Three marks of existence
In Buddhism, the three marks of existence are three characteristics (Pali: tilakkhaṇa; Sanskrit: trilakṣaṇa) of all existence and beings, namely impermanence (anicca), unsatisfactoriness or suffering (dukkha), and non-self (anattā). These three characteristics are mentioned in verses 277, 278 and 279 of the Dhammapada. That humans are subject to delusion about the three marks, that this delusion results in suffering, and that removal of that delusion results in the end of suffering, is a central theme in the Buddhist Four Noble Truths and Noble Eightfold Path.
According to Thich Nhat Hanh, the the 3 sels are impermanence, non-self and nirvana. He says in "The heart of the Buddha's Teaching" that "In several sutras the Buddha taught that nirvana, the joy of completely extinguishing our ideas and concepts, rather than suffering, is one of the Three Dharma Seals."
sabbe dhammā anattā — "all dharmas (conditioned or unconditioned things) are not self"
sabbe saṅkhārā dukkhā — "all saṅkhāras are unsatisfactory"
 But according to Thic Nhat Hanh, this is a mistake. The third is
- nirvana - "the joy of completely extinguishing our ideas and concepts, rather than suffering, is one of the Three Dharma Seals."
Impermanence (Pali anicca, Sanskrit anitya) means that all conditioned things (saṅkhāra) are in a constant state of flux. Buddhism states that all physical and mental events come into being and dissolve. Human life embodies this flux in the aging process, the cycle of repeated birth and death (Samsara), nothing lasts, and everything decays. This is applicable to all beings and their environs, including beings who are reborn in deva (god) and naraka (hell) realms. This is in contrast to nirvana, the reality that is nicca, or knows no change, decay or death.
Dukkha (Sanskrit duhkha) means "unsatisfactoriness, suffering, pain". The dukkha includes the physical and mental sufferings that follows each rebirth, aging, illness, dying; dissatisfaction from getting what a being wishes to avoid or not getting the desired, and no satisfaction from Sankhara dukkha, in which everything is conditioned and conditioning, or because all things are not experienced as impermanent and without any essence.
While anicca and dukkha apply to "all conditioned phenomena" (saṅkhārā), anattā has a wider scope because it applies to all dhammā without "conditioned, unconditioned" qualification. Thus, nirvana too is a state of "without Self" or anatta. The phrase "sabbe dhamma anatta" includes within its scope each skandha (aggregate, heap) that compose any being, and the belief "I am" is a mark of conceit which must be destroyed to end all Dukkha. The Anattā doctrine of Buddhism denies that there is anything called a 'Self' in any person or anything else, and that a belief in 'Self' is a source of Dukkha. Some Buddhist traditions and scholars, however, interpret the anatta doctrine to be strictly in regard to the five aggregates rather than a universal truth. Religious studies scholar Alexander Wynne calls anattā a "not-self" teaching rather than a "no-self" teaching.
In Buddhism, ignorance of (avidyā, or moha; i.e. a failure to grasp directly) the three marks of existence is regarded as the first link in the overall process of saṃsāra whereby a being is subject to repeated existences in an endless cycle of suffering. As a consequence, dissolving that ignorance through direct insight into the three marks is said to bring an end to saṃsāra and, as a result, to that suffering (dukkha nirodha or nirodha sacca, as described in the third of the Four Noble Truths).
Gautama Buddha taught that all beings conditioned by causes (saṅkhāra) are impermanent (anicca) and suffering (dukkha), and that not-self (anattā) characterises all dhammas, meaning there is no "I", "me", or "mine" in either the conditioned or the unconditioned (i.e. nibbāna). The teaching of three marks of existence in the Pali Canon is credited to the Buddha.
- Steven Collins (1998). Nirvana and Other Buddhist Felicities. Cambridge University Press. p. 140. ISBN 978-0-521-57054-1.
- Richard Gombrich (2006). Theravada Buddhism. Routledge. p. 47. ISBN 978-1-134-90352-8., Quote: "All phenomenal existence [in Buddhism] is said to have three interlocking characteristics: impermanence, suffering and lack of soul or essence."
- Robert E. Buswell Jr.; Donald S. Lopez Jr. (2013). The Princeton Dictionary of Buddhism. Princeton University Press. pp. 42–43, 47, 581. ISBN 978-1-4008-4805-8.
- Carl Olson (2005). The Different Paths of Buddhism: A Narrative-Historical Introduction. Rutgers University Press. pp. 63–64. ISBN 978-0-8135-3778-8.
- Maggavagga: The Path Dhammapada Chapter XX, Translated by Acharya Buddharakkhita (1996)
- HAHN, Thic Nhat. The Heart of the Buddha's Teaching. New York: Broadway books. 1999, p. 22.
- Walsh 1995, p. 30.
- Anicca Buddhism, Encyclopædia Britannica (2013)
- Damien Keown (2013). Buddhism: A Very Short Introduction. Oxford University Press. pp. 32–38. ISBN 978-0-19-966383-5.
