India Wrote Down Six Rival Rules for What Counts as Evidence — and Two of Its "Orthodox" Schools Never Needed God

Allahabad, 1913: a logician's hill catches fire

The Indian Press, Allahabad. A printer named Apurva Krishna Bose is setting type for Volume VIII of the Sacred Books of the Hindus, to be published from the Panini Office in Bahadurganj. The translator is Satish Chandra Vidyabhusana, Principal of the Sanskrit College in Calcutta; the book is the Nyaya Sutras of Gotama, a complete English rendering of India's foundational text on logic.

Its first sentence is a list. "Supreme felicity is attained by the knowledge about the true nature of sixteen categories," the sutra says, and names them: means of right knowledge, object of right knowledge, doubt, purpose, familiar instance, established tenet, members, confutation, ascertainment, discussion, wrangling, cavil, fallacy, quibble, futility, and occasion for rebuke. (Nyaya Sutra 1.1.1, trans. Vidyabhusana, p. 1)

Discussion. Wrangling. Cavil. Quibble. Rebuke. This is not a book about God. It is a book about how to win an argument fairly, written for people who expected to spend their lives in public debate.

Nine pages on, under sutra 1.1.32, Vidyabhusana lays out the argument every Indian student of logic learned first. "Proposition. This hill is fiery. Reason. Because it is smoky. Example. Whatever is smoky is fiery, as a kitchen. Application. So is this hill (smoky). Conclusion. Therefore this hill is fiery." (gloss on 1.1.32, p. 10)

Nyaya was one of six. The others were Vaisheshika, Sankhya, Yoga, Mimamsa and Vedanta. Each has a founder, a core text, a list of what it accepts as evidence, and one argument it is remembered for. Together they are called the six darshanas, and together they are called orthodox. This Investigation opens each one's sutras and asks what that word was about.

At a glance

• Sixteen categories open the Nyaya Sutra, and most of them are about debate. (Nyaya Sutra 1.1.1, trans. Vidyabhusana 1913, p. 1)
• Four means of knowledge in Nyaya; three in Sankhya and Yoga; two in Vaisheshika; six in Bhatta Mimamsa and Vedanta. (Vidyabhusana's note on 1.1.3, p. 2; Sankhya Karika 4; Yoga Sutra 1.7)
• Six "predicables" make up the Vaisheshika world, and the eternal is "that which is existent and uncaused." (Vaisheshika Sutra 1.1.4 and 4.1.1, trans. Sinha 1911, 2nd ed. 1923)
• Zero mentions of a creator in the seventy-two verses of the Sankhya Karika; Gaudapada's commentary on verse 61 argues against one. (Colebrooke and Wilson 1837)
• The Veda is eternal, not authored: a section called Kathaka is named for the man who studied it best, not its author. (Mimamsa Sutra 1.1.29–30, trans. Jha 1916)
• Between 300 and 500 CE is Woods's dating of the Yoga Sutra; Vidyabhusana puts Gautama of Nyaya at about 550 BCE but says only Book I can safely be his. (Woods 1914, Introduction §4; Vidyabhusana 1913, Introduction)

First, the words a beginner needs

Darshana (darśana). Literally "a seeing": a complete system with its own answers to what exists, how we know it, and what to do about it. After this we say "school."

Sutra (sūtra). "A thread." A very short aphorism designed to be memorised. Because sutras are so compressed, every sutra text needs a commentary (bhāṣya); quotations below say which is which.

Pramana (pramāṇa). "A means of right knowledge": a source of evidence a school accepts as able to settle a question. The six argued over are perception (pratyakṣa), inference (anumāna), testimony (śabda: the word of a reliable source, including scripture), comparison (upamāna: knowing a thing by its likeness to something known), postulation (arthāpatti: assuming what must be true to explain a fact) and non-apprehension (abhāva: knowing something is absent because you would have seen it).

