According to Koller, Shankara, and his contemporaries, made a significant contribution in understanding Buddhism and the ancient Vedic traditions, then transforming the extant ideas, particularly reforming the Vedanta tradition of Hinduism, making it India's most important "spiritual tradition" for more than a thousand years. Benedict Ashley credits Adi Shankara for unifying two seemingly disparate philosophical doctrines in Hinduism, namely
Atman and
Brahman. According to Nakamura, Shankara was not an original thinker, but systematised the works of preceding philosophers. The central theme of Shankara's writings is the liberating knowledge of the identity of the Self (
Ātman) and
Brahman.
Moksha is
attained in this life by recognizing the identity of
Atman and
Brahman, as mediated by the
Mahavakyas, especially
Tat Tvam Asi, "That you are."
Historical context Shankara lived in the time of the great "Late classical Hinduism", which lasted from 650 till 1100 CE. This era was one of political instability that followed the
Gupta dynasty and
King Harsha of the 7th century CE. Power became decentralised in India. Several larger kingdoms emerged, with "countless vassal states". The kingdoms were ruled via a feudal system. Smaller kingdoms were dependent on the protection of the larger kingdoms. "The great king was remote, was exalted and deified", as reflected in the
Tantric Mandala, which could also depict the king as the centre of the mandala. The disintegration of central power also led to regionalisation of religiosity and religious rivalry. Local cults and languages were enhanced, and the influence of "Brahmanic ritualistic Hinduism" was diminished. Rural and devotional movements arose, along with
Shaivism,
Vaisnavism,
Bhakti and
Tantra, though "sectarian groupings were only at the beginning of their development". Religious movements had to compete for recognition by the local lords, and
Buddhism,
Jainism,
Islam and various traditions within Hinduism were competing for members. Buddhism in particular had emerged as a powerful influence in India's spiritual traditions in the first 700 years of the 1st millennium CE, but lost its position after the 8th century, and began to disappear in India. This was reflected in the change of puja-ceremonies at the courts in the 8th century, where Hindu gods replaced the Buddha as the "supreme, imperial deity".
Systematizer of Advaita According to Nakamura, comparison of the known teachings of the 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". According to Nakamura, after the growing influence of Buddhism on Vedānta, culminating in the works of Gauḍapāda, Adi Shankara gave a Vedantic character to the Buddhistic elements in these works, synthesising and rejuvenating the doctrine of Advaita. According to Koller, using ideas in ancient Indian texts, Shankara systematized the foundation for Advaita
Vedānta in the 8th century, reforming
Badarayana's Vedānta tradition. According to Mayeda, Shankara represents a turning point in the development of Vedānta, yet he also notices that it is only since
Deussens's praise that Shankara "has usually been regarded as the greatest philosopher of India." Mayeda further notes that Shankara was primarily concerned with
moksha, "and not with the establishment of a complete system of philosophy or theology," following Potter, who qualifies Shankara as a "speculative philosopher." Lipner notes that Shankara's "main literary approach was commentarial and hence perforce disjointed rather than procedurally systematic [...] though a systematic philosophy can be derived from Samkara's thought." Shankara has been described as influenced by Shaivism and Shaktism, but his works and philosophy suggest greater overlap with Vaishnavism, influence of
Yoga school of Hinduism, but most distinctly express his Advaitin convictions with a monistic view of spirituality, and his commentaries mark a turn from realism to idealism.
Moksha - liberating knowledge of Brahman The central theme of Shankara's writings is the liberating knowledge of the true identity of
jivatman (individual self) as
Ātman-Brahman. One of Shankara's main concerns was establishing the Upanishads as an independent means of knowledge beyond the ritually oriented
Mimansa exegesis of the vedas. According to Shankara, the one unchanging entity (Brahman) alone is real, while changing entities do not have absolute existence. Shankara's primary objective was to explain how
moksha is
attained in this life by recognizing the true identity of
jivatman as
Atman-Brahman, as mediated by the
Mahāvākyas, especially
Tat Tvam Asi, "That you are." Correct knowledge of
jivatman and
Atman-Brahman is the attainment of
Brahman, immortality, and leads to
moksha (liberation) from suffering and
samsara, the cycle of rebirth. This is stated by Shankara as follows: {{blockquote| 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.
