Overview — Astika vs Nastika Schools

Ancient Indian philosophical thought is broadly divided into two categories based on their relationship to Vedic authority:

Category Definition Schools
Astika (Orthodox) Accept the authority and validity of the Vedas as a source of knowledge Six Darshanas: Nyaya, Vaisheshika, Samkhya, Yoga, Mimamsa, Vedanta
Nastika (Heterodox) Do not accept Vedic authority as supreme or reject it entirely Buddhism, Jainism, Charvaka/Lokayata

Important note: The term "Nastika" does not mean "atheist" in the Western sense — Jainism, for example, accepts the existence of souls and karma but rejects the Vedas' authority. Even within astika schools, there are significant debates about the nature of God.

The six orthodox schools are collectively called Shad Darshana (six viewpoints/visions). They emerged and developed primarily between 600 BCE and 300 CE, though their foundational texts were composed over a long period.


The Six Orthodox Darshanas (Shad Darshana)

1. Nyaya — The School of Logic

Founder: Sage Gautama (also called Aksapada Gautama), who composed the Nyaya Sutras

Core focus: Logic, epistemology (theory of knowledge), and correct methods of argumentation

Central concern: How do we know what we know? What are the valid means of acquiring knowledge (pramana)?

Concept Explanation
Pramanas (valid sources of knowledge) Nyaya accepts 4 pramanas: pratyaksha (perception), anumana (inference), upamana (comparison/analogy), sabda (verbal testimony)
16 Padarthas (categories) The Nyaya system categorises reality into 16 categories — including pramana (sources), prameya (objects of knowledge), samshaya (doubt), prayojana (purpose), vada (debate), drishthanta (examples)
Anumana (inference) The most developed part of Nyaya — a formal syllogism (nyaya) using vyapti (invariable concomitance/pervasion)
Liberation (apavarga) Attained through right knowledge, freeing the soul from bondage

Classic Nyaya syllogism:

  • Pratijña (proposition): The hill has fire
  • Hetu (reason/evidence): Because there is smoke
  • Udaharana (example): Wherever there is smoke, there is fire — like in a kitchen
  • Upanaya (application): This hill has smoke
  • Nigamana (conclusion): Therefore this hill has fire

UPSC significance: The Nyaya tradition developed into one of the world's earliest formal logics; influenced Buddhist and Jain philosophy too.


2. Vaisheshika — Atomic Pluralism

Founder: Sage Kanada (also called Uluka), who composed the Vaisheshika Sutras

Core focus: Ontology (nature of reality), atomism, and natural philosophy

Concept Explanation
Six Padarthas (categories) Dravya (substance), Guna (quality), Karma (action), Samanya (universal), Vishesha (particularity), Samavaya (inherence) — a seventh, abhava (non-existence), was added later
Paramanu (atoms) Matter is composed of indivisible eternal atoms (paramanu); different atoms form earth, water, fire, air
Non-atomic substances Space (akasha), time (kala), space/direction (dik), soul (atman), mind (manas) are eternal but non-atomic
Relationship with Nyaya The two schools are closely allied — together called Nyaya-Vaisheshika; they share similar views on liberation through knowledge

Kanada's atomic theory (c. 6th–2nd century BCE) predates the Greek atomists Democritus and Leucippus or is roughly contemporaneous — a remarkable proto-scientific contribution.


3. Samkhya — Dualistic Cosmology

Founder: Sage Kapila, traditionally credited with the Samkhya Sutras (though Ishvarakrishna's Samkhyakarika is the classical text)

Core focus: Metaphysical dualism between consciousness and matter

Concept Explanation
Purusha (consciousness) Pure passive consciousness; multiple individual selves; neither acts nor changes
Prakriti (matter/nature) The active, dynamic, unconscious material cause of the universe; single undifferentiated primordial matter
Evolution of the universe When Purusha comes into proximity with Prakriti, evolution occurs: Prakriti produces Mahat (cosmic intelligence) → Ahamkara (ego) → 5 sense organs, 5 motor organs, mind, 5 tanmatras (subtle elements), 5 mahabhutas (gross elements) — totalling 25 tattvas
Three Gunas Prakriti has three constituent qualities: Sattva (purity/lightness), Rajas (activity/passion), Tamas (inertia/darkness). Their interplay drives all change
Liberation (Kaivalya) Through discriminative knowledge (Vivekakhyati) — realising that Purusha is distinct from Prakriti; liberation is isolation of pure consciousness
Theism Classical Samkhya is typically non-theistic — it does not require God to explain creation; Prakriti is the material cause

Yoga relationship: Patanjali's Yoga school accepts Samkhya's metaphysics but adds the concept of Ishvara (a special, unaffected Purusha — God) and prescribes practical methods (asanas, pranayama, meditation) to achieve liberation.


