Advaita Vedanta

Advaita Vedānta ; Sanskrit: अद्वैतवेदान्त, IAST: Advaita Vedānta, literally, "non-duality") is a school of Hindu philosophy, and is a classic system of spiritual realization in Indian tradition. The term Advaita refers to the idea that Brahman alone is ultimately real, the phenomenal transient world is an illusory appearance (maya) of Brahman, and the true self, atman, is not different from Brahman.

Originally known as Puruṣavāda and as māyāvāda, the followers of this school are known as Advaita Vedantins, or just Advaitins, regarding the phenomenal world as mere illusory appearance of plurality, experienced through the sense-impressions by ignorance (avidya), an illusion superimposed (adhyāsa) on the sole reality of Brahman. They seek moksha (liberation) through recognizing this illusoriness of the phenomenal world and acquiring vidyā (knowledge) of one's true identity as Atman, and the identity of Atman and Brahman.

Advaita Vedānta traces its roots to the oldest Upanishads. It relies on three textual sources called the Prasthanatrayi. It gives "a unifying interpretation of the whole body of Upanishads", the Brahma Sutras, and the Bhagavad Gitā. Advaita Vedānta is the oldest extant sub-school of Vedānta, which is one of the six orthodox (āstika) Hindu philosophies (darśana). Although its roots trace back to the 1st millennium BCE, the most prominent exponent of the Advaita Vedānta is considered by tradition to be the 8th century scholar Adi Shankara.

Advaita Vedānta emphasizes Jivanmukti, the idea that moksha (freedom, liberation) is achievable in this life in contrast to other Indian philosophies that emphasize videhamukti, or moksha after death. The school uses concepts such as Brahman, Atman, Maya, Avidya, meditation and others that are found in major Indian religious traditions, but interprets them in its own way for its theories of moksha. Advaita Vedānta is one of the most studied and most influential schools of classical Indian thought. Many scholars describe it as a form of monism, while others describe the Advaita philosophy as non-dualistic. Advaita is considered to be a philosophy or spiritual pathway rather than a religion, as it does not require those who follow it to be of a particular faith or sect.

Advaita influenced and was influenced by various traditions and texts of Hindu philosophies such as Samkhya, Yoga, Nyaya, other sub-schools of Vedānta, Vaishnavism, Shaivism, the Puranas, the Agamas, as well as social movements such as the Bhakti movement. Beyond Hinduism, Advaita Vedānta interacted and developed with the other traditions of India such as Jainism and Buddhism. Advaita Vedānta texts espouse a spectrum of views from idealism, including illusionism, to realist or nearly realist positions expressed in the early works of Shankara. In modern times, its views appear in various Neo-Vedānta movements. It has been termed as the paradigmatic example of Hindu spirituality.

Etymology and nomenclature

The word Advaita is a composite of two Sanskrit words:

·         Prefix "a-" (अ), meaning "non-"

·         "Dvaita" (द्वैत), which means 'duality' or 'dualism'.^]

Advaita is often translated as "non-duality," but a more apt translation is "non-secondness." It means that there is no other reality than Brahman, that "Reality is not constituted by parts," that is, ever-changing "things" have no existence of their own, but are appearances of the one Existent, Brahman; and that there is no duality between the essence, or Being, of a person (atman), and Brahman, the Ground of Being.

The word Vedānta is a composition of two Sanskrit words: The word Veda refers to the whole corpus of vedic texts, and the word "anta" means 'end'. The meaning of Vedānta can be summed up as "the end of the vedas" or "the ultimate knowledge of the vedas". Vedānta is one of six orthodox schools of Hindu philosophy.

Originally known as Puruṣavāda, and as māyāvāda, akin to Madhyamaka Buddhism, due to their insistence that phenomena ultimately lack an inherent essence or reality, the Advaita Vedānta school has been historically referred to by various names, such as Advaita-vada (speaker of Advaita), Abheda-darshana (view of non-difference), Dvaita-vada-pratisedha (denial of dual distinctions), and Kevala-dvaita (non-dualism of the isolated).

According to Richard King, a professor of Buddhist and Asian studies, the term Advaita first occurs in a recognizably Vedantic context in the prose of Mandukya Upanishad. In contrast, according to Frits Staal, a professor of philosophy specializing in Sanskrit and Vedic studies, the word Advaita is from the Vedic era, and the Vedic sage Yajnavalkya (8th or 7th-century BCE) is credited to be the one who coined it. Stephen Phillips, a professor of philosophy and Asian studies, translates the Advaita containing verse excerpt in Brihadaranyaka Upanishad, as "An ocean, a single seer without duality becomes he whose world is Brahman."

Darśana (view) – central concerns

Advaita is a subschool of Vedānta, the latter being one of the six classical Hindu darśanas, an integrated body of textual interpretations and religious practices which aim at the attainment of moksha, release or liberation from transmigratory existence. Traditional Advaita Vedānta centers on the study and what it believes to be correct understanding of the sruti, revealed texts, especially the Principal Upanishads, along with the Brahma Sutras and the Bhagavad Gitā, which are collectively called as Prasthantrayi.

Correct understanding is believed to provide knowledge of one's true identity as Ātman, the dispassionate and unchanging witness-consciousness, and the identity of Ātman and Brahman, which results in liberation. This is achieved through what Adi Shankara refers to as anubhava, immediate intuition, a direct awareness which is construction-free, and not construction-filled. It is not an awareness of Brahman, but instead an awareness that is Brahman.

Correct knowledge, which destroys avidya, the ignorance that constitutes the psychological and perceptual errors which obscure the true nature of Atman and Brahman, is obtained by following the four stages of samanyasa (self-cultivation), sravana, listening to the teachings of the sages, manana, reflection on the teachings, and svādhyāya, contemplation of the truth "that art Thou".

The Advaita Vedānta tradition rejects the dualism of Samkhya purusha (primal consciousness) and prakriti (inert primal matter), By accepting this postulation, various theoretical difficulties arise which Advaita and other Vedānta traditions offer different answers for.

A main question is the relation between Atman and Brahman, which is solved by regarding them to be identical. This truth is established from the oldest Principal Upanishads and Brahma Sutras, and is also found in parts of the Bhagavad Gitā and numerous other Hindu texts, and is regarded to be self-evident. The main aim of the commentaries is to support this nondualistic (of Atman and Brahman) reading of the sruti. Reason is being used to support revelation, the sruti, the ultimate source of truth.

Another question is how Brahman can create the world, and how to explain the manifoldness of phenomenal reality. By declaring phenomenal reality to be an 'illusion,' the primacy of Atman/Brahman can be maintained.

The Advaita literature also provide a criticism of opposing systems, including the dualistic school of Hinduism, as well as other Nastika (heterodox) philosophies such as Buddhism.

Moksha – liberation through knowledge of Brahman

Puruṣārtha – the four goals of human life

Advaita, like other schools, accepts Puruṣārtha – the four goals of human life as natural and proper:

·         Dharma: the right way to life, the "duties and obligations of the individual toward himself and the society as well as those of the society toward the individual";

·         Artha: the means to support and sustain one's life;

·         Kāma: pleasure and enjoyment;

·         Mokṣa: liberation, release.

Of these, much of the Advaita Vedānta philosophy focuses on the last, gaining liberation in one's current life. The first three are discussed and encouraged by Advaitins, but usually in the context of knowing Brahman and Self-realization.

Moksha – liberation

The soteriological goal, in Advaita, is to gain self-knowledge and complete understanding of the identity of Atman and Brahman. Correct knowledge of Atman and Brahman leads to dissolution of all dualistic tendencies and to liberation, Moksha is attained by realizing one's true identity as Ātman, and the identity of Atman and Brahman, the complete understanding of one's real nature as Brahman in this life. This is stated by Shankara as follows:

I am other than name, form and action.
My nature is ever free!
I am Self, the supreme unconditioned Brahman.
I am pure Awareness, always non-dual.

— Adi Shankara, Upadesasahasri 11.7,

According to Advaita Vedānta, liberation can be achieved while living, and is called Jivanmukti. The Atman-knowledge, that is the knowledge of true Self and its relationship to Brahman is central to this liberation in Advaita thought. Atman-knowledge, to Advaitins, is that state of full awareness, liberation and freedom which overcomes dualities at all levels, realizing the divine within oneself, the divine in others and all beings, the non-dual Oneness, that Brahman is in everything, and everything is Brahman.

According to Rambachan, in Advaita, this state of liberating self-knowledge includes and leads to the understanding that "the self is the self of all, the knower of self sees the self in all beings and all beings in the self."

Jivanmukta

In Advaita Vedānta, the interest is not in liberation in after life, but in one's current life. This school holds that liberation can be achieved while living, and a person who achieves this is called a Jivanmukta.

The concept of Jivanmukti of Advaita Vedānta contrasts with Videhamukti (moksha from samsara after death) in theistic sub-schools of Vedānta. Jivanmukti is a state that transforms the nature, attributes and behaviors of an individual, after which the liberated individual shows attributes such as:

·    by disrespect and endures cruel words, treats others with respect regardless of how others treat him;

·         when confronted by an angry person he does not return anger, instead replies with soft and kind words;

·         even if tortured, he speaks and trusts the truth;

·         he does not crave for blessings or expect praise from others;

·         he never injures or harms any life or being (ahimsa), he is intent in the welfare of all beings;

·         he is as comfortable being alone as in the presence of others;

·         he is as comfortable with a bowl, at the foot of a tree in tattered robe without help, as when he is in a mithuna (union of mendicants), grama (village) and nagara (city);

·         he does not care about or wear sikha (tuft of hair on the back of head for religious reasons), nor the holy thread across his body. To him, knowledge is sikha, knowledge is the holy thread, knowledge alone is supreme. Outer appearances and rituals do not matter to him, only knowledge matters;

·         for him there is no invocation nor dismissal of deities, no mantra nor non-mantra, no prostrations nor worship of gods, goddess or ancestors, nothing other than knowledge of Self;

·         he is humble, high spirited, of clear and steady mind, straightforward, compassionate, patient, indifferent, courageous, speaks firmly and with sweet words.

Vidya, Svādhyāya and Anubhava

Sruti (scriptures), proper reasoning and meditation are the main sources of knowledge (vidya) for the Advaita Vedānta tradition. It teaches that correct knowledge of Atman and Brahman is achievable by svādhyāya, study of the self and of the Vedic texts, and three stages of practice: sravana (perception, hearing), manana (thinking) and nididhyasana (meditation), a three-step methodology that is rooted in the teachings of chapter 4 of the Brihadaranyaka Upanishad.

Sravana literally means hearing, and broadly refers to perception and observations typically aided by a counsellor or teacher (guru), wherein the Advaitin listens and discusses the ideas, concepts, questions and answers. Manana refers to thinking on these discussions and contemplating over the various ideas based on svadhyaya and sravana. Nididhyāsana refers to meditation, realization and consequent conviction of the truths, non-duality and a state where there is a fusion of thought and action, knowing and being. Bilimoria states that these three stages of Advaita practice can be viewed as sadhana practice that unifies Yoga and Karma ideas, and was most likely derived from these older traditions.

Adi Shankara uses anubhava interchangeably with pratipatta, "understanding". Dalal and others state that anubhava does not center around some sort of "mystical experience," but around the correct knowledge of Brahman. Nikhalananda states that (knowledge of) Atman and Brahman can only be reached by buddhi, "reason," stating that mysticism is a kind of intuitive knowledge, while buddhi is the highest means of attaining knowledge.

Mahavakya – The Great Sentences

Several Mahavakyas, or "the great sentences", have Advaitic theme, that is "the inner immortal self and the great cosmic power are one and the same".