Pramanas - means of knowledge Shankara recognized the means of knowledge, but his thematic focus was upon
metaphysics and
soteriology, and he took for granted the
pramanas, that is
epistemology or "means to gain knowledge, reasoning methods that empower one to gain reliable knowledge". According to Sengaku Mayeda, "in no place in his works [...] does he give any systematic account of them," taking
Atman-Brahman to be self-evident (
svapramanaka) and self-established (
svatahsiddha), and "an investigation of the means of knowledge is of no use for the attainment of final release." Mayeda notes that Shankara's arguments are "strikingly realistic and not idealistic," arguing that
jnana is based on existing things (
vastutantra), and "not upon Vedic injunction (
codanatantra) nor upon man (
purusatantra). According to Michael Comans (aka Vasudevacharya), Shankara considered perception and inference as a primary most reliable epistemic means, and where these means to knowledge help one gain "what is beneficial and to avoid what is harmful", there is no need for or wisdom in referring to the scriptures. In certain matters related to metaphysics and ethics, says Shankara, the testimony and wisdom in scriptures such as the Vedas and the Upanishads become important. 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 the
pramanas (means of knowledge) of reason and experience. Hacker and Phillips note that his insight into rules of reasoning and hierarchical emphasis on epistemic steps is "doubtlessly the suggestion" of Shankara in Brahma-sutra-bhasya, an insight that flowers in the works of his companion and disciple Padmapada.
Logic versus revelation Stcherbatsky in 1927 criticized Shankara for demanding the use of logic from
Madhyamika Buddhists, while himself resorting to revelation as a source of knowledge. Sircar in 1933 offered a different perspective and stated, "Sankara recognizes the value of the law of contrariety and self-alienation from the standpoint of idealistic logic; and it has consequently been possible for him to integrate appearance with reality." Recent scholarship states that Shankara's arguments on revelation are about
apta vacana (Sanskrit: आप्तवचन, sayings of the wise, relying on word, testimony of past or present reliable experts). It is part of his and Advaita Vedanta's epistemological foundation. The Advaita Vedanta tradition considers such testimony epistemically valid, asserting 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. Shankara considered the teachings in the Vedas and Upanishads as
apta vacana and a valid source of knowledge. To Shankara, that knowledge of
Brahman springs only from inquiry into the teachings of the Upanishads. The method of yoga, encouraged in Shankara's teachings notes Comans, includes withdrawal of mind from sense objects as in Patanjali's system, but it is not complete thought suppression, instead it is a "meditative exercise of withdrawal from the particular and identification with the universal, leading to contemplation of oneself as the most universal, namely, Consciousness". Describing Shankara's style of yogic practice, Comans writes: the type of yoga which Sankara presents here is a method of merging, as it were, the particular (visesa) into the general (samanya). For example, diverse sounds are merged in the sense of hearing, which has greater generality insofar as the sense of hearing is the locus of all sounds. The sense of hearing is merged into the mind, whose nature consists of thinking about things, and the mind is in turn merged into the intellect, which Sankara then says is made into 'mere cognition' (vijnanamatra); that is, all particular cognitions resolve into their universal, which is cognition as such, thought without any particular object. And that in turn is merged into its universal, mere Consciousness (prajnafnaghana), upon which everything previously referred to ultimately depends. 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".
The Mahāvākyas - true identity as Ātman-Brahman Moksha, liberation from suffering and rebirth and attaining immortality, is attained by disidentification from the body-mind complex and gaining self-knowledge as being in essence
Atman-Brahman. According to Shankara, the individual jivĀtman 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. The real self is
Sat, "the Existent," that is,
Ātman-Brahman. Whereas the difference between Ātman and non-Ātman is deemed self-evident, knowledge of the true identity of jivĀtman as Brahman is revealed by the
shruti, especially the Upanishadic statement
tat tvam asi.
Mahāvākyas According to Shankara, a large number of Upanishadic statements reveal the true identity of
jivĀtman as
Brahman. In the Advaita Vedānta tradition, four of those statements, the
Mahāvākyas, which are taken literal, in contrast to other statements, have a special importance in revealing this identity. They are: • तत्त्वमसि,
tat tvam asi,
Chandogya VI.8.7. Traditionally rendered as "That Thou Art" (that you are), with
tat in Ch.U.6.8.7 referring to
sat, "the Existent"); correctly translated as "That's how [thus] you are," with
tat in Ch.U.6.12.3, it' original location from where it was copied to other verses, referring to "the very nature of all existence as permeated by [the finest essence]" • अहं ब्रह्मास्मि,
aham brahmāsmi,
Brhadāranyaka I.4.10, "I am Brahman," or "I am Divine." • प्रज्ञानं ब्रह्म,
prajñānam brahma,
Aitareya V.3, "
Prajñānam is Brahman." • अयमात्मा ब्रह्म,
ayamātmā brahma,
Mandukya II, "This Atman is Brahman."
