Four Noble Truths
The Four Noble Truths sit at the heart of how Buddhism describes the way things really are when seen correctly. In Pali they are the cattāri ariyasaccāni, sometimes rendered as the truths of the noble one, the Buddha. Four short formulas carry them: dukkha, samudaya, nirodha, and marga. They are traditionally identified as the first teaching the Buddha gave after his awakening. Yet that traditional status hides a more tangled story. The truths appear in many grammatical forms across the ancient texts. The most commonly used version contains grammatical errors. Some scholars argue they were not part of the earliest layer of Buddhist teaching at all. So what do these four truths actually claim about existence? Why do they carry both a symbolic and a propositional weight? And how did a formula that academic scholars place at a slightly later period come to be presented in the west as the central teaching of Buddhism?
Dukkha is named first, an innate characteristic of transient existence. Nothing is forever, and this is painful. The word is most commonly translated as suffering, but according to Khantipalo that translation is incorrect. It refers to the ultimately unsatisfactory nature of temporary states and things, including pleasant but temporary experiences. According to Emmanuel, dukkha is the opposite of sukha, non-transient pleasure, and is better translated as pain. The term traces to dush-stha, standing unstable.
Samudaya names the origin or arising. Together with this transient world and its pain, there is also thirst, the craving for and attachment to an unsatisfactory existence. Brazier and Batchelor point to the wider sense of samudaya as coming into existence together. On this reading craving does not cause dukkha but arises alongside it. The craving has three forms in the Dhammacakkappavattana Sutta: kama-tanha for sense-pleasures, bhava-tanha for becoming, and vibhava-tanha for not experiencing the world.
Nirodha names cessation, ending, confinement. The attachment to this transient world and its pain can be severed or contained by letting go of craving. When craving is confined, nirvana is attained. Marga names the road or path. The Noble Eightfold Path leads to the confinement of desire and the release from dukkha. Kondañña grasped the lesson at the close of the first discourse with a single phrase: whatever arises ceases.
Carol S. Anderson argues the four truths are set apart not because they are by definition sacred, but because they are both a symbol and a doctrine. As a symbol they evoke the possibility of enlightenment, representing the awakening and liberation of the Buddha and the potential for his followers to reach the same freedom. Where they appear as a religious symbol in the Sutta-pitaka and the Vinaya-pitaka, they stand for the enlightenment experience itself and for the possibility of enlightenment for all Buddhists within the cosmos.
As propositions, the truths defy exact definition. They sit inside what Anderson calls a network of teachings, the entire dhamma matrix, which must be taken together. Within that network the four noble truths are one doctrine among others and are not particularly central. A long recognized feature of the Theravada canon is that it lacks an overarching and comprehensive structure of the path to nibbana. So one teaching may explain another in one passage, and the relationship may be reversed in another talk. There is, in Anderson's words, no single way of understanding the teachings.
The Pali phrase ariya sacca, in Sanskrit arya satya, is usually translated as noble truths, a convention started by the earliest translators of Buddhist texts into English. Paul Williams insists there is no particular reason it should be rendered that way. It could equally mean the nobles' truths, the truths for nobles, the nobilising truths, or the truths possessed by the noble ones. The Pali commentators themselves rank the noble truths reading as the least important.
The term arya was later added to the four truths, and it can be translated as noble, not ordinary, valuable, precious, or pure. The aryas, Williams writes, are the noble ones, the saints, those who have attained the fruits of the path. The term sacca, Sanskrit satya, is a central term in Indian thought. It means truth, but also that which is in accord with reality. Rupert Gethin describes the four truths as four true things or realities whose nature the Buddha finally understood on the night of his awakening. K. R. Norman judges the best translation to be the truth of the noble one, the Buddha: a statement of how things really are when seen correctly.
The Dhammacakkappavattana Sutta, Setting in Motion the Wheel of Dhamma, gives the best-known presentation, and it contains two sets of the four truths. The full set used in modern expositions carries grammatical errors that point to multiple sources and to translation problems within the ancient Buddhist community. The Pali tradition considered them correct and did not correct them. K. R. Norman records a basic set running idaṃ dukkhaṃ, this is pain, through to the path leading to the cessation of pain.