Sr. No.	Vakya	Meaning	Upanishad	Veda
1	प्रज्ञानंब्रह्म (prajñānam brahma)	Prajñānam is Brahman	Aitareya V.3	Rigveda
2.	अहंब्रह्मास्मि (ahambrahmāsmi)	I am Brahman, or I am Divine	Brhadāranyaka I.4.10	Shukla Yajurveda
3.	तत्त्वमसि (tat tvamasi)	That thou art, or You are that	Chandogya VI.8.7	Samaveda
4.	अयमात्माब्रह्म (ayamātmā brahma)	This Atman is Brahman	Mandukya II	Atharvaveda

Stages and practices

Advaita Vedānta entails more than self-inquiry or bare insight into one's real nature, but also includes self-restraint, textual studies and ethical perfection. It is described in classical Advaita books like Shankara's Upadesasahasri and the Vivekachudamani, which is also attributed to Shankara.

Jnana Yoga – path of practice

Classical Advaita Vedāntaemphasises the path of Jnana Yoga, a progression of study and training to attain moksha. It consists of fourfold qualities, or behavioral qualifications (Samanyasa, Sampattis, sādhana-catustaya): student is Advaita Vedānta tradition is required to develop these four qualities -

1.    Nityānitya vastu viveka (नित्यानित्यवस्तुविवेकम्) – Viveka is the ability to correctly discriminate between the real and eternal (nitya) and the substance that is apparently real, illusory, changing and transitory (anitya).

2.    Ihāmutrārtha phala bhoga virāga (इहाऽमुत्रार्थफलभोगविरागम्) – The renunciation (virāga) of all desires of the mind (bhog) for sense pleasures, in this world (iha) and other worlds. Willing to give up everything that is an obstacle to the pursuit of truth and self-knowledge.

3.    Śamādi ṣatka sampatti (शमादिषट्कसम्पत्ति) – the sixfold virtues or qualities -

1.    Śama - mental tranquility, ability to focus the mind.

2.    Dama - self-restraint, the virtue of temperance. restraining the senses.

3.    Uparati - dispassion, lack of desire for worldly pleasures, ability to be quiet and disassociated from everything; discontinuation of all religious duties and ceremonies

4.    Titikṣa - endurance, perseverance, putting up with pairs of opposites (like heat and cold, pleasure and pain), ability to be patient during demanding circumstances

5.    Śraddhā - having faith in teacher and the Sruti scriptural texts

6.    Samādhāna - contentedness, satisfaction of mind in all conditions, attention, intentness of mind

4.    Mumukṣutva (मुमुक्षुत्वम्) – An intense longing for freedom, liberation and wisdom, driven to the quest of knowledge and understanding. Having moksha as the primary goal of life

Correct knowledge, which destroys avidya, psychological and perceptual errors related to Atman and Brahman, is obtained in jnanayoga through three stages of practice, sravana (hearing), manana (thinking) and nididhyasana (meditation). This three-step methodology is rooted in the teachings of chapter 4 of the Brihadaranyaka Upanishad:

·         Sravana, listening to the teachings of the sages on the Upanishads and Advaita Vedānta, studying the Vedantic texts, such as the Brahma Sutras, and discussions with the guru (teacher, counsellor);

·         Manana, refers to thinking on these discussions and contemplating over the various ideas based on svadhyaya and sravana. It is the stage of reflection on the teachings;

·         Nididhyāsana, the stage of meditation and introspection. This stage of practice aims at realization and consequent conviction of the truths, non-duality and a state where there is a fusion of thought and action, knowing and being.

Samadhi

While Shankara emphasized śravaṇa ("hearing"), manana ("reflection") and nididhyāsana ("repeated meditation"), later texts like the Dṛg-Dṛśya-Viveka (14th century) and Vedāntasara (of Sadananda) (15th century) added samādhi as a means to liberation, a theme that was also emphasized by Swami Vivekananda.

Guru

Advaita Vedānta school has traditionally had a high reverence for Guru (teacher), and recommends that a competent Guru be sought in one's pursuit of spirituality. However, finding a Guru is not mandatory in the Advaita school, states Clooney, but the reading of Vedic literature and reflection, is. Adi Shankara, states Comans, regularly employed compound words "such as Sastracaryopadesa (instruction by way of the scriptures and the teacher) and Vedāntacaryopadesa (instruction by way of the Upanishads and the teacher) to emphasize the importance of Guru". This reflects the Advaita tradition which holds a competent teacher as important and essential to gaining correct knowledge, freeing oneself from false knowledge, and to self-realization.

A guru is someone more than a teacher, traditionally a reverential figure to the student, with the guru serving as a "counselor, who helps mold values, shares experiential knowledge as much as literal knowledge, an exemplar in life, an inspirational source and who helps in the spiritual evolution of a student. The guru, states Joel Mlecko, is more than someone who teaches specific type of knowledge, and includes in its scope someone who is also a "counselor, a sort of parent of mind and soul, who helps mold values and experiential knowledge as much as specific knowledge, an exemplar in life, an inspirational source and who reveals the meaning of life."

Ontology

The swan is an important motif in Advaita. The swan symbolises the ability to discern Satya (Real, Eternal) from Mithya(Unreal, Changing), just like the mythical swan Paramahamsa discerns milk from water.

Absolute Reality

Brahman

According to Advaita Vedānta, Brahman is the highest Reality, That which is unborn and unchanging, and "not sublatable", and cannot be superseded by a still higher reality. Other than Brahman, everything else, including the universe, material objects and individuals, are ever-changing and therefore maya. Brahman is Paramarthika Satyam, "Absolute Truth", and

the true Self, pure consciousness ... the only Reality (sat), since It is untinged by difference, the mark of ignorance, and since It is the one thing that is not sublatable".

In Advaita, Brahman is the substrate and cause of all changes. Brahman is considered to be the material cause and the efficient cause of all that exists. Brahman is the "primordial reality that creates, maintains and withdraws within it the universe." It is the "creative principle which lies realized in the whole world".

Advaita's Upanishadic roots state Brahman's qualities to be Sat-cit-ānanda (being-consciousness-bliss) It means "true being-consciousness-bliss," or "Eternal Bliss Consciousness". Adi Shankara held that satcitananda is identical with Brahman and Atman. The Advaitin scholar Madhusudana Sarasvati explained Brahman as the Reality that is simultaneously an absence of falsity (sat), absence of ignorance (cit), and absence of sorrow/self-limitation (ananda). According to Adi Shankara, the knowledge of Brahman that Shruti provides cannot be obtained in any other means besides self inquiry.

Ātman

Ātman (Sanskrit: आत्मन्) is a central idea in Hindu philosophy and a foundational premise of Advaita Vedānta. It is a Sanskrit word that means "real self" of the individual, "essence",and soul Yet, according to Ram-Prasad, "it" is not an object, but "the irreducible essence of being [as] subjectivity, rather than an objective self with the quality of consciousness." It is "a stable subjectivity, or a unity of consciousness through all the specific states of individuated phenomenality, but not an individual subject of consciousness.”

Ātman is the first principle in Advaita Vedānta, along with its concept of Brahman, with Ātman being the perceptible personal particular and Brahman the inferred unlimited universal, both synonymous and interchangeable. It is, to an Advaitin, the unchanging, enduring, eternal absolute. It is the "true self" of an individual, a consciousness, states SthaneshwarTimalsina, that is "self-revealed, self-evident and self-aware (svaprakashata)". Ātman, states Eliot Deutsch, is the "pure, undifferentiated, supreme power of awareness", it is more than thought, it is a state of being, that which is conscious and transcends subject-object divisions and momentariness.

Advaita Vedānta philosophy considers Ātman as self-existent awareness, limitless and non-dual. It asserts that there is "spirit, soul, self" (Ātman) within each living entity, which are same as each other and identical to the universal eternal Brahman. It is an experience of "oneness" which unifies all beings, in which there is the divine in every being, in which all existence is a single Reality, and in which there is no "divine" distinct from the individual Ātman.

Ātman is not the constantly changing body, not the desires, not the emotions, not the ego, nor the dualistic mind in Advaita Vedānta. It is the introspective, inwardly self-conscious "on-looker" (saksi). To Advaitins, human beings, in a state of unawareness and ignorance, see their "I-ness" as different than the being in others, then act out of impulse, fears, cravings, malice, division, confusion, anxiety, passions, and a sense of distinctiveness.

Identity of Ātman and Brahman

According to Advaita Vedānta, Atman is identical to Brahman. This is expressed in the mahavakya "tat tvamasi", "thou are that." There is "a common ground, viz. consciousness, to the individual and Brahman." Each soul, in Advaita view, is non-different from the infinite. According to Shankara, Ātman and Brahman seem different at the empirical level of reality, but this difference is only an illusion, and at the highest level of reality they are really identical.

Moksha is attained by realizing the identity of Ātman and Brahman, the complete understanding of one's real nature as Brahman in this life. This is frequently stated by Advaita scholars, such as Shankara, as:

I am other than name, form and action.
My nature is ever free!
I am Self, the supreme unconditioned Brahman.
I am pure Awareness, always non-dual.

— Adi Shankara, Upadesasahasri 11.7,

Levels of Reality, Truths

The classical Advaita Vedānta explains all reality and everything in the experienced world to be same as the Brahman. To Advaitins, there is a unity in multiplicity, and there is no dual hierarchy of a Creator and the created universe. All objects, all experiences, all matter, all consciousness, all awareness, in Advaita philosophy is not the property but the very nature of this one fundamental reality Brahman. With this premise, the Advaita school states that any ontological effort must presuppose a knowing self, and this effort needs to explain all empirical experiences such as the projected reality while one dreams during sleep, and the observed multiplicity of living beings. This Advaita does by positing its theory of three levels of reality, the theory of two truths, and by developing and integrating these ideas with its theory of errors (anirvacaniyakhyati).

Shankara proposes three levels of reality, using sublation as the ontological criterion:

·         Pāramārthika (paramartha, absolute), the Reality that is metaphysically true and ontologically accurate. It is the state of experiencing that "which is absolutely real and into which both other reality levels can be resolved". This reality is the highest, it can't be sublated (assimilated) by any other.

·         Vyāvahārika (vyavahara), or samvriti-saya, consisting of the empirical or pragmatical reality. It is ever changing over time, thus empirically true at a given time and context but not metaphysically true. It is "our world of experience, the phenomenal world that we handle every day when we are awake". It is the level in which both jiva (living creatures or individual souls) and Iswara are true; here, the material world is also true but this is incomplete reality and is sublatable.

·         Prāthibhāsika (pratibhasika, apparent reality, unreality), "reality based on imagination alone". It is the level of experience in which the mind constructs its own reality. Well-known examples of pratibhasika is the imaginary reality such as the "roaring of a lion" fabricated in dreams during one's sleep, and the perception of a rope in the dark as being a snake.

Advaita Vedānta acknowledges and admits that from the empirical perspective there are numerous distinctions. It states that everything and each reality has multiple perspectives, both absolute and relative. All these are valid and true in their respective contexts, states Advaita, but only from their respective particular perspectives. This "absolute and relative truths" explanation, Advaitins call as the "two truths" doctrine. John Grimes, a professor of Indian Religions specializing on Vedānta, explains this Advaita doctrine with the example of light and darkness. From the sun's perspective, it neither rises nor sets, there is no darkness, and "all is light". From the perspective of a person on earth, sun does rise and set, there is both light and darkness, not "all is light", there are relative shades of light and darkness. Both are valid realities and truths, given their perspectives. Yet, they are contradictory. What is true from one point of view, states Grimes, is not from another. To Advaita Vedānta, this does not mean there are two truths and two realities, but it only means that the same one Reality and one Truth is explained or experienced from two different perspectives.

