Samatha (Pāli) or śamatha[note 1] (Sanskrit: शमथ; Chinese: 止 zhǐ) is a Buddhist term that is often translated as the "tranquility of the mind", or "mind-calmness". The Pali Canon describes it as one of two qualities of mind which is developed (bhāvanā) in Buddhist meditation, the other being vipassana (insight). Samatha is said to be achieved by practicing single-pointed meditation. This includes a variety of mind-calming techniques. Samatha is common to many Buddhist traditions.
The semantic field of Tibetan shi and Sanskrit shama is "pacification", "the slowing or cooling down", "rest". The semantic field of Tibetan né is "to abide or remain" and this is cognate or equivalent with the final syllable of the Sanskrit, thā.
The Buddha is said to have identified two paramount mental qualities that arise from wholesome meditative practice:
The Buddha is said to have extolled serenity and insight as conduits for attaining the unconditioned state of nibbana (Pāli; Skt.: Nirvana). For example, in the Kimsuka Tree Sutta (SN 35.245), the Buddha provides an elaborate metaphor in which serenity and insight are "the swift pair of messengers" who deliver the message of nibbana via the noble eightfold path.
In the Pāli canon, the Buddha never mentions independent samatha and vipassana meditation practices; instead, samatha and vipassana are two "qualities of mind" to be developed through meditation. As Thanissaro Bhikkhu writes,
When [the Pāli suttas] depict the Buddha telling his disciples to go meditate, they never quote him as saying 'go do vipassana,' but always 'go do jhana.' And they never equate the word "vipassana" with any mindfulness techniques. In the few instances where they do mention vipassana, they almost always pair it with samatha — not as two alternative methods, but as two qualities of mind that a person may 'gain' or 'be endowed with,' and that should be developed together.
Some traditions speak of two types of meditation, insight meditation (vipassana) and calm meditation (samatha). In fact the two are indivisible facets of the same process. Calm is the peaceful happiness born of meditation; insight is the clear understanding born of the same meditation. Calm leads to insight and insight leads to calm."
Buddhist and Asian studies scholar Robert Buswell Jr. states that the most common meditation method described in the Pāli canon is one where samatha is first done to induce jhana and then jhana is used to go on to vipassana. Buddhist texts describe that all Buddhas and their chief disciples used this method. Texts also describe a method where vipassana is done alone, but this is less common.
In modern Theravada, liberation is thought to be attained by insight into the transitory nature of phenomena. This is accomplished by establishing sati (mindfulness) and samatha through the practice of anapanasati (mindfulness of breathing), using mindfulness for observing the impermanence in the bodily and mental changes, to gain insight (vipassanā (P: vipassanā; S: vipaśyana), sampajañña) c.q. wisdom (P: paññā, S: prajñā) into the true nature of phenomena. According to the Theravada tradition, samatha refers to techniques that assist in calming the mind. Samatha is thought to be developed by samadhi ("concentration"), which is thought to be the ability to rest the attention on a single object of perception. One of the principal techniques for this purpose is mindfulness of breathing (Pali: ānāpānasati). Samatha is commonly practiced as a prelude to and in conjunction with wisdom practices.
According to modern Theravada, mindfulness of breathing leads the practitioner into concentration (Dhyāna), the domain of experience wherein the senses are subdued and the mind abides in uninterrupted concentration upon the object (i.e., the breath), if not in meditative absorption (samādhi). According to modern Theravada, it is the condition for insight (vipassanā) and subsequently the development of liberating wisdom (paññā). In Theravada-Buddhism morality (śīla) is understood to be a stable foundation upon which to attain samatha. According to the Theravada tradition, samatha and vipassanā form an integral part of the Noble Eightfold Path as described by the Buddha in his core teaching, the Four Noble Truths.
Samatha meditation and jhana (dhyana) are often considered synonymous by modern Theravada, but the four jhanas involve a heightened awareness, instead of a narrowing of the mind. Vetter notes that samadhi may refer to the four stages of dhyana meditation, but that only the first stage refers to strong concentration, from which arise the other stages, which include mindfulness.[note 3] According to Richard Gombrich, the sequence of the four rupa-jhanas describes two different cognitive states.[note 4][note 5] Gombrich and Wynne note that, while the second jhana denotes a state of absorption, in the third and fourth jhana one comes out of this absorption, being mindfully aware of objects while being indifferent to it. According to Gombrich, "the later tradition has falsified the jhana by classifying them as the quintessence of the concentrated, calming kind of meditation, ignoring the other – and indeed higher – element. Alexander Wynne further explains that the dhyana-scheme is poorly understood. According to Wynne, words expressing the inculcation of awareness, such as sati, sampajāno, and upekkhā, are mistranslated or understood as particular factors of meditative states, whereas they refer to a particular way of perceiving the sense objects.[note 6]
Through the meditative development of calm abiding, one is able to suppress the obscuring five hindrances: sensual desire, ill-will, tiredness and sleepiness, excitement and depression, and doubt. With the suppression of these hindrances, the meditative development of insight yields liberating wisdom.