Norman also identifies a mnemonic set, intended to remind the hearer of the full form. Its earliest version was dukkham samudayo nirodho marga, without the terms sacca or arya, which were added later. According to L. S. Cousins the four truths are not restricted to the form where dukkha is the subject. Other forms take the world, the arising of the world, or the āsavas as their subject. The well-known form, Cousins says, is simply shorthand for all of the forms. The Dhammacakkappavattana Sutta also lays out three stages for understanding each truth, sacca-ñāṇa, kicca-ñāṇa, and kata-ñāṇa, for a total of twelve insights.
As early as 1935, Caroline Rhys Davids observed that for a teaching so central to Theravada Buddhism, the four truths were missing from critical passages in the Pali canon. Gethin notes that the four truths and the eightfold path are only two lists among literally hundreds of similar lists covering ancient Buddhism. According to Anderson, only by the time of the commentaries in the fifth century CE did the truths come to be identified in the Theravada tradition as the central teaching of the Buddha.
According to Feer and Anderson, the four truths probably entered the Sutta Pitaka from the Vinaya, the rules for monastic order. They were first added to enlightenment-stories containing the four jhanas, replacing terms for liberating insight. According to Vetter and Bronkhorst, the earliest Buddhist path consisted of practices culminating in dhyana, a calm of mind that Vetter regards as the liberation being sought. Later, liberating insight came to be regarded as equally liberating, a response to other religious groups in India who held such insight indispensable for moksha. Bronkhorst points to an inconsistency: the four truths name the eightfold path as the means to liberation, yet insight into the truths is portrayed as liberating in itself.
By about the fifth century CE the four truths grew to central importance in the Theravada tradition, which holds that insight into them is liberating in itself. Walpola Rahula writes that when the truth is seen, all the forces that feverishly produce the continuity of samsara become calm. This liberation can be attained in a single moment, when the four truths are understood together. The Ekavyāvahārika sect held the words of the Buddha carried one transcendent meaning, and that the truths are understood simultaneously in one moment of insight.
In the Mahayana traditions the truths are less prominent, which emphasize insight into Śūnyatā, emptiness, and the Bodhisattva path. According to Makransky the Bodhisattva ideal created tensions, since a fully enlightened Buddha does not leave samsara but remains in the world out of compassion. The truths, aimed at ending samsara, had to be reinterpreted to explain how a liberated being can still be pervasively operative in this world. Nichiren Buddhism, based on the Japanese priest Nichiren, treats the four truths as a provisional teaching, while holding the Lotus Sutra to be the most wonderful, unsurpassed great Dharma.
Beginning in the 19th century, British missionaries studied Buddhism to be more effective in their efforts, and the four truths were discovered by reading the texts. According to Harris, the Buddha was de-mystified and reduced from a superhuman to a compassionate, heroic human, situated firmly below the divine. Anderson links the simplification of the truths to the colonial project of gaining control over Buddhism. Walpola Rahula's What the Buddha Taught uses the four truths as a framework, and Gimello calls it an example of so-called Protestant Buddhism, created in nearly diametrical opposition to Buddhism as actually practised in traditional Theravada.
In 1882 Hendrik Kern proposed the four truths might be an analogy with classical Indian medicine, with the Buddha as physician and the truths as diagnosis. The analogy became popular, though there is not sufficient historical evidence that the Buddha deliberately drew on a medical model. For many western Buddhists the rebirth doctrine is a problematic notion. Some interpreters have proposed a naturalized Buddhism, stripped of rebirth, karma, and nirvana. Melford Spiro warns this approach leaves unanswered the existential question of why live, and not hasten the end of dukkha. The same B. R. Ambedkar who built the Navayana around social action dismissed the four truths as the invention of wrong-headed monks.
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Common questions
What are the Four Noble Truths in Buddhism?
The Four Noble Truths are dukkha, samudaya, nirodha, and marga. They state that transient existence is unsatisfactory and painful, that craving arises together with this pain, that the craving can be confined or let go, and that the Noble Eightfold Path leads to release from dukkha.
What does dukkha mean in the Four Noble Truths?
Dukkha is the first of the Four Noble Truths and is most commonly translated as suffering, though Khantipalo calls that translation incorrect. It refers to the ultimately unsatisfactory nature of temporary states and things, and according to Emmanuel is better translated as pain, the opposite of the non-transient pleasure called sukha. The term derives from dush-stha, standing unstable.