As they developed these theories, Advaita Vedānta scholars were influenced by some ideas from the Nyaya, Samkhya and Yoga schools of Hindu philosophy. These theories have not enjoyed universal consensus among Advaitins, and various competing ontological interpretations have flowered within the Advaita tradition.

Empirical reality – illusion and ignorance

According to Advaita Vedānta, Brahman is the sole reality. The status of the phenomenal world is an important question in Advaita Vedānta, and different solutions have been proposed. The perception of the phenomenal world as real is explained by maya (constantly changing reality) and avidya ("ignorance"). Other than Brahman, everything else, including the universe, material objects and individuals, are ever-changing and therefore maya. Brahman is Paramarthika Satyam, "Absolute Truth", and "the true Self, pure consciousness, the only Reality (sat), since It is untinged by difference, the mark of ignorance, and since It is the one thing that is not sublatable".

Māyā (illusion

The doctrine of Maya is used to explain the empirical reality in Advaita. Jiva, when conditioned by the human mind, is subjected to experiences of a subjective nature, states Vedānta school, which leads it to misunderstand Maya and interpret it as the sole and final reality. Advaitins assert that the perceived world, including people and other existence, is not what it appears to be". It is Māyā, they assert, which manifests and perpetuates a sense of false duality or divisional plurality. The empirical manifestation is real but changing, but it obfuscates the true nature of metaphysical Reality which is never changing. Advaita school holds that liberation is the unfettered realization and understanding of the unchanging Reality and truths – the Self, that the Self (Soul) in oneself is same as the Self in another and the Self in everything (Brahman).

In Advaita Vedānta philosophy, there are two realities: Vyavaharika (empirical reality) and Paramarthika (absolute, spiritual Reality). Māyā is the empirical reality that entangles consciousness. Māyā has the power to create a bondage to the empirical world, preventing the unveiling of the true, unitary Self—the Cosmic Spirit also known as Brahman. This theory of māyā was expounded and explained by Adi Shankara. Competing theistic Dvaita scholars contested Shankara's theory, and stated that Shankara did not offer a theory of the relationship between Brahman and Māyā. A later Advaita scholar Prakasatman addressed this, by explaining, "Maya and Brahman together constitute the entire universe, just like two kinds of interwoven threads create a fabric. Maya is the manifestation of the world, whereas Brahman, which supports Maya, is the cause of the world."

Brahman is the sole metaphysical truth in Advaita Vedānta, Māyā is true in epistemological and empirical sense; however, Māyā is not the metaphysical and spiritual truth. The spiritual truth is the truth forever, while what is empirical truth is only true for now. Complete knowledge of true Reality includes knowing both Vyavaharika (empirical) and Paramarthika (spiritual), the Māyā and the Brahman. The goal of spiritual enlightenment, state Advaitins, is to realize Brahman, realize the unity and Oneness of all reality.

Avidya (ignorance)

Due to ignorance (avidyā), Brahman is perceived as the material world and its objects (namarupavikara). According to Shankara, Brahman is in reality attributeless and formless. Brahman, the highest truth and all (Reality), does not really change; it is only our ignorance that gives the appearance of change. Also due to avidyā, the true identity is forgotten, and material reality, which manifests at various levels, is mistaken as the only and true reality.

The notion of avidyā and its relationship to Brahman creates a crucial philosophical issue within Advaita Vedānta thought: how can avidyā appear in Brahman, since Brahman is pure consciousness? Sengaku Mayeda writes, in his commentary and translation of Adi Shankara's Upadesasahasri:

Certainly the most crucial problem which Sankara left for his followers is that of avidyā. If the concept is logically analysed, it would lead the Vedanta philosophy toward dualism or nihilism and uproot its fundamental position.

To Advaitins, human beings, in a state of unawareness and ignorance of this Universal Self, see their "I-ness" as different than the being in others, then act out of impulse, fears, cravings, malice, division, confusion, anxiety, passions, and a sense of distinctiveness.

Subsequent Advaitins gave somewhat various explanations, from which various Advaita schools arose.

Causality

All schools of Vedānta subscribe to the theory of Satkāryavāda, which means that the effect is pre-existent in the cause. But there are different views on the causal relationship and the nature of the empirical world from the perspective of metaphysical Brahman. The Brahma Sutras, the ancient Vedantins, most sub-schools of Vedānta, as well as Samkhya school of Hindu philosophy, support Parinamavada, the idea that the world is a real transformation (parinama) of Brahman.

Scholars disagree on the whether Adi Shankara and his Advaita system explained causality through vivarta. According to Andrew Nicholson, instead of parinama-vada, the competing causality theory is Vivartavada, which says "the world, is merely an unreal manifestation (vivarta) of Brahman. Vivartavada states that although Brahman appears to undergo a transformation, in fact no real change takes place. The myriad of beings are unreal manifestation, as the only real being is Brahman, that ultimate reality which is unborn, unchanging, and entirely without parts". The advocates of this illusive, unreal transformation based causality theory, states Nicholson, have been the Advaitins, the followers of Shankara. "Although the world can be described as conventionally real", adds Nicholson, "the Advaitins claim that all of Brahman’s effects must ultimately be acknowledged as unreal before the individual self can be liberated".

However, other scholars such as Hajime Nakamura and Paul Hacker disagree. Hacker and others state that Adi Shankara did not advocate Vivartavada, and his explanations are "remote from any connotation of illusion". According to these scholars, it was the 13th century scholar Prakasatman who gave a definition to Vivarta, and it is Prakasatman's theory that is sometimes misunderstood as Adi Shankara's position. Andrew Nicholson concurs with Hacker and other scholars, adding that the vivarta-vada isn't Shankara's theory, that Shankara's ideas appear closer to parinama-vada, and the vivarta explanation likely emerged gradually in Advaita subschool later.

According to Eliot Deutsch, Advaita Vedānta states that from "the standpoint of Brahman-experience and Brahman itself, there is no creation" in the absolute sense, all empirically observed creation is relative and mere transformation of one state into another, all states are provisional and a cause-effect driven modification.

Three states of consciousness and Turiya

Advaita posits three states of consciousness, namely waking (jagrat), dreaming (svapna), deep sleep (suṣupti), which are empirically experienced by human beings, and correspond to the Three Bodies Doctrine:

1.    The first state is the waking state, in which we are aware of our daily world. This is the gross body.

2.    The second state is the dreaming mind. This is the subtle body.

3.    The third state is the state of deep sleep. This is the causal body.

Advaita also posits the fourth state of Turiya, which some describe as pure consciousness, the background that underlies and transcends these three common states of consciousness. Turiya is the state of liberation, where states Advaita school, one experiences the infinite (ananta) and non-different (advaita/abheda), that is free from the dualistic experience, the state in which ajativada, non-origination, is apprehended. According to Candradhara Sarma, Turiya state is where the foundational Self is realized, it is measureless, neither cause nor effect, all prevading, without suffering, blissful, changeless, self-luminous, real, immanent in all things and transcendent. Those who have experienced the Turiya stage of self-consciousness have reached the pure awareness of their own non-dual Self as one with everyone and everything, for them the knowledge, the knower, the known becomes one, they are the Jivanmukta.

Advaita traces the foundation of this ontological theory in more ancient Sanskrit texts. For example, chapters 8.7 through 8.12 of Chandogya Upanishad discuss the "four states of consciousness" as awake, dream-filled sleep, deep sleep, and beyond deep sleep. One of the earliest mentions of Turiya, in the Hindu scriptures, occurs in verse 5.14.3 of the Brihadaranyaka Upanishad. The idea is also discussed in other early Upanishads.

Epistemology

The ancient and medieval texts of Advaita Vedānta and other schools of Hindu philosophy discuss Pramana (epistemology). The theory of Pramana discusses questions like how correct knowledge can be acquired; how one knows, how one doesn't; and to what extent knowledge pertinent about someone or something can be acquired. Advaita Vedānta, accepts the following six kinds of pramāṇas:

1.    Pratyakṣa (प्रत्यक्षाय) – perception

2.    Anumāṇa (अनुमान) – inference

3.    Upamāṇa (उपमान) – comparison, analogy

4.    Arthāpatti (अर्थापत्ति) – postulation, derivation from circumstances

5.    Anupalabdi (अनुपलब्धि) – non-perception, negative/cognitive proof

6.    Śabda (शब्द) – relying on word, testimony of past or present reliable experts

Pratyakṣa (perception)

Pratyakṣa (प्रत्यक्षाय), perception, is of two types: external – that arising from the interaction of five senses and worldly objects, and internal – perception of inner sense, the mind. Advaita postulates four pre-requisites for correct perception: 1) Indriyarthasannikarsa (direct experience by one's sensory organ(s) with the object, whatever is being studied), 2) Avyapadesya (non-verbal; correct perception is not through hearsay, according to ancient Indian scholars, where one's sensory organ relies on accepting or rejecting someone else's perception), 3) Avyabhicara (does not wander; correct perception does not change, nor is it the result of deception because one's sensory organ or means of observation is drifting, defective, suspect) and 4) Vyavasayatmaka (definite; correct perception excludes judgments of doubt, either because of one's failure to observe all the details, or because one is mixing inference with observation and observing what one wants to observe, or not observing what one does not want to observe). The internal perception concepts included pratibha (intuition), samanyalaksanapratyaksa (a form of induction from perceived specifics to a universal), and jnanalaksanapratyaksa (a form of perception of prior processes and previous states of a 'topic of study' by observing its current state).

Anumāṇa (inference)

Anumāṇa (अनुमान), inference, is defined as applying reason to reach a new conclusion about truth from one or more observations and previous understanding of truths. Observing smoke and inferring fire is an example of Anumana. This epistemological method for gaining knowledge consists of three parts: 1) Pratijna (hypothesis), 2) Hetu (a reason), and 3) drshtanta (examples). The hypothesis must further be broken down into two parts: 1) Sadhya (that idea which needs to proven or disproven) and 2) Paksha (the object on which the Sadhya is predicated). The inference is conditionally true if Sapaksha (positive examples as evidence) are present, and if Vipaksha (negative examples as counter-evidence) are absent. For rigor, the Indian philosophies further demand Vyapti – the requirement that the hetu (reason) must necessarily and separately account for the inference in "all" cases, in both sapaksha and vipaksha. A conditionally proven hypothesis is called a nigamana (conclusion).

Upamāṇa (comparison, analogy)

Upamāṇa (उपमान), comparison, analogy. Some Hindu schools consider it as a proper means of knowledge. Upamana, states Lochtefeld, may be explained with the example of a traveler who has never visited lands or islands with endemic population of wildlife. He or she is told, by someone who has been there, that in those lands you see an animal that sort of looks like a cow, grazes like cow but is different from a cow in such and such way. Such use of analogy and comparison is, state the Indian epistemologists, a valid means of conditional knowledge, as it helps the traveller identify the new animal later. The subject of comparison is formally called upameyam, the object of comparison is called upamanam, while the attribute(s) are identified as samanya.

Arthāpatti (postulation)

Arthāpatti (अर्थापत्ति), postulation, derivation from circumstances. In contemporary logic, this pramana is similar to circumstantial implication. As example, if a person left in a boat on river earlier, and the time is now past the expected time of arrival, then the circumstances support the truth postulate that the person has arrived. Many Indian scholars considered this Pramana as invalid or at best weak, because the boat may have gotten delayed or diverted. However, in cases such as deriving the time of a future sunrise or sunset, this method was asserted by the proponents to be reliable.

