Hindu philosophy

Hindu philosophy or Vedic philosophy is the set of Indian philosophical systems that developed in tandem with early Hindu religious traditions during the iron and classical ages of India. In Indian tradition, the word used for philosophy is Darshana (Sanskrit: दर्शन; meaning: "viewpoint or perspective"), from the Sanskrit root 'दृश' (drish) meaning 'to see, to experience'.^[1]

The schools of thought or Darshanas within Hindu philosophy largely equate to the six ancient orthodox schools: the āstika (Sanskrit : आस्तिक) schools, defined by their acceptance of the Vedas, the oldest collection of Sanskrit texts, as an authoritative source of knowledge.^{[2][note 1][note 2]} Of these six, Samkhya (सांख्य) is the earliest school of dualism; Yoga (योग) combines the metaphysics of Samkhya with meditation and breath techniques; Nyaya (न्याय) is a school of logic emphasising direct realism; Vaisheshika (वैषेशिक) is an offshoot of Nyaya concerned with atomism and naturalism; Mimamsa (मीमांसा) is a school justifying ritual, faith, and religious obligations; and Vedanta (वेदान्त) contains various traditions that mostly embrace nondualism.^{[5][6][7][8][9]}

Indian philosophy during the ancient and medieval periods also yielded philosophical systems that share concepts with the āstika traditions but reject the Vedas. These have been called nāstika (heterodox or non-orthodox) philosophies,^[6][2] and they include: Buddhism, Jainism, Charvaka, Ajivika, and others,^[10] which are thus broadly classified under Indian but not Hindu philosophy. Western scholars have debated the relationship and differences within āstika philosophies and with the nāstika philosophies, starting with the writings of Indologists and Orientalists of the 18th and 19th centuries, based on limited availability of Indian literature and medieval doxographies.^[6] The various sibling traditions included in Indian philosophies are diverse and are united by: shared history and concepts, textual resources, ontological and soteriological focus, and cosmology.^[11][12] Some heterodox (nāstika) traditions such as Charvaka are often considered as distinct schools within Hindu philosophy because the word Hindu is an exonym historically used as a geographical and cultural identifier for people living in the Indian subcontinent.^{[13][14][15][16]}

Hindu philosophy also includes several sub-schools of theistic philosophies that integrate ideas from two or more of the six orthodox philosophies. Examples of such schools include: Pāśupata Śaiva, Śaiva siddhānta, Pratyabhijña, Raseśvara and Vaiṣṇava.^[7][8] Some sub-schools share Tantric ideas with those found in some Buddhist traditions,^[17] which are nevertheless found in the Puranas and the Āgamas.^[18][19][20] Each school of Hindu philosophy has extensive epistemological literature called Pramana,^[21][22] as well as theories on metaphysics, axiology, and other topics.^[23]

In the history of India, the six orthodox schools had emerged before the start of the Common Era, and some schools emerged possibly even before the Buddha.^[24] Some scholars have questioned whether the orthodox and heterodox schools classification is sufficient or accurate, given the diversity and evolution of views within each major school of Indian philosophy, with some sub-schools combining heterodox and orthodox views.^[25]

Since ancient times, Indian philosophy has been categorised into āstika and nāstika schools of thought.^[26] The orthodox schools of Indian philosophy have been called ṣaḍdarśana ('six systems'). This schema was created between the 12th and 16th centuries by Vedantins.^{[27]: 2–3} It was then adopted by the early Western Indologists, and pervades modern understandings of Indian philosophy.^{[27]: 4–5}

Sāmkhya(Sanskrit: सांख्य) is the oldest of the orthodox philosophical systems in Hinduism,^[53] with origins in the 1st millennium BCE.^[29] It is a rationalist school of Indian philosophy,^[45] and had a strong influence on other schools of Indian philosophies.^[54] Sāmkhya is an enumerationist philosophy whose epistemology accepted three of six pramāṇas as the only reliable means of gaining knowledge. These were pratyakṣa (perception), anumāṇa (inference) and sabda (Āptavacana, word/testimony of reliable sources).^[55][51]

