Advaita Vedanta Philosophy, Concepts and Practice

Advaita Vedanta (literally, "non-duality") is a school of Hindu philosophy, which was originally known as Puruṣavāda. It is a classic system of spiritual realization in Indian tradition and essentially a liberation theology which aims to lead a seeker beyond duality and delusion. The term Advaita refers to the idea that the true self, Atman, and the highest metaphysical reality of the universe, Brahman, are identical, and the phenomenal world is not ultimately real. Followers of this school are known as Advaita Vedantins, or just Advaitins or Mayavadins. They believe that the phenomenal world is a mere appearance of plurality, which experienced through sense-impressions due to ignorance (avidya), or an illusion which is superimposed (adhyāsa) on the supreme reality and singularity of Brahman. They seek spiritual liberation by recognizing this illusoriness of the phenomenal world and acquiring the true knowledge (vidyā) of oneself as Atman, and its oneness or relationship with the Supreme Self or Atman and Brahman. Adi Shankara, was the most prominent exponent of the Advaita Vedanta tradition.

The school traces its roots to the oldest Upanishads. It relies on three textual sources called the Prasthanatrayi namely the Upanishads, the Brahmasutras and the Bhagavadgita. It gives "a unifying interpretation of these texts which provide valid knowledge of Brahman and his manifestations. It is the oldest extant sub-school of Vedanta, which is recognized as one of the six philosophies (tattvas) of philosophical views (darshanas) of Hinduism. Although one can trace its roots to the first millennium BCE, the most prominent exponent of the Advaita Vedanta is considered by tradition to be the 8th century scholar Adi Shankara.

Advaita Vedanta emphasizes Jivanmukti, the idea that moksha (freedom, liberation) is achievable in this life, in contrast to other Indian philosophies which emphasize videhamukti, or moksha after death. The school derives it ideas regarding Brahman, Atman, Maya, Avidya, meditation, etc., from the Vedic texts, and some from other religious traditions, but interprets them in its own way. Hence, it is one of the most studied and most influential schools of classical Indian thought. Many scholars describe it as a form of monism nondualism. Monism implies that Brahman is one and only. Nondualism suggests Brahman is without a second or the supreme realism of Brahman is without duality or diversity. Advaita is a school of Hinduism. Historically, it has been recognized as a Hindu philosophy or pathway to liberation rather than a religion. More so because Advaita Vedanta is found in all the major Hindu sects such as Shaivism and Vaishnavism. Each of them regards their supreme deity as Brahman only.

Advaita influenced and was influenced by various traditions and texts of Hindu philosophies such as Samkhya, Yoga, Nyaya, other sub-schools of Vedanta, Vaishnavism, Shaivism, the Puranas, the Agamas, as well as social movements such as the Bhakti movement. Beyond Hinduism, Advaita Vedanta interacted with the other traditions of India such as Jainism and Buddhism and strengthened its roots. Its texts espouse a spectrum of views from idealism (including illusionism) to realism or the expositions found in the early works of Shankara regarding the supreme reality. In modern times, its views appear in various Neo-Vedanta movements. It has been termed as the classical example of Hindu spirituality which looks beyond the empirical reality and acknowledge the union of the opposites in a singular, self-existent and absolute reality without being influenced by them

Etymology and nomenclature

The word Advaita is a composite of two Sanskrit words. Prefix "A-" which means "Non-" and “Dvaita", which means 'Duality' or 'Dualism'. The word Vedanta is composed of two Sanskrit words. Veda refers to the whole corpus of Vedic texts, and "Anta" means 'the End'. Thus, the meaning of Vedanta can be summed up as "the end of the Vedas" or "the ultimate knowledge of the Vedas". Vedanta is one of six orthodox schools of Hindu philosophy.

The Advaita Vedanta 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.”