Anupalabdi (non-perception, negative/cognitive proof)

Anupalabdi (अनुपलब्धि), non-perception, negative/cognitive proof. Anupalabdhipramana suggests that knowing a negative, such as "there is no jug in this room" is a form of valid knowledge. If something can be observed or inferred or proven as non-existent or impossible, then one knows more than what one did without such means. In Advaita school of Hindu philosophy, a valid conclusion is either sadrupa (positive) or asadrupa (negative) relation – both correct and valuable. Like other pramana, Indian scholars refined Anupalabdi to four types: non-perception of the cause, non-perception of the effect, non-perception of object, and non-perception of contradiction. Only two schools of Hinduism accepted and developed the concept "non-perception" as a pramana. Advaita considers this method as valid and useful when the other five pramanas fail in one's pursuit of knowledge and truth. A variation of Anupaladbi, called Abhava (अभाव) has also been posited as an epistemic method. It means non-existence. Some scholars consider Anupalabdi to be same as Abhava, while others consider Anupalabdi and Abhava as different. Abhava-pramana has been discussed in Advaita in the context of Padārtha (पदार्थ, referent of a term). A Padartha is defined as that which is simultaneously Astitva (existent), Jneyatva (knowable) and Abhidheyatva (nameable). Abhava was further refined in four types, by the schools of Hinduism that accepted it as a useful method of epistemology: dhvamsa (termination of what existed), atyanta-abhava (impossibility, absolute non-existence, contradiction), anyonya-abhava (mutual negation, reciprocal absence) and pragavasa (prior, antecedent non-existence).

Śabda (relying on testimony)

Śabda (शब्द), relying on word, testimony of past or present reliable experts. Hiriyanna explains Sabda-pramana as a concept which means reliable expert testimony. The schools of Hinduism which consider it epistemically valid suggest that a human being needs to know numerous facts, and with the limited time and energy available, he can learn only a fraction of those facts and truths directly. He must rely on others, his parent, family, friends, teachers, ancestors and kindred members of society to rapidly acquire and share knowledge and thereby enrich each other's lives. This means of gaining proper knowledge is either spoken or written, but through Sabda (words). The reliability of the source is important, and legitimate knowledge can only come from the Sabda of reliable sources. The disagreement between Advaita and other schools of Hinduism has been on how to establish reliability.

Ethics

Some claim, states Deutsch, "that Advaita turns its back on all theoretical and practical considerations of morality and, if not unethical, is at least 'a-ethical' in character". However, adds Deutsch, ethics does have a firm place in this philosophy. Its ideology is permeated with ethics and value questions enter into every metaphysical and epistemological analysis, and it considers "an independent, separate treatment of ethics are unnecessary". According to Advaita Vedānta, states Deutsch, there cannot be "any absolute moral laws, principles or duties", instead in its axiological view Atman is "beyond good and evil", and all values result from self-knowledge of the reality of "distinctionless Oneness" of one's real self, every other being and all manifestations of Brahman.  Advaitin ethics includes lack of craving, lack of dual distinctions between one's own soul and another being's, good and just Karma.

The values and ethics in Advaita Vedānta emanate from what it views as inherent in the state of liberating self-knowledge. This state, according to Rambachan, includes and leads to the understanding that "the self is the self of all, the knower of self sees the self in all beings and all beings in the self." Such knowledge and understanding of the indivisibility of one's and other's Atman, Advaitins believe leads to "a deeper identity and affinity with all". It does not alienate or separate an Advaitin from his or her community, rather awakens "the truth of life's unity and interrelatedness". These ideas are exemplified in the Isha Upanishad – a sruti for Advaita, as follows:

One who sees all beings in the self alone, and the self of all beings,
feels no hatred by virtue of that understanding.
For the seer of oneness, who knows all beings to be the self,
where is delusion and sorrow?

— Isha Upanishad 6–7, Translated by A Rambachan

Adi Shankara, a leading proponent of Advaita, in verse 1.25 to 1.26 of his Upadeśasāhasrī, asserts that the Self-knowledge is understood and realized when one's mind is purified by the observation of Yamas (ethical precepts) such as Ahimsa (non-violence, abstinence from injuring others in body, mind and thoughts), Satya (truth, abstinence from falsehood), Asteya (abstinence from theft), Aparigraha (abstinence from possessiveness and craving) and a simple life of meditation and reflection. Rituals and rites can help focus and prepare the mind for the journey to Self-knowledge, however, Shankara discourages dogmatic ritual worship and oblations to Devas (deities), because that assumes the Self within is different than Brahman. The "doctrine of difference" is wrong, asserts Shankara, because, "he who knows the Brahman is one and he is another, does not know Brahman".

Elsewhere, in verses 1.26–1.28, the Advaita text Upadesasahasri states the ethical premise of equality of all beings. Any Bheda (discrimination), states Shankara, based on class or caste or parentage is a mark of inner error and lack of liberating knowledge. This text states

that the fully liberated person understands and practices the ethics of non-difference.

One, who is eager to realize this highest truth spoken of in the Sruti, should rise above the fivefold form of desire: for a son, for wealth, for this world and the next, and are the outcome of a false reference to the Self of Varna (castes, colors, classes) and orders of life. These references are contradictory to right knowledge, and reasons are given by the Srutis regarding the prohibition of the acceptance of difference. For when the knowledge that the one non-dual Atman (Self) is beyond phenomenal existence is generated by the scriptures and reasoning, there cannot exist a knowledge side by side that is contradictory or contrary to it.

— Adi Shankara, Upadesha Sahasri 1.44, 

Texts

The Upanishads, the Bhagavad Gitā and Brahma Sutras are the central texts of the Advaita Vedānta tradition, providing doctrines about the identity of Atman and Brahman and their changeless nature.

Adi Shankara gave a nondualist interpretation of these texts in his commentaries. Adi Shankara's Bhashya (commentaries) have become central texts in the Advaita Vedānta philosophy, but are one among many ancient and medieval manuscripts available or accepted in this tradition. The subsequent Advaita tradition has further elaborated on these sruti and commentaries. Adi Shankara is also credited for the famous text Nirvana Shatakam.

Prasthanatrayi

The Vedānta tradition provides exegeses of the Upanishads, the Brahma Sutras, and the Bhagavadgita, collectively called the Prasthanatrayi, literally, three sources.

1.    The Upanishads, or Śrutiprasthāna; considered the Śruti (Vedic scriptures) foundation of Vedānta. Most scholars, states Eliot Deutsch, are convinced that the Śruti in general, and the Upanishads in particular, express "a very rich diversity" of ideas, with the early Upanishads such as Brihadaranyaka Upanishad and Chandogya Upanishad being more readily amenable to Advaita Vedānta school's interpretation than the middle or later Upanishads. In addition to the oldest Upanishads, states Williams, the Sannyasa Upanishads group composed in pre-Shankara times "express a decidedly Advaita outlook".

2.    The Brahma Sutras, or Nyaya prasthana / Yukti prasthana; considered the reason-based foundation of Vedānta. The Brahma Sutras attempted to synthesize the teachings of the Upanishads. The diversity in the teachings of the Upanishads necessitated the systematization of these teachings. The only extant version of this synthesis is the Brahma Sutras of Badarayana. Like the Upanishads, Brahma Sutras is also an aphoristic text, and can be interpreted as a non-theistic Advaita Vedānta text or as a theistic Dvaita Vedānta text. This has led, states Stephen Phillips, to its varying interpretations by scholars of various sub-schools of Vedānta. The Brahmasutra is considered by the Advaita school as the Nyaya Prasthana (canonical base for reasoning).

3.    The Bhagavad Gitā, or Smriti prasthāna; considered the Smriti (remembered tradition) foundation of Vedānta. It has been widely studied by Advaita scholars, including a commentary by Adi Shankara.

Textual authority

The identity of Atman and Brahman, and their unchanging, eternal nature, are basic doctrines in Advaita Vedānta. The school considers the knowledge claims in the Vedas to be the crucial part of the Vedas, not its karma-kanda (ritual injunctions).  The knowledge claims about self being identical to the nature of Atman and Brahman are found in the Upanishads, which Advaita Vedānta has regarded as "errorless revealed truth." Nevertheless, states Koller, Advaita Vedantins did not entirely rely on revelation, but critically examined their teachings using reason and experience, and this led them to investigate and critique competing theories.

Advaita Vedānta, like all orthodox schools of Hindu philosophy, accepts as an epistemic premise that Śruti (Vedic literature) is a reliable source of knowledge. The Śruti includes the four Vedas including its four layers of embedded texts – the Samhitas, the Brahmanas, the Aranyakas and the early Upanishads. Of these, the Upanishads are the most referred to texts in the Advaita school.

The possibility of different interpretations of the Vedic literature, states Arvind Sharma, was recognized by ancient Indian scholars. The Brahmasutra (also called Vedānta Sutra, composed in 1st millennium BCE) accepted this in verse 1.1.4 and asserts the need for the Upanishadic teachings to be understood not in piecemeal cherrypicked basis, rather in a unified way wherein the ideas in the Vedic texts are harmonized with other means of knowledge such as perception, inference and remaining pramanas. This theme has been central to the Advaita school, making the Brahmasutra as a common reference and a consolidated textual authority for Advaita.

The Bhagavad Gitā, similarly in parts can be interpreted to be a monist Advaita text, and in other parts as theistic Dvaita text. It too has been widely studied by Advaita scholars, including a commentary by Adi Shankara.

History of Advaita Vedānta

Advaita Vedānta existed prior to Adi Shankara but found in him its most influential expounder

Pre-Shankara Advaita Vedānta

Of the Vedānta-school before the composition of the Brahma Sutras (400–450 CE), wrote Nakamura in 1950, almost nothing is known. The two Advaita writings of pre-Shankara period, known to scholars such as Nakamura in the first half of 20th-century, were the Vākyapadīya, written by Bhartṛhari (second half 5th century), and the Māndūkya-kārikā written by Gaudapada (7th century CE).

Scholarship after 1950 suggests that almost all Sannyasa Upanishads, which belong to the minor Upanishads and are of a later date than the major Upanishads, namely the first centuries CE, and some of which are of a sectarian nature, have a strong Advaita Vedānta outlook. The Advaita Vedānta views in these ancient texts may be, states Patrick Olivelle, because major Hindu monasteries of this period (early medieaval period, starting mid 6th century CE) belonged to the Advaita Vedānta tradition, preserving only Advaita views, and recasting other texts into Advaita texts.

Earliest Vedānta – Upanishads and Brahma Sutras

The Upanishads form the basic texts, of which Vedānta gives an interpretation. The Upanishads do not contain "a rigorous philosophical inquiry identifying the doctrines and formulating the supporting arguments". This philosophical inquiry was performed by the darsanas, the various philosophical schools.

Bādarāyana's Brahma Sutras

The Brahma Sutras of Bādarāyana, also called the Vedānta Sutra, were compiled in its present form around 400–450 CE, but "the great part of the Sutra must have been in existence much earlier than that". Estimates of the date of Bādarāyana's lifetime differ between 200 BCE and 200 CE.

The Brahma Sutra is a critical study of the teachings of the Upanishads, possibly "written from a BhedābhedaVedāntic viewpoint." It was and is a guide-book for the great teachers of the Vedantic systems.  Bādarāyana was not the first person to systematise the teachings of the Upanishads. He refers to seven Vedantic teachers before him:

From the way in which Bādarāyana cites the views of others it is obvious that the teachings of the Upanishads must have been analyzed and interpreted by quite a few before him and that his systematization of them in 555 sutras arranged in four chapters must have been the last attempt, most probably the best.