Samkhya school espouses dualism between witness-consciousness and 'nature' (mind, perception, matter).^[56] It regards the universe as consisting of two realities: Puruṣa (witness-consciousness) and prakriti ('nature'). Jiva (a living being) is that state in which puruṣa is bonded to prakriti in some form.^[57] This fusion, state the Samkhya scholars, led to the emergence of buddhi (awareness, intellect) and ahankara (individualised ego consciousness, "I-maker"). The universe is described by this school as one created by Purusa-Prakriti entities infused with various permutations and combinations of variously enumerated elements, senses, feelings, activity and mind.^[57]

Samkhya philosophy includes a theory of gunas (qualities, innate tendencies, psyche).^[58] Guna, it states, are of three types: Sattva being good, compassionate, illuminating, positive, and constructive; Rajas guna is one of activity, chaotic, passion, impulsive, potentially good or bad; and Tamas being the quality of darkness, ignorance, destructive, lethargic, negative. Everything, all life forms and human beings, state Samkhya scholars, have these three gunas, but in different proportions.^[59] The interplay of these gunas defines the character of someone or something, of nature and determines the progress of life.^[60][61] Samkhya theorises a pluralism of Selfs (Jeevatmas) who possess consciousness.^[62] Samkhya has historically been theistic or non-theistic, and there has been debate about its specific view on God.^{[63][64][65][66]}

The Samkhya karika, one of the key texts of this school of Hindu philosophy, opens by stating its goal to be "three^[67] kinds of human suffering" and means to prevent them.^[68] The text then presents a distillation of its theories on epistemology, metaphysics, axiology and soteriology. For example, it states,

From the triad of suffering, arises this inquiry into the means of preventing it.
That is useless – if you say so, I say: No, because suffering is not absolute and final. – Verse 1

The Guṇas (qualities) respectively consist in pleasure, pain and dullness, are adapted to manifestation, activity and restraint; mutually domineer, rest on each other, produce each other, consort together, and are reciprocally present. – Verse 12
Goodness is considered to be alleviating and enlightening; foulness, urgent and persisting; darkness, heavy and enveloping. Like a lamp, they cooperate for a purpose by union of contraries. – Verse 13

There is a general cause, which is diffuse. It operates by means of the three qualities, by mixture, by modification; for different objects are diversified by influence of the several qualities respectively. – Verse 16
Since the assemblage of perceivable objects is for use (by man); Since the converse of that which has the three qualities with other properties must exist (in man); Since there must be superintendence (within man); Since there must be some entity that enjoys (within man); Since there is a tendency to abstraction (in man), therefore soul is. – Verse 17

— Samkhya karika, ^[68][69]

The soteriology in Samkhya aims at the realisation of Puruṣa as distinct from Prakriti; this knowledge of the Self is held to end transmigration and lead to absolute freedom (kaivalya).^[70]

In Indian philosophy, Yōga(Sanskrit: योग) is, among other things, the name of one of the six āstika philosophical schools.^[71] The Yoga philosophical system aligns closely with the dualist premises of the Samkhya school.^[72][73] The Yoga school accepts Samkhya psychology and metaphysics, but is considered theistic because it accepts the concept of personal god (Ishvara, unlike Samkhya.^[74][75][76] The epistemology of the Yoga school, like the Sāmkhya school, relies on three of six prāmaṇas as the means of gaining reliable knowledge:^[51] pratyakṣa (perception), anumāṇa (inference) and śabda (āptavacana, word/testimony of reliable sources).^[52][51]

The universe is conceptualised as a duality in Yoga school: puruṣa (witness-consciousness) and prakṛti (mind, perception, matter); however, the Yoga school discusses this concept more generically as "seer, experiencer" and "seen, experienced" than the Samkhya school.^[77]