Were the Four Noble Truths the Buddha's first teaching?
The Four Noble Truths are traditionally identified as the first teaching the Buddha gave after his awakening, presented in the Dhammacakkappavattana Sutta. According to L. S. Cousins many scholars hold that this discourse was identified as the first sermon only at a later date, and Carol S. Anderson argues the four truths may originally not have been part of the sutta but were added in some versions.
Why are the Four Noble Truths called noble truths?
The Pali phrase ariya sacca, Sanskrit arya satya, is rendered as noble truths by a convention started by the earliest English translators. Paul Williams argues it could equally mean the nobles' truths or the truths of the noble ones, and K. R. Norman judges the best translation to be the truth of the noble one, the Buddha.
How do the Four Noble Truths differ between Theravada and Mahayana Buddhism?
By about the fifth century CE the four truths grew to central importance in Theravada Buddhism, which holds that insight into them is liberating in itself. They are less prominent in the Mahayana traditions, which emphasize insight into Śūnyatā and the Bodhisattva path, and which reinterpreted the truths to explain how a liberated being can remain pervasively operative in the world.
Why did the Four Noble Truths become central in western Buddhism?
Beginning with 19th century British missionaries who studied the texts, the four truths were popularized in the west, which Carol S. Anderson links to the colonial project of gaining control over Buddhism. Walpola Rahula's What the Buddha Taught used them as a framework, and Gimello describes this so-called Protestant Buddhism as created in nearly diametrical opposition to traditional Theravada practice.
All sources
171 references cited across the entry
- 3Payutto, Dependent Origination: the Buddhist Law of Causality
- 4Paticcasamuppada: Practical dependent OriginationBhikkhu Buddhadasa
- 5Governing Board12 May 2021
- 12na duhkha-samudaya-nirodha-margah11 June 2012
- 20BookPali-English DictionaryThomas William Rhys Davids et al. — Motilal Banarsidass Publ. — 23 May 1993
- 27The Pali Canon What a Buddhist Must KnowP.A. Payutto
- 28The Authenticity of the Early Buddhist TextsBhante Sujato et al. — Chroniker Press — 2015
- 29Shulman, Eviatar Rethinking the Buddha (Cambridge University Press, 2017), p. 140 ff.
- 38Nichiren Shu Buddhist Temple of UK NewsletterSeptember–October 2008
- 44BookRoutledge Handbook of Contemporary IndiaEleanor Zelliot — Taylor & Francis — 2015
- 45BookEncyclopedia of BuddhismRoutledge — 2013
- 46The Connected Discourses of the Buddha: A New Translation of the Samyutta NikayaBhikkhu Bodhi — Wisdom Publications — 2000
- 47The Middle Length Discourses of the Buddha: A New Translation of the Majjhima NikayaBhikkhu Nanamoli (translator) — Wisdom Publications — 1995
- 48The Four Noble TruthsAjahn Sumedho — Amaravati Publications — 2002
- 49Turning the Wheel of Truth: Commentary on the Buddha's First TeachingAjahn Sucitto — Shambhala — 2010
- 50A Secular BuddhismStephen Batchelor — 2012
- 51The Middle Length Discourses of the Buddha. A New Translation of the Majjhima NikayaBhikkhu Bodhi — Wisdom Publications — 1995a
- 52The Noble Eightfold Path: Way to the End of SufferingBhikkhu Bodhi — Independent Publishers Group — 2011
- 53The Feeling BuddhaDavid Brazier — Robinson Publishing — 2001
- 54The First Discourse of the BuddhaVen. Dr. Rewata Dhamma — Wisdom — 1997
- 55Thoughts Without A Thinker: Psychotherapy from a Buddhist PerspectiveMark Epstein — Basic Books — 2004
- 56The Four Noble Truths: The Foundation of Buddhist Thought, Volume IGeshe Tashi Tsering — Wisdom — 2005
