Zen Meditation (Zazen)

Chan in medieval China

The Stanford Encyclopedia of Philosophy entry on Chan describes the Chan School as an indigenous form of Chinese Buddhism that developed from the sixth century CE and later spread to Japan (Zen), Korea (Sŏn) and Vietnam (Thiền). The Chinese word chan transliterates the Sanskrit dhyāna, meaning meditation, but the entry notes that Chan was not distinctive within Chinese Buddhism for its use of meditative techniques. It was set apart, in that account, by its use of language, its narrative forms and its stress on direct, embodied realisation of awakening.

In the traditional account an Indian monk, Bodhidharma, is the first Chinese ancestor of the lineage. The entry places the 'five houses', including Linji and Caodong, after the Huichang-era suppression of Buddhism (841 to 846), and says that by the twelfth century most public monasteries supported by the Song court (960 to 1279) were devoted to Chan. Foulk adds that Rinzai and Sōtō are the Japanese pronunciations of Linji and Caodong.

Transmission to Japan

T. Griffith Foulk, a historian of Chan and Zen, writes that the Chan lineage's texts and rituals reached Japan in the Kamakura period (1185 to 1333), together with Song-dynasty monastery organisation and elite literary culture, and that this became the Japanese Zen School. Both the Sōtō and Rinzai denominations trace their heritage to Song China. The Stanford Encyclopedia entry on Japanese Zen names Dōgen (1200 to 1254) as founder of the Sōtō school and Hakuin (1685 to 1768) as the figure who systematised kōan practice in the modern Rinzai tradition.

Foulk also reports that during the first century of the Edo period (1600 to 1868) Chinese Chan masters were invited to Japan and established the Ōbaku school, which he says has about 450 temples. He notes that the Korean Chogye order draws on the Chan of the Song and Yuan dynasties as interpreted by Chinul (1158 to 1210), and that the Korean term Sŏn should not be treated as a perfect synonym of Chan.

A contested lineage history

Both general sources caution that the traditional story is not simple biography. Hershock writes that contemporary scholars regard much of what Chan came to hold as its own history, including the account of Bodhidharma, as an invention of tradition. Foulk describes the lineage as a spiritual genealogy through which the 'mind' of Śākyamuni Buddha was said to pass through twenty-eight Indian and then Chinese ancestors, and says that modern historians recognise the mythological character of much of that account. These descriptions record how the tradition understands itself, and they should not be read as dated events.

Chan, Zen and zazen

Foulk explains that the Japanese word zen began as a borrowing of the Chinese chan, with a great deal of overlap in meaning, but that not everything called Zen in Japan was necessarily Chan in China. Ink painting, calligraphy and landscape gardening cultivated by Song literati later became known in Japan as Zen arts. He traces the Chinese word through several meanings: meditation, then a synonym of wisdom, then a name for lineages claiming Bodhidharma as founder, and finally the name of a school with a large family tree of ancestors. 'Zen' can therefore refer to a meditation practice, a school or a cultural style.

The Stanford Encyclopedia entry on Japanese Zen glosses za-zen as sitting meditation and calls it a foundational method across the schools of Zen. This page uses zazen for the seated practice and Zen meditation for the wider set of methods that Zen traditions use, including kōan work.

Shikantaza, kōan and related terms

The Japanese Zen entry defines shikantaza as 'just sitting', a method associated with the Sōtō school, in which 'just' means meditating without ego-directed interest, concern or desire. It says the Sōtō approach is for this reason called the school of 'silent illumination'. A kōan is described there as a formulation like a riddle that reasoning alone cannot solve, and the kōan method is mainly associated with the Rinzai school.

Makyō is a Zen term for largely perceptual side-effects that arise during practice and are sometimes read as signs of progress, according to a study of meditation-related challenges. The same study notes that Zen traditions have long acknowledged a prolonged illness-like condition called 'Zen sickness'. These are terms from within the tradition and are not diagnoses.