A key text of the Yoga school is the Yoga Sutras of Patanjali. Patanjali may have been, as Max Müller explains, "the author or representative of the Yoga-philosophy without being necessarily the author of the Sutras."^[78] Hindu philosophy recognises many types of Yoga, such as rāja yoga, jñāna yoga,^[79] karma yoga, bhakti yoga, tantra yoga, mantra yoga, laya yoga, and hatha yoga.^[80]

The Yoga school builds on the Samkhya school theory that jñāna (knowledge) is a sufficient means to moksha. It suggests that systematic techniques/practice (personal experimentation) combined with Samkhya's approach to knowledge is the path to moksha.^[72] Yoga shares several central ideas with Advaita Vedanta, with the difference that Yoga is a form of experimental mysticism while Advaita Vedanta is a form of monistic personalism.^[81][82][83] Like Advaita Vedanta, the Yoga school of Hindu philosophy holds that liberation/freedom in this life is achievable, and that this occurs when an individual fully understands and realises the equivalence of Atman (Self) and Brahman.^[84][85]

The Vaiśeṣika(Sanskrit: वैशेसिक) philosophy is a naturalist school.^[48] It is a form of atomism in natural philosophy.^[86] It postulates that all objects in the physical universe are reducible to paramāṇu (atoms), and that one's experiences are derived from the interplay of substance (a function of atoms, their number and their spatial arrangements), quality, activity, commonness, particularity and inherence.^[87] Knowledge and liberation are achievable by complete understanding of the world of experience, according to Vaiśeṣika school.^[87] The Vaiśeṣika darśana is credited to Kaṇāda Kaśyapa from the second half of the first millennium BCE.^[87][88] The foundational text, the Vaiśeṣika Sūtra, opens as follows:

Dharma is that from which results the accomplishment of Exaltation and of the Supreme Good. The authoritativeness of the Veda arises from its being an exposition of dharma. The Supreme Good results from knowledge, produced from a particular dharma, of the essence of the Predicables, Substance, Attribute, Action, Genus, Species and Combination, by means of their resemblances and differences.

— Vaiśeṣika Sūtra 1.1.1–1.1.4, ^[89]

The Vaiśeṣika school is related to the Nyāya school but features differences in its epistemology, metaphysics and ontology.^[90] The epistemology of the Vaiśeṣika school, like Buddhism, accepted only two means to knowledge as reliable – perception and inference.^[52][91] The Vaiśeṣika school and Buddhism both consider their respective scriptures as indisputable and valid means to knowledge, the difference being that the scriptures held to be a valid and reliable source by Vaiśeṣikas were the Vedas.^[52][92]

Vaiśeṣika metaphysical premises are founded on a form of atomism, that reality is composed of four substances (earth, water, air, and fire). Each of these four are of two types:^[86] atomic (paramāṇu) and composite. An atom is, according to Vaiśeṣika scholars, that which is indestructible (anitya), indivisible, and has a special kind of dimension, called "small" (aṇu). A composite, in this philosophy, is defined to be anything which is divisible into atoms. Whatever human beings perceive is composite, while atoms are invisible.^[86] The Vaiśeṣikas stated that size, form, truths and everything that human beings experience as a whole is a function of atoms, their number and their spatial arrangements, their guṇa (quality), karma (activity), sāmānya (commonness), viśeṣa (particularity) and amavāya (inherence, inseparable connectedness of everything).^[87][93]

The Nyāya(Sanskrit: न्याय) school is a realist āstika philosophy.^[94][95] The school's most significant contributions to Indian philosophy were its systematic development of the theory of logic, methodology, and its treatises on epistemology.^[96][97] The foundational text of the Nyāya school is the Nyāya Sūtras of the first millennium BCE. The text is credited to Aksapada Gautama and its composition is variously dated between the sixth and second centuries BCE.^[98][88]

