Ten systems of Indian philosophy — what each one is actually trying to say, how they argue with one another, and where they end up. No background is assumed. Every Sanskrit term is given in plain English, in IAST and in Devanagari.
Some of what follows is technical. The first section is not. If you read only one part of this page, read that one.
Going further. Each of the ten systems below also has a page of its own — the ten darśanas in full — and under Vedānta a further tier takes its eight schools one at a time. Nothing there repeats what is on this page; it assumes it.
Strip away the technical apparatus and all six of the Vedic systems are answering the same question: why does life hurt, and what can actually be done about it?
They agree on the shape of the answer. We suffer not because the world is badly made but because we have misread something basic about ourselves. Correct the misreading and the suffering loses its root. Where the six part company is on what exactly has been misread — and therefore on what kind of work will fix it.
Nyāya says the problem is sloppy thinking. You believe things without checking them, and one of those unchecked beliefs is about who you are. So learn to think properly — what counts as evidence, what a good argument looks like, where reasoning goes wrong — and the false belief will not survive the scrutiny.
Vaiśeṣika says the problem is that you do not know what the world is made of. You treat a temporary arrangement of parts as a solid, lasting thing worth clinging to. Take an honest inventory of what actually exists, down to the atoms, and the clinging has nothing left to hold.
Sāṅkhya says the problem is mistaken identity. You are the one who watches, but you have confused yourself with what you are watching — the body, the emotions, the running commentary of thought. Learn to tell the seer from the seen and you are already free, because you were never actually bound.
Yoga agrees with all of that and raises the obvious objection: knowing it does not make it true for you. The mind is too restless to hold the insight for more than a moment. So here is the training — ethics first, then the body, the breath, and finally attention itself — that makes the mind steady enough for the insight to land and stay.
Mīmāṃsā says stop looking inward for a moment. What you actually want to know is what to do. That cannot be worked out from first principles, because rightness is not a property you can observe or measure in an action. It has been told to us. So learn to read the instruction correctly, and then carry it out, carefully, for its own sake rather than for what you get out of it.
Vedānta says the deepest misreading is separation itself. You take yourself to be a small, bounded thing inside a large indifferent universe. You are not. What you most fundamentally are, and what everything else most fundamentally is, are not two different realities. Realise that, and there is nothing left to be anxious about.
The short version of the short version: two of them say think clearly, two say see clearly, one says act rightly, and one says you are already what you are looking for.
Three further traditions rejected the authority the other six rest on, and they are not footnotes. For a thousand years they set the terms of the argument.
Cārvāka says there is no misreading to correct, because there is no soul to free. Consciousness is something bodies do, and it stops when they stop. You get one life. Spend it well, and stop paying priests for results nobody has ever verified.
Jaina says the misreading is one-sidedness. Reality has more aspects than any single statement can capture, so the schools contradicting each other are each holding a real piece of it and mistaking that piece for the whole. Learn to qualify every claim by the standpoint it is made from.
Bauddha says the misreading is the search itself. You are looking for the true self behind the changing show, and there is nothing back there — only the show, one moment causing the next. Once you stop grasping at a self that was never there, the grasping stops, and so does the suffering that came from it.
The word darśana (दर्शन) comes from the root dṛś (दृश्), to see. A darśana is not a "philosophy" in the sense of a body of opinion; it is a way of seeing, and by extension the disciplined discourse that establishes and defends that way of seeing. The two senses matter. Each system claims both to describe how things are and to be a practice that ends in direct seeing.
The received classification sorts the systems by a single test: does the school accept the Veda as an independent means of knowledge? A school that does is āstika (आस्तिक); one that does not is nāstika (नास्तिक). Note carefully what this test is not. It is not about belief in God — Sāṅkhya and Mīmāṃsā are āstika and yet do not admit a creator, while several nāstika schools admit gods within the cosmos. The word āstika is often mistranslated as "theist," and nearly every confusion about this classification begins there.
The six are not six independent systems but three pairs, traditionally called samāna-tantra (समानतन्त्र), systems that share a doctrinal frame. In each pair one member supplies the theory and the other the application:
Learning the pairs is half the work. Taken by itself, Vaiśeṣika looks like an inventory of the world with no account of how anyone could know it, and Yoga looks like a set of techniques with no reason behind them. Each pair is one system in two halves.
Most of the confusion around this subject comes from a handful of persistent errors. Clearing them early saves a great deal of trouble later.
It means accepting the Veda as a valid source of knowledge, and nothing more. Classical Sāṅkhya has no God at all and Mīmāṃsā actively argues against a creator, yet both are āstika. Meanwhile several schools classed as nāstika accept the existence of gods, just not their ultimate importance. The test is textual authority, not theism.
These schools disagree with each other about as sharply as any philosophers ever have. A Naiyāyika and a Buddhist do not differ in emphasis; they differ on whether there is a self, whether wholes exist, whether words refer to anything real, and whether inference works. The literature is overwhelmingly polemical, written by people trying to defeat each other in public.
Postures are one of eight limbs in Patañjali's scheme, and he devotes exactly three short aphorisms to them, none of which describes a posture. The system is a theory of mind attached to Sāṅkhya's metaphysics, and its subject is the stilling of mental activity. Modern postural yoga is a real and interesting tradition, but it is a much later development and is not what the Yoga-sūtra is about.
