(a) How do the advocates of anirvacanīya-khyāti refute the position of the Naiyāyikas and establish the position of Advaitins…

(a) Anirvacanīya-khyāti against Nyāya on the problem of error

Take the standard case, the shell mistaken for silver. Advaita holds that the silver seen is anirvacanīya, indescribable as either real or unreal. It is not real (sat), since later knowledge ("this is not silver") sublates it. It is not wholly unreal (asat), like a hare's horn, since it is actually perceived and induces action. It is produced by avidyā, whose power of veiling (āvaraṇa) hides the shell and whose power of projection (vikṣepa) casts silver in its place. Such silver is prātibhāsika (apparent) and lasts only until sublated (Vedāntaparibhāṣā).

The Naiyāyika view is anyathā-khyāti: real silver elsewhere is perceived as present here, by the contact of memory (jñāna-lakṣaṇa pratyāsatti). Advaitins object as follows.

First, the silver in a shop is not available to the perceiver's sense, so it cannot be perceived here; invoking a memory link makes error a mere remembering, but the erring person feels immediate presentation ("this is silver").

Second, the sublating judgement is "this is not silver", not "silver is elsewhere", so what is denied is the silver here.

Third, the person stoops to pick it up, so the silver functions as present, which a remembered thing cannot do.

Advaita concludes that error needs a positive indescribable appearance caused by avidyā, a pattern that applies also to the world as seen through Brahman (rope-snake analogy).

Evaluation: Rāmānuja (sat-khyāti) says every cognition has a real object, and error arises from partial mixing of elements. Critics say "neither real nor unreal" violates the law of excluded middle; Advaitins answer that reality means "unsublatable at all times", and that indescribability follows from this definition. But avidyā itself is invoked as indescribable, which a rival may call a circle.

(b) Momentariness, memory and personal identity

If everything is momentary (kṣaṇikavāda), a Buddhist needs to explain why we remember and why we seem to be the same person. The answer is causal continuity, not a permanent substrate. A person is a stream (santāna) of five aggregates in which each moment arises dependent on the previous one (pratītyasamutpāda), and transmits to the next its impressions (saṃskāra, vāsanā). Memory then arises because the later moment inherits the impression of the earlier one, as the milk's quality passes to curd. In the Milindapañha, Nāgasena compares identity with the flame lit from another lamp: neither the same nor different.

The Yogācāra school adds the storehouse consciousness (ālayavijñāna) where karmic seeds (bīja) are kept and ripen. This explains karma and rebirth too, since the responsible agent is the continuing stream.

Critically: Naiyāyikas say recognition ("this is the same Devadatta") requires one enduring knower. Buddhists answer that recognition rests on similarity and is a conceptual construct. A subtler objection is that responsibility becomes odd if the doer and the one rewarded are not identical, which led the Pudgalavādins to posit an ineffable pudgala. Buddhists reply that the lineage of causation is enough for moral continuity, as with flame to flame.

(c) The Jain view of seven-fold naya

The question joins two Jain ideas. A naya is a partial standpoint taken to express one aspect of a reality that has infinite aspects (anekāntavāda). Jainism has seven nayas: naigama (common-sense, purposive), saṅgraha (general, class-wise), vyavahāra (particular, practical), ṛjusūtra (the present moment), śabda (verbal usage), samabhirūḍha (etymological difference of synonyms) and evambhūta (the word applies only to the thing performing the act it denotes). Together they cover the aspects of a thing from the wider to the narrower. Each is true as far as it goes, while claiming it is the whole turns it into a fallacy (nayābhāsa).

Sapta-bhaṅgī is the seven-fold predication of syādvāda, with each assertion qualified by syāt ("in a way"): (1) syād asti, (2) syān nāsti, (3) syād asti nāsti, (4) syād avaktavyam, (5) syād asti avaktavyam, (6) syān nāsti avaktavyam, (7) syād asti nāsti avaktavyam. Each is stated from some standpoint, so the nayas supply the viewpoint and the sapta-bhaṅgī the form of the judgement. Together they show that reality can be partly known from many angles and no single view is final.