Between Brahma Sutras and Shankara

According to Nakamura, "there must have been an enormous number of other writings turned out in this period, but unfortunately all of them have been scattered or lost and have not come down to us today". In his commentaries, Shankara mentions 99 different predecessors of his Sampradaya. In the beginning of his commentary on the Brhadaranyaka Upanishad Shankara salutes the teachers of the Brahmavidya Sampradaya. Pre-Shankara doctrines and sayings can be traced in the works of the later schools, which does give insight into the development of early Vedānta philosophy.

The names of various important early Vedānta thinkers have been listed in the Siddhitraya by Yamunācārya (c.1050), the Vedārthasamgraha by Rāmānuja (c.1050–1157), and the Yatīndramatadīpikā by Śrīnivāsa-dāsa. Combined together, at least fourteen thinkers are known to have existed between the composition of the Brahman Sutras and Shankara's lifetime.

Although Shankara is often considered to be the founder of the Advaita Vedānta school, according to Nakamura, comparison of the known teachings of these early Vedantins and Shankara's thought shows that most of the characteristics of Shankara's thought "were advocated by someone before Śankara". Shankara "was the person who synthesized the Advaita-vāda which had previously existed before him". In this synthesis, he was the rejuvenator and defender of ancient learning. He was an unequalled commentator, due to whose efforts and contributions the Advaita Vedānta assumed a dominant position within Indian philosophy.

Gaudapada and Māṇḍukya Kārikā

Gaudapada (6th century) was the teacher of Govinda Bhagavatpada and the grandteacher of Shankara. Gaudapada uses the concepts of Ajativada and Maya to establish "that from the level of ultimate truth the world is a cosmic illusion," and "suggests that the whole of our waking experience is exactly the same as an illusory and insubstantial dream." In contrast, Adi Shankara insists upon a distinction between waking experience and dreams.

Mandukya Karika

Gaudapada wrote or compiled the Māṇḍukya Kārikā, also known as the Gauḍapāda Kārikā or the Āgama Śāstra. The Māṇḍukya Kārikā is a commentary in verse form on the Mandukya Upanishad, one of the shortest Upanishads consisting of just 13 prose sentences. Of the ancient literature related to Advaita Vedānta, the oldest surviving complete text is the MāṇḍukyaKārikā. Many other texts with same type of teachings and which were older than MāṇḍukyaKārikā existed and this is unquestionable because other scholars and their views are cited by Gaudapada, Shankara and Anandagiri, according to Hajime Nakamura. Gaudapada relied particularly on Mandukya Upanishad, as well as Brihadaranyaka and Chandogya Upanishads.

The Mandukya Upanishad was considered to be a Śruti before the era of Adi Shankara, but not treated as particularly important. In later post-Shankara period its value became far more important, and regarded as expressing the essence of the Upanishad philosophy. The entire Karika became a key text for the Advaita school in this later era.

Shri Gaudapadacharya Math

Around 740 AD Gaudapada founded Shri Gaudapadacharya Math, also known as Kavaḷē maṭha. It is located in Kavale, Ponda, Goa, and is the oldest matha of the South Indian Saraswat Brahmins.

Adi Shankara

Adi Shankara, 20th verse of Brahmajnanavalimala:

ब्रह्मसत्यंजगन्मिथ्या
जीवोब्रह्मैवनापरः

Brahman is real, the world is an illusion
Brahman and Jiva are not different.

Brahmajnanavalimala 

Adi Shankara (788–820), also known as Śaṅkara Bhagavatpādācārya and Ādi Śaṅkarācārya, represents a turning point in the development of Vedānta. After the growing influence of Buddhism on Vedānta, culminating in the works of Gaudapada, Adi Shankara gave a Vedantic character to the Buddhistic elements in these works, synthesising and rejuvenating the doctrine of Advaita. Using ideas in ancient Indian texts, Shankara systematized the foundation for Advaita Vedānta in the 8th century CE, reforming Badarayana's Vedānta tradition. His thematic focus extended beyond metaphysics and soteriology, and he laid a strong emphasis on Pramanas, that is epistemology or "means to gain knowledge, reasoning methods that empower one to gain reliable knowledge". Rambachan, for example, summarizes the widely held view on one aspect of Shankara's epistemology before critiquing it as follows,

According to these [widely represented contemporary] studies, Shankara only accorded a provisional validity to the knowledge gained by inquiry into the words of the Śruti (Vedas) and did not see the latter as the unique source (pramana) of Brahmajnana. The affirmations of the Śruti, it is argued, need to be verified and confirmed by the knowledge gained through direct experience (anubhava) and the authority of the Śruti, therefore, is only secondary.

Sengaku Mayeda concurs, adding Shankara maintained the need for objectivity in the process of gaining knowledge (vastutantra), and considered subjective opinions (purushatantra) and injunctions in Śruti (codanatantra) as secondary. Mayeda cites Shankara's explicit statements emphasizing epistemology (pramana-janya) in section 1.18.133 of Upadesasahasri and section 1.1.4 of Brahmasutra-bhasya.

Adi Shankara cautioned against cherrypicking a phrase or verse out of context from Vedic literature, and remarked that the Anvaya (theme or purport) of any treatise can only be correctly understood if one attends to the SamanvayatTatparya Linga, that is six characteristics of the text under consideration:

1 The common in Upakrama (introductory statement) and Upasamhara (conclusions)

2.    Abhyasa (message repeated)

3.    Apurvata (unique proposition or novelty)

4.    Phala (fruit or result derived)

5.    Arthavada (explained meaning, praised point)

6.    Yukti (verifiable reasoning).

While this methodology has roots in the theoretical works of Nyaya school of Hinduism, Shankara consolidated and applied it with his unique exegetical method called Anvaya-Vyatireka, which states that for proper understanding one must "accept only meanings that are compatible with all characteristics" and "exclude meanings that are incompatible with any".

Hacker and Phillips note that this insight into rules of reasoning and hierarchical emphasis on epistemic steps is "doubtlessly the suggestion" of Shankara in Brahma-sutra, an insight that flowers in the works of his companion and disciple Padmapada. Merrell-Wolff states that Shankara accepts Vedas and Upanishads as a source of knowledge as he develops his philosophical theses, yet he never rests his case on the ancient texts, rather proves each thesis, point by point using pranamas (epistemology), reason and experience.

Historical context

Shankara lived in the time of the so-called "Late classical Hinduism", which lasted from 650 to 1100 CE. This era was one of political instability that followed Gupta dynasty and King Harsha of the 7th century CE. It was a time of social and cultural change as the ideas of Buddhism, Jainism, and various traditions within Hinduism were competing for members. Buddhism in particular influenced India's spiritual traditions in the first 700 years of the 1st millennium CE.  Shankara and his contemporaries made a significant contribution in understanding Buddhism and the ancient Vedic traditions; they then transformed the extant ideas, particularly reforming the Vedānta tradition of Hinduism, making it India's most important tradition for more than a thousand years.

Writings

Adi Shankara is best known for his systematic reviews and commentaries (Bhasyas) on ancient Indian texts. Shankara's masterpiece of commentary is the Brahmasutrabhasya (literally, commentary on Brahma Sutra), a fundamental text of the Vedānta school of Hinduism. His commentaries on ten Mukhya (principal) Upanishads are also considered authentic by scholars. Other authentic works of Shankara include commentaries on the Bhagavad Gitā (part of his Prasthana Trayi Bhasya).

Shankara's Vivarana (tertiary notes) on the commentary by Vedavyasa on Yogasutras as well as those on Apastamba Dharma-sũtras (Adhyatama-patala-bhasya) are accepted by scholars as authentic works of Adi Shankara. Among the Stotra (poetic works), the Daksinamurti Stotra, Bhajagovinda Stotra, Sivanandalahari, Carpata-panjarika, Visnu-satpadi, Harimide, Dasa-shloki, and Krishna-staka are likely to be authentic. He also authored Upadesasahasri, his most important original philosophical work. Of other original Prakaranas (प्रकरण, monographs, treatise), 76 works are attributed to Adi Shankara. Modern era Indian scholars Belvalkar and Upadhyaya accept five and thirty nine works, respectively, as authentic.

Several commentaries on Nrisimha-Purvatatapaniya and Shveshvatara Upanishads have been attributed to Adi Shankara, but their authenticity is highly doubtful. Similarly, commentaries on several early and later Upanishads attributed to Shankara are rejected by scholars as his works, and are likely works of later Advaita Vedānta scholars; these include the Kaushitaki Upanishad, Maitri Upanishad, Kaivalya Upanishad, Paramahamsa Upanishad, Sakatayana Upanishad, Mandala Brahmana Upanishad, Maha Narayana Upanishad, and Gopalatapaniya Upanishad.

The authenticity of Shankara being the author of Vivekacūḍāmaṇi has been questioned, and "modern scholars tend to reject its authenticity as a work by Shankara." The authorship of Shankara of his Mandukya Upanishad Bhasya and his supplementary commentary on Gaudapada's Māṇḍukya Kārikā has been disputed by Nakamura. However, other scholars state that the commentary on Mandukya, which is actually a commentary on Madukya-Karikas by Gaudapada, may be authentic.

Influence of Shankara

Shankara's status in the tradition of Advaita Vedānta is unparallelled. He travelled all over India to help restore the study of the Vedas. His teachings and tradition form the basis of Smartism and have influenced Sant Mat lineages. He introduced the Pañcāyatana form of worship, the simultaneous worship of five deities – Ganesha, Surya, Vishnu, Shiva, and Devi. Shankara explained that all deities were but different forms of the one Brahman, the invisible Supreme Being.

Benedict Ashley credits Adi Shankara for unifying two seemingly disparate philosophical doctrines in Hinduism, namely Atman and Brahman. Isaeva states that Shankara's influence extended to reforming Hinduism, founding monasteries, edifying disciples, disputing opponents, and engaging in philosophic activity that, in the eyes of Indian tradition, helped revive "the orthodox idea of the unity of all beings" and Vedānta thought.

Some scholars doubt Shankara's early influence in India. According to King and Roodurmun, until the 10th century Shankara was overshadowed by his older contemporary Mandana-Misra, who was considered to be the major representative of Advaita. Other scholars state that the historical records for this period are unclear, and little reliable information is known about the various contemporaries and disciples of Shankara.

Several scholars suggest that the historical fame and cultural influence of Shankara grew centuries later, particularly during the era of the Muslim invasions and consequent devastation of India. Many of Shankara's biographies were created and published in and after the 14th century, such as the widely cited Vidyaranya's Śankara-vijaya. Vidyaranya, also known as Madhava, who was the 12th Jagadguru of the ŚringeriŚaradaPītham from 1380 to 1386, inspired the re-creation of the Hindu Vijayanagara Empire of South India in response to the devastation caused by the Islamic Delhi Sultanate. He and his brothers, suggest Paul Hacker and other scholars, wrote about Śankara as well as extensive Advaitic commentaries on the Vedas and Dharma. Vidyaranya was a minister in the Vijayanagara Empire and enjoyed royal support, and his sponsorship and methodical efforts helped establish Shankara as a rallying symbol of values, spread historical and cultural influence of Shankara's Vedānta philosophies, and establish monasteries (mathas) to expand the cultural influence of Shankara and Advaita Vedānta.

Post-Shankara – early medieval times

Sureśvara (fl. 800–900 CE) and MaṇḍanaMiśra were contemporaries of Shankara, Sureśvara often (incorrectly) being identified with MaṇḍanaMiśra. Both explained Sankara "on the basis of their personal convictions". Sureśvara has also been credited as the founder of a pre-Shankara branch of Advaita Vedānta.