Astika and nastika (āstika, nāstika). "Orthodox" and "heterodox." Classically, astika means accepting the authority of the Veda; nastika means rejecting it. Buddhists, Jains and the materialist Charvakas were nastika. The word does not say "believes in God."

Veda. The oldest Sanskrit scriptures. For these schools, not a book someone wrote but a body of sound that was heard, not composed.

Ishvara (īśvara). "The Lord": a personal God who rules the world. Distinct from Brahman, the impersonal ultimate reality of the Upanishads. A school can accept one, both, or neither.

Purusha and prakriti (puruṣa, prakṛti). In Sankhya and Yoga, the conscious witness (Colebrooke's "soul") and unconscious matter-energy (his "nature"). Everything we experience, including the mind, is prakriti.

Guna (guṇa). The three strands of prakriti: sattva (clarity), rajas (energy) and tamas (heaviness). Colebrooke's words are "goodness, foulness, and darkness."

Brahman. In Vedanta, the one reality from which the world comes.

The claim we are testing

The popular version: "Hinduism has six orthodox schools, which all accept God and the Veda, as against the atheist Buddhists and Jains." Layer by layer:

1. Six schools, each with a founder and a sutra text, grouped in three pairs. True of the texts, though no early sutra text says "there are six."
2. All six accept the Veda. True: none rejects it; Sankhya and Yoga accept scripture as one of three evidences.
3. All six accept God. Myth as a generalisation. Nyaya argues for God. Yoga names Ishvara as "a special kind of Self." The Sankhya Karika never mentions a creator and its oldest commentary argues against one. Mimamsa holds the Veda has no author; its sutras refute human authorship, and the later school extended the refusal to a divine one. Vaisheshika's sutra on the Veda is ambiguous, though sutra 6.1.1 gives the Veda an intelligent author; the commentator supplies the name of God.
4. "Orthodox" meant "theist," and the six agreed on what counts as evidence. Myth on both counts. The line is the Veda, not God; and they accepted from two to six pramanas, with the disagreement written into their opening sutras.

School one: Nyaya, and the kitchen that proves the hill

The Nyaya Sutra is ascribed to Gautama, also called Akshapada, "having eyes in the feet." Vidyabhusana places him at about 550 BCE by combining the Vayu Purana with the teacher-lists of the Satapatha Brahmana, and adds that "we do not know whether the whole of the Nyaya-Sutra, as it exists at present, was the work of Aksapada," that only Book I can safely be his, and that Books II–IV quote "almost verbatim" from Buddhist works of the early centuries CE. (Vidyabhusana 1913, Introduction) The core is old; the text is layered.

Its theory of evidence is one sutra:

pratyakṣānumānopamānaśabdāḥ pramāṇāni — "Perception, inference, comparison and word (verbal testimony) — these are the means of right knowledge." (Nyaya Sutra 1.1.3, trans. Vidyabhusana, p. 2)

Perception is "knowledge which arises from the contact of a sense with its object and which is determinate, unnameable and non-erratic." (1.1.4, p. 3) Inference is "knowledge which is preceded by perception," of three kinds, the third being the commonly seen: "one seeing smoke on a hill infers that there is fire on it." (1.1.5, p. 3)

Then the five-step argument: sutra 1.1.32 lists the members, sutras 33 to 39 define each. The example is not decoration: it is the evidence that "whatever is smoky is fiery" holds in at least one place everyone has seen. Nyaya also provides for a negative example: "Whatever is not non-eternal is not produced, as the soul." (1.1.37, p. 12) Vidyabhusana notes that some logicians added objections, including "that which you call smoke may be nothing but vapour," and "in a red-hot iron-ball there is no smoke." (gloss on 1.1.32, p. 10) That is the Nyaya temperament: build the rule, then hunt for the case that breaks it.

Does Nyaya need God? Its sutras argue that it does. Book IV weighs the view that "God ... is the sole cause of fruits" against the view that without human acts there are no fruits, and settles it: "Since fruits are awarded by God, man's acts, we conclude, are not the sole cause thereof." The commentary calls this God "a soul specially endowed with qualities," "as it were, the father of all beings." (Nyaya Sutra 4.1.19–21 and gloss) Nyaya is theist, and states it as a settled tenet; the same gloss adds that God "transcends the evidences of perception, inference and scripture."