Purusharthas and liberation

Vedic tradition prescribes the Purusharthas or the four goals of human life for all householders (grihastas). Just as the other schools, Advaita accepts Purusharthas as natural and proper in the journey of life upon earth. Dharma is the right way to life. It consists of the "duties and obligations of each individual toward himself and the society as well as those of the society toward the individual.” Artha (wealth) is the means to support and sustain one's life. Kama refers to the right to enjoy worldly pleasure material comforts as a fruit of one's actions and ethical behavior. Moksha refers to final liberation or release from the cycle of births and deaths. Of them, much of the Advaita Vedanta philosophy focuses on the last, gaining liberation in one's current life. Liberation is gained through knowledge of Brahman. The first three are discussed and encouraged by the followers of the school, but usually in the context of knowing Brahman and Self-realization. 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 Atman, and the identity of Atman and Brahman, the complete understanding of one's real nature as Brahman in this life. This is stated by Adi Shankara (Upadesasahasri 11.7) 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.

According to Advaita Vedanta, 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, according to the school, 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 Vedanta, 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. Ramana Maharshi, the Indian sage who was widely regarded as a Jivanmukta. The concept of Jivanmukti of Advaita Vedanta contrasts with Videhamukti (moksha from samsara after death) in theistic sub-schools of Vedanta. Jivanmukti is a state that transforms the nature, attributes and behaviors of an individual, after which the liberated individual shows attributes such as the following.

• He is not bothered 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, Svadhyaya and Anubhava

Sruti (scriptures), proper reasoning and meditation are the main sources of knowledge (vidya) for the Advaita Vedanta tradition. It teaches that correct knowledge of Atman and Brahman is achievable by svadhyaya, 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 counselor or teacher (guru), wherein the Advaitins 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.

Mahavakyas – The Great Sentences

Mahavakyas are great statements which are used in meditation and concentration to gain insight into its hidden knowledge and meaning. They are mostly taken from the Upanishads. Several Mahavakyas reflect the central beliefs of Advaita affirming, that "the inner immortal self and the great cosmic power are one and the same. The following ones are a few examples

1.  Prajnanam brahma. Brahman is intelligence. (From the Aitareya Upanishad of the Rigveda)
2. Aham Brahmasmi. I am Brahman. (From the Brihadaranyaka Upanishad of Shukla Yajurveda)
3. Tat tvam asi. You are that. (From the Chandogya Upanishad of the Samaveda)
4. Ayamātmā brahma. This Atman is Brahman. (From the Mandukya Upanishad of the Atharvaveda)

Stages and practices

Advaita Vedanta 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 Vedanta emphasizes 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), which a student is Advaita Vedanta has to develop through practice. They are listed below.

1.  Knowing the difference between the permanent and the impermanent. (nityānitya vastu viveka) It is cultivating the discerning intelligence (viveka) to correctly discriminate between the real and eternal (nitya) and that reality which is apparently real, but illusory, changing and transitory (anitya).
2. The renunciation (virāga) of all desires of the mind (bhog) for sense pleasures, in this world (iha) and other worlds (ihāmutrārtha phala bhoga virāga). It means one has to willingly give up everything which is an obstacle to the pursuit of truth and self-knowledge.
3. Cultivating the six fold virtues such equanimity (samadhi ṣatka sampatti. The six fold virtues are:
4.  Mumukstavam, which is an intense longing for freedom, liberation and wisdom, driven by the quest of knowledge and understanding, with moksha as the primary goal of life. It leads to correct knowledge, which destroys ignorance (avidya), psychological and perceptual errors related to Atman and Brahman, and which is obtained by jnanayoga through three stages of practice, namely sravana (hearing), manana (thinking) and nididhyasana (meditation). This three-step methodology is rooted in the teachings of chapter 4 of the Brihadaranyaka Upanishad.

Sravana means listening to the teachings of the sages on the Upanishads and Advaita Vedanta, studying the Vedantic texts, such as the Brahma Sutras, and discussions with the guru (teacher, counselor). 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 refers to the practice of meditation and introspection, to arrive at the realization and consequent conviction of the truth of non-duality. It culminates in a state where there is a fusion of thought and action, knowing and being. Samadhi refers to absorption in nonduality (Samadhi). While Shankara emphasized śravaṇa ("hearing"), manana ("reflection") and nididhyāsana ("repeated meditation"), later texts like the Dṛg-Dṛśya-Viveka (14th century) and Vedantasara (of Sadananda) (15th century) added samadhi as a means to liberation, a theme that was also emphasized by Swami Vivekananda.