- 57Buddhist Psychology: The Foundation of Buddhist Thought, Volume IIIGeshe Tashi Tsering — Perseus Books Group — 2006
- 58The Discourse SummariesS.N. Goenka — Pariyatti — 2000
- 59One Dharma: The Emerging Western BuddhismJoseph Goldstein — HarperCollins — 2002
- 60Mindfulness: A Practical Guide to AwakeningJoseph Goldstein — Sounds True — 2013
- 61Healing the Heart and Mind with Mindfulness: Ancient Path, Present MomentMalcolm Huxter — Routledge — 2016
- 62Vast as the Heavens, Deep as the Sea: Verses in Praise of BodhicittaKhunu Rinpoche — Wisdom — 2012
- 63Calm and Insight: A Buddhist Manual for MeditatorsBhikkhu Phra Khantipalo — Routledge — 2003
- 64Awakening the Buddha WithinLama Surya Das — Broadway Books — 1997
- 65The Joy of Living: Unlocking the Secret and Science of HappinessMingyur Rinpoche — Harmony — 2007
- 66Comfortable with Uncertainty: 108 Teachings on Cultivating Fearlessness and CompassionPema Chodron — Shambhala — 2010
- 67What the Buddha TaughtWalpola Rahula — Grove Press — 2007
- 68What the Buddha TaughtWalpola Rahula — 2007a
- 69Daring Steps Toward Fearlessness: The Three Vehicles of Tibetan BuddhismRingu Tulku — Snow Lion — 2005
- 70Old Path White CloudsThich Nhat Hanh — Parallax Press — 1991
- 71The Heart of the Buddha's TeachingThich Nhat Hanh — Three River Press — 1999
- 72The Essence of BuddhismTraleg Kyabgon — Shambhala — 2001
- 73Een Lamp voor het Pad naar VerlichtingTsenshap Serkong Rinpoche — Uitgeverij Maitreya — 1996
- 74Michael Oakeshott on Authority, Governance, and the StateJames Alexander — Springer — 2019
- 75Satipatthana. The Direct Path to RealizationAnalayo — Windhorse Publications — 2003
- 78The Chinese Parallels to the Dhammacakkappavattana-sutta (1)Analayo — 2012
- 79The Chinese Parallels to the Dhammacakkappavattana-sutta (2)Analayo — 2013
- 80Pain and Its Ending: The Four Noble Truths in the Theravada Buddhist CanonCarol Anderson — Routledge — 1999
- 81Pain and Its Ending: The Four Noble Truths in the Theravada Buddhist CanonCarol Anderson — Motilall Banarsidas — 2001
- 82Encyclopedia of BuddhismCarol Anderson — Macmillan Reference Books — 2003
- 83BookEncyclopedia of BuddhismCarol Anderson — MacMillan Reference, Thomson Gale — 2004
- 84Pain and Its Ending: The Four Noble Truths in the Theravada Buddhist CanonCarol Anderson — Routledge — 2013
- 85Buddhism in the Krishna River ValleyAnthony W. Barber — 2008
- 86BookGreek Buddha: Pyrrho's Encounter with Early Buddhism in Central AsiaChristopher I. Beckwith — Princeton University Press — 2015
- 87Handbook of Mindfulness: Culture, Context, and Social EngagementBhikkhu Bodhi — Springer — 2016
- 88The Two Traditions of Meditation in Ancient IndiaJohannes Bronkhorst — Motilal Banarsidass Publ. — 1993
- 89Karma and Teleology: A Problem and its Solutions in Indian PhilosophyJohannes Bronkhorst — 2000
- 90The Buddhist Path to Liberation: An Analysis of the Listing of StagesRod Bucknell — 1984
- 91Paths to Liberation. The Marga and its Transformations in Buddhist ThoughtMotilal Banarsidass Publishers — 1994
- 92The Princeton Dictionary of BuddhismRobert E. Jr. Buswell et al. — Princeton University Press — 2003
- 93Princeton Dictionary of BuddhismBuswell et al. — Princeton University Press — 2014
- 94MacMillan Encyclopedia of ReligionsJohn Ross Carter — MacMillan — 1987
- 95Buddhism, Reincarnation, and Dalai Lamas of TibetM. G. Chitkara — APH Publishing — 1998
- 96The Fundamental Teachings of Early Buddhism: A Comparative Study Based on the Sutranga Portion of the Pali Samyutta-Nikaya and the Chinese SamyuktagamaMun-keat Choong — Otto Harrassowitz Verlag — 2000
- 97Beyond Enlightenment: Buddhism, Religion, ModernityRobert S. Cohen — Routledge — 2006