Nyāya epistemology accepts four out of six prāmaṇas as reliable means of gaining knowledge – pratyakṣa (perception), anumāṇa (inference), upamāṇa (comparison and analogy) and śabda (word, testimony of past or present reliable experts).^[51][99][50]

In its metaphysics, the Nyāya school is closer to the Vaiśeṣika school than the others.^[94] It holds that human suffering results from mistakes/defects produced by activity under wrong knowledge (notions and ignorance).^[100] Moksha (liberation), it states, is gained through right knowledge. This premise led Nyāya to concern itself with epistemology, that is, the reliable means to gain correct knowledge and to remove wrong notions. False knowledge is not merely ignorance to Naiyayikas; it includes delusion. Correct knowledge is discovering and overcoming one's delusions, and understanding the true nature of the soul, self and reality.^[101] The Nyāya Sūtras begin:

Perception, Inference, Comparison and Word – these are the means of right knowledge.
Perception is that knowledge which arises from the contact of a sense with its object and which is determinate, unnameable and non-erratic.
Inference is knowledge which is preceded by perception, and is of three kinds: a priori, a posteriori, and commonly seen.
Comparison is the knowledge of a thing through its similarity to another thing previously well known.
Word is the instructive assertion of a reliable person.
It [knowledge] is of two kinds: that which is seen, and that which is not seen.
Soul, body, senses, objects of senses, intellect, mind, activity, fault, transmigration, fruit, suffering and release – are the objects of right knowledge.

— Nyāya Sūtras 1.1.3–1.1.9, ^[102]

The Nyāya school uses a three-fold procedure: enumeration, definition, and examination. This procedure of enumeration, definition, and examination is recurrent in Navya-Nyāya texts like The Manual of Reason (Tarka-Sangraha).^[86]

The Mīmāṃsā(Sanskrit: मीमांसा) school emphasises religious hermeneutics and exegesis.^[103][104] It is a form of philosophical realism.^[105] Key texts of the Mīmāṃsā school are the Purva Mimamsa Sutras of Jaimini.^[30][106] The classical Mīmāṃsā school is sometimes referred to as pūrvamīmāṃsā or Karmamīmāṃsā in reference to the first part of the Vedas.^[30]

The Mīmāṃsā school has several sub-schools defined by epistemology. The Prābhākara subschool of Mīmāṃsā accepted five means to gaining knowledge as epistimetically reliable: pratyakṣa (perception), anumāṇa (inference), upamāṇa (comparison and analogy), arthāpatti (postulation, derivation from circumstances), and śabda (word, testimony of past or present reliable experts).^[99][50] The Kumārila Bhaṭṭa sub-school of Mīmāṃsā added a sixth way of knowing to its canon of reliable epistemology: anupalabdi (non-perception, negative/cognitive proof).^[51]

The metaphysics of the Mīmāṃsā school consists of both atheistic and theistic doctrines, and the school showed little interest in systematic examination of the existence of God. Rather, it held that the Self (Atma) is an eternal, omnipresent, inherently active spiritual essence, then focussed on the epistemology and metaphysics of dharma.^{[30][107][108]} To them, dharma meant rituals and duties, not devas (gods), because devas existed only in name.^[30] The Mīmāṃsākas held that the Vedas are "eternal authorless infallible", that Vedic vidhi (injunctions) and mantras in rituals are prescriptive karya (actions), and that the rituals are of primary importance and merit. They considered the Upanishads and other texts related to self-knowledge and spirituality to be of secondary importance, a philosophical view that the Vedanta school disagreed with.^[103][30]