School two: Vaisheshika, and the smallest thing that can exist

Kanada's Vaisheshika Sutra was translated by Nandalal Sinha in the same Allahabad series. It opens athāto dharmaṃ vyākhyāsyāmaḥ, "Now, therefore, we shall explain Dharma." (1.1.1, trans. Sinha 1911, 2nd ed. 1923) Its real subject is sutra 1.1.4: "The Supreme Good (results) from the knowledge ... of the essence of the Predicables, Substance, Attribute, Action, Genus, Species, and Combination." Those six padārtha are Vaisheshika's inventory of everything that can be named.

Its famous argument is about the smallest things. Book IV opens: sad akāraṇavan nityam, "The eternal is that which is existent and uncaused." The next sutra, tasya kāryaṃ liṅgam: "The effect is the mark (of the existence) of the ultimate [atom]." (4.1.1–2, trans. Sinha) The reasoning, spelled out in Shankara Mishra's Upaskāra which Sinha prints alongside: a pot has parts; the parts have parts; the division cannot go on for ever. So there must be a smallest, partless, uncaused thing, the paramāṇu. Two of these make a dyad (dvyaṇuka), and the commentator describes "the formation of a dyad by two ultimate atoms, and so on" as the way "a large whole made up of parts" is built. (Upaskāra on 2.1.11, trans. Sinha) The Nyaya Sutra uses the same argument against a Buddhist: "If all things were indefinitely divisible we should find a large thing and a small one to be of equal dimensions as both possess an infinite number of parts." (Nyaya Sutra 4.2.25 gloss) This is not modern atomic physics. It is an argument from the impossibility of infinite division, and a good one.

And God? Vaisheshika's sutra on the Veda reads, in Sinha's translation, "The authoritativeness of the Veda (arises from its) being the Word of God [or being an exposition of dharma]." (1.1.3) Look at that bracket. The Sanskrit is tadvacanād āmnāyasya prāmāṇyam, "the Veda is authoritative because it is the utterance of that." The sutra does not say whose. It is the fifteenth-century commentator Shankara Mishra who writes that "'Tat' alludes to God whose existence is well-known, although the word does not appear in the context," before allowing that "'tat' refers to dharma only"; a later gloss adds that "the word 'tat' itself denotes Isvara." (Upaskara and Vivriti on 1.1.3, trans. Sinha) The sutra never names Ishvara. It is not silent on an author of the Veda, though: sutra 6.1.1, buddhipūrvā vākyakṛtir vede, "In the Veda the composition of sentence has been preceded by understanding," gives the Veda an intelligent author, and the commentators read that as God. (6.1.1, trans. Sinha) The premise is in the text; the name was supplied later.

School three: Sankhya, and the world with no maker

The Sankhya Karika of Ishvarakrishna is seventy-two memorial verses, the oldest complete Sankhya work that survives. Henry Thomas Colebrooke translated the verses; Horace Hayman Wilson published them at Oxford in 1837 with Gaudapada's commentary. The first verse states the purpose: "The inquiry is into the means of precluding the three sorts of pain." (Karika 1, Colebrooke 1837)

Its theory of evidence is verse 4:

dṛṣṭam anumānam āptavacanaṃ ca sarvapramāṇasiddhatvāt — "Perception, inference, and right affirmation, are admitted to be threefold proof; for they (are by all acknowledged, and) comprise every mode of demonstration." (Karika 4, Colebrooke, p. 18)

Gaudapada explains why only three: the others are folded in. "Presumption is included in inference, and proportion, privation, comprehension, oral communication, and comparison, are comprehended in right affirmation." (Gaudapada on Karika 4) That is how the schools fought about evidence: not by denying you can know a thing from its absence, but by arguing whether that is a separate kind of knowing.