Some meditation practices such as contemplation of a kasina object favor the development of samatha, others such as contemplation of the aggregates are conducive to the development of vipassana, while others such as mindfulness of breathing are classically used for developing both mental qualities.
The Visuddhimagga (5th century CE) mentions forty objects of meditation. Mindfulness (sati) of breathing (ānāpāna: ānāpānasati; S. ānāpānasmṛti) is the most common samatha practice. Samatha can include other samādhi practices as well.
Theravada Buddhism describes the development of Samatha in terms of three successive mental images or 'signs' (nimitta) and five stages of joy (Pīti). Pīti is a feeling of joy, gladness or rapture arising from the abandonment of the five hindrances in favor of concentration on a single object. These stages are outlined by the Theravada exegete Buddhaghosa in his Visuddhimagga (also in Atthasālinī) and the earlier Upatissa (author of the Vimuttimagga).
The three nimittas are the preparatory sign, the acquired sign and the counterpart sign. These are certain mental images, perceptions or sensations which indicate a further refinement of the state of meditative awareness.
In the Theravada-tradition various understandings of samatha exist.[note 7]
In Sri Lanka samatha includes all the meditations directed at static objects.
In Burma, samatha comprises all concentration practices, aimed at calming the mind.
Tibetan writers usually define samatha practice as when one's mind remains fixed on a single object without moving. Dakpo Tashi Namgyal for example, defines samatha as:
by fixing the mind upon any object so as to maintain it without distraction . . . by focusing the mind on an object and maintaining it in that state until finally it is channeled into one stream of attention and evenness.
just a one-pointedness of mind (cittaikagrata) on a meditative object (alambana). Whatever the object may be . . . if the mind can remain upon its object one-pointedly, spontaneously and without effort (nabhisamskara), and for as long a period of time as the meditator likes, it is approaching the attainment of meditative stabilization (samatha).
A number of Mahāyāna sūtras address śamatha, usually in conjunction with vipaśyanā.
One of the most prominent, the Cloud of Jewels Sutra (Ārya Ratnamegha Sutra, Tib. 'phags-pa dkon-mchog sprin-gyi mdo, Chinese 寶雲經 T658, 大乘寶雲經 T659) divides all forms of meditation into either śamatha or vipaśyanā, defining śamatha as "single-pointed consciousness" and vipaśyanā as "seeing into the nature of things."
The Sūtra Unlocking the Mysteries (Samdhinirmocana Sūtra), a yogācāra sūtra, is also often used as a source for teachings on śamatha. The Samādhirāja Sūtra is often cited as an important source for śamatha instructions by the Kagyu tradition, particularly via commentary by Gampopa, although scholar Andrew Skilton, who has studied the Samādhirāja Sūtra extensively, reports that the sūtra itself "contains no significant exposition of either meditational practices or states of mind."
Śamatha furthers the right concentration aspect of the noble eightfold path. The successful result of śamatha is also sometimes characterized as meditative absorption (samādhi, ting nge ’dzin) and meditative equipoise (samāhita, mnyam-bzhag), and freedom from the five obstructions (āvaraṇa, sgrib-pa). It may also result in the siddhis of clairvoyance (abhijñā, mgon shes) and magical emanation (nirmāna, sprul pa).