4. Yoga — Path of Liberation through Practice

Founder: Sage Patanjali, who compiled the Yoga Sutras (c. 200 BCE–400 CE)

Core focus: Practical method for achieving liberation through mental discipline and the cessation of mental modifications (chitta vritti nirodha)

Concept Explanation
Metaphysics Accepts Samkhya's Purusha-Prakriti dualism; adds Ishvara (God) as a special liberated self
Goal Chitta vritti nirodha — cessation of the fluctuations of the mind; leads to Kaivalya (liberation)
Ashtanga Yoga (Eight Limbs) The systematic path described in the Yoga Sutras

The Eight Limbs of Ashtanga Yoga:

Limb Sanskrit Meaning
1 Yama Ethical restraints (ahimsa, satya, asteya, brahmacharya, aparigraha)
2 Niyama Observances (saucha, santosha, tapas, svadhyaya, Ishvara pranidhana)
3 Asana Physical postures — stability and comfort
4 Pranayama Breath control
5 Pratyahara Withdrawal of senses from external objects
6 Dharana Concentration on a single object
7 Dhyana Meditation — sustained concentration
8 Samadhi Absorption — the final state of unity with the object of meditation; liberation

The inner four (Pratyahara to Samadhi) constitute Samyama — the highest practices.


5. Mimamsa — Vedic Ritualism and Dharma

Founder: Sage Jaimini, who composed the Mimamsa Sutras (also called Purva Mimamsa Sutras)

Core focus: Correct interpretation of Vedic injunctions (vidhis) and the nature of dharma — the obligatory Vedic duties

Concept Explanation
Sabda-pramana (verbal testimony) Sabda (the Vedas as eternal sound) is the primary valid source of knowledge — the Vedas are self-validating, authorless (apaurusheya) and eternal
Dharma Dharma = Vedic injunction (vidhi); what ought to be done; not knowable through perception or inference but only through Vedic testimony
Svarga (heaven) Rituals performed properly lead to the attainment of heaven; later Mimamsa debated liberation
Apurva The unseen potency generated by a ritual that bridges the performance of a rite and its future fruit — a form of moral causality
God Classic Mimamsa is typically non-theistic — rituals work by their own power, without requiring a God
Kumarila Bhatta and Prabhakara Two important sub-schools within Mimamsa; differed on the nature of error and the grounds of validity of knowledge

Mimamsa's philosophical influence was immense — it was the guardian of Brahmanical orthopraxis and its debates with Buddhism shaped much of classical Indian intellectual history.


6. Vedanta — The Philosophy of the Upanishads

Founder: Sage Badarayana (also identified as Vyasa), who composed the Brahma Sutras (also called Vedanta Sutras or Uttara Mimamsa Sutras)

Core texts (Prasthanatrayi):

  1. Upanishads (primary)
  2. Bhagavad Gita
  3. Brahma Sutras (Badarayana)

Core focus: Nature of Brahman (ultimate reality), Atman (individual soul), and the relationship between the two

Vedanta developed into multiple sub-schools, the three most significant being:

Sub-School Founder Period Core Teaching
Advaita (Non-dualism) Adi Shankaracharya ~788–820 CE Brahman alone is real; Atman = Brahman; the world is maya (illusion/appearance)
Vishishtadvaita (Qualified Non-dualism) Ramanuja ~1017–1137 CE Brahman is real, the world and souls are real but exist as attributes of Brahman — qualified unity
Dvaita (Dualism) Madhvacharya ~1238–1317 CE Brahman (Vishnu) and individual souls are eternally distinct and independent realities

Advaita Vedanta (Shankaracharya)

  • Brahman is the only ultimate reality — infinite, undifferentiated pure consciousness
  • Atman (individual self) is identical to Brahman: Tat Tvam Asi ("That Thou Art") — Chandogya Upanishad
  • Maya: The world appears real through the power of maya (cosmic illusion/ignorance) but has no ultimate ontological status (mithya — neither real nor unreal)
  • Two levels of truth: Vyavaharika (conventional/empirical truth — the world exists in practice) and Paramarthika (ultimate truth — only Brahman exists)
  • Liberation (Moksha): Through jnana (knowledge) — realising the identity of Atman and Brahman
  • Shankaracharya also established four mathas (monasteries) at Sringeri, Dwarka, Puri, and Joshimath (Badrinath) — consolidating Hindu philosophical thought

Vishishtadvaita (Ramanuja)