The six fold virtues are listed below.

1. Śama, which requires the cultivation of mental tranquility, concentration or the ability to focus the mind.
2. Dama – which consists of self-restraint, temperance and restraining of the senses.
3. Uparati, which means dispassion, lack of desire for worldly pleasures, ability to be quiet, mental and physical detachment from everything and renunciation of all religious duties and ceremonies.
4. Titikṣa, which means endurance, perseverance, putting up with pairs of opposites (like heat and cold, pleasure and pain), ability to be patient during demanding circumstances, etc.
5. Sraddha - having faith in teacher and the Sruti scriptural texts
6. Samadhana, which means contentment, the satisfaction of mind in all conditions, attention, intentness of mind

The significance of a guru

Advaita Vedanta school recognizes the importance of a guru (teacher) in liberation and traditionally places high reverence for him, suggesting that one should seek a competent Guru in the pursuit of liberation. However, Clooney states that the guru is not mandatory in Advaita school. The view is not widely accepted. The teachings of Adi Shankara and emphasis upon scriptures and their teaching (sastracaryopadesa) point to the importance of a guru in the tradition. The consensus is that a competent teacher is important and essential to gain correct knowledge, overcome false knowledge, and attain self-realization.

On the path of Advaita, a guru is more than a teacher. Traditionally, he is a reverential figure to the student, who guides him as a "counselor, molds his thinking and values, shares experiential knowledge as much as literal knowledge, sets an example in life, serves as an inspirational source and 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.”

Reality and Truth

Classical Advaita recognizes the oneness of all existence beyond the apparent diversity and division. It acknowledges all reality and everything in the experienced world to be the same as the Brahman. Followers of the school perceive unity in multiplicity. The do not accept the dual hierarchy of the Creator and creation. All objects, experiences, material things, consciousness and awareness in Advaita philosophy is not the property but the very nature of this one fundamental reality known as Brahman. With this premise, the Advaita school states that any ontological effort must presuppose a knowing self, and it needs to explain all empirical experiences such as the projected reality while one dreams during sleep, and the observed multiplicity of living beings. Advaita does it by its theory of three levels of reality and the theory of two truths, and developing and integrating these ideas with its theory of errors (anirvacaniya khyati).

Shankara proposed three levels of reality, using contradiction (sublation) as the ontological criterion.

1. The absolute and ultimate Reality (Pāramārthik), which is metaphysically true and ontologically accurate. It is the state of experiencing that "which is absolutely real and in which other realities resolve themselves in harmony. It is the highest, which cannot be contradicted, dissolved, changed or assimilated by any other.
2. The empirical or pragmatic reality (Vyāvahārika or samvriti-saya). It consists of the everyday, experiential and consequential reality which is unstable and impermanent but not reliable as a source of stability or constancy. It is empirically true in a given set of circumstances, at a given time and in a particular context, but metaphysically untrue. It consists of our worldly experience of the phenomenal world, which we handle every day in the wakeful state, in which both the supreme Self and the individual selves are present in their projected state as seemingly true. However, in comparison to the first, it is incomplete, contradictory and negatable.
3. The apparent or the reflective reality (prāthibhāsika), which arises in the mind due to imagination, reflection, delusion, projection or a mistaken notion. For all practical purposes, it is a construct of the mind, created by the mind stuff, in which it constructs its own reality, which its creator may acknowledge as true or untrue, according to his state of mind. A well know example is the imaginary reality which arises in dreams during sleep. Mistaking a rope in the dark for a snake is another.

Advaita Vedanta acknowledges and admits that from the empirical perspective there are numerous distinctions. Everything and each reality have multiple perspectives, both absolute and relative. All are valid and true in their respective contexts, but only from their respective particular perspectives. The presence of "absolute and relative truths" is the basis of the "two truths" doctrine in Advaita. John Grimes, a professor of Indian Religions specializing on Vedanta, explains this Advaita doctrine using the analogy 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. It does not mean Advaita Vedanta accepts two truths and two realities, but that the same one Reality and one Truth appears differently from two different perspectives.