The famous Sankhya idea is the split between purusha and prakriti. Verse 3 lays out twenty-five principles: nature, which produces; seven which are produced and produce; sixteen which are only produced; and soul, which "is neither a production nor productive." (Karika 3, p. 16) Prakriti is made of "goodness, foulness, and darkness," and everything that evolves from it, including intellect, ego and the senses, shares them. Soul is "the reverse": "devoid of qualities," and in verse 19 "witness, solitary, bystander, spectator, and passive." (Karikas 11, 19, pp. 45, 78) Verse 17 gives five reasons soul must exist, the first being that "the assemblage of sensible objects is for another's use": a chair implies a sitter. (Karika 17, p. 65) The upshot: your mind is not you. Your thoughts are prakriti, matter moving; you are the unmoving light they are seen by.

Now God. Verse 59 compares nature to a dancer who leaves the stage when her performance is done; verse 61 adds that once she has been seen by soul she does not show herself again. Commenting on it, Gaudapada reports what "the Sankhya teachers have said" to those who make Ishvara the cause of the world: "How can beings endowed with qualities proceed from Iswara, who is devoid of qualities? ... from white threads white cloth is fabricated; from black threads black cloth: and in the same manner, from nature, endowed with the three qualities, the three worlds ... are produced." (Gaudapada on Karika 61, trans. Wilson)

We looked for Ishvara in the seventy-two verses. He is not there. Sankhya builds a complete account of the world, the mind and liberation and finds no job for a creator. For that it was called nirīśvara, "without a Lord," and it was still astika, because it never denied the Veda.

School four: Yoga, and the mind as a thing that can be stilled

Patanjali's Yoga Sutra takes Sankhya's map and turns it into a method. James Haughton Woods's 1914 Harvard translation dates the text "between A.D. 300 and A.D. 500." (Woods 1914, Introduction §4) Its second sutra is among the most quoted lines in Indian philosophy:

yogaś cittavṛttinirodhaḥ — "Yoga is the restriction of the fluctuations of mind-stuff." (Yoga Sutra 1.2, trans. Woods)

"Mind-stuff" is Woods's word for citta, the whole apparatus of thinking and perceiving treated as a material thing. The next sutra says why you would still it: "Then the Seer [that is, the Self] abides in himself." (1.3) This is Sankhya exactly: the mind moves, the self watches, and suffering is the watcher mistaking the movements for itself. Yoga's pramanas are Sankhya's: "Sources-of-valid-ideas are perception and inference and verbal-communication." (1.7)

But Yoga parts from Sankhya on God. Sutra 1.23 says concentration "is attained by devotion to the Içvara," and 1.24 defines him:

kleśakarmavipākāśayair aparāmṛṣṭaḥ puruṣaviśeṣa īśvaraḥ — "Untouched by hindrances or karmas or fruition or by latent-deposits, the Içvara is a special kind of Self." (1.24, trans. Woods)

Note what kind of God this is. Not a creator. A purusha like every other, except never bound, and therefore "Teacher of the Primal [Sages] also." (1.26) Yoga is seśvara Sankhya, "Sankhya with a Lord": the same twenty-five principles, plus one perfect soul to meditate on.

School five: Mimamsa, and the book that nobody wrote

Jaimini's Mimamsa Sutra is the largest of the six and the least read, because its subject is Vedic ritual. But it contains the sharpest argument any of the six makes about evidence, and it is an argument that scripture has no author at all.