Mīmāṃsā gave rise to the study of philology and the philosophy of language.^[109] While their deep analysis of language and linguistics influenced other schools,^[110] their views were not shared by others. Mīmāṃsākas considered the purpose and power of language was to clearly prescribe the proper, correct and right. In contrast, Vedantins extended the scope and value of language as a tool to also describe, develop and derive.^[30] Mīmāṃsākas considered orderly, law-driven, procedural life as the central purpose and noblest necessity of dharma and society, and divine (theistic) sustenance means to that end. The Mimamsa school was influential and foundational to the Vedanta school, with the difference that Mīmāṃsā developed and emphasises karmakāṇḍa (the portion of the śruti which relates to ceremonial acts and sacrificial rites, the early parts of the Vedas), while the Vedanta school developed and emphasises jñānakāṇḍa (the portion of the Vedas that relates to knowledge of monism, the latter parts of the Vedas).^[103]

The Vedānta(Sanskrit: वेदान्त) school built upon the teachings of the Upanishads and Brahma Sutras from the first millennium BCE^[88][111] and is the most developed^{[citation needed]} and best-known of the Hindu schools. The epistemology of the Vedantins included, depending on the sub-school, five or six methods as proper and reliable means of gaining any form of knowledge:^[92] pratyakṣa (perception), anumāṇa (inference), upamāṇa (comparison and analogy), arthāpatti (postulation, derivation from circumstances), anupalabdi (non-perception, negative/cognitive proof) and śabda (word, testimony of past or present reliable experts).^[52][51][50] All of these have been further categorised by each sub-school of Vedanta in terms of conditionality, completeness, confidence and possibility of error.^[92]

The emergence of the Vedanta school represented a period in which a more knowledge-centered understanding began to emerge, focusing on jnana (knowledge) driven aspects of the Vedic religion and the Upanishads. These included metaphysical concepts such as ātman and Brahman, and an emphasis on meditation, self-discipline, self-knowledge and abstract spirituality, rather than ritualism. The Upanishads were variously interpreted by ancient- and medieval-era Vedanta scholars. Consequently, the Vedanta separated into many sub-schools, ranging from theistic dualism to non-theistic monism, each interpreting the texts in its own way and producing its own series of sub-commentaries.^[112][113]

The Cārvāka(Sanskrit: चार्वाक) school is one of the nāstika or "heterodox" philosophies .^{[145][15][146]} It rejects supernaturalism, emphasises materialism and philosophical skepticism, holding empiricism, perception and conditional inference as the proper source of knowledge^[147][148] Cārvāka is an atheistic school of thought.^[149] It holds that there is neither afterlife nor rebirth, all existence is mere combination of atoms and substances, feelings and mind are an epiphenomenon, and free will exists.^[32][33]

Bṛhaspati is sometimes referred to as the founder of Cārvāka (also called Lokayata) philosophy. Much of the primary literature of Cārvāka, the Barhaspatya sutras (ca. 600 BCE), however, are missing or lost.^[149][150] Its theories and development has been compiled from historic secondary literature such as those found in the shastras, sutras and the Indian epic poetry as well as from the texts of Buddhism and from Jain literature.^{[149][151][152]} The Tattvôpaplava-siṁha by the skeptic philosopher Jayarāśi Bhaṭṭa has been considered by many scholars to be an unorthodox Cārvāka text.^[153]

One of the widely studied principles of Cārvāka philosophy was its rejection of inference as a means to establish valid, universal knowledge, and metaphysical truths.^[154] In other words, the Cārvāka epistemology states that whenever one infers a truth from a set of observations or truths, one must acknowledge doubt; inferred knowledge is conditional.^[155]

Early history of Shaivism is difficult to determine.^[156] However, the Śvetāśvatara Upanishad (400 – 200 BCE)^[157] is considered to be the earliest textual exposition of a systematic philosophy of Shaivism.^[158] Shaivism is represented by various philosophical schools, including non-dualist (abheda), dualist (bheda), and non-dualist-with-dualist (bhedābheda) perspectives. Vidyaranya in his works mentions three major schools of Shaiva thought: Pashupata Shaivism, Shaiva Siddhanta and Pratyabhijña (Kashmir Shaivism).^[159]