MaṇḍanaMiśra was a Mimamsa scholar and a follower of Kumarila, but also wrote a seminal text on Advaita that has survived into the modern era, the Brahma-siddhi.  According to tradition, MaṇḍanaMiśra and his wife were defeated by Shankara in a debate, after which he became a follower of Shankara. Yet, his attitude toward Shankara was that of a "self-confident rival teacher of Advaita", and his influence was such that some regard the Brahma-siddhi to have "set forth a non-Shankaran brand of Advaita" The "theory of error" set forth in this work became the normative Advaita Vedānta theory of error. It was Vachaspati Misra's commentary on this work that linked it to Shankara's teaching. His influential thesis in the Advaita tradition has been that errors are opportunities because they "lead to truth", and full correct knowledge requires that not only should one understand the truth but also examine and understand errors as well as what is not truth.

Hiriyanna and Kuppuswami Sastra have pointed out that Sureśvara and MaṇḍanaMiśra had different views on various doctrinal points:

·         The locus of avidya: according to MaṇḍanaMiśra, the individual jiva is the locus of avidya, whereas Suresvara contends that the avidya regarding Brahman is located in Brahman. These two different stances are also reflected in the opposing positions of the Bhamati school and the Vivarana school.

·         Liberation: according to MaṇḍanaMiśra, the knowledge that arises from the Mahavakya is insufficient for liberation. Only the direct realization of Brahma is liberating, which can only be attained by meditation. According to Suresvara, this knowledge is directly liberating, while meditation is at best a useful aid.

Advaita Vedānta sub-schools

After Shankara's death, several sub-schools developed. Two of them still exist today, the Bhāmatī and the Vivarana. Two defunct schools are the Pancapadika and Istasiddhi, which were replaced by Prakasatman'sVivarana school.

These schools worked out the logical implications of various Advaita doctrines. Two of the problems they encountered were the further interpretations of the concepts of māyā and avidya.

Padmapada – Pancapadika school

Padmapada (c. 800 CE) was a direct disciple of Shankara who wrote the Pancapadika, a commentary on the Sankara-bhaya. Padmapada diverged from Shankara in his description of avidya, designating prakrti as avidya or ajnana.

Vachaspati Misra – Bhamati school

Vachaspati Misra (800–900 CE) wrote the Brahmatattva-samiksa, a commentary on MaṇḍanaMiśra's Brahma-siddhi, which provides the link between Mandana Misra and Shankara and attempts to harmonise Shankara's thought with that of Mandana Misra. According to Advaita tradition, Shankara reincarnated as Vachaspati Misra "to popularise the Advaita System through his Bhamati". Only two works are known of Vachaspati Misra, the Brahmatattva-samiksa on MaṇḍanaMiśra's Brahma-siddhi, and his Bhamati on the Sankara-bhasya, Shankara's commentary on the Brahma-sutras. The name of the Bhamati sub-school is derived from this Bhamati.

The Bhamati school takes an ontological approach. It sees the Jiva as the source of avidya. It sees meditation as the main factor in the acquirement of liberation, while the study of the Vedas and reflection are additional factors.

Prakasatman – Vivarana school

Prakasatman (c.1200–1300) wrote the Pancapadika-Vivarana, a commentary on the Pancapadika by Padmapadacharya. The Vivarana lends its name to the subsequent school. According to Roodurmum, "[H]is line of thought [...] became the leitmotif of all subsequent developments in the evolution of the Advaita tradition."

The Vivarana school takes an epistemological approach. Prakasatman was the first to propound the theory of mulavidya or maya as being of "positive beginningless nature", and sees Brahman as the source of avidya. Critics object that Brahman is pure consciousness, so it cannot be the source of avidya. Another problem is that contradictory qualities, namely knowledge and ignorance, are attributed to Brahman.

Vimuktatman – Ista-Siddhi

Vimuktatman (c. 1200 CE) wrote the Ista-siddhi. It is one of the four traditional siddhi, together with Mandana's Brahma-siddhi, Suresvara's Naiskarmya-siddhi, and Madusudana's Advaita-siddhi. According to Vimuktatman, absolute Reality is "pure intuitive consciousness". His school of thought was eventually replaced by Prakasatman'sVivarana school.

Late medieval times (Islamic rule of India) – "Greater Advaita Vedānta"

Michael s. Allen and Anand Venkatkrishnan note that Shankara is very well-studies, but "scholars have yet to provide even a rudimentary, let alone comprehensive account of the history of Advaita Vedānta in the centuries leading up to the colonial period."

Prominent teachers

According to Sangeetha Menon, prominent names in the later Advaita tradition are:

·         Prakāsātman, Vimuktātman, Sarvajñātman (10th century)(see above)

·         ŚrīHarṣa, Citsukha (12th century)

·         ānandagiri, Amalānandā (13th century)

·         Vidyāraņya, Śaṅkarānandā (14th century)

·         Sadānandā (15th century)

·         Prakāṣānanda, Nṛsiṁhāśrama (16th century)

·         Madhusūdhana Sarasvati, DharmarājaAdvarindra, Appaya Dīkśita (17th century)

Influence of yogic tradition

While Indologists like Paul Hacker and Wilhelm Halbfass took Shankara's system as the measure for an "orthodox" Advaita Vedānta, the living Advaita Vedānta tradition in medieval times was influenced by, and incorporated elements from, the yogic tradition and texts like the Yoga Vasistha and the Bhagavata Purana. The Yoga Vasistha became an authoritative source text in the Advaita vedānta tradition in the 14th century, while Vidyāraņya's Jivanmuktiviveka (14th century) was influenced by the (Laghu-)Yoga-Vasistha, which in turn was influenced by Kashmir Shaivism. Vivekananda's 19th century emphasis on nirvikalpa samadhi was preceded by medieval yogic influences on Advaita Vedānta. In the 16th and 17th centuries, some Nath and hatha yoga texts also came within the scope of the developing Advaita Vedānta tradition.

Development of central position

Highest Indian philosophy

Already in medieval times, Advaita Vedānta came to be regarded as the highest of the Indian religious philosophies, a development which was reinforced in modern times due to western interest in Advaita Vedānta, and the subsequent influence of western perceptions on Indian perceptions of Hinduism.

In contrast, King states that its present position was a response of Hindu intellectuals to centuries of Christian polemic aimed at establishing "Hindu inferiority complex" during the colonial rule of the Indian subcontinent. The "humanistic, inclusivist" formulation, now called Neo-Vedānta, attempted to respond to this colonial stereotyping of "Indian culture was backward, superstitious and inferior to the West", states King. Advaita Vedānta was projected as the central philosophy of Hinduism, and Neo-Vedānta subsumed and incorporated Buddhist ideas thereby making the Buddha a part of the Vedānta tradition, all in an attempt to reposition the history of Indian culture. Thus, states King, neo-Vedānta developed as a reaction to western Orientalism and Perennialism. With the efforts of Vivekananda, modern formulation of Advaita Vedānta has "become a dominant force in Indian intellectual thought", though Hindu beliefs and practices are diverse.

Unifying Hinduism

Advaita Vedānta came to occupy a central position in the classification of various Hindu traditions. To some scholars, it is with the arrival of Islamic rule, first in the form of Delhi Sultanate thereafter the Mughal Empire, and the subsequent persecution of Indian religions, Hindu scholars began a self-conscious attempts to define an identity and unity. Between the twelfth and the fourteen century, according to Andrew Nicholson, this effort emerged with a classification of astika and nastika systems of Indian philosophies. Certain thinkers, according to Nicholson thesis, began to retrospectively classify ancient thought into "six systems" (saddarsana) of mainstream Hindu philosophy.

Other scholars, acknowledges Nicholson, present an alternate thesis. The scriptures such as the Vedas, Upanishads and Bhagavad Gitā, texts such as Dharmasutras and Puranas, and various ideas that are considered to be paradigmatic Hinduism are traceable to being thousands of years old. Unlike Christianity and Islam, Hinduism as a religion does not have a single founder, rather it is a fusion of diverse scholarship where a galaxy of thinkers openly challenged each other's teachings and offered their own ideas. The term "Hindu" too, states Arvind Sharma, appears in much older texts such as those in Arabic that record the Islamic invasion or regional rule of Indian subcontinent. Some of these texts have been dated to between the 8th and the 11th century. Within these doxologies and records, Advaita Vedānta was given the highest position, since it was regarded to be most inclusive system.

Modern times (colonial rule and independence)

According to Sangeetha Menon, SadaśivaBrahmendra was a prominent 18th century Advaita Vedantin.

Influence on Hindu nationalism

According to King, along with the consolidation of the British imperialist rule came orientalism wherein the new rulers viewed Indians through "colonially crafted lenses". In response, emerged Hindu nationalism for collective action against the colonial rule, against the caricature by Christian and Muslim communities, and for socio-political independence. In this colonial era search of identity, Vedānta came to be regarded as the essence of Hinduism, and Advaita Vedānta came to be regarded as "then paradigmatic example of the mystical nature of the Hindu religion" and umbrella of "inclusivism". This umbrella of Advaita Vedānta, according to King, "provided an opportunity for the construction of a nationalist ideology that could unite Hindus in their struggle against colonial oppression".

Among the colonial era intelligentsia, according to Anshuman Mondal, a professor of Literature specializing in post-colonial studies, the monistic Advaita Vedānta has been a major ideological force for Hindu nationalism. Mahatma Gandhi professed monism of Advaita Vedānta, though at times he also spoke with terms from mind-body dualism schools of Hinduism. Other colonial era Indian thinkers, such as Vivekananda, presented Advaita Vedānta as an inclusive universal religion, a spirituality that in part helped organize a religiously infused identity, and the rise of Hindu nationalism as a counter weight to Islam-infused Muslim communitarian organizations such as the Muslim League, to Christianity-infused colonial orientalism and to religious persecution of those belonging to Indian religions.

Swami Vivekananda

A major proponent in the popularisation of this Universalist and Perennialist interpretation of Advaita Vedānta was Swami Vivekananda, who played a major role in the revival of Hinduism, and the spread of Advaita Vedānta to the west via the Ramakrishna Mission. His interpretation of Advaita Vedānta has been called "Neo-Vedānta". Vivekananda discerned a universal religion, regarding all the apparent differences between various traditions as various manifestations of one truth. He presented karma, bhakti, jnana and raja yoga as equal means to attain moksha, to present Vedānta as a liberal and universal religion, in contrast to the exclusivism of other religions.

Vivekananda emphasised nirvikalpa samadhi as the spiritual goal of Vedānta, he equated it to the liberation in Yoga and encouraged Yoga practice he called Raja yoga. This approach, however, is missing in historic Advaita texts. In 1896, Vivekananda claimed that Advaita appeals to modern scientists:

I may make bold to say that the only religion which agrees with, and even goes a little further than modern researchers, both on physical and moral lines is the Advaita, and that is why it appeals to modern scientists so much. They find that the old dualistic theories are not enough for them, do not satisfy their necessities. A man must have not only faith, but intellectual faith too".

According to Rambachan, Vivekananda interprets anubhava as to mean "personal experience", akin to religious experience, whereas Shankara used the term to denote liberating understanding of the sruti.

Vivekananda's claims about spirituality as "science" and modern, according to David Miller, may be questioned by well informed scientists, but it drew attention for being very different than how Christianity and Islam were being viewed by scientists and sociologists of his era.

Sarvepalli Radhakrishnan

Sarvepalli Radhakrishnan, first a professor at Oxford University and later a President of India, further popularized Advaita Vedānta, presenting it as the essence of Hinduism. According to Michael Hawley, a professor of Religious Studies, Radhakrishnan saw other religions, as well as "what Radhakrishnan understands as lower forms of Hinduism," as interpretations of Advaita Vedānta, thereby "in a sense Hindusizing all religions". To him, the world faces a religious problem, where there is unreflective dogmatism and exclusivism, creating a need for "experiential religion" and "inclusivism". Advaita Vedānta, claimed Radhakrishnan, best exemplifies a Hindu philosophical, theological, and literary tradition that fulfills this need. Radhakrishnan did not emphasize the differences between Buddhism, Jainism, Sikhism versus Hinduism that he defined in terms of Advaita Vedānta, rather he tended to minimize their differences. This is apparent, for example, in his discussions of Buddhist "Madhyamika and Yogacara" traditions versus the Advaita Vedānta tradition.