Ganganatha Jha's 1916 translation reaches the definition at its second sutra: codanālakṣaṇo 'rtho dharmaḥ, "Dharma or Duty is that which, being desirable, is indicated (or taught) by Vedic injunction." (1.1.2, trans. Jha) Then the sutra every later school had to answer:

autpattikas tu śabdasyārthena sambandhaḥ — "The relation of the word with its meaning is inborn (and eternal); consequently injunction (which is a form of word) is the means of knowing dharma; and it is unfailing in regard to objects not perceived (by other means of knowledge); it is authoritative, according to Badarayana, specially as it is independent or self-sufficient in its authority." (1.1.5, trans. Jha)

Words and their meanings were never invented; they are as old as the world. Then, in sutras 27 to 31, Jaimini meets the obvious objection. The opponent says the Veda must have authors, "being, as they are, named after men": the Kathaka branch after Katha, the Paippalada after Pippalada. (1.1.27) And the Veda mentions people, "Auddalaki desired," who lived in time. (1.1.28) Jaimini's reply is two words: ākhyā pravacanāt, "The name [of the Vedic sections] is based upon exceptionally excellent study and teaching [of that section by a particular person]." (1.1.30) Katha did not write the Kathaka; he taught it so well that it took his name. The names of persons in the text are "only a similarity of sounds." (1.1.31)

Later writers call this apauruṣeya, "not from a person." The word is not in these sutras; the idea is. And it has a consequence most readers miss. If the Veda had a divine author, its authority would rest on his reliability, and you would need a separate proof that he exists and does not lie. Mimamsa refuses the detour: scripture is self-authorising because nobody made it. God is not denied so much as made unnecessary, and the school's standing as astika was never questioned, because nobody accepted the Veda harder.

School six: Vedanta, and the sentence three men read three ways

Badarayana's Brahma Sutra is so compressed that the school is defined by its commentators. George Thibaut translated Shankara's commentary in 1890 (Sacred Books of the East 34) and Ramanuja's in 1904 (volume 48); S. Subba Rau published Madhva's in Madras in 1904. All three open on the same words:

athāto brahmajijñāsā — "Then therefore the enquiry into Brahman." (Brahma Sutra 1.1.1, trans. Thibaut, SBE 34, p. 9)

The second sutra defines the subject: janmādy asya yataḥ, "(Brahman is that) from which the origin, &c. (i.e. the origin, subsistence, and dissolution) of this (world proceed)." (1.1.2, p. 15) Thibaut's footnote here identifies the rival accounts of the world's cause that Shankara lists as those of "the followers of the Nyaya, the Sankhya, and the Yoga-philosophy," "various materialistic schools" and "two sects of Bauddha philosophers." (SBE 34, p. 15 n.)

Vedanta's evidence is the Upanishads, and its central text is one sentence from the Chhandogya, tat tvam asi, "That art thou," spoken by a father to his son Shvetaketu. Three commentators read it three ways.

Advaita ("non-dual"), Shankara, eighth century. The self and Brahman are one; the difference is an error. Shankara opens with a page on adhyāsa, which Thibaut renders "superimposition," "(mistaken) ascription ... to something, of an essential nature or attributes not belonging to it." (SBE 34, p. 3 n.) In Thibaut's summary, the student "whom passages such as the great saying, 'That art thou,' have taught that there is no difference between his true Self and the highest Self, obtains at the moment of death immediate final release." (SBE 34, Introduction, p. xxvii) The sentence is a statement of identity.

Vishishtadvaita ("qualified non-dualism"), Ramanuja, eleventh to twelfth century. Brahman is "that highest Person who is the ruler of all ... omniscient, omnipotent, supremely merciful," (SBE 48, p. 156) and souls and matter are real and are his body: "the entire aggregate of things, intelligent and non-intelligent, has its Self in Brahman in so far as it constitutes Brahman's body," so "the text 'that art thou' we therefore understand merely as a special expression of the truth already propounded in the clause 'in that all this has its Self.'" (SBE 48, pp. 134–135) You belong to God; you are not God.

Dvaita ("dualism"), Madhva, thirteenth century. Souls, matter and God are eternally different, and God is Vishnu. We could not open Madhva's commentary sutra by sutra; Subba Rau's 1904 summary of the first adhyaya puts his approach in one sentence: "The difference consistently stated by the Sruti cannot be refuted or abandoned by mere ingenuity of syllogistic reasoning." (Subba Rau 1904, p. xxiii) Madhva's own reading of the sentence is famous in the tradition; we have not verified it and say so below.