It means action, and the residue action leaves. The doctrine that everything is fixed in advance is niyati, and it belonged to the Ājīvikas — who were attacked for it by Buddhists, Jainas and Vedic thinkers alike, precisely because a fixed future would make moral effort pointless. Karma is the opposite claim: what you do matters, and keeps mattering.
It means extinguishing — of craving, aversion and delusion, as a flame goes out when its fuel is withdrawn. Whether anything remains is one of the questions the Buddha explicitly declined to answer, on the grounds that both yes and no would mislead. Reading it as personal annihilation imports exactly the assumption about a persisting self that the tradition is trying to dislodge.
Most of this literature is dense technical argument about perception, inference, meaning, universals and causation. The schools accuse one another of infinite regress, circularity, equivocation and question-begging, and they name those fallacies with a precision that a modern logician would recognise. There is a contemplative dimension, but the texts you would actually read are closer to legal reasoning than to poetry.
That arrangement comes from Mādhava's fourteenth-century survey, which orders the schools in ascending sequence towards Advaita because Mādhava was an Advaitin. It is a rhetorical structure, not a historical or logical one. Haribhadra, writing as a Jaina, arranges them quite differently and treats them far more evenhandedly.
Goal niḥśreyasa, the end of suffering through the destruction of false knowledge · Context logic, epistemology and the rules of public debate · Approach testing every claim by four means of knowledge and a five-membered inference.
Root text: the Nyāya-sūtra (न्यायसूत्र) of Gautama, also called Akṣapāda. The commentarial spine runs Vātsyāyana's Bhāṣya, Uddyotakara's Vārttika, Vācaspati Miśra's Tātparyaṭīkā and Udayana's Tātparyapariśuddhi. From Gaṅgeśa's Tattvacintāmaṇi (c. 1325) the school reinvents itself as Navya-Nyāya (नव्यन्याय), the new logic, whose technical language becomes the medium of scholarly Sanskrit across every discipline including Vedānta and poetics.
The opening sūtra makes an unusually specific claim, and it is worth quoting in full:
प्रमाणप्रमेयसंशयप्रयोजनदृष्टान्तसिद्धान्तावयवतर्कनिर्णयवादजल्पवितण्डाहेत्वाभासच्छलजातिनिग्रहस्थानानां तत्त्वज्ञानान्निःश्रेयसाधिगमः॥
"From true knowledge of the means of knowledge, the knowable, doubt, purpose, example, established tenet, the members of inference, hypothetical reasoning, ascertainment, debate, disputation, refutation, fallacies, quibbling, futile rejoinder and points of defeat — the highest good is attained."
Nyāya-sūtra 1.1.1
Notice what is being claimed. Liberation is said to follow from knowing sixteen things, and most of them are not entities in the world at all but procedures of enquiry. Only the second, prameya, contains anything metaphysical. The other fifteen are the apparatus by which the truth about the self is reached and then held against attack. That structure is the distinctive Nyāya contribution: it treats method itself as soteriologically load-bearing.
The mechanism is given in the very next sūtra, and it is a chain of five links in which each item is the cause of the one before it in the list:
दुःखजन्मप्रवृत्तिदोषमिथ्याज्ञानानामुत्तरोत्तरापाये तदनन्तराभावादपवर्गः॥
Nyāya-sūtra 1.1.2 — "Suffering, birth, activity, faults, false knowledge: on the successive removal of each later one, through the absence of the one next to it, comes release."
The list at Nyāya-sūtra 1.1.9 is itself a compressed statement of the whole path, running from the self through the machinery of bondage to release: ātman, śarīra, indriya, artha, buddhi, manas, pravṛtti, doṣa, pretyabhāva, phala, duḥkha, apavarga (आत्मन्, शरीर, इन्द्रिय, अर्थ, बुद्धि, मनस्, प्रवृत्ति, दोष, प्रेत्यभाव, फल, दुःख, अपवर्ग). Ātman comes first because everything else is defined by its relation to it, and apavarga last because it is the terminus.
Nyāya's syllogism has five members rather than the three of Western logic, because it is designed for a public debate where the opponent must be brought along step by step, not for a formal calculus.
| Member | Devanāgarī | Statement |
|---|---|---|
| pratijñā | प्रतिज्ञा | The hill has fire. |
| hetu | हेतु | Because it has smoke. |
| udāharaṇa | उदाहरण | Wherever there is smoke there is fire, as in a kitchen. |
| upanaya | उपनय | This hill is such a case. |
| nigamana | निगमन | Therefore the hill has fire. |
The third member is the load-bearing one. It states the vyāpti and cites an instance where both terms are observed together, so the inference is anchored in perception rather than in form alone. Where the vyāpti fails, we get one of the hetvābhāsas: the deviating reason (savyabhicāra), the contradictory (viruddha), the counterbalanced (satpratipakṣa), the unestablished (asiddha) and the stultified (bādhita).
Goal niḥśreyasa through dharma and true knowledge of the categories of the real · Context ontology and physics: an exhaustive inventory of what exists · Approach classification into seven padārthas, with matter resolved into indivisible atoms.
Root text: the Vaiśeṣika-sūtra (वैशेषिकसूत्र) of Kaṇāda. The system as it is actually studied descends less from the sūtras than from Praśastapāda's Padārthadharmasaṃgraha, effectively an independent treatise. The name comes from viśeṣa (विशेष), the ultimate particulariser that distinguishes one atom from another otherwise identical one.