According to Culadasa (2015), "Samatha has five characteristics: effortlessly stable attention (samādhi), powerful mindfulness (sati), joy (pīti), tranquility (passaddhi), and equanimity (upekkhā). The complete state of samatha results from working with stable attention (samādhi) and mindfulness (sati) until joy emerges. Joy then gradually matures into tranquility, and equanimity arises out of that tranquility. A mind in samatha is the ideal instrument for achieving Insight and Awakening" 
In a formulation originating in the Śrāvakabhūmi section of the Yogācārabhūmi-śāstra[note 8] śamatha practice is said to progress through nine "mental abidings" or Nine stages of training the mind (S. navākārā cittasthiti, Tib. sems gnas dgu), leading to śamatha proper (the equivalent of "access concentration" in the Theravāda system), and from there to a state of meditative concentration called the first dhyāna (Pāli: jhāna; Tib. bsam gtan) which is often said to be a state of tranquillity or bliss. An equivalent succession of stages is described in the Ten oxherding pictures of Zen. The Nine Mental Abidings as described by Kamalaśīla are:
The textual tradition of Tibetan Buddhism identifies five faults and eight antidotes within the practice of śamatha meditation. The five faults identify obstacles to meditation practice, and the eight antidotes are applied to overcome the five faults. This formulation originates with Maitreyanātha's Madhyānta-vibhāga and is elaborated upon in further texts, such as the Stages of Meditation (Bhāvanākrama) by Kamalaśīla.
The following eight antidodes (pratipakṣa, gnyen-po) or applications (abhisamskāra, ’du-byed pa) can be applied to overcome the five faults:
Four modes of mental engagement (manaskāra, yid-la byed-pa) are said to be possible:
In the practice of Mahamudra tranquility meditation ... we treat all thoughts as the same in order to gain sufficient distance and detachment from our current mental state, which will allow us to ease naturally into a state of tranquility without effort or contrivance [...] In order for the mind to settle, we need to suspend the value judgments that we impose on our mental activities [...] it is essential that we not try to create a state of tranquility but allow the mind to enter into tranquility naturally. This is an important notion in the Mahamudra tradition, that of nondoing. We do not do tranquility meditation, we allow tranquility to arise of its own accord, and it will do so only if we stop thinking of the meditative state as a thing that we need to do actively [...] In a manner of speaking, catching yourself in the act of distraction is the true test of tranquility meditation, for what counts is not the ability to prevent thoughts or emotions from arising but the ability to catch ourselves in a particular mental or emotional state. This is the very essence of tranquility meditation [in the context of Mahāmudrā] [...] The Mahamudra style of meditation does not encourage us toward the different levels of meditative concentration traditionally described in the exoteric meditation manuals [...] From the Mahamudra point of view, we should not desire meditative equipoise nor have an aversion to discursive thoughts and conflicting emotions but view both of these states with equanimity. Again, the significant point is not whether meditative equipoise is present but whether we are able to maintain awareness of our mental states. If disturbing thoughts do arise, as they certainly will, we should simply recognize these thoughts and emotions as transient phenomena.
For the Kagyupa, in the context of mahāmudrā, śamatha by means of mindfulness of breathing is thought to be the ideal way for the meditator to transition into taking the mind itself as the object of meditation and generating vipaśyanā on that basis.
Quite similar is the approach to śamatha found in dzogchen semde (Sanskrit: mahāsandhi cittavarga). In the semde system, śamatha is the first of the four yogas (Tib. naljor, Wylie: rnal-’byor), the others being vipaśyanā (Wylie: lhag-mthong), nonduality (advaya, Tib. nyime,Wylie: gnyis-med), and spontaneous presence (anābogha or nirābogha, Tib. lhundrub, Wylie: lhun-grub). These parallel the four yogas of mahāmudrā.
Ajahn Amaro, a longtime student in the Thai Forest Theravādin tradition of Ajahn Chah, has also trained in the dzogchen semde śamatha approach under Tsoknyi Rinpoche. He found similarities in the approaches of the two traditions to śamatha.
Dzogchen Pönlop Rinpoche clearly charts the developmental relationship of the practices of śamatha and vipaśyanā:
The ways these two aspects of meditation are practised is that one begins with the practice of shamatha; on the basis of that, it becomes possible to practice vipashyana or lhagthong. Through one's practice of vipashyana being based on and carried on in the midst of shamatha, one eventually ends up practicing a unification [yuganaddha] of shamatha and vipashyana. The unification leads to a very clear and direct experience of the nature of all things. This brings one very close to what is called the absolute truth.
Meditations from other religious traditions may also be recognized as samatha meditation, that differ in the focus of concentration. In this sense, samatha is not a strictly Buddhist meditation. Samatha in its single-pointed focus and concentration of mind is cognate with the sixth "limb" of aṣṭanga yoga', rāja yoga which is concentration (dhāraṇā). For further discussion, see the Yoga Sūtras of Patañjali.