- 98The New Buddhism. The Western Transformation of an Ancient TraditionJames William Coleman — Oxford University Press — 2002
- 99Review of Pain and its Ending: The Four Noble Truths in the Theravada Buddhist CanonL.S. Cousins — 2001
- 100Theravada Buddhism: Continuity, Diversity, and IdentityKate Crosby — John Wiley & Sons — 2013
- 101Indian Esoteric BuddhismRonald M. Davidson — Columbia University Press — 2003
- 102Religious Giving and the Invention of Karma in Theravada BuddhismJames Egge — Routledge — 2013
- 103Japanese BuddhismCharles Eliot — Routledge — 2014
- 104A Companion to Buddhist PhilosophySteven M. Emmanuel — John Wiley & Sons — 2015
- 105Dhamma-Vinaya, Essays in Honour of Venerable Professor DhammavihariToshiichi Endo — Sri Lanka Association for Buddhist Studies — 2005
- 106The Bodhisattva's Brain: Buddhism NaturalizedOwen Flanagan — MIT Press — 2011
- 107Science for Monks: Buddhism and Science: A BIT of The Really Hard ProblemOwen Flanagan — MIT Press — 2014
- 108Buddhism: Beliefs and PracticesMerv Fowler — Sussex Academic Press — 1999
- 109The Faces of Buddhism in AmericaGil Fronsdal — University of California Press — 1998
- 110The Issue at HandGil Fronsdal — self-published — 2001
- 111The Reincarnation SensationNorman Geisler et al. — Wipf and Stock Publishers — 2004
- 112Foundations of BuddhismRupert Gethin — Oxford University Press — 1998
- 113The Buddhist Path to AwakeningR.M. Gethin — OneWorld Publications — 2003
- 114Buddhism Transformed: Religious Change in Sri LankaRichard Gombrich et al. — Motilall Banarsidass — 1988
- 115How Buddhism Began: The Conditioned Genesis of the Early TeachingsRichard F. Gombrich — Routledge — 1997
- 116What the Buddha ThoughtRichard Gombrich — Equinox — 2009
- 117Philosophy of the Buddha: An IntroductionChristopher Gowans — Routledge — 2004
- 118Buddhist Moral Philosophy: An IntroductionChristopher W. Gowans — Routledge — 2014
- 119Theravada Buddhism and the British Encounter: Religious, Missionary and Colonial Experience in Nineteenth Century Sri LankaElizabeth Harris — Routledge — 2006
- 120Religions in Focus: New Approaches to Tradition and Contemporary PracticesGraham Harvey — Routledge — 2016
- 121An Introduction to BuddhismPeter Harvey — Cambridge University Press — 2013
- 122A Companion to Buddhist PhilosophyPeter Harvey — John Wiley & Sons — 2015
- 123American Buddhism: Methods and Findings in Recent ScholarshipRichard P. Hayes — Routledge — 2013
- 124Death and Eternal LifeJohn Hick — Westminster John Knox Press — 1994
- 125A History of Indian Buddhism. From Sakyamuni to Early MahayanaAkira Hirakawa — University of Hawai'i Press — 1990
- 126Facets of Buddhist Thought: Collected EssaysK.N. Jayatilleke — Buddhist Publication Society — 2009
- 127The Beginnings of BuddhismJ.W. de Jong — 1993
- 128A history of Buddhist philosophyDavid J. Kalupahana — Motilal Banarsidass Publishers Private Limited — 1992
- 129Modernisation of Buddhism: Contributions of Ambedkar and Dalai Lama XIVLella Karunyakara — Gyan Books — 2002
- 130Buddhism: A Very Short IntroductionDamien Keown — Oxford University Press — 2000
- 131BuddhismDamien Keown — Sterling Publishing — 2009
- 132Buddhism: A Very Short IntroductionDamien Keown — Oxford University Press — 2013
- 133Siddhartha's Brain: Unlocking the Ancient Science of EnlightenmentJames Kingsland — HarperCollins — 2016
- 134Buddhism and Transgression: The Appropriation of Buddhism in the Contemporary WestAdrian Konik — BRIIL — 2009
- 135BuddhismChristopher Lamb — Bloomsbury Publishing — 2001
- 136The Happiness ProjectRon Leifer — Snow Lion — 1997
- 137Buddhism in PracticeDonald S Lopez — Princeton University Press — 1995
