing scholarship points to the second century CE, while others claim an earlier origin.

In any case, the compendium has served as the foundational text for the Nyaya school - and fostered ~2000 years of refinement, critique, and conceptual development that have proven essential to India’s theological substrate.

A Paradigm of Validity

Gautama opens the Nyaya Sutras by delineating sixteen categories of knowledge, which apply to any field of study - whether vocational, religious, or altogether without practical application. These categories include the process of reasoning (tarka), the attributes of valid discussion (vāda), the nature of fallacies (hetvābhāsa), among others. The heart of the text, however, is Gautama’s exposition on epistemology, where he outlines the requirements for valid, truthful knowledge. He begins by explaining that, in the Nyaya framework, any valid claim must satisfy three discrete conditions.

The first condition is known as asamdigdha, or decisive cognition. This is essentially a phenomenological qualification, asserting that a given subject must be reliably and independently ascertainable. If there are conflicting perspectives on how to identify the subject in question (or whether the subject even exists at all), it is classified as indecisive cognition - and outside the scope of formal inquiry. The second condition for validity is known as yathartha, or consistency in the intrinsic attributes associated with a particular subject. This amounts to ongoing confidence that these intrinsic properties - however they are defined - do not change situationally or randomly. Taken together, these first two criteria present the table stakes: if a subject cannot be clearly and independently ascertained, or if a subject eludes any stable qualitative definition, then it cannot be the source of truly defensible information.

The third and final condition is known as anubhava - a textured term that, in the Nyaya context, pertains to direct perception. I.e., information obtained via indirect, recollective, or representational perception cannot form the basis of valid knowledge; the subject has to be immediately perceived. As will be discussed, there is a degree of nuance here - since valid knowledge can be transmitted between people through representative forms. The key, in these cases, is that the valid knowledge was established through direct perception, prior to any subsequent transmission.

The Components of Cognition

Any claim that satisfies the three aforementioned criteria can qualify as prama (प्रमा) - i.e., an epistemologically valid piece of knowledge. An individual instance of prama is always considered in tandem with the method, or pramana (प्रमाण), that produced it; e.g., direct perception, inferential reasoning, or other practical methods that will be detailed in this and future posts. The different schools of Indian philosophy differ not only in their criteria for prama, but also in the particular pramanas that are considered to be methodologically trustworthy. The remainder of this post will focus on the Nyaya school’s (foundational) version of both concepts.

In his writings, Gautama describes four components that are essential to every pramana. The first component is the cognizer, or the person who is engaged in the potential acquisition of knowledge. In Nyaya’s metaphysics, valid knowledge (prama) is processed within the cognizer’s physical faculties, but ultimately retained in their soul. The second component is the decisive and unambiguous subject - whether a physical object, a blend of material substances, or a subtle (e.g., mental) phenomenon.

The third aspect of every pramana is known as karanam, or the proximate causation that facilitates the cognitive process. As an example: through direct perception I might observe that water causes solid clay to lose its shape. The dynamic that exists between the water and the clay is key to forming the insight; without this specific set of subject-centric interactions, I would be unable to glean the relevant information. The fourth and final component of the knowledge process is, naturally, the cognition itself - which occurs within the mind, and in Nyaya’s framework, imprints upon the soul. This seemingly mundane detail is essential to Nyaya’s placement among the āstika traditions. While other schools have critiqued Nyaya’s ambiguous definitions of the divine, and its overwhelming focus on methodology and rational inquiry - Gautama here considers participation by the immortal soul to be a non-negotiable requirement for any pramana.

Four Pramanas

In Nyaya epistemology, the first and foremost of the pramanas is pratyaksa (प्रत्यक्ष) - or direct perception. Perception is broadly categorized into external and internal modes. External perception is what you might expect: the direct interaction between the cognizer’s five senses and a set of worldly phenomena. If the aforementioned three criteria are met, this is the most straightforward method of obtaining knowledge (prama). Internal perception involves subtle phenomenon that can be reliably grasped within one’s mind, but do not have overtly material features. The bar for demonstrating validity is higher, in these cases - since independent verification is more difficult to establish. Nyaya even includes supernatural perception (yoga pratyaksa) within this same framework; as the steady accumulation of knowledge gradually removes the cognizer’s mental impurities, Gautama asserts that it becomes possible to detect and rigorously establish more advanced (and even traditionally hidden) knowledge.

The second pramana is known as anumana (अनुमान), or inferential reasoning. The canonical example that Gautama uses to explain this method is observing smoke on a forest hill, and inferring that fire must have caused it. In order to trust this inference, there must be preexisting trust in the relationship between fire and smoke; this mirrors aspects of Aristotle’s writing on syllogistic reasoning. The Nyaya Sutras provide a set of criteria for establishing confidence in such “reasoned relational inferences” - including the fundamental requirement that the link was established through a valid instance of direct perception. In other words: inference is a valid pramana, as long it depends upon knowledge derived from direct perception.

The third pramana is upamana (उपमान), or knowledge gained through comparison or analogy. Gautama depicts this as the ability to gain knowledge on a particular subject, based on its similarity to existing knowledge. The illustrative example is that of a wild cow, which the cognizer has never seen before. They are told that the wild cow is like a normal cow - but with different horns, and a different color. This mental abstraction is then used to identify a wild cow, when one is eventually encountered. Like with inferential reasoning, the process hinges on direct perception; in this case, the eventual direct perception of the wild cow is required for the preliminary comparative abstraction to transform into valid knowledge.

The fourth and final pramana that the Nyaya tradition accepts as valid is known as sabda (शब्द), or verbal testimony. This pramana is the source of much debate, among the different schools; some find it impossible to defend claims that are simply the result of spoken word. Others, like the Nyaya school, allow it - with considerable caveats. These include intricate criteria for how to determine which people are credible on which topics, and the level of detail required (which depends on the type of subject one is attempting to learn about). It’s generally understood that all of the āstika schools accept some degree of verbal testimony, given The Vedas were - and remain to this day - canonically transmitted through spoken word and sound.

Onward

Suffice to say, this post has only provided a glimpse into the Nyaya school’s realm of consideration, and the broader epistemic fabric that it helped define. In future posts, I’ll explore the metaphysics of the Nyaya and associated Vaisheshika teachings, and also delve deeper into the nuances of the pramanas - both the primary four, and the remaining handful that are relevant to the other key traditions. You’ll have to decide for yourself whether or not what I’ve written can be accepted as valid knowledge…