- Peter Harvey (2012). An Introduction to Buddhism: Teachings, History and Practices. Cambridge University Press. pp. 32–33, 38–39, 46–49. ISBN 978-0-521-85942-4.
- Thomas William Rhys Davids; William Stede (1921). Pali-English Dictionary. Motilal Banarsidass. pp. 355, Article on Nicca. ISBN 978-81-208-1144-7.
- Peter Harvey (2015). Steven M. Emmanuel, ed. A Companion to Buddhist Philosophy. John Wiley & Sons. pp. 26–31. ISBN 978-1-119-14466-3.
- Carol Anderson (2013). Pain and Its Ending: The Four Noble Truths in the Theravada Buddhist Canon. Routledge. pp. 1, 22 with note 4. ISBN 978-1-136-81332-0., Quote: "(...) the three characteristics of samsara/sankhara (the realm of rebirth): anicca (impermance), dukkha (pain) and anatta (no-self)."
- Malcolm Huxter (2016). Healing the Heart and Mind with Mindfulness: Ancient Path, Present Moment. Routledge. p. 10. ISBN 978-1-317-50540-2., Quote: " dukkha (unsatisfactoriness or suffering) (....) In the Introduction I wrote that dukkha is probably best understood as unsatisfactoriness."
- Malcolm Huxter (2016). Healing the Heart and Mind with Mindfulness: Ancient Path, Present Moment. Routledge. pp. 1–10, Introduction. ISBN 978-1-317-50540-2.
- Bhikkhu Bodhi (2005). In the Buddha's Words: An Anthology of Discourses from the Pali Canon. Simon and Schuster. pp. 67–68. ISBN 978-0-86171-491-9.
- Anatta Buddhism, Encyclopædia Britannica (2013)
- [a] Christmas Humphreys (2012). Exploring Buddhism. Routledge. pp. 42–43. ISBN 978-1-136-22877-3.
[b] Brian Morris (2006). Religion and Anthropology: A Critical Introduction. Cambridge University Press. p. 51. ISBN 978-0-521-85241-8., Quote: "(...) anatta is the doctrine of non-self, and is an extreme empiricist doctrine that holds that the notion of an unchanging permanent self is a fiction and has no reality. According to Buddhist doctrine, the individual person consists of five skandhas or heaps - the body, feelings, perceptions, impulses and consciousness. The belief in a self or soul, over these five skandhas, is illusory and the cause of suffering."
[c] Richard Gombrich (2006). Theravada Buddhism. Routledge. p. 47. ISBN 978-1-134-90352-8., Quote: "(...) Buddha's teaching that beings have no soul, no abiding essence. This 'no-soul doctrine' (anatta-vada) he expounded in his second sermon."
- Richard Francis Gombrich; Cristina Anna Scherrer-Schaub (2008). Buddhist Studies. Motilal Banarsidass. pp. 209, for context see pp. 195–223. ISBN 978-81-208-3248-0.
- Joaquín Pérez Remón (1980). Self and Non-self in Early Buddhism. Walter de Gruyter. pp. 218–222, 234. ISBN 978-90-279-7987-2.
- Peter Harvey (2012). An Introduction to Buddhism: Teachings, History and Practices. Cambridge University Press. pp. 57–62. ISBN 978-0-521-85942-4.
- Peter Harvey (2015). Steven M. Emmanuel, ed. A Companion to Buddhist Philosophy. John Wiley & Sons. pp. 34–37. ISBN 978-1-119-14466-3.
- "Selves & Not-self: The Buddhist Teaching on Anatta", by Thanissaro Bhikkhu. Access to Insight (Legacy Edition), 30 November 2013, http://www.accesstoinsight.org/lib/authors/thanissaro/selvesnotself.html Archived 2013-02-04 at the Wayback Machine.
- Bhikkhu, Thanissaro. ""There is no self."". Tricycle: The Buddhist Review. Archived from the original on 2018-08-19. Retrieved 2018-08-19.
- Thepyanmongkol, Phra (2009). The Heart of Dhammakaya Meditation. Wat Luang Phor Sodh. p. 12. ISBN 9789748097534.
- Wynne, Alexander (2009). "Early Evidence for the 'no self' doctrine?" (PDF). Oxford Centre for Buddhist Studies: 63–64. Archived (PDF) from the original on 2017-06-02. Retrieved 2017-04-22.
- Nārada, The Dhammapada (1978), pp. 224.
- Bodhi, Bhikkhu (2003). The Connected Discourses of the Buddha: A Translation of the Samyutta Nikaya. Somerville, MA: Wisdom Publications. p. 1457. ISBN 978-0-86171-331-8.
- Dhammapada Verses 277, 278 and 279
- Joaquín Pérez Remón (1980). Self and Non-self in Early Buddhism. Walter de Gruyter. pp. 210–225. ISBN 978-90-279-7987-2.
- Walsh, Maurice (1995), The Long Discourses of the Buddha. A Translation of the Dīgha Nikāya, Wisdom Publications