  • Brahman is real and personal — identified with Vishnu/Narayana (Saguna Brahman with attributes)
  • The world and individual souls are real but constitute the "body" of Brahman — they are not illusion
  • Jiva (individual soul) and jagat (world) are real but exist in a relation of apritak-siddhi (inseparable existence) with Brahman
  • Liberation: Through bhakti (devotion) combined with jnana and karma — the soul attains proximity (not merger) with Brahman
  • Ramanuja's philosophy influenced the Bhakti movement strongly — particularly the Vaishnava traditions

Dvaita Vedanta (Madhvacharya)

  • Five eternal distinctions (pancha-bheda): Between God and soul; between God and matter; between soul and matter; between individual souls; between material objects
  • Brahman (Vishnu) is the only independent reality (svatantra) — souls and matter are dependent (paratantra)
  • Souls are eternally distinct from God — liberation means eternal life in the presence of Vishnu, not merger
  • Madhvacharya's tradition headquartered at Udupi (Karnataka)

Heterodox Schools (Nastika Darshanas)

1. Buddhism

Buddhism rejected Vedic authority and the caste system. Its philosophical development is vast:

School Key Figure Core Concept
Theravada/Hinayana Traditional — attributed to historical Buddha Dependent origination (pratityasamutpada), Four Noble Truths, Eightfold Path
Madhyamaka Nagarjuna (c. 150–250 CE) Sunyavada — all phenomena are empty (sunya) of inherent existence; the middle way between existence and non-existence
Yogacara / Vijnanavada Asanga and Vasubandhu (4th–5th CE) "Mind-only" (cittamatra) — external reality is a projection of consciousness
Buddhist Logic/Epistemology Dignaga (5th CE) and Dharmakirti (7th CE) Developed a rigorous pramana (epistemology) tradition; influenced Nyaya debates; only perception and inference as valid

Nagarjuna's Madhyamaka: The most influential Buddhist philosophical school globally — "sunyata" (emptiness) does not mean nihilism but the absence of svabhava (inherent/self-subsistent nature) in all phenomena. This underpinned Mahayana Buddhism's emphasis on compassion and the Bodhisattva path.

2. Jainism — Many-Sidedness of Truth

Jainism developed a sophisticated epistemology rooted in its metaphysics of multiple independent souls:

Concept Meaning
Anekantavada Doctrine of the many-sidedness of reality — reality has multiple aspects; no single viewpoint captures the whole truth
Syadvada (Saptabhangi) Theory of conditional predication — any statement about reality must be qualified with syat ("in some respect" / "perhaps"); 7 possible qualified truth-values
Nayavada Theory of partial perspectives (naya = viewpoint); every assertion is made from a particular standpoint
Ahimsa Non-violence as the supreme ethical principle — extends to all living beings; basis for Jain dietary practices
Karma (Jain view) Karma is a physical substance (karma vargana) that attaches to the soul, binding it; liberation through shedding karma

UPSC relevance: Anekantavada is cited as an ancient Indian contribution to tolerance and pluralism; Gandhi acknowledged its influence on his thought.

3. Charvaka / Lokayata — Indian Materialism

The Charvaka (or Lokayata) school is India's ancient materialist philosophy — the only school that rejected all metaphysical speculation.

Concept Position
Epistemology Only pratyaksha (perception) is a valid source of knowledge — inference is unreliable since vyapti (invariable concomitance) cannot be established through perception alone
Metaphysics Only the four material elements (earth, water, fire, air) are real; consciousness arises from matter
Soul No immortal soul — consciousness is a product of the body; ceases at death
Afterlife No afterlife, no rebirth, no karma, no liberation
Ethics Hedonism — the pursuit of pleasure (kama) and avoidance of pain is the purpose of life; dharma and moksha are superfluous
God Atheistic — no creator God

Charvaka writings have largely survived only through quotations in rival texts (Shankaracharya's commentary, Jayanta Bhatta's Nyayamanjari, etc.) — a remarkable case of philosophical transmission through refutation.


Indian Epistemology — Pramanas (Valid Sources of Knowledge)

Different schools accepted different numbers of valid knowledge sources:

Pramana Meaning Schools Accepting
Pratyaksha (Perception) Direct sensory perception All schools (Charvaka: only this)
Anumana (Inference) Logical inference through vyapti (universal relation) All except Charvaka
Upamana (Comparison) Knowledge through analogy — knowing a new thing by comparing to a known thing Nyaya, Mimamsa
Sabda (Verbal Testimony) Reliable testimony — Vedas or trustworthy person Most schools; elevated to supreme by Mimamsa
Arthapatti (Postulation) Presumption — inferring an unexpressed fact to explain an apparent contradiction Mimamsa, Advaita
Anupalabdhi (Non-perception) Knowledge of absence — knowing a pot is not on the table by not perceiving it Mimamsa, Advaita
School Pramanas Accepted Count
Charvaka Pratyaksha only 1
Buddhism (Dignaga/Dharmakirti) Pratyaksha, Anumana 2
Samkhya-Yoga Pratyaksha, Anumana, Sabda 3
Nyaya Pratyaksha, Anumana, Upamana, Sabda 4
Mimamsa, Advaita Vedanta All six 6