Read the actual document

Vidyabhusana's note on Nyaya Sutra 1.1.3 gives the whole map of who trusts what in six lines:

"The Carvakas admit only one means of right knowledge, viz., perception (pratyaksa), the Vaisesikas and Bauddhas admit two, viz., perception and inference (anumana), the Sankhyas admit three, viz., perception, inference and verbal testimony (agama or sabda) while the Naiyayikas whose fundamental work is the Nyaya-sutra admit four, viz., perception, inference, verbal testimony and comparison (upamana). The Prabhakaras admit a fifth means of right knowledge called presumption (arthapatti), the Bhattas and Vedantins admit a sixth, viz., non-existence (abhava) and the Pauranikas recognise a seventh and eighth means of right knowledge, named probability (sambhava) and rumour (aitihya)." — Nyaya Sutras of Gotama, trans. S.C. Vidyabhusana (Allahabad, 1913), note on 1.1.3, p. 2

In plain words: the materialists trust only their eyes. Vaisheshika and the Buddhists add reasoning. Sankhya and Yoga add the word of a reliable person, which is how scripture gets in. Nyaya adds knowing by likeness: a forester says a gavaya is like a cow; you see a cow-like animal; you know it is a gavaya. (1.1.6, p. 4) The Mimamsa sub-schools add presumption (Devadatta is fat and never eats by day, so he eats at night) and absence (no pot on the table, because I would see it). Vedanta takes all six.

How they fought the Buddhists and the Jains

The six were not six quiet monasteries. Their sutras are full of other people's voices, and the most important were nastika.

Nyaya Book IV takes on the Yogachara Buddhist claim that only thoughts are real: "Things, some say, do not possess a reality if they are separated from our thoughts, just as there is no reality in a web separated from its threads." Gautama's answer is one line, "The reason, we reply, is not good as it hurts itself": if things can be separated from thoughts they are not unreal, and if they are unreal they cannot be separated. (Nyaya Sutra 4.2.26–27)

Shankara takes on the Jains at Brahma Sutra 2.2.33, and gives one of the clearest early descriptions of anekāntavāda, the Jain doctrine of many-sidedness. The Jains, he reports, "apply the following method of reasoning, which they call the saptabhanginaya: somehow it is; somehow it is not; somehow it is and is not; somehow it is indescribable; somehow it is and is indescribable; somehow it is not and is indescribable; somehow it is and is not and is indescribable." (SBE 34, p. 429) The Jain point is that every statement is true only from a standpoint. Shankara's reply is the law of non-contradiction: "it is impossible that contradictory attributes such as being and non-being should at the same time belong to one and the same thing; just as observation teaches us that a thing cannot be hot and cold at the same moment." He adds that the claim "all things are of a non-exclusive nature" is itself a thing, and so must be "somehow" false. (SBE 34, p. 429) Whether that is fair to the Jains is a question they answered at length; we have not opened their reply.

The pattern is the same in every school: state the opponent's view as fairly as a sutra can, then refute it. The opponents did the same back. That is why these texts read like court records.

The three pairs

Nyaya and Vaisheshika share a world: Vaisheshika supplies the inventory, Nyaya the method, and by the medieval period they were taught as one system. Sankhya and Yoga share a map and differ on one point: Yoga adds Ishvara and a method.

Mimamsa and Vedanta share the Veda and divide it. Mimamsa (pūrva, "earlier") reads the ritual portion and asks what you must do; Vedanta (uttara, "later") reads the Upanishads and asks what you must know. Both begin athāto, "then therefore," and the commentators fight over the "then." Ramanuja says the enquiry "follows immediately in the case of him who, having read the Veda together with its auxiliary disciplines, has reached the knowledge that the fruit of mere works is limited." (SBE 48, commentary on 1.1.1) Shankara says ritual is no prerequisite. (SBE 34, pp. 9–10) The pairing is a quarrel inside a family.