Where Nyāya asks how we know, Vaiśeṣika asks what there is, and answers with a finite list. Every item in the universe falls under one of seven headings, and nothing falls under two. This is the most thoroughly realist ontology produced in India: universals are real, relations are real, and even absence is a positive object of knowledge.
Earth, water, fire and air resolve on analysis into paramāṇu (परमाणु), partless and eternal atoms. Division cannot proceed indefinitely, because an infinite regress would make a mustard seed and a mountain equal in the number of their parts. Two atoms combine into a dyad (dvyaṇuka, द्व्यणुक), three dyads into a triad (tryaṇuka, त्र्यणुक), which is the smallest perceptible magnitude — the mote visible in a sunbeam. Composites are genuinely new wholes (avayavin, अवयविन्) inhering in their parts, not mere aggregates. This is asatkāryavāda (असत्कार्यवाद), the doctrine that the effect did not exist before its production, and it is the direct antithesis of Sāṅkhya's position.
Goal kaivalya, the definitive ending of the threefold suffering · Context an enumerative metaphysics resting on a dualism of consciousness and nature · Approach discriminative discernment of puruṣa from prakṛti, worked out through twenty-five principles.
Attributed to Kapila; the surviving system is the Sāṅkhya-kārikā (साङ्ख्यकारिका) of Īśvarakṛṣṇa in seventy verses, with the commentaries of Gauḍapāda and Vācaspati Miśra's Tattvakaumudī. The later Sāṅkhya-sūtra with Vijñānabhikṣu's commentary belongs to a much later revival. The name means enumeration, and the system earns it.
दुःखत्रयाभिघाताज्जिज्ञासा तदपघातके हेतौ॥
Sāṅkhya-kārikā 1 — "From the assault of the threefold suffering arises the desire to know the means of removing it."
The three sufferings are ādhyātmika, ādhibhautika and ādhidaivika (आध्यात्मिक, आधिभौतिक, आधिदैविक): what arises from oneself, from other beings, and from forces beyond either. Ordinary remedies are rejected in the second verse as neither certain nor permanent, which is why an enquiry into principles is needed at all.
Puruṣa (पुरुष) is pure consciousness: inactive, unchanging, a witness (sākṣin, साक्षिन्), plural, and never an agent. Prakṛti (प्रकृति) is unconscious but active, one, and the material cause of everything else. It is constituted of three strands, the guṇas (गुण) — sattva, rajas and tamas — in equilibrium before evolution and in disturbed proportion afterwards. All bondage arises from a failure to keep these two apart: the witness appears to act, and nature appears to be conscious.
Evolution proceeds by satkāryavāda (सत्कार्यवाद): the effect pre-exists in its cause and production is only its manifestation. Curd is already in milk; sesame oil is already in the seed. The arguments given at kārikā 9 are compact enough to hold in mind: what does not exist cannot be brought into being, a specific material is required for a specific product, and the effect is of the same nature as the cause.
Bondage is not a real bond. Puruṣa never actually becomes entangled; it merely appears to, as a spectator absorbed in a dance forgets he is watching. When discriminative discernment — viveka-khyāti (विवेकख्याति) — arises in the buddhi, prakṛti withdraws, "like a dancer who ceases once she has been seen by the audience" (kārikā 59). Kaivalya (कैवल्य) is aloneness: puruṣa simply as it always was.
Goal kaivalya, the seer abiding in its own nature · Context Sāṅkhya's metaphysics turned into a graded discipline, with Īśvara added · Approach stilling the modifications of the mind through eight limbs.
Root text: the Yoga-sūtra (योगसूत्र) of Patañjali in four pādas, with the Bhāṣya attributed to Vyāsa, Vācaspati Miśra's Tattvavaiśāradī and Bhoja's Rājamārtaṇḍa. The school is called seśvara Sāṅkhya (सेश्वरसाङ्ख्य), Sāṅkhya with a Lord — but Īśvara here is a special puruṣa untouched by affliction and action, an object of devotion and a shortcut to concentration, not a creator.
योगश्चित्तवृत्तिनिरोधः॥ तदा द्रष्टुः स्वरूपेऽवस्थानम्॥
Yoga-sūtra 1.2–3 — "Yoga is the stilling of the modifications of the mind. Then the seer abides in its own nature."
The definition is exact and is worth dwelling on. Yoga is not a state achieved but a cessation brought about; and what results is not a new condition of the seer but the removal of what obscured its own. The two disciplines that accomplish it are abhyāsa (अभ्यास), sustained practice, and vairāgya (वैराग्य), dispassion — sūtra 1.12. Everything else is elaboration.
| IAST | Devanāgarī | Sense |
|---|---|---|
| avidyā | अविद्या | Taking the impermanent, impure, painful and not-self for their opposites. The field in which the other four grow. |
| asmitā | अस्मिता | Identifying the power of seeing with the instrument of seeing. |
| rāga | राग | Attraction, following on remembered pleasure. |
| dveṣa | द्वेष | Aversion, following on remembered pain. |
| abhiniveśa | अभिनिवेश | Clinging to life, present even in the learned. |
Note the structural parallel with Nyāya: avidyā occupies exactly the position mithyā-jñāna occupies there, and for the same reason. Every Indian soteriology is at bottom a claim about which cognitive error is doing the damage.
Goal dharma, what the Veda enjoins, performed rightly · Context the exegesis of the ritual portion of the Veda · Approach rules of interpretation applied to an authorless text, with the injunction as the core of meaning.