- 138The Story of BuddhismDonald S. Lopez — HarperCollins — 2001
- 139Buddhism and Science: A Guide for the PerplexedDonald, jr. Lopez — University of Chicago Press — 2009
- 140The Scientific Buddha: His Short and Happy LifeDonald S. Lopez — Yale University Press — 2012
- 141Buddhahood Embodied: Sources of Controversy in India and TibetJohn J. Makransky — SUNY — 1997
- 142The Kathāvatthu Kamma DebatesJames Paul McDermott — 1975
- 143The Making of Buddhist ModernismDavid L. McMahan — Oxford University Press — 2008
- 144Dancing with Life: Buddhist Insights for Finding Meaning and Joy in the Face of SufferingPhilip Moffitt — Rodale — 2008
- 145A Sanskrit-English DictionaryMonier Monier-Williams — Oxford University Press — 1899
- 147K.R. Norman Collected Papers IIK.R. Norman — 2003
- 148Buddhist DictionaryNyanatiloka — Buddhist Publication Society — 1980
- 149JournalThe Dhamma wheel from Chainat, Thailand: an epigraphic excerpt from the Pali Dhammacakkappavattana, and related findsEng Jin Ooi et al. — 2026
- 150The Encyclopedia of Indian Philosophies, Vol. IX: Buddhist philosophy from 350 to 600 ADKarl Potter — 2004
- 151The White Buddhist: the Asian odyssey of Henry Steel OlcottStephen R. Prothero — Indiana University Press — 1996
- 152Structural Depths of Indian ThoughtP. T. Raju — State University of New York Press — 1985
- 153Curious Omissions in Pali Canonical TextsC. A. F. Rhys Davids — 1935
- 154The life of the Buddha and the early history of his order, derived from Tibetan works in the Bkah-Hgyur and Bstan-Hgyur, followed by notices on the early history of Tibet and KhotenWilliam Woodville Rockhill — Trübner — 1884
- 155The Origins of Yoga and Tantra: Indic Religions to the Thirteenth CenturyGeoffrey Samuel — Cambridge University Press — 2008
- 156Understanding BuddhismPerry Schmidt-Leukel — Dunedin Academic Press — 2006
- 157On some Aspects of Descriptions or Theories of 'Liberating Insight' and 'Enlightenment' in Early Buddhism". In: Studien zum Jainismus und Buddhismus (Gedenkschrift für Ludwig Alsdorf), hrsg. von Klaus Bruhn und Albrecht Wezler, WiesbadenLambert Schmithausen — 1981
- 158Karma and rebirth: Post-Classical DevelopmentsLambert Schmithausen — State University of New York — 1986
- 159Buddhist Modernism and the Rhetoric of Meditative ExperienceRobert H. Sharf — 1995
- 160The Rhetoric of Experience and the Study of ReligionRobert H. Sharf — 2000
- 161Buddhism: A Concise IntroductionHuston Smith et al. — HarperOne — 2009
- 162The Buddhist handbook. A Complete Guide to Buddhist Teaching and PracticeJohn Snelling — Century Paperbacks — 1987
- 163Buddhism and Society: A Great Tradition and Its Burmese VicissitudesMelford E. Spiro — University of California Press — 1982
- 164Modernity and Re-enchantment: Religion in Post-revolutionary VietnamPhilip Taylor — Institute of Southeast Asian Studies — 2007
- 165Buddhism: The Illustrated GuideKevin Trainor — Oxford University Press — 2004
- 166The Ideas and Meditative Practices of Early BuddhismTilmann Vetter — BRILL — 1988
- 167Westward Dharma: Buddhism Beyond AsiaB. Alan Wallace — University of California Press — 2002
- 168Indian BuddhismA.K. Warder — 1999
- 169Indian BuddhismA.K. Warder — Motilal Banarsidass Publ. — 2000
- 170The Lotus SutraBurton Watson — Columbia University Press — 1993
- 171Mahayana BuddhismPaul Williams — 1989
- 172Mahayana Buddhism: The Doctrinal FoundationsPaul Williams — Routledge — 2008
- 173Buddhist ThoughtPaul Williams et al. — Taylor & Francis — 2002
- 174Buddhist ThoughtPaul Williams et al. — Routledge — 2012
- 175BookThe Origin of Buddhist MeditationAlexander Wynne — Routledge — 16 April 2007