That you are The longest chapter of Shankara's
Upadesasahasri, chapter 18, "That Art Thou," is devoted to considerations on the insight "I am ever-free, the existent" (
sat), and the identity expressed in
Chandogya Upanishad 6.8.7 in the
mahavakya (great sentence) "
tat tvam asi", "that thou art." In this statement, according to Shankara,
tat refers to
Sat, "the Existent" Existence, Being, or Brahman, the Real, the "Root of the world," the true essence or root or origin of everything that exists. As Shankara states in the
Upadesasahasri: The statement "tat tvam asi" sheds the false notion that
Atman is different from
Brahman. According to Nakamura, the non-duality of
atman and
Brahman "is a famous characteristic of Sankara's thought, but it was already taught by Sundarapandya" ( or earlier). Shankara cites Sundarapandya in his comments to
Brahma Sutra verse I.1.4: From this, and a large number of other accordances, Nakamura concludes that Shankar was not an original thinker, but "a synthesizer of existing Advaita and the rejuvenator, as well as a defender, of ancient learning."
Meditation on the Mahāvākya In the
Upadesasahasri Shankara, Shankara is ambivalent on the need for meditation on the Upanishadic
mahavyaka. He states that "right knowledge arises at the moment of hearing," and rejects
prasamcaksa or
prasamkhyana meditation, that is, meditation on the meaning of the sentences, and in Up.II.3 recommends
parisamkhyana, separating
Atman from everything that is not
Atman, that is, the sense-objects and sense-organs, and the pleasant and unpleasant things and merit and demerit connected with them. Yet, Shankara then concludes with declaring that only
Atman exists, stating that "all the sentences of the
Upanishads concerning non-duality of
Atman should be fully contemplated, should be contemplated." As Mayeda states, "how they [
prasamcaksa or
prasamkhyana versus
parisamkhyana] differ from each other is not known."
Prasamkhyana was advocated by Mandana Misra, the older contemporary of Shankara who was the most influential Advaitin until the 10th century. "According to Mandana, the
mahavakyas are incapable, by themselves, of bringing about
brahmajnana. The
Vedanta-vakyas convey an indirect knowledge which is made direct only by deep meditation (
prasamkhyana). The latter is a continuous contemplation of the purport of the
mahavakyas. Vācaspati Miśra, a student of Mandana Misra, agreed with Mandana Misra, and their stance is defended by the Bhamati-school, founded by Vācaspati Miśra. In contrast, the
Vivarana school founded by Prakasatman (–1300) follows Shankara closely, arguing that the
mahavakyas are the direct cause of gaining knowledge.
Renouncement of ritualism Shankara, in his text
Upadesasahasri, discourages ritual worship such as oblations to
Deva (God), because that assumes the Self within is different from the
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". The false notion that
Atman is different from
Brahman is connected with the novice's conviction that (
Upadeshasahasri II.1.25) Recognizing oneself as "the Existent-
Brahman," which is mediated by scriptural teachings, is contrasted with the notion of "I act," which is mediated by relying on sense-perception and the like. According to Shankara, the statement "Thou art That" "remove[s] the delusion of a hearer," "so through sentences as "Thou art That" one knows one's own
Atman, the witness of all internal organs," and not from any actions. With this realization, the performance of rituals is prohibited, "since [the use of] rituals and their requisites is contradictory to the realization of the identity [of
Atman] with the highest
Atman." However, Shankara also asserts that Self-knowledge is realized when one's mind is purified by an ethical life that observes
Yamas such as
Ahimsa (non-injury, non-violence to others in body, mind and thoughts) and
Niyamas. Rituals and rites such as
yajna (a fire ritual), asserts Shankara, can help draw and prepare the mind for the journey to Self-knowledge. He emphasizes the need for ethics such as
Akrodha and
Yamas during
Brahmacharya, stating the lack of ethics as causes that prevent students from attaining knowledge.
Īśvara Shankara, while rejecting empirical reality due to his position of nonduality, still attributes value to the universe as it identifies with
Īśvara. He sometimes blurs the distinction between
Īśvara and
Brahman, using various terms for both. However, he generally separates
Īśvara, associated with the universe and its attributes, from the absolute nondual Brahman. Drawing from the Upanishads, Shankara sees
Īśvara as the universe's material and intelligent cause, emanating it through the power of
maya, thereby making the universe sentient and self-aware. In relation to the
Mandukya Upanishad, Shankara compares the universe's unmanifest state to
Īśvara in a deep dreamless cosmic state. Shankara's conception of Brahman as the cause of the world does not invoke creation in the literal sense but
vivartta (manifoldness without transformation), distinct from
satkaryavada (actual transformation). Shankara argues that insentient matter cannot act purposefully and rejects any actual transformation of Brahman. ==Influences of Mahayana Buddhism==