Root text: the Pūrva-mīmāṃsā-sūtra (पूर्वमीमांसासूत्र) of Jaimini in twelve books, with Śabara's Bhāṣya. From Śabara the school divides into two, following Kumārila Bhaṭṭa (Ślokavārttika, Tantravārttika) and Prabhākara Miśra (Bṛhatī). The differences between the Bhāṭṭa and Prābhākara schools are substantial enough that "Mīmāṃsā holds that..." is usually an unsafe sentence.
अथातो धर्मजिज्ञासा॥ चोदनालक्षणोऽर्थो धर्मः॥
Mīmāṃsā-sūtra 1.1.1–2 — "Now therefore the enquiry into dharma. Dharma is that good which is characterised by injunction."
Read the second sūtra strictly. Dharma is not defined as what is beneficial, or what the virtuous do, or what conduces to welfare. It is defined by its source: dharma is whatever the Veda commands. Nothing else can tell you what it is, because dharma is not an observable property of actions. This gives Mīmāṃsā its characteristic shape as a science of textual interpretation rather than a moral philosophy.
The Veda is apauruṣeya (अपौरुषेय), not composed by any person, human or divine. This is not a claim about miraculous origin but an argument from defect: every error in testimony traces back to a defect in a speaker, so a text with no speaker has nothing to be defective. Supporting this is svataḥ-prāmāṇya (स्वतःप्रामाण्य), the doctrine that a cognition is valid by itself and needs no external certification; only invalidity requires explanation.
Mīmāṃsā's lasting contribution outside religion is its hermeneutics. When two textual indications conflict, they are ranked in a fixed order of strength: śruti, liṅga, vākya, prakaraṇa, sthāna, samākhyā (श्रुति, लिङ्ग, वाक्य, प्रकरण, स्थान, समाख्या) — direct statement, implication of a word's power, syntactic connection, context, position and traditional name. Indian jurisprudence adopted this scheme wholesale, and the Mīmāṃsā maxims (nyāya, न्याय) are still cited in Indian courts.
Goal mokṣa, in which knowing brahman one becomes brahman · Context the exegesis of the knowledge portion of the Veda, the Upaniṣads · Approach the threefold canon read through hearing, reflection and sustained contemplation.
Root text: the Brahma-sūtra (ब्रह्मसूत्र) of Bādarāyaṇa, also called Uttara-mīmāṃsā or Śārīraka-sūtra. Together with the principal Upaniṣads and the Bhagavad-gītā it forms the prasthāna-traya (प्रस्थानत्रय), the threefold point of departure. A school of Vedānta is constituted by writing a commentary on all three; this is why Śaṅkara, Rāmānuja and Madhva each did so.
अथातो ब्रह्मजिज्ञासा॥ जन्माद्यस्य यतः॥
Brahma-sūtra 1.1.1–2 — "Now therefore the enquiry into brahman. That from which the origin and so on of this world proceed."
The parallel with Jaimini's opening is deliberate and the difference is the whole point. Jaimini's "now therefore" follows the study of the Veda; Bādarāyaṇa's, on Śaṅkara's reading, follows the discernment that no ritual result is permanent. The prerequisite is not more ritual competence but sādhana-catuṣṭaya (साधनचतुष्टय): discrimination between eternal and non-eternal, dispassion, the sixfold discipline, and the longing for release.
The method is śravaṇa, manana, nididhyāsana (श्रवण, मनन, निदिध्यासन) — hearing the texts from a teacher, reasoning them through until doubt is removed, and sustained contemplation until the truth heard becomes immediate. Śaṅkara's expository device is adhyāropa-apavāda (अध्यारोप-अपवाद): deliberately superimpose a description on brahman, then withdraw it, since brahman can be indicated but not described.
Three schools reject the Veda as an independent means of knowledge, and are therefore classed as nāstika. They are not marginal. For roughly a millennium the Buddhist and Jaina logicians set the terms of debate, and the Vedic schools sharpened their own positions largely in answer to them.
Two cautions before the details. First, "rejecting the Veda" means rejecting its authority as a pramāṇa, not necessarily rejecting everything in it; Jaina and Buddhist texts are full of Vedic vocabulary put to new use. Second, our knowledge of these schools is unevenly preserved. Jaina and Buddhist literature survives in quantity. Cārvāka survives almost entirely in the summaries of its opponents, and Ājīvika hardly at all. Reading about Cārvāka means largely reading what Mādhava and Śaṅkara supposed a Cārvāka would say.
Goal kāma and artha — a pleasant life, competently managed · Context a thoroughgoing materialism admitting only what can be perceived · Approach perception alone as a means of knowledge, and the rejection of everything that requires more.
Also Lokāyata (लोकायत), "prevalent in the world," and Bārhaspatya after the lost Bṛhaspati-sūtra. No primary text survives complete. The reconstruction rests on the first chapter of Mādhava's Sarvadarśanasaṃgraha, on refutations scattered through Buddhist, Jaina and Vedic works, and on the one surviving sceptical treatise, Jayarāśi Bhaṭṭa's Tattvopaplavasiṃha (c. 800), which is more radical still.
Four elements only — earth, water, fire and air. Ākāśa is dropped because it is not perceived. Consciousness is not a property of a separate self but an emergent property of the body, arising when the elements combine in a certain way, as the power to intoxicate arises from the mixing of ingredients none of which is individually intoxicating. This is dehātmavāda (देहात्मवाद), the doctrine that the body is the self. When the body dissolves, consciousness ends; there is no transmigration, no karmic residue, and nothing to be released.