Radhakrishnan metaphysics was grounded in Advaita Vedānta, but he reinterpreted Advaita Vedānta for contemporary needs and context. He acknowledged the reality and diversity of the world of experience, which he saw as grounded in and supported by the transcendent metaphysical absolute concept (nirguna Brahman). Radhakrishnan also reinterpreted Shankara's notion of maya. According to Radhakrishnan, maya is not a strict absolute idealism, but "a subjective misperception of the world as ultimately real."

Mahatama Gandhi

Gandhi declared his allegiance to Advaita Vedānta, and was another popularizing force for its ideas. According to Nicholas Gier, this to Gandhi meant the unity of God and humans, that all beings have the same one soul and therefore equality, that atman exists and is same as everything in the universe, ahimsa (non-violence) is the very nature of this atman. Gandhi called himself advaitist many times, including his letters, but he believed that others have a right to a viewpoint different than his own because they come from a different background and perspective. According to Gier, Gandhi did not interpret maya as illusion, but accepted that "personal theism" leading to "impersonal monism" as two tiers of religiosity.

Contemporary Advaita Vedānta

Contemporary teachers are the orthodox Jagadguru of Sringeri Sharada Peetham; the more traditional teachers Sivananda Saraswati (1887–1963), Chinmayananda Saraswati (1916-1993), Dayananda Saraswati (Arsha Vidya) (1930-2015), Swami Paramarthananda, Swami Tattvavidananda Sarasvati, Carol Whitfield (Radha), Sri Vasudevacharya  and less traditional teachers such as Narayana Guru. According to Sangeetha Menon, prominent names in 20th century Advaita tradition are Shri Chandrashekhara Bharati Mahaswami, Chandrasekharendra Saraswati Swamigal, Sacchidānandendra Saraswati.

Influence on New religious movements

Neo-Advaita is a New Religious Movement based on a popularised, western interpretation of Advaita Vedānta and the teachings of Ramana Maharshi. Neo-Advaita is being criticised for discarding the traditional prerequisites of knowledge of the scriptures and "renunciation as necessary preparation for the path of jnana-yoga". Notable neo-advaita teachers are H. W. L. Poonja, his students Gangaji Andrew Cohen, and Eckhart Tolle.

Non-dualism

Advaita Vedānta has gained attention in western spirituality and New Age, where various traditions are seen as driven by the same non-dual experience. Nonduality points to "a primordial, natural awareness without subject or object". It is also used to refer to interconnectedness, "the sense that all things are interconnected and not separate, while at the same time all things retain their individuality".

Sampradaya

Advaita Vedānta is not just a philosophical system, but also a tradition of renunciation. Philosophy and renunciation are closely related:

Most of the notable authors in the advaita tradition were members of the sannyasa tradition, and both sides of the tradition share the same values, attitudes and metaphysics.

Shankara organized monks under 10 names and established mathas for them. These mathas contributed to the influence of Shankara, which was "due to institutional factors". The mathas which he established remain active today, and preserve the teachings and influence of Shankara, "while the writings of other scholars before him came to be forgotten with the passage of time".

Shri Gaudapadacharya Math

Around 740 AD Gaudapada founded Shri Gaudapadacharya Math, also known as Kavaḷē maṭha. It is located in Kavale, Ponda, Goa, and is the oldest matha of the South Indian Saraswat Brahmins.

Shankara's monastic tradition

Shankara, himself considered to be an incarnation of Shiva, established the Dashanami Sampradaya, organizing a section of the Ekadandi monks under an umbrella grouping of ten names. Several Hindu monastic and Ekadandi traditions, however, remained outside the organisation of the Dasanāmis.

Sankara organised the Hindu monks of these ten sects or names under four Maṭhas (Sanskrit: मठ) (monasteries), called the Amnaya Mathas, with the headquarters at Dvārakā in the West, Jagannatha Puri in the East, Sringeri in the South and Badrikashrama in the North. Each math was first headed by one of his four main disciples, and the tradition continues since then. According to another tradition in Kerala, after Sankara's samadhi at Vadakkunnathan Temple, his disciples founded four mathas in Thrissur, namely NaduvilMadhom, ThekkeMadhom, IdayilMadhom and Vadakke Madhom.

The table below gives an overview of the four Amnaya Mathas founded by Adi Shankara, and their details.

Shishya (lineage)	Direction	Maṭha	Mahāvākya	Veda	Sampradaya
Padmapāda	East	Govardhana Pīṭhaṃ	Prajñānam brahma (Consciousness is Brahman)	Rig Veda	Bhogavala
Sureśvara	South	Sringeri Śārada Pīṭhaṃ	Aham brahmāsmi (I am Brahman)	Yajur Veda	Bhūrivala
Hastāmalakācārya	West	Dvāraka Pīṭhaṃ	Tattvamasi (That thou art)	Sama Veda	Kitavala
Toṭakācārya	North	Jyotirmaṭha Pīṭhaṃ	Ayamātmā brahma (This Atman is Brahman)	Atharva Veda	Nandavala

Monks of these ten orders differ in part in their beliefs and practices, and a section of them is not considered to be restricted to specific changes made by Shankara. While the dasanāmis associated with the Sankara maths follow the procedures enumerated by Adi Śankara, some of these orders remained partly or fully independent in their belief and practices; and outside the official control of the Sankara maths. The advaita sampradaya is not a Saiva sect, despite the historical links with Shaivism. Nevertheless, contemporary Sankaracaryas have more influence among Saiva communities than among Vaisnava communities.

Relationship with other forms of Vedānta

The Advaita Vedānta ideas, particularly of 8th century Adi Shankara, were challenged by theistic Vedānta philosophies that emerged centuries later, such as the 11th-century Vishishtadvaita (qualified nondualism) of Ramanuja, and the 14th-century Dvaita (theistic dualism) of Madhvacharya.

Vishishtadvaita

Ramanuja's Vishishtadvaita school and Shankara's Advaita school are both nondualism Vedānta schools, both are premised on the assumption that all souls can hope for and achieve the state of blissful liberation; in contrast, Madhvacharya and his Dvaita subschool of Vedānta believed that some souls are eternally doomed and damned. Shankara's theory posits that only Brahman and causes are metaphysical unchanging reality, while the empirical world (Maya) and observed effects are changing, illusive and of relative existence. Spiritual liberation to Shankara is the full comprehension and realization of oneness of one's unchanging Atman (soul) as the same as Atman in everyone else as well as being identical to the nirguna Brahman. In contrast, Ramanuja's theory posits both Brahman and the world of matter are two different absolutes, both metaphysically real, neither should be called false or illusive, and saguna Brahman with attributes is also real. God, like man, states Ramanuja, has both soul and body, and all of the world of matter is the glory of God's body. The path to Brahman (Vishnu), asserted Ramanuja, is devotion to godliness and constant remembrance of the beauty and love of personal god (saguna Brahman, Vishnu), one which ultimately leads one to the oneness with nirguna Brahman.

Shuddhadvaita

Vallabhacharya (1479–1531 CE), the proponent of the philosophy of Shuddhadvaita Brahmvad enunciates that Ishvara has created the world without connection with any external agency such as Maya (which itself is his power) and manifests Himself through the world. That is why shuddhadvaita is known as 'Unmodified transformation' or 'AvikṛtaPariṇāmavāda'. Brahman or Ishvara desired to become many, and he became the multitude of individual souls and the world. Vallabha recognises Brahman as the whole and the individual as a 'part' (but devoid of bliss).

Dvaita

Madhvacharya was also a critic of Advaita Vedānta. Advaita's nondualism asserted that Atman (soul) and Brahman are identical, there is interconnected oneness of all souls and Brahman, and there are no pluralities. Madhva in contrast asserted that Atman (soul) and Brahman are different, only Vishnu is the Lord (Brahman), individual souls are also different and depend on Vishnu, and there are pluralities. Madhvacharya stated that both Advaita Vedānta and Mahayana Buddhism were a nihilistic school of thought. Madhvacharya wrote four major texts, including Upadhikhandana and Tattvadyota, primarily dedicated to criticizing Advaita.

Present-day Krishna-devotees are highly critical of Advaita Vedānta, regarding it as māyāvāda, identical to Mahayana Buddhism.

Historical influence

Mahatma Gandhi stated "I am an advaitist".

Scholars are divided on the historical influence of Advaita Vedānta. Some Indologists state that it is one of the most studied Hindu philosophy and the most influential schools of classical Indian thought. Advaita Vedānta, states Eliot Deutsch, "has been and continues to be the most widely accepted system of thought among philosophers in India, and it is, we believe, one of the greatest philosophical achievements to be found in the East or the West".

Smarta Tradition

The Smarta tradition of Hinduism is an ancient tradition, particularly found in south and west India, that revers all Hindu divinities as a step in their spiritual pursuit. Their worship practice is called Panchayatana puja. The worship symbolically consists of five deities: Shiva, Vishnu, Devi or Durga, Surya and an Ishta Devata or any personal god of devotee's preference.

In the Smarta tradition, Advaita Vedānta ideas combined with bhakti are its foundation. Adi Shankara is regarded as the greatest teacher and reformer of the Smarta. According to Alf Hiltebeitel, Shankara's Advaita Vedānta and practices became the doctrinal unifier of previously conflicting practices with the smarta tradition.

Philosophically, the Smarta tradition emphasizes that all images and statues (murti), or just five marks or any anicons on the ground, are visibly convenient icons of spirituality saguna Brahman. The multiple icons are seen as multiple representations of the same idea, rather than as distinct beings. These serve as a step and means to realizing the abstract Ultimate Reality called nirguna Brahman. The ultimate goal in this practice is to transition past the use of icons, then follow a philosophical and meditative path to understanding the oneness of Atman (soul, self) and Brahman – as "That art Thou".

Other Hindu traditions

Within the ancient and medieval texts of Hindu traditions, such as Vaishnavism, Shaivism and Shaktism, the ideas of Advaita Vedānta have had a major influence. Advaita Vedānta influenced Krishna Vaishnavism in the different parts of India One of its most popular text, the Bhagavata Purana, adopts and integrates in Advaita Vedānta philosophy. The Bhagavata Purana is generally accepted by scholars to have been composed in the second half of 1st millennium CE.

In the ancient and medieval literature of Shaivism, called the Āgamas, the influence of Advaita Vedānta is once again prominent. Of the 92 Āgamas, ten are Dvaita texts, eighteen are Bhedabheda, and sixty-four are Advaita texts. According to Natalia Isaeva, there is an evident and natural link between 6th-century Gaudapada's Advaita Vedānta ideas and Kashmir Shaivism.

Shaktism, the Hindu tradition where a goddess is considered identical to Brahman, has similarly flowered from a syncretism of the monist premises of Advaita Vedānta and dualism premises of Samkhya–Yoga school of Hindu philosophy, sometimes referred to as Shaktadavaitavada (literally, the path of nondualistic Shakti).

Other influential ancient and medieval classical texts of Hinduism such as the Yoga Yajnavalkya, Yoga Vashishta, AvadhutaGitā, Markandeya Purana and Sannyasa Upanishads predominantly incorporate premises and ideas of Advaita Vedānta.