The strongest case for the other side

The "other side" here is a different way of classifying, and it deserves its best statement.

First, "six schools" is a tidy number the sources do not use. The sutra texts name opponents one by one and never say "we are one of six." The grouping is a convention of medieval doxographers, and others counted differently: Thibaut's footnote to Shankara's Jain section sends the reader to Cowell's translation of the Jain chapter of the Sarvadarśanasaṃgraha (SBE 34, p. 428 n.), a fourteenth-century survey, which we did not open, that is generally described as treating sixteen systems, Charvaka, Buddhist and Jain among them, as darshanas on the same footing.

Second, the astika line is not as clean as "accepts the Veda." Sankhya and Yoga accept āptavacana, "the word of a reliable person," which is broader than the Veda and could in principle include a Buddha.

Third, Sankhya's atheism is a reading of silence plus one commentary. The Karika does not deny Ishvara; it does not mention him. Gaudapada is later than the verses, and the much later Sankhya Sutra, which we did not open, has a sutra usually read as "Ishvara is unproven," īśvarāsiddheḥ, not "Ishvara does not exist." Unproven is weaker than false.

Fourth, Vaisheshika's sutra 1.1.3 can honestly be read either way, and the tradition that read "that" as God is old and unbroken.

Finally, the pramana table flattens a thousand years: the two Mimamsa counts belong to sub-schools of the seventh and eighth centuries. It is a snapshot, not a history.

What we could not prove

• Any early text that says "there are six darshanas." We opened all six sutra collections and found none that counts itself as one of six.
• Madhva's own reading of "That art thou." The tradition reports he read it as atat tvam asi, "thou art not that." We found Subba Rau's summary of Madhva's method and his identification of Brahman with Vishnu, not that reading. It stays out of the body.
• Dates for Kanada, Jaimini and Badarayana. None of the translators we opened gives one; Wilson says only that Ishvarakrishna "must date anterior to the eighth century"; Vidyabhusana's 550 BCE for Gautama is his inference from the Vayu Purana and Vedic teacher-lists.
• The Sankhya Sutra's "Ishvara is unproven." Not opened; it appears only in the other side's case.
• Radhakrishnan and Moore's Source Book in Indian Philosophy (1957). Only a damaged OCR of a reprint was obtainable; every quotation here is from the earlier translations instead.
• The Jain reply to Shankara. We did not open a Jain source.
• Vaisheshika's dyad in the sutra text itself. It is in Shankara Mishra's Upaskāra; we cite it as commentary, not as Kanada. Page numbers in Sinha's edition and in Book IV of Vidyabhusana's are unclear in the scans; those passages are cited by sutra number only.

Why it still matters today

The six darshanas are usually taught as a list to memorise. Read as documents, they are a 1,500-year argument about what you are allowed to believe and why. Every modern argument about evidence, from a courtroom to a fact-check, is a position on the pramana table.

And "orthodox" turns out to have been about a text, not a God. A school could leave the creator out, or make him one soul among many, or make him Vishnu, and still be inside the fold, so long as it did not reject the Veda. These were schools in the literal sense: places where people learned to disagree in public, with rules, and to lose gracefully.

Verdict

The documents prove that six Indian schools each left a text of aphorisms, that each states its own rule for what counts as evidence, that those rules differ (from two sources in Vaisheshika to six in Vedanta), and that each is remembered for one argument that is actually in its text: the five-step proof, the uncaused atom, the witness and the dancer, the stilled mind, the authorless Veda, the sentence read three ways.

They prove that "orthodox" was not a creed. Nyaya argues for God; Yoga names him as a never-bound Self; Vaisheshika's sutra leaves his name to the commentator; the Sankhya Karika never mentions him and its commentary argues against him; Mimamsa builds its theory of scripture on the premise that nobody wrote it. All were astika. The line was the Veda.

What the documents do not prove is the tidy number six, or any single date, or the slogan that India's philosophers all agreed. They did not agree. They wrote down, with unusual care, exactly how they disagreed, and that is the inheritance.