The interesting move is not the materialism but the epistemology that supports it. Cārvāka denies that inference is a pramāṇa at all. An inference needs a vyāpti, an exceptionless relation between smoke and fire. But how is that exceptionlessness established? Not by perception, which reaches only observed cases. Not by another inference, which would need its own vyāpti and start a regress. Not by testimony, which Cārvāka has already rejected. Therefore no vyāpti is ever established, and inference collapses into probable guessing.
Every subsequent Indian logician had to answer this. Nyāya's response is the theory of sāmānya-lakṣaṇa perception, by which a universal is grasped in a particular; Buddhist logicians answer with causal and identity relations that guarantee concomitance. The whole Indian theory of induction develops as a reply to a school with no surviving books.
Goal release, reached not by effort but by the exhaustion of a fixed term · Context a strict determinism of cosmic order · Approach ascetic practice undertaken without the belief that it causes anything.
Associated with Makkhali Gosāla, a contemporary and one-time associate of Mahāvīra. The school's central doctrine is niyati (नियति), destiny: every event, including every apparent choice and every ascetic austerity, is fixed. There is no cause and no condition for the defilement or the purification of beings; each soul traverses a fixed number of births and is released at the end of that term regardless of what it does.
The position is philosophically serious and was treated as a major threat. It voids the karma doctrine on which every other school depends: if outcomes are fixed, action has no moral weight and the entire soteriological apparatus of Vedic, Jaina and Buddhist practice is idle. The Buddha's suttas single out Gosāla's teaching as the most dangerous of the rival views, precisely because it is internally consistent and cannot be refuted by pointing at consequences.
Ājīvikas survived in south India into the medieval period and then vanished. No Ājīvika text survives. Everything above is reconstructed from Buddhist and Jaina polemics and from Aśokan inscriptions recording cave donations to them, so read it as a sketch of a position, not a report of a literature.
Goal mokṣa, the soul's shedding of all karmic matter and rise to its natural omniscience · Context a pluralist realism in which reality has infinitely many aspects · Approach the threefold jewel of right view, right knowledge and right conduct, with judgement always qualified by standpoint.
Founded, in the tradition's own account, by a lineage of twenty-four tīrthaṅkaras (तीर्थङ्कर) of whom Mahāvīra is the last and Pārśva the historically attested predecessor. The standard doctrinal summary accepted by both Digambara and Śvetāmbara traditions is Umāsvāti's Tattvārtha-sūtra (तत्त्वार्थसूत्र), c. 2nd–5th century.
The distinctive Jaina thesis is anekāntavāda (अनेकान्तवाद), non-one-sidedness: every real thing has infinitely many aspects, and any assertion captures only some of them. It follows that the great metaphysical disputes are not straight contradictions but partial truths taken for total ones. Sāṅkhya says the effect pre-exists; Nyāya says it does not; Jainism says a substance is permanent as substance and impermanent as mode, and both parties have seized one aspect and denied the other.
The disciplines that operationalise this are nayavāda (नयवाद), the doctrine of standpoints, and syādvāda (स्याद्वाद), the doctrine of qualified assertion. Every claim is prefixed by syāt (स्यात्) — "in a certain respect" — yielding seven and only seven predications.
| № | Formula | Devanāgarī | Sense |
|---|---|---|---|
| 1 | syād asti | स्यादस्ति | In a certain respect, it is. |
| 2 | syān nāsti | स्यान्नास्ति | In a certain respect, it is not. |
| 3 | syād asti ca nāsti ca | स्यादस्ति च नास्ति च | In certain respects it is and it is not — taken successively. |
| 4 | syād avaktavyam | स्यादवक्तव्यम् | In a certain respect it is inexpressible — both aspects taken at once, which no word can do. |
| 5 | syād asti ca avaktavyaṃ ca | स्यादस्ति चावक्तव्यं च | It is, and it is inexpressible. |
| 6 | syān nāsti ca avaktavyaṃ ca | स्यान्नास्ति चावक्तव्यं च | It is not, and it is inexpressible. |
| 7 | syād asti ca nāsti ca avaktavyaṃ ca | स्यादस्ति च नास्ति चावक्तव्यं च | It is, it is not, and it is inexpressible. |
The list is not arbitrary: it is the exhaustive combination of affirmation, negation and their simultaneous assertion. Opponents from Śaṅkara to Dharmakīrti charged it with violating non-contradiction. The Jaina reply is that the qualifier syāt shifts the respect in each case, so nothing is affirmed and denied in the same respect at the same time. Whether that reply succeeds is still argued over, and there is no settled answer.
Six substances make up the world: jīva, pudgala, dharma, adharma, ākāśa, kāla (जीव, पुद्गल, धर्म, अधर्म, आकाश, काल). Note the unusual sense of dharma and adharma here — not merit and demerit but the medium of motion and the medium of rest, without which movement and stillness would be impossible. This is one of the few genuinely original ontological proposals in Indian philosophy.
Goal nirvāṇa, the extinction of craving and so of suffering · Context a process ontology with no enduring substance anywhere, self included · Approach the fourfold diagnosis, the eightfold path, and analysis of everything into momentary dependently-arisen events.