Relationship with Buddhism

Advaita Vedānta and Mahayana Buddhism share similarities and have differences, their relationship a subject of dispute among scholars. The similarities between Advaita and Buddhism have attracted Indian and Western scholars attention, and have also been criticised by concurring schools. The similarities have been interpreted as Buddhist influences on Advaita Vedānta, while others deny such influences, or see them as variant expressions. According to Daniel Ingalls, the Japanese Buddhist scholarship has argued that Adi Shankara did not understand Buddhism.

Some Hindu scholars criticized Advaita for its Maya and non-theistic doctrinal similarities with Buddhism. Ramanuja, the founder of VishishtadvaitaVedānta, accused Adi Shankara of being a PrachannaBauddha, that is, a "crypto-Buddhist", and someone who was undermining theistic Bhakti devotionalism. The non-Advaita scholar Bhaskara of the BhedabhedaVedānta tradition, similarly around 800 CE, accused Shankara's Advaita as "this despicable broken down Mayavada that has been chanted by the Mahayana Buddhists", and a school that is undermining the ritual duties set in Vedic orthodoxy.

A few Buddhist scholars made the opposite criticism in the medieval era toward their Buddhist opponents. In the sixth century CE, for example, the Mahayana Buddhist scholar Bhaviveka redefined Vedantic concepts to show how they fit into Madhyamaka concepts, and "equate[d] the Buddha's Dharma body with Brahman, the ultimate reality of the Upanishads." In his Madhyamakahṛdayakārikaḥ, Bhaviveka stages a Hinayana (Theravada) interlocutor, who accuses Mahayana Buddhists of being "crypto-Vedantins". Medieval era Tibetan Gelugpa scholars accused the Jonang school of being "crypto-Vedantist." Contemporary scholar David Kalupahana called the seventh century Buddhist scholar Chandrakirti a "crypto-Vedantist", a view rejected by scholars of Madhayamika Buddhism.

The Advaita Vedānta tradition has historically rejected accusations of crypto-Buddhism highlighting their respective views on Atman, Anatta and Brahman.

Similarities with Buddhism

According to scholars, the influence of Mahayana Buddhism on Advaita Vedānta has been significant. Advaita Vedānta and various other schools of Hindu philosophy share numerous terminology, doctrines and dialectical techniques with Buddhism. According to a 1918 paper by the Buddhism scholar O. Rozenberg, "a precise differentiation between Brahmanism and Buddhism is impossible to draw."

Both traditions hold that "the empirical world is transitory, a show of appearances", and both admit "degrees of truth or existence". Both traditions emphasize the human need for spiritual liberation (moksha, nirvana, kaivalya), however with different assumptions. Adi Shankara, states Natalia Isaeva, incorporated "into his own system a Buddhist notion of maya which had not been minutely elaborated in the Upanishads". Similarly, there are many points of contact between Buddhism's Vijnanavada and Shankara's Advaita.

According to Frank Whaling, the similarities between Advaita Vedānta and Buddhism are not limited to the terminology and some doctrines, but also includes practice. The monastic practices and monk tradition in Advaita are similar to those found in Buddhism.

Dasgupta and Mohanta suggest that Buddhism and Shankara's Advaita Vedānta represent "different phases of development of the same non-dualistic metaphysics from the Upanishadic period to the time of Sankara." The influence of Mahayana Buddhism on other religions and philosophies was not limited to Vedānta. Kalupahana notes that the Visuddhimagga of Theravada Buddhism tradition contains "some metaphysical speculations, such as those of the Sarvastivadins, the Sautrantikas, and even the Yogacarins". According to John Plott,

We must emphasize again that generally throughout the Gupta Dynasty, and even more so after its decline, there developed such a high degree of syncretism and such toleration of all points of view that Mahayana Buddhism had been Hinduized almost as much as Hinduism had been Buddhaized.

Gaudapada

The influence of Buddhist doctrines on Gaudapada has been a vexed question.

One school of scholars, such as Bhattacharya and Raju, state that Gaudapada took over the Buddhist doctrines that ultimate reality is pure consciousness (vijñapti-mātra) and "that the nature of the world is the four-cornered negation, which is the structure of Māyā".

Of particular interest is Chapter Four of Gaudapada's text Karika, in which according to Bhattacharya, two karikas refer to the Buddha and the term Asparsayoga is borrowed from Buddhism. According to Murti, "the conclusion is irresistible that Gaudapada, a Vedānta philosopher, is attempting an Advaitic interpretation of Vedānta in the light of the Madhyamika and Yogacara doctrines. He even freely quotes and appeals to them." However, adds Murti, the doctrines are unlike Buddhism. Chapter One, Two and Three are entirely Vedantin and founded on the Upanishads, with little Buddhist flavor. Further, state both Murti and King, no Vedānta scholars who followed Gaudapada ever quoted from Chapter Four, they only quote from the first three. According to Sarma, "to mistake him [Gaudapada] to be a hidden or open Buddhist is absurd". The doctrines of Gaudapada and Buddhism are totally opposed, states Murti:

We have been talking of borrowing, influence and relationship in rather general terms. It is necessary to define the possible nature of the borrowing, granting that it did take place. (...) The Vedantins stake everything on the Atman (Brahman) and accept the authority of the Upanishads. We have pointed out at length the Nairatmya standpoint of Buddhism and its total opposition to the Atman (soul, substance, the permanent and universal) in any form.

— TRV Murti, The Central Philosophy of Buddhism

Advaitins have traditionally challenged the Buddhist influence thesis. Modern scholarship generally accepts that Gaudapada was influenced by Buddhism, at least in terms of using Buddhist terminology to explain his ideas, but adds that Gaudapada was a Vedantin and not a Buddhist. Gaudapada adopted some Buddhist terminology and borrowed its doctrines to his Vedantic goals, much like early Buddhism adopted Upanishadic terminology and borrowed its doctrines to Buddhist goals; both used pre-existing concepts and ideas to convey new meanings. While there is shared terminology, the Advaita doctrines of Gaudapada and Buddhism are fundamentally different.

Differences from Buddhism

Atman and anatta

Advaita Vedānta holds the premise, "Soul exists, and Soul (or self, Atman) is a self evident truth". Buddhism, in contrast, holds the premise, "Atman does not exist, and An-atman (or Anatta, non-self) is self evident".

Chakravarthi Ram-Prasad gives a more nuanced view, stating that the Advaitins "assert a stable subjectivity, or a unity of consciousness through all the specific states of indivuated consciousness, but not an individual subject of consciousness [...] the Advaitins split immanent reflexivity from 'mineness'."

In Buddhism, Anatta (Pali, Sanskrit cognate An-atman) is the concept that in human beings and living creatures, there is no "eternal, essential and absolute something called a soul, self or atman". Buddhist philosophy rejects the concept and all doctrines associated with atman, call atman as illusion (maya), asserting instead the theory of "no-self" and "no-soul." Most schools of Buddhism, from its earliest days, have denied the existence of the "self, soul" in its core philosophical and ontological texts. In contrast to Advaita, which describes knowing one's own soul as identical with Brahman as the path to nirvana, in its soteriological themes Buddhism has defined nirvana as the state of a person who knows that he or she has "no self, no soul".

The Upanishadic inquiry fails to find an empirical correlate of the assumed Atman, but nevertheless assumes its existence, and Advaitins "reify consciousness as an eternal self." In contrast, the Buddhist inquiry "is satisfied with the empirical investigation which shows that no such Atman exists because there is no evidence." states Jayatilleke.

Yet, some Buddhist texts chronologically placed in the 1st millennium of common era, such as the Mahayana tradition's Tathāgatagarbhasūtras suggest self-like concepts, variously called Tathagatagarbha or Buddha nature. These have been controversial idea in Buddhism, and "eternal self" concepts have been generally rejected. In modern era studies, scholars such as Wayman and Wayman state that these "self-like" concepts are neither self nor sentient being, nor soul, nor personality. Some scholars posit that the Tathagatagarbha Sutras were written to promote Buddhism to non-Buddhists.

Epistemology

The epistemological foundations of Buddhism and Advaita Vedānta are different. Buddhism accepts two valid means to reliable and correct knowledge – perception and inference, while Advaita Vedānta accepts six (described elsewhere in this article). However, some Buddhists in history, have argued that Buddhist scriptures are a reliable source of spiritual knowledge, corresponding to Advaita's Śabda pramana, however Buddhists have treated their scriptures as a form of inference method.

Ontology

Advaita Vedānta posits a substance ontology, an ontology which holds that underlying the change and impermanence of empirical reality is an unchanging and permanent absolute reality, like an eternal substance it calls Atman-Brahman. In its substance ontology, as like other philosophies, there exist a universal, particulars and specific properties and it is the interaction of particulars that create events and processes.

In contrast, Buddhism posits a process ontology, also called as "event ontology". According to the Buddhist thought, particularly after the rise of ancient Mahayana Buddhism scholarship, there is neither empirical nor absolute permanent reality and ontology can be explained as a process. There is a system of relations and interdependent phenomena (pratityasamutpada) in Buddhist ontology, but no stable persistent identities, no eternal universals nor particulars. Thought and memories are mental constructions and fluid processes without a real observer, personal agency or cognizer in Buddhism. In contrast, in Advaita Vedānta, like other schools of Hinduism, the concept of self (atman) is the real on-looker, personal agent and cognizer.

The Pali Abdhidhamma and Theravada Buddhism considered all existence as dhamma, and left the ontological questions about reality and the nature of dhamma unexplained.

According to Renard, Advaita's theory of three levels of reality is built on the two levels of reality found in the Madhyamika.

Shankara on Buddhism

A central concern for Shankara, in his objections against Buddhism, is what he perceives as nihilism of the Buddhists. Shankara states that there "must be something beyond cognition, namely a cognizer," which he asserts is the self-evident Atman or witness. Buddhism, according to Shankara, denies the cognizer. He also considers the notion of Brahman as pure knowledge and "the quintessence of positive reality."

The teachings in Brahma Sutras, states Shankara, differ from both the Buddhist realists and the Buddhist idealists. Shankara elaborates on these arguments against various schools of Buddhism, partly presenting refutations which were already standard in his time, and partly offering his own objections. Shankara's original contribution in explaining the difference between Advaita and Buddhism was his "argument for identity" and the "argument for the witness". In Shankara's view, the Buddhist are internally inconsistent in their theories, because "the reservoir-consciousness that [they] set up, being momentary, is no better than ordinary consciousness. Or, if [they] allow the reservoir-consciousness to be lasting, [they] destroy [their] theory of momentariness." In response to the idealists, he notes that their alaya-vijnana, or store-house consciousness, runs counter to the Buddhist theory of momentariness. With regard to the Sunyavada (Madhyamaka), Shankara states that "being contradictory to all valid means of knowledge, we have not thought worth while to refute" and "common sense (loka-vyavahara) cannot be denied without the discovery of some other truth".

Reception

Advaita Vedānta is most often regarded as an idealist monism. According to King, Advaita Vedānta developed "to its ultimate extreme" the monistic ideas already present in the Upanishads. In contrast, states Milne, it is misleading to call Advaita Vedānta "monistic," since this confuses the "negation of difference" with "conflation into one." Advaita is a negative term (a-dvaita), states Milne, which denotes the "negation of a difference," between subject and object, or between perceiver and perceived. 

According to Deutsch, Advaita Vedānta teaches monistic oneness, however without the multiplicity premise of alternate monism theories. According to Jacqueline Hirst, Adi Shankara positively emphasizes "oneness" premise in his Brahma-sutra Bhasya 2.1.20, attributing it to all the Upanishads.

Nicholson states Advaita Vedānta contains realistic strands of thought, both in its oldest origins and in Shankara's writings.