In the development of these theories, the school was influenced by corresponding ideals from other schools such as the Nyaya, Samkhya and Yoga schools of Hinduism. These theories have not enjoyed universal consensus among the followers of the school, whereby various competing ontological interpretations emerged which are now an integral part of its history and philosophy.

Three states of consciousness and Turiya

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

1. The first state is the waking state, in which we are aware of our daily world. It corresponds to the gross body.
2. The second state is the dreaming mind. It corresponds to the subtle body.
3. The third state is the state of deep sleep. It corresponds to the causal body.

Advaita also postulates the fourth state of Turiya, which some describe as pure consciousness, which corresponds to the unified state of Brahman in which neither duality nor division nor separation exists. It is the transcendental substratum of the three realities and exists beyond them. According to Advaita, turiya is the state of liberation where one experiences the infinite (ananta) and non-different (advaita/abheda), free from the dualistic experience, and 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-pervading, without suffering, blissful, changeless, self-luminous, real, immanent in all things and transcendent. Those who have experienced the Turiya state of self-consciousness reach the state of oneness or the pure awareness of the non-dual absolute Self in unity with everyone and everything. For them, the knowledge, the knower, the known become one, whereby they attain the status of a Jivanmukta, a liberated soul in a living body.

Advaita traces the foundation of this ontological theory in more ancient Sanskrit texts. For example, Chandogya Upanishad (8.7-8.12) discusses the "four states of consciousness" as wakeful, dream, deep sleep, and beyond deep sleep. One of the earliest mentions of Turiya is found in a verse in the Brihadaranyaka Upanishad (5.14.3) One may also find vague references to it in some early Upanishads in reference to the nature of the self.

Absolute Reality - Brahman

According to Advaita Vedanta, Brahman is the highest Reality, which is unborn, unchanging and undeniable and which cannot be superseded by a still higher reality. Other than Brahman, everything else, including the universe, material objects and individuals, are ever-changing. They represent the work of maya and unreal. Brahman is the absolute truth (paramarthika satyam) and the only truth. As the true Self and pure consciousness, it is the only Reality (sat), since It is untouched by difference, division, ignorance, and not sublatable. According to the school, as the support and the cause of all changes, Brahman is not only the material cause and the efficient cause of all that exists but also the "primordial reality that creates, maintains and withdraws within itself the universe. It is the creative principle which comes to fruition in the whole world.

The Upanishads portray the Advaitic concept of Brahman when they describe him as truth, consciousness and bliss (satchidananda). Adi Shankara held that satchidananda is identical with Brahman and Atman. According to him, the knowledge of Brahman which is found in the shruti (Vedas) cannot be grasped in any other means without self-inquiry. Another nondualistic scholar Madhusudana Sarasvati explained Brahman as the Reality which is simultaneously devoid of falsity (sat), devoid of ignorance (cit), and devoid of sorrow/self-limitation (ananda).

Atman, the individual self

Atman is a central to many concepts of Hindu philosophy, besides being the foundational premise of Advaita. It is a Sanskrit word that means the true self, the individual self, the essence, the soul and the breathing one. Atman is the first principle in Advaita Vedanta, along with the concept of Brahman, with Both Atman as the perceptible personal particular and Brahman as the inferred unlimited universal are used in Advaita as synonymous and interchangeable. Just as Brahman, Atman is unchanging, enduring, eternal and absolute. It is the true self of each being and pure consciousness in its essence. As described by Eliot Deutsch, atman is the "pure, undifferentiated, supreme power of awareness." It is more than thought and being, and represents a unique reality which is ungraspable, indefinable, unlimited, extensive and beyond the duality of subject and object, divisions and momentariness.

Advaita Vedanta philosophy considers Atman as self-existent awareness, limitless and non-dual. It asserts that there is "spirit, soul, self" (Atman) 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 Atman.