The framing is medical rather than metaphysical, and that is the first thing to notice about it. The four noble truths — duḥkha, samudaya, nirodha, mārga (दुःख, समुदय, निरोध, मार्ग) — are a diagnosis, an aetiology, a prognosis and a treatment. Metaphysical questions that do not bear on the treatment are set aside as avyākṛta (अव्याकृत), unanswered.
Three marks characterise everything conditioned: anitya, duḥkha, anātman (अनित्य, दुःख, अनात्मन्) — impermanent, unsatisfactory, without self. The third is the doctrinal fault line with every other Indian school. There is no ātman, no substance underlying the process; what we call a person is five aggregates (skandha, स्कन्ध) in continuous causal succession: rūpa, vedanā, saṃjñā, saṃskāra, vijñāna.
Pratītyasamutpāda (प्रतीत्यसमुत्पाद) is the positive counterpart of the denial of self: nothing has independent existence, everything arises in dependence on conditions. Its standard formulation is a chain of twelve links spanning three lives.
Buddhist philosophy is not one position. The four classical schools can be arranged along a single line of increasing distance from common-sense realism, and arranging them this way is the quickest route into the material.
| School | Devanāgarī | On external objects | Key figures |
|---|---|---|---|
| Vaibhāṣika | वैभाषिक | External objects exist and are directly perceived. Momentary dharmas of past, present and future are all real — hence sarvāstivāda. | Saṅghabhadra |
| Sautrāntika | सौत्रान्तिक | External objects exist but are inferred, not directly perceived; what we perceive is a representation they cause. | Vasubandhu (early) |
| Yogācāra | योगाचार | Only consciousness is established. The apparent externality of objects is a construction of the store-consciousness, ālaya-vijñāna (आलयविज्ञान). | Asaṅga, Vasubandhu |
| Madhyamaka | माध्यमिक | Neither external objects nor consciousness has intrinsic nature. All things are empty, śūnya (शून्य), which is just what it means to be dependently arisen. | Nāgārjuna, Candrakīrti |
The systems come clear faster if you compare them question by question rather than school by school. On each of the six questions below every school has a position, and being able to place them all is a fair test of having understood the material. Ājīvika is left out of these tables — not because it has no position, but because too little of its doctrine survives to state one without inventing it.
| School | Position |
|---|---|
| Nyāya-Vaiśeṣika | An eternal, all-pervading substance, plural, whose cognition is an adventitious quality rather than its nature. |
| Sāṅkhya-Yoga | Pure consciousness, plural, inactive, never an agent or an enjoyer except by mistaken attribution. |
| Mīmāṃsā | An eternal agent and enjoyer, plural, whose existence is required for the injunctions to have anyone to bind. |
| Advaita Vedānta | Identical with brahman; plurality of selves belongs to the level of appearance. |
| Cārvāka | The living body. Consciousness is emergent and ends with it. |
| Jaina | A substance coextensive with the body it occupies, naturally omniscient, contracted by karmic matter. |
| Bauddha | No self. A causally continuous series of momentary aggregates, which is what conventionally gets called a person. |
| Doctrine | Devanāgarī | Held by | Claim |
|---|---|---|---|
| satkāryavāda | सत्कार्यवाद | Sāṅkhya, Yoga | The effect pre-exists in the cause; production is manifestation. Real transformation, pariṇāma. |
| asatkāryavāda | असत्कार्यवाद | Nyāya-Vaiśeṣika | The effect is a genuinely new whole that did not exist before. Also called ārambhavāda. |
| vivartavāda | विवर्तवाद | Advaita Vedānta | The transformation is only apparent; brahman does not actually change, as the rope does not become the snake. |
| pratītyasamutpāda | प्रतीत्यसमुत्पाद | Bauddha | Neither identical with nor different from the cause; events arise in dependence on conditions and nothing endures. |
| sadasatkāryavāda | सदसत्कार्यवाद | Jaina | The effect pre-exists as substance and does not pre-exist as mode. Anekāntavāda applied to causation. |
| svabhāvavāda | स्वभाववाद | Cārvāka | Things behave as they do by their own nature; no unseen agency need be postulated. |
| School | Term | What the released state is |
|---|---|---|
| Nyāya-Vaiśeṣika | apavarga | The self stripped of all nine of its particular qualities, cognition included. No experience of any kind. |
| Sāṅkhya-Yoga | kaivalya | Aloneness. Puruṣa exactly as it always was, with prakṛti withdrawn. |
| Mīmāṃsā | apavarga | Absent from the older layer, where dharma is the terminus; admitted by the later Bhāṭṭa and Prābhākara authors. |
| Advaita Vedānta | mokṣa | Not a state attained but the removal of ignorance about a fact already true. |
| Cārvāka | — | Death, which requires no method. The category is rejected. |
| Jaina | mokṣa | The soul rises to the summit of the universe and remains there in unobstructed omniscience and bliss. |
| Bauddha | nirvāṇa | The extinction of craving, aversion and delusion. What survives is not asked, being one of the unanswered questions. |
| School | Position |
|---|---|
| Nyāya-Vaiśeṣika | Yes. Īśvara is the efficient cause who sets the eternal atoms in motion; Udayana's Nyāyakusumāñjali gives the classical arguments. |
| Sāṅkhya | No. Prakṛti's ordering towards release needs no designer, as milk flows for the calf without intending to. |
| Yoga | Īśvara is a special puruṣa untouched by affliction — an object of devotion and an aid to concentration, not a creator. |
| Mīmāṃsā | No. A creator would give the authorless Veda an author, and the rites produce their results by their own power. |
| Vedānta | Brahman is both the material and the efficient cause. Whether that is a personal God is exactly what the sub-schools dispute. |