Posture, breath and attention

Nagatomo's entry describes a three-step procedure, following Dōgen, of adjusting the body, the breathing and the mind, with the order reversed at the end of a sitting so that the person returns to everyday activity. The postures recognised are the lotus and half-lotus, and sitting on a chair with a straight spine is given as an initial substitute for a lay practitioner who cannot assume them. The breathing exercise counts incoming and outgoing breaths using abdominal breathing, and 'wandering thoughts' is the term for mental objects that interrupt concentration.

The same entry attributes physiological effects to this breathing, including regulation of autonomic functions and the expelling of 'negative toxic energy'. These are statements in a philosophical reference work, and none of the research sources reviewed here tested them.

Shikantaza and kōan practice

In shikantaza, as the Stanford entry presents it, a person sits without aiming at a goal, on the premise that practice already takes place within original enlightenment. Dōgen's hyphenated term 'practice-realisation' expresses the view that meditation is not a means to an end. In the Rinzai school a student works on a kōan and must pass it in a private consultation with a teacher who verifies the student's state of mind. Hakuin is reported to have counted about 1,700 formal cases, roughly 3,000 with sub-questions, grouped in five categories.

The entry holds that both schools emphasise the same sitting practice and that differences in how people describe their experience arise from personality, intellect and linguistic ability. That is the author's interpretation within the tradition, and no source reviewed here compared the two methods in a completed trial.

Monastic, retreat and lay settings

Foulk reports that Sōtō and Rinzai in Japan together comprise about 20,000 temples, 22,000 ordained clergy and 3,000,000 lay followers, citing a Japanese religious yearbook; he gives no breakdown of how many people sit regularly. Research has also taken place in monasteries, including an EEG study in two Vietnamese Zen monasteries that recorded monks during morning and evening sessions, one of which lasted about 1.5 hours.

Intensive retreats also feature in research. One study scanned 19 meditators and 14 non-meditators before and after a seven-day Zen retreat, and a study of 60 Western Buddhist practitioners found that 43 of them (72%) reported that meditation-related challenges began during or just after a retreat. Retreat length and daily hours vary by centre, and the sources reviewed here do not describe a standard schedule.

Aims within the tradition

In Nagatomo's presentation, zazen is a foundational practice aimed at realising nondiscriminatory wisdom together with compassion. The Rinzai approach stresses moments of breakthrough or insight (kenshō), typically prompted by kōan practice, while the Sōtō approach treats sitting as an expression of realisation already present. Hershock similarly describes Chan's defining concerns as experiential and centred on the direct realisation of awakening. These are religious aims and not health claims.

Uses proposed in health contexts

Marchand's overview for clinicians presents Zen meditation beside mindfulness-based stress reduction (MBSR) and mindfulness-based cognitive therapy (MBCT) as approaches that originated in Buddhist practice, and notes that only Zen is an actual Buddhist tradition, while MBSR and MBCT are secular, manualised methods. The abstract attributes a role in pain management to MBSR and Zen meditation.

Chiesa's review lists stress, blood pressure, cognitive decline with age and antioxidant activity among areas in which Zen meditation had been studied, and mentions positive findings in therapists and musicians. It concluded that the evidence was scarce. Such uses are described here as topics of study and not as established benefits.

Reviews

Chiesa's 2009 review searched MEDLINE, the ISI Web of Knowledge and the Cochrane database for randomised controlled and controlled cross-sectional studies in English published before May 2008. It reported increased alpha and theta EEG activity in Zen meditators, with theta greater in more experienced practitioners, and possible links with less age-related cognitive decline, antioxidant activity, stress and blood pressure. The author concluded that evidence about Zen meditation was scarce.

Marchand's 2012 overview attributes broad antidepressant and antianxiety effects to MBSR and MBCT, and a role in pain management to MBSR and Zen meditation. A PubMed search of title and abstract terms for Zen meditation or zazen (76 records) found no systematic review or meta-analysis specific to Zen meditation after 2009, although other databases were not searched.

Controlled studies and a kōan protocol

A randomised trial in 59 adults aged 60 or over with raised blood pressure compared Zen meditation, 20 minutes twice a day for three months, with a waiting list; medication was kept stable. Systolic pressure fell in the meditation group relative to controls at the second monthly measurement, but later values were similar to those of controls, and psychological quality-of-life scores improved.