According to the school, Atman is not the constantly changing body, not the desires, not the emotions, not the ego, nor the dualistic mind in Advaita Vedanta. It is the introspective, inwardly self-conscious witness (sakshi). Because of delusion, ignorance and egos (I-ness) people perceive themselves as different and distinct from others and fail to realize their underlying unity and oneness. As a result, they succumb to desires, selfishness, attachment, impulses, fears, cravings, malice, division, confusion, anxiety, passions, and the sense of distinctiveness.

Identity of Atman and Brahman

According to Advaita Vedanta, Atman is identical to Brahman, which is affirmed in the great saying (mahavakya) of the Upanishad namely ‘tat tvam asi,’ which means you are That. The essential nature of both is pure consciousness only. Each soul, in Advaita view, is indistinguishable and undifferentiated from the infinite. According to Shankara, Atman 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 oneness of Atman and Brahman, with a complete understanding of one's real nature as Brahman in this life. This is frequently stated by Advaita scholars, such as Shankara (Upadesasahasri 11.7), in the following manner.

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.

Empirical reality – illusion and ignorance

The status of the phenomenal world is an important question in Advaita Vedanta, since it holds Brahman as the sole reality. Different solutions have been proposed to explain the nature of empirical reality and distinguish from Brahman. The illusory perception of the phenomenal world as real is attributed to the influence of maya (constantly changing reality) and avidya ("ignorance"). Other than Brahman, everything else, including the universe, material objects and individuals, are ever-changing and therefore constitute maya (illusion or unreal). Brahman is Paramarthika Satyam, the absolute Truth, the true Self, pure consciousness, and the only Reality (sat), since It is untainted by duality, ignorance, and contradiction.

Causality or the theory of cause and effect

All schools of Vedanta 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 scholars of Vedanta, the Samkhya schools and many sub-schools of Vedanta, support the opposite theory (parinamavada), according to which the world (the effect) is a real transformation (parinama) of Brahman (the cause).

There is a third theory of causation (vivartavada) according to which the world, is merely an unreal manifestation (vivarta) of Brahman. Scholars disagree on the question of whether Adi Shankara and his Advaita system espoused causality through vivarta. Vivartavada suggests that although Brahman appears to undergo transformation, in reality no such transformation takes place. What appears to be transformation is a mere superficial projection, in which Brahman remain unchanged and unaffected. The myriad beings which arise from him are unreal manifestations, while he remains as the only real being, that ultimate reality which is unborn, unchanging, and entirely without parts. Nicholson states that the followers of Shankara were the advocates of the vivartavada, the unreal and illusory transformation. He further states that although the world appears as conventionally real, according to Advaita-vadins all of Brahman’s effects must ultimately be acknowledged as unreal before the self is liberated.

However, other scholars such as Hajime Nakamura and Paul Hacker disagree. They state that Adi Shankara did not advocate Vivartavada, and his explanations do not connote the illusory nature of the empirical reality. According to them, it was Prakasatman (a 13th century scholar), who injected Vivartavada into the school, which is sometimes misunderstood as Adi Shankara's original position. Andrew Nicholson concurs with Hacker and other scholars, adding that the vivarta-vada isn't Shankara's theory, and his ideas appear closer to parinama-vada, while the vivarta explanation likely emerged gradually much later.

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

Maya (illusion)

The doctrine of Maya is used to explain the nature of empirical reality in Advaita. According to the school, when a jiva is conditioned by the human mind, he is subjected to the experiences of subjective nature, which leads to the mistaken and deluded notion of Maya as the sole and final reality. The perceived world, including people and other objects and things, is not what it appears to be. It is Maya, they assert, which manifests and perpetuates a sense of false duality or divisional plurality. The empirical manifestation is unstable and ever-changing. It obfuscates the true nature of metaphysical Reality which is eternal and fixed. Advaita school holds that liberation is the unfettered realization and understanding of the unchanging Reality and truth of the Self, that it is the same Self in all and in everything.

In Advaita Vedanta philosophy, there are two realities: Vyavaharika (empirical reality) and Paramarthika (absolute, spiritual Reality). Maya is the empirical reality, which entangles consciousness. Maya 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 maya 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 Maya. A later Advaita scholar Prakasatman addressed this, by explaining that "Maya and Brahman together constitute the entire universe, just as 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, while Maya is true in epistemological and empirical sense. However, Maya 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 empirical (vyavaharika) and spiritual (paramarthika) realities as represented by Maya and Brahman respectively. The goal of spiritual enlightenment is to realize Brahman, and the unity and Oneness of all reality.