| Jaina | No creator. Liberated souls are perfect and worshipped, but they made nothing and intervene in nothing. |
| Bauddha | Gods exist within the cosmos and are as impermanent as anything else. No creator, and no need for one. |
| School | Position |
|---|---|
| Mīmāṃsā, Vedānta | The Veda, because it has no author. Every defect in testimony traces to a defect in a speaker, so a text with no speaker has nothing to go wrong. |
| Nyāya | A trustworthy speaker, āpta (आप्त). The Veda is authoritative because Īśvara composed it — the exact reverse of the Mīmāṃsā argument, arriving at the same conclusion. |
| Sāṅkhya-Yoga | Reliable testimony is accepted as a means of knowledge but is not made the foundation of the system. |
| Cārvāka | Nothing. Testimony is not a means of knowledge at all, so no text can settle anything. |
| Jaina | The word of one who has attained omniscience, whose knowledge is unobstructed and therefore cannot mislead. |
| Bauddha | The Buddha's word, and only because it can be checked. Dharmakīrti reduces reliable testimony to a species of inference. |
| School | Position |
|---|---|
| Nyāya-Vaiśeṣika | Real, built from eternal atoms. Composite things genuinely come into being and genuinely perish. |
| Sāṅkhya-Yoga | Real, and one continuous transformation of a single material nature. Nothing new is ever added. |
| Mīmāṃsā | Real and beginningless. There is no creation and no universal dissolution; the world and the Veda have always been here. |
| Advaita Vedānta | Real at the everyday level, and not ultimately. Only brahman is real without qualification. |
| Cārvāka | Real, and the only thing there is. |
| Jaina | Real, and both permanent and changing: substances endure while their modes come and go. |
| Bauddha | Real as a process, but momentary. Nothing survives into a second instant; what looks like persistence is rapid succession. |
All dates before about 500 CE are contested, sometimes by centuries, and the sūtra collections are layered compositions rather than single-author works. Treat what follows as relative order rather than absolute date.
The literature is enormous and much of it is written for readers who already know the vocabulary. A few starting points that do not assume that.
| If you want | Start with | Why |
|---|---|---|
| A whole system, briefly | Sāṅkhya-kārikā | Seventy verses containing a complete metaphysics. Readable in an evening, and everything else on this page argues with it. |
| Something practical | Yoga-sūtra | Short, and the most widely read philosophical text India produced. Get an edition with Vyāsa's commentary; without it the aphorisms are too compressed to follow. |
| The Upaniṣadic voice | Kena and Kaṭha | Two of the shortest principal Upaniṣads, and the source material the whole of Vedānta is competing to interpret. |
| Argument at full strength | Mūlamadhyamaka-kārikā | Difficult, but the fastest cure for the idea that this is a soft tradition. Nāgārjuna dismantles positions for twenty-seven chapters. |
| The logic itself | Tarkasaṃgraha | Annaṃbhaṭṭa's beginner's manual of Nyāya-Vaiśeṣika, written in the seventeenth century and still the standard way in. |
| A survey first | Hiriyanna, Outlines of Indian Philosophy | Clear, honest about disagreements, and still the most readable one-volume account. |
Two further recommendations for going deeper. Radhakrishnan and Moore's Source Book in Indian Philosophy puts substantial primary extracts in one volume, so you can read the schools in their own words rather than in summary. For the epistemology and logic specifically, B. K. Matilal's work — particularly Perception and The Character of Logic in India — treats these thinkers as philosophers with arguments to assess rather than as a tradition to admire, which is the right posture and a surprisingly rare one.
Read translations alongside a commentary wherever one exists. These texts were never meant to be read alone; the sūtra style is deliberately compressed to the point of unintelligibility, because it was designed to be memorised and then unpacked by a teacher. A bare translation of the Brahma-sūtra is close to meaningless.
Be wary of books that harmonise everything — that present the six as complementary facets of a single vision with no real disagreement between them. It is a comforting picture and it dissolves on contact with the primary sources, where these authors are plainly trying to refute one another. The disagreements are the interesting part. A tradition that argued this hard for two thousand years deserves to be read as though the arguments mattered.
| School | Root text | Devanāgarī | Principal commentary |
|---|---|---|---|
| Nyāya | Nyāya-sūtra of Gautama | न्यायसूत्र | Vātsyāyana, Nyāya-bhāṣya |
| Vaiśeṣika | Vaiśeṣika-sūtra of Kaṇāda | वैशेषिकसूत्र | Praśastapāda, Padārthadharmasaṃgraha |
| Sāṅkhya | Sāṅkhya-kārikā of Īśvarakṛṣṇa | साङ्ख्यकारिका | Vācaspati Miśra, Tattvakaumudī |
| Yoga | Yoga-sūtra of Patañjali | योगसूत्र | Vyāsa, Yoga-bhāṣya |
| Mīmāṃsā | Pūrva-mīmāṃsā-sūtra of Jaimini | पूर्वमीमांसासूत्र | Śabara, Śābara-bhāṣya; Kumārila, Ślokavārttika |
| Vedānta | Brahma-sūtra of Bādarāyaṇa | ब्रह्मसूत्र | Śaṅkara, Rāmānuja and Madhva, each a Bhāṣya |
| Cārvāka | Bṛhaspati-sūtra, lost | बृहस्पतिसूत्र | Jayarāśi, Tattvopaplavasiṃha; Mādhava's summary |
| Jaina | Tattvārtha-sūtra of Umāsvāti | तत्त्वार्थसूत्र | Pūjyapāda, Sarvārthasiddhi; Akalaṅka, Rājavārttika |
| Bauddha | Mūlamadhyamaka-kārikā of Nāgārjuna | मूलमध्यमककारिका | Candrakīrti, Prasannapadā |
For a single doxographic survey covering all of them, Mādhava's Sarvadarśanasaṃgraha (सर्वदर्शनसंग्रह) remains the standard, though it arranges the schools in ascending order towards Advaita and should be read with that agenda in view. Haribhadra's Jaina Ṣaḍdarśanasamuccaya (षड्दर्शनसमुच्चय) is notably fairer to its opponents and makes a good corrective.
