(a) How do I know that I know ? Answer this question with reference to the Naiyāyikas, the Bhāṭṭa Mīmāṃsākas and the Prābhākaras…

(a) How do I know that I know?

The question of meta-cognition and epistemic justification reveals fundamental divergences in classical Indian epistemology regarding whether knowledge is self-luminous (svaprakāśa) or known through another cognition (paraprakāśa), and whether its validity is intrinsic (svataḥ) or extrinsic (parataḥ).

The Naiyāyikas advocate paraprakāśa and parataḥ-pramāṇyavāda. A primary cognition (vyavasāya, e.g., "This is a pot") reveals only its external object, not itself. I know that I know through a subsequent, distinct introspective perception termed anuvyavasāya ("I perceive this pot"). This second-order cognition takes the first cognition as its object through mental perception (mānasa-pratyakṣa). Furthermore, the epistemic truth of this cognition is not self-certified; its validity (prāmāṇya) is established extrinsically through successful pragmatic action (saṃvādi-pravṛtti-sāmarthya).

The Bhāṭṭa Mīmāṃsākas reject both anuvyavasāya and self-luminosity. Knowledge is an act (kriyā) that is imperceptible (atīndriya). When an object is known, an epistemic property called "cognizedness" or "manifestedness" (jñātatā or prākaṭya) is produced in the object. I know that I know through an inference from this result (phala): "The object has the property of knownness; this knownness must have a cause; therefore, I have a cognition of the object." Many Bhāṭṭas describe this as postulation (arthāpatti) rather than inference proper. For Bhāṭṭas, while the apprehension of knowledge is indirect, its validity is intrinsic (svataḥ-pramāṇya), held to be valid unless vitiated by defeaters (bādhaka-jñāna).

The Prābhākara Mīmāṃsākas propose the doctrine of tripuṭī-saṃvit-vāda (triune perception). Knowledge is self-luminous (svaprakāśa). In every act of knowing, three factors are simultaneously revealed: the knower (mātā), the known object (meya), and the knowing itself (miti). There is no need for a subsequent anuvyavasāya or an inferential jñātatā. In knowing the pot, I immediately know that I know it. Prābhākaras also uphold svataḥ-pramāṇyavāda, asserting that all apprehensions (anubhūti) are intrinsically valid; what is called error is merely a practical failure of non-discrimination (akhyāti).

(b) The candidate never seen studying: Bhāṭṭa versus Nyāya

The case of a candidate never observed studying by day yet securing a high rank illustrates the epistemological clash between postulation (arthāpatti) and inference (anumāna).

The Bhāṭṭa Mīmāṃsākas explain this success through arthāpatti (presumption/postulation), as articulated by Kumārila Bhaṭṭa in the Ślokavārttika. There is an apparent contradiction (virodha) between two established facts: the observed daytime leisure and the exceptional examination success. To resolve this conflict and render the facts coherent, the mind posits the unobserved fact: "The candidate studies secretly at night." This is exactly the classic example 'fat Devadatta does not eat by day', from which eating at night is postulated. Arthāpatti cannot be reduced to inference, because before the postulation we have no known vyāpti linking the reason to night-study in this case. For Bhāṭṭas, arthāpatti is an independent pramāṇa rooted in dṛṣṭa-arthāpatti or śruta-arthāpatti, operating to eliminate an epistemic impasse rather than deriving conclusions from a universal rule.

The Naiyāyikas, represented by Gaṅgeśa in the Tattvacintāmaṇi, reject arthāpatti as an independent source of knowledge, reducing it to anumāna (inference), as already argued in Nyāya Sūtra 2.2.1–2; later Nyāya treats it as a purely negative (kevala-vyatirekī) inference. The success is explained through a standard five-membered syllogism (pañcāvayava) grounded in invariable concomitance (vyāpti) between the effect (high rank) and the cause (diligent study): The candidate possesses night-study (pratijñā); because of exceptional exam success despite daytime leisure (hetu); whoever achieves exam success without daytime study engages in night-study, like other past successful candidates (dṛṣṭānta). Since effect cannot arise without cause (kāraṇa-kārya-sambandha), daytime absence logically restricts the locus of study to the night via contrapositive inference (vyatireki-anumāna).

(c) Rejection of memory as a pramāṇa

Both Prābhākaras and Naiyāyikas exclude memory (smṛti) from the status of valid knowledge (pramā), but on distinct technical grounds.

The Prābhākaras define pramā strictly as anubhūti (fresh apprehension). Memory (smaraṇa) is rejected because it is entirely caused by the revival of past residual impressions (saṃskāra-mātra-janya). It lacks novelty, merely reproducing what was already apprehended. It grasps what has already been grasped (gṛhīta-grāhī) and presents its object as 'that' (tattā), as previously experienced. Prābhākaras also use it to explain error: in 'this is silver', a remembered silver loses its 'that' mark (smṛti-pramoṣa) and is not discriminated from the perceived shell (akhyāti). Because memory depends upon a previous cognition, it lacks epistemic autonomy.

The Naiyāyikas define pramā as yathārtha-anubhava (veridical present apprehension). Memory is classified as smṛti-jñāna rather than pramāṇa-janya jñāna. It lacks the requisite causal apparatus (pratyakṣa-lakṣaṇa) of a valid source: it operates without present sense-object contact (indriyārtha-sannikarṣa) in perception and lacks a present middle term (liṅga) in inference. The object in memory is past and may no longer exist as remembered, and memory's truth is borrowed from the original experience. Nyāya grants that memory can be true (yathārtha), but it is not anubhava and so not pramā; Jainas, by contrast, accept smṛti as a form of indirect (parokṣa) valid knowledge.

These debates mirror deeper philosophical commitments: Nyāya realism demands external verification (parataḥ) and strict causal chains for valid apprehension, while Mīmāṃsā asserts the self-validating nature of cognition (svataḥ) to secure the unquestionable authority of Vedic injunctions without falling into infinite regress.