Avidya (ignorance)

Due to ignorance (avidya), Brahman is perceived as the material world and its objects (nama rupa vikara). According to Shankara, Brahman is in reality without attributes and without form. As the highest truth and all (Reality), he does not really change. It is our ignorance and other impurities which give the illusion of change. Again, due to avidya, the true identity is forgotten, and material reality, which manifests at various levels, is mistaken as the only and true reality.

The notion of avidya and its relationship to Brahman creates a crucial philosophical issue within Advaita Vedanta thought. One of the questions which has been raised is how can avidya appear in error free Brahman, since he is pure consciousness and a truth being? In his commentary and translation of Adi Shankara's Upadesasahasri writes, “Certainly the most crucial problem which Shankara left for his followers is that of avidya.

If the concept is logically analyzed, it would lead the Vedanta philosophy toward dualism or nihilism and uproot its fundamental position.” To Advaita vadins, human beings, in a state of unawareness and ignorance of this Universal Self, see their "I-ness" as different than the being in others. They, they act out of impulse, fears, cravings, malice, division, confusion, anxiety, passions, and a sense of distinctiveness. Subsequent proponents of Advaita gave somewhat different explanations, from which various Advaita schools arose.

Ethics

Deutsch states that according to one theory Advaita turns its back on all theoretical and practical considerations of morality and, if not unethical, it is at least 'a-ethical' in character." However, he disagrees and adds that ethics have a firm place in its philosophy and practice. Shankara himself led an exemplary life and epitomized great character and conduct. There is little doubt that Advaita Vedanta is permeated with ethics. Value judgments are integral to its every metaphysical and epistemological analysis. Hence, it regards an independent, separate treatment of ethics as unnecessary. Deutsch states that there cannot be "any absolute moral laws, principles or duties." Instead in its axiological view, the Self (Atman) is "beyond good and evil", and all values result from the knowledge of the indistinct Self, and all beings and manifestations of Brahman. Its ethics include lack of craving and lack of duality between oneself and others, righteousness and just karma.

The values and ethics in Advaita Vedanta 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 (6-7) in the following manner.

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?

In the Upadeśasāhasrī (1.25 to 1.26) Adi Shankara, affirms that the knowledge of the Self is understood and realized when one's mind is purified by the observation of ethical restraints (yamas) such as Ahimsa (non-violence or 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 may be helpful to focus and prepare the mind for the journey liberation. However, ritual worship and oblations to Deva (God) are not encouraged, because they create duality between oneself and Brahman or between the worshipper and the worshipped. The "doctrine of difference" is wrong, asserts Shankara, because, anyone who thinks that he is one and Brahman is another does not know him. In the Upadeśasāhasrī (1.26 to 1.28) he refers to the ethical premise of equality of all beings, according to which any difference or distinction (bheda) based on class or caste or parentage is a mark of inner error and lack of liberating knowledge. Therefore, a fully liberated person understands and practices the ethics of non-discrimination.

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.

The foundational texts of Advaita

The Upanishads, the Bhagavad Gita and Brahma Sutras are the central texts of the Advaita Vedanta 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 commentaries (bhashyas) have become central texts in the Advaita Vedanta philosophy, although they are but a part of a vast collection of many ancient and medieval manuscripts that are available or accepted by the tradition. The subsequent Advaita tradition has further elaborated on these sruti and commentaries. Adi Shankara is also credited for the famous text Nirvana Shatakam.

Reference may also be made of Prasthanatrayi, which in the Vedanta tradition refers to the trilogy of the Brahma Sutras, and the Bhagavadgita. The Upanishads are considered the foundation of Vedanta because they are considered shruti (the heard ones) or the Sruti prasthāna. The Brahma Sutras an ancient text consisting of several aphorisms on the ultimate reality of Brahman is considered a Nyaya prasthana or Yukti prasthana providing the logical and rational foundation not only to the doctrine of Advaita but to the entire gamut of the Upanishadic philosophy. They synthesize the teachings of the Upanishads. However, the same text also provides rationale for other schools as well such as Dvaita.