Terms used on this page, with the school that most relies on each where that is useful.
| IAST | Devanāgarī | Sense |
|---|---|---|
| adhyāropa-apavāda | अध्यारोप-अपवाद | Deliberate superimposition followed by withdrawal; Śaṅkara's method for indicating what cannot be described. |
| ahaṃkāra | अहङ्कार | The I-maker; the principle that appropriates experience as mine. Sāṅkhya. |
| anātman | अनात्मन् | Absence of self; the Buddhist denial of any enduring substance in a person. |
| anekāntavāda | अनेकान्तवाद | Non-one-sidedness; the Jaina view that reality has infinitely many aspects. |
| anumāna | अनुमान | Inference. |
| apauruṣeya | अपौरुषेय | Not composed by any person; the Mīmāṃsā account of the Veda's status. |
| apavarga | अपवर्ग | Release, as Nyāya and Vaiśeṣika name it. |
| apūrva | अपूर्व | The unseen potency by which a completed rite yields a later result. Mīmāṃsā. |
| āsrava | आस्रव | Influx of karmic matter toward the soul. Jaina. |
| ātman | आत्मन् | Self; the subject of nearly every dispute on this page. |
| avidyā | अविद्या | Ignorance, in the strong sense of positive misapprehension rather than mere absence of information. |
| brahman | ब्रह्मन् | The single reality of which the world and the self are, on the Vedānta account, not independent. |
| buddhi | बुद्धि | Intellect; the first evolute of nature and the seat of discrimination. Sāṅkhya. |
| darśana | दर्शन | A way of seeing, and the disciplined discourse that establishes it. |
| dharma | धर्म | Duty, right order, the enjoined good. In Jaina usage, the medium of motion. |
| dravya | द्रव्य | Substance; the first of the Vaiśeṣika categories. |
| duḥkha | दुःख | Suffering, unsatisfactoriness. |
| guṇa | गुण | Quality, in Vaiśeṣika; one of the three strands of nature, in Sāṅkhya. |
| hetvābhāsa | हेत्वाभास | A reason that only appears to be one; a fallacy of inference. |
| jīva | जीव | The individual living soul. |
| kaivalya | कैवल्य | Aloneness; release as Sāṅkhya and Yoga name it. |
| karman | कर्मन् | Action, and the residue it leaves. |
| kleśa | क्लेश | Affliction; the five obstacles listed by Patañjali. |
| kṣaṇikatva | क्षणिकत्व | Momentariness; the Buddhist thesis that nothing lasts into a second instant. |
| mokṣa | मोक्ष | Release from the cycle of birth and death. |
| nirvāṇa | निर्वाण | Extinguishing, as a flame goes out when its fuel is withdrawn. |
| padārtha | पदार्थ | Literally the meaning of a word; a category of the real. |
| paramāṇu | परमाणु | The partless atom of Vaiśeṣika physics. |
| prakṛti | प्रकृति | Nature; the unconscious, active material principle of Sāṅkhya. |
| pramāṇa | प्रमाण | A means of valid knowledge. |
| prameya | प्रमेय | The knowable; what a means of knowledge delivers. |
| pratītyasamutpāda | प्रतीत्यसमुत्पाद | Dependent origination; nothing arises independently of conditions. |
| pratyakṣa | प्रत्यक्ष | Perception. Accepted by every school without exception. |
| puruṣa | पुरुष | The conscious witness of Sāṅkhya; inactive and plural. |
| samavāya | समवाय | Inherence; the relation binding quality to substance and whole to part. Vaiśeṣika. |
| saṃsāra | संसार | The beginningless round of birth and death. |
| satkāryavāda | सत्कार्यवाद | The doctrine that the effect already exists in its cause. Sāṅkhya. |
| śabda | शब्द | Word; reliable verbal testimony as a means of knowledge. |
| śūnyatā | शून्यता | Emptiness; absence of intrinsic nature, not absence of existence. Madhyamaka. |
| syādvāda | स्याद्वाद | Qualified assertion; every claim prefixed by "in a certain respect". Jaina. |
| tanmātra | तन्मात्र | Subtle element, from which the gross elements evolve. Sāṅkhya. |
| vidhi | विधि | Injunction; for Mīmāṃsā the only part of the Veda with independent authority. |
| viveka-khyāti | विवेकख्याति | Discriminative discernment of the seer from the seen; the operative insight in Sāṅkhya and Yoga. |
| vyāpti | व्याप्ति | Invariable concomitance; the relation that makes an inference work, and the thing Cārvāka says can never be established. |