A 2007 randomised double-blind study assigned 18 psychotherapists in training to practise Zen meditation or not and compared 124 inpatients they treated over nine weeks. Patients of the meditating therapists gave higher session ratings and showed greater symptom reduction on several scales. The intervention was delivered to therapists, not patients, and the number of therapists was small.

For kōan practice, a published protocol describes a planned randomised trial of about 240 participants in four groups, including the kōan Mu and mindful breathing, with outcomes on non-dual experience and wellbeing. The protocol reports no results, and no completed trial of kōan practice appeared in the PubMed searches run for this draft.

Studies of experienced practitioners

Most Zen-specific research compares experienced meditators with non-meditators at one time point. In a functional MRI study, Zen practitioners had lower pain sensitivity than controls and different patterns of brain activity during heat pain, with greater experience linked to larger reductions in some regions; this design cannot show that meditation caused the differences. A high-density EEG study of 31 people, 17 of them Sōtō Zen meditators, expected a rise in beta power and found none, and reported correlations between weekly practice frequency and theta measures.

In the monastery EEG study, monks showed higher alpha and theta power than non-practising controls during meditation and no change in beta power. In the seven-day retreat study, task performance was similar in meditators and non-meditators, while brain activation changed in different directions in the two groups; the authors suggest that differences in expertise may explain this.

Design limits of the research

The studies summarised above are mostly small, and many compare self-selected experienced meditators with controls, so differences may reflect who chooses to practise as well as the practice. The one controlled trial of Zen meditation for blood pressure used a waiting list, and its early difference was not maintained. Chiesa's review likewise called for comparisons with active treatments and for work on mechanisms.

EEG findings are not uniform across the sources. Chiesa reports increased alpha and theta activity, the monastery study reports higher alpha and theta without a change in beta, and the Sōtō study found correlations with practice frequency rather than a group difference in beta. Different tasks, recording methods and participant groups limit comparison.

Zen meditation and mindfulness programmes

Marchand distinguishes Zen, an actual Buddhist tradition, from MBSR and MBCT, which are secular and manualised, and most of the clinical trial evidence he describes concerns the secular programmes. The monastery EEG authors state that the pattern they found differs from patterns often reported for other mindfulness practices. Findings for one approach should not be transferred automatically to the other, and neither should results for shikantaza be assumed to apply to kōan work.

Lindahl and colleagues note that Buddhist-derived meditation is now widely used for health promotion, while Buddhist textual sources acknowledge a wider range of effects than health outcomes. Research that isolates a technique from its religious setting therefore examines only part of how the practice is understood within the tradition.

Difficult experiences reported by practitioners

A mixed-methods study interviewed 60 Western Buddhist practitioners, 20 each from Theravāda, Zen and Tibetan traditions, and 32 teachers and clinicians. It catalogued 59 meditation-related experiences across seven domains, with a valence ranging from very positive to very negative and levels of distress and impairment from minimal and transient to severe and enduring. Fear, anxiety, panic or paranoia was reported by 82% of the practitioners, and 72% said their challenges arose during or just after a retreat.

The study documents experiences that people described as challenging, so its percentages do not give a rate among all practitioners, and the results are not specific to Zen. The authors identified 26 influencing factors in four domains, including practice-level factors, and noted that 75% of participants were working with a teacher when challenges arose. No source reviewed here reports adverse events in the Zen trials it describes, which does not show that none occurred.

Suitability and care boundaries

No source reviewed for this draft lists formal contraindications for zazen or for extended sitting. Nagatomo's entry offers chair sitting as an initial substitute for lay practitioners who cannot take the traditional postures. A person who experiences distress, new or worsening mental health symptoms or thoughts of self-harm during or after practice can seek assessment from a qualified health professional, and meditation is not a substitute for necessary medical or mental health care.

Training and teaching authority

The sources describe teaching authority mainly through lineage. Rinzai kōan work involves private consultation with a teacher who verifies the student's state of mind, and Foulk reports about 22,000 ordained clergy in the Japanese Sōtō and Rinzai denominations. No source reviewed describes statutory regulation or a common training standard for people who teach zazen to the public, and professional registers or codes of ethics were not searched. Requirements for teaching differ by lineage and by centre.