The Bhagavad Gita, or the Smriti prasthana provides the intellectual or expository foundation of the Vedanta. It has been widely studied by Advaita scholars, including Adi Shankara, who wrote a commentary upon it. Apart from them there is a vast body of Advaita literature composed by numerous scholars who contributed to the development of its doctrine and its popularity as the leading philosophical school of Hinduism which is adapted by almost every Hindu sect and some Buddhist Tantric schools.

Advaita Vedanta sub-schools

After Shankara's death, several sub-schools of Advaita developed. Two of them still exist today namely the Bhāmatī and the Vivarana. Mention may also be made of two defunct schools, the Pancapadika and Istasiddhi, which were replaced by Prakasatman's Vivarana 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 maya and avidya.

Vachaspati Misra (800–900 CE) wrote the Brahmatattva-samiksa, a commentary on Maṇḍana Miśra's Brahma-siddhi, which provides the link between Mandana Misra and Shankara and attempts to harmonize Shankara's thought with that of Mandana Misra. According to Advaita tradition, Shankara reincarnated as Vachaspati Misra "to popularize the Advaita System through his Bhamati". Only two works are known of Vachaspati Misra, the Brahmatattva-samiksa on Maṇḍana Miśra'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 Mandana Misra’s Bhamati on Shakara’s commentary (bhashya) of Brahmasutras. The Bhamati school takes an ontological approach, viewing the Jiva as the source of avidya. It regards meditation as the main factor in the acquirement of liberation, while the study of the Vedas and reflection are additional factors. The Vivarna school derives its name from the Pancapadika-Vivarana of Prakasatman (c. 1200–1300) which is a commentary on the Pancapadika by Padmapadacharya. 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”. He saw 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.

Influence of yogic tradition

While Indologists like Paul Hacker and Wilhelm Halbfass took Shankara's system as the measure for an "orthodox" Advaita Vedanta, the living Advaita Vedanta 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 vedanta 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 Vedanta. In the 16th and 17th centuries, some Nath and hatha yoga texts also came within the scope of the developing Advaita Vedanta tradition.

Already in medieval times, Advaita Vedanta 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 Vedanta, 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-Vedanta, attempted to respond to this colonial stereotyping of "Indian culture was backward, superstitious and inferior to the West", states King. Advaita Vedanta was projected as the central philosophy of Hinduism, and Neo-Vedanta subsumed and incorporated Buddhist ideas thereby making the Buddha a part of the Vedanta tradition, all in an attempt to reposition the history of Indian culture. Thus, states King, neo-Vedanta developed as a reaction to western Orientalism and Perennialism. With the efforts of Vivekananda, modern formulation of Advaita Vedanta has "become a dominant force in Indian intellectual thought", though Hindu beliefs and practices are diverse.

Unifying Hinduism

Advaita Vedanta 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 Gita, texts such as Dharma sutras 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 Vedanta was given the highest position, since it was regarded to be most inclusive system.

Modern times (Colonial rule and independence)

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, Vedanta came to be regarded as the essence of Hinduism, and Advaita Vedanta came to be regarded as "then paradigmatic example of the mystical nature of the Hindu religion" and umbrella of "inclusivism". This umbrella of Advaita Vedanta, 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 Vedanta has been a major ideological force for Hindu nationalism. Mahatma Gandhi professed monism of Advaita Vedanta, 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 Vedanta 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 popularization of this Universalist and Perennialist interpretation of Advaita Vedanta was Vivekananda, who played a major role in the revival of Hinduism, and the spread of Advaita Vedanta to the west via the Ramakrishna Mission. His interpretation of Advaita Vedanta has been called "Neo-Vedanta". 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 Vedanta as a liberal and universal religion, in contrast to the exclusivism of other religions. Vivekananda emphasized nirvikalpa samadhi as the spiritual goal of Vedanta, 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 shruti. 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.