Relevance for UPSC Ethics (GS4)

Ancient Indian philosophical traditions have direct relevance for GS4 (Ethics, Integrity and Aptitude):

Tradition Ethical Contribution Modern Connection
Yoga (Patanjali) — Yamas Ahimsa, Satya, Asteya as universal ethical principles Gandhi's satyagraha; Ambedkar's rights discourse
Jain Anekantavada Tolerance, humility about one's own viewpoint Constitutional secularism; pluralistic democracy
Advaita Vedanta Unity of all beings (Vasudhaiva Kutumbakam) Vivekananda's universal ethics; universal brotherhood
Buddhist Madhyamaka Middle path; compassion for all sentient beings B.R. Ambedkar's turn to Buddhism; compassion in governance
Mimamsa — Dharma Duty-based ethics; obligation without expectation of personal gain Resonates with Kant's deontological ethics; Gita's Nishkama Karma
Samkhya — Gunas Understanding human nature (sattva/rajas/tamas) as basis for leadership character Civil services character formation; administrative ethics

Previous Year Questions (PYQs)

Prelims

  1. (UPSC CSE Prelims 2021): "With reference to Indian history, the term 'Anekantavada' is most closely associated with which of the following?"

    • Jainism — the doctrine of many-sidedness of reality.
  2. (UPSC CSE Prelims 2020): "In the context of Indian philosophy, the 'Vyapti' is associated with which school?"

    • Nyaya — vyapti is the principle of invariable concomitance used in inference (anumana).
  3. (UPSC CSE Prelims 2018): "'Pratyaksha', 'Anumana', 'Upamana' and 'Sabda' are the four Pramanas of which school of Indian philosophy?"

    • Nyaya school.
  4. (UPSC CSE Prelims 2014): "Who among the following is associated with the founding of the Dvaita school of Vedanta?"

    • Madhvacharya.

Mains

  1. (UPSC CSE Mains GS1 2022): "Discuss the major philosophical schools of ancient India. How do they contribute to understanding Indian civilisation?" (250 words)

  2. (UPSC CSE Mains GS4 2021): "How are ancient Indian ethical concepts relevant to the ethics of public service? Illustrate with examples from specific philosophical schools." (150 words)

  3. (UPSC CSE Mains GS1 2019): "What is the significance of Shankaracharya's Advaita Vedanta in the context of Indian philosophical tradition? How did it differ from Ramanuja's Vishishtadvaita?" (200 words)

  4. (UPSC CSE Mains GS4 2015): "The Charvaka school is sometimes dismissed as mere hedonism. Evaluate the philosophical contributions of the Charvaka/Lokayata tradition to Indian epistemology." (150 words)


Exam Strategy

For Prelims:

  • Pair each Darshana with its founder: Nyaya–Gautama, Vaisheshika–Kanada, Samkhya–Kapila, Yoga–Patanjali, Mimamsa–Jaimini, Vedanta–Badarayana
  • Vedanta sub-schools: Advaita–Shankaracharya (non-dual, maya), Vishishtadvaita–Ramanuja (qualified non-dual), Dvaita–Madhvacharya (dualist, Udupi)
  • Pramanas: Charvaka=1, Buddhist=2, Samkhya=3, Nyaya=4, Mimamsa/Advaita=6
  • Anekantavada = Jainism; Sunyavada = Nagarjuna/Buddhism; Vivekakhyati = Samkhya liberation
  • Charvaka: perception only, materialist, hedonist, no soul/afterlife

For Mains (GS1 + GS4):

  • GS1 asks about ancient philosophical contributions — structure your answer: Orthodox (Shad Darshana) → Heterodox (B, J, C) → Legacy
  • GS4 (Ethics): Always link philosophical concepts to modern administrative ethics — Yamas as civil service conduct; Anekantavada as tolerance; Nishkama karma as public duty
  • Compare Indian and Western traditions: Nyaya syllogism vs Aristotelian syllogism; Charvaka vs Greek materialists; Indian pramana vs Western epistemology
  • Shankaracharya's mathas — national integration significance (4 corners of India)

Mnemonic for Six Darshanas: N-V-S-Y-M-V = Nyaya, Vaisheshika, Samkhya, Yoga, Mimamsa, Vedanta (Never Visit Strange Yellow Mountain Villages)