Meditation usually refers to a state of extreme relaxation and concentration, in which the body is generally at rest and the mind quieted of surface thoughts. Several major religions include ritual meditation; however, meditation itself need not be a religious or spiritual activity. It is widely thought to be of Indian origin. The earliest mention of meditation comes from the Vedas, and Yoga, with the Sanskrit term 'Dhayana'.
Another form of meditation is more closely akin to prayer and worship, wherein the practitioner turns spiritual thoughts over in the mind and engages the brain in higher thinking processes. The goal in this case is the receipt of spiritual insights and understanding. From the point of view of psychology, meditation can induce, or is itself, an altered state of consciousness.
Strategies common to many forms
Meditation generally involves avoiding wandering thoughts and fantasies, and calming and focusing the mind. Meditation does not necessarily require effort and can be experienced as "just happening". Physical postures include sitting cross-legged, standing, lying down, and walking (sometimes along designated floor patterns). Quiet is often desirable, and some people use repetitive activities such as deep breathing, humming or chanting to help induce a meditative state.
Meditation can be done with the eyes closed (as long as one does not fall asleep), or with the eyes open: focusing the eyes on a certain point of an object or image, and keeping the eyes constantly looking at that point.
Purposes of meditation
The purposes for which people meditate vary almost as widely as practices. It may serve simply as a means of relaxation from a busy daily routine, or even as a means of gaining insight into the nature of reality or of communing with one's God. Many have found improved concentration, awareness, self-discipline and equanimity through meditation. The self-disciplining aspect of meditation plays a central role in Hinduism and Zen Buddhism.
In the Samadhi or Shamatha, or concentrative, techniques of meditation, the mind is kept closely focused on a particular word, image, sound, person, or idea. This form of meditation is often found in Hindu Yoga and Buddhist traditions, as well as in Medieval Christianity, Jewish Kabbalah, and in some modern metaphysical schools. Eknath Easwaran developed another, related, method. He called it "passage meditation" -- silent repetition in the mind of memorized inspirational passages from the world's great religions. Easwaran believe that, "The slow, sustained concentration on these passages drives them deep into our minds; and whatever we drive deep into consciousness, that we become." It should be noted that this concept of Japa Mantra, or repetitive mantra, was not initially conceived of by Easwaran and is a long-standing tradition of Hinduism dating back to Vedic times.
Mindful awareness traditions
Vipassana and anapanasati are parts of broader notion of mindful awareness, which is part of the Noble Eightfold Path, the ultimate goal in Buddhism that leads to Enlightenment, and expounded upon the in the Satipatthana sutta. While in anapanasati meditation the attention is focused on the breath, in vipassana the mind is instead trained to be acutely aware of not only breathing, but all things that one comes to experience.
The concept of vipassana works in believing that the meditator's mind will eventually take note of every physical and mental experience "real-time" or as it happens, the goal being that it will gradually reveal to the practitioner how one's mind unknowingly attaches itself to things that are impermanent in nature. Thus, when such things cease to exist, one experiences the suffering from its loss. This very wisdom, achievable solely through vipassana meditation, in turn gradually frees one's mind from the attachment that is the root of suffering. For one practicing this form of meditation, it is also very important to note that the wisdom presents itself into the mind of the meditator only when he or she is NOT thinking but yet possessing an acute awareness of what goes on in his or her mind, body and surroundings. The nature of vipassana is sophisticated; one may desire a veteran instructor to provide initial guidance.
In other words, in Vipassana (insight, or seeing things as they are) meditation, the mind is trained to notice each perception or thought that passes without "stopping" on any one. This is a characteristic form of meditation in Buddhism, especially in some Theravada traditions, and is also a component of Zazen, the term for meditation practice in Zen. However, in at least some forms of vipassana, one does not attend to whatever perceptions arise, but purposely moves one's attention over their body part by part, checking for perceptions, being aware and equanimous with them, and moving on. This form of meditation has some resemblance with 'choiceless awareness', the kind of meditation that J. Krishnamurti addressed.
Jesus, according to the New Age writing The Urantia Book, often left his apostles and the crowds to distance himself in the wilderness areas of Palestine to engage in long periods of dynamic-mind, spiritual meditation wherein he communicated with God. The 40 days following his baptism were spent in such a manner.
The Urantia Book describes it this way: "On every mountaintop of intellectual thought are to be found relaxation for the mind, strength for the soul, and communion for the spirit. From such vantage points of high living, man is able to transcend the material irritations of the lower levels of thinking -- worry, revenge, and the pride of immature personality. These high-climbing souls deliver themselves from a multitude of the crosscurrent conflicts of the trifles of living, thus becoming free to attain consciousness of the higher currents of spirit concept and celestial communication. But the life purpose must be jealously guarded from the temptation to seek for easy and transient attainment; likewise must it be so fostered as to become immune to the disastrous threats of fanaticism."
Health applications of meditation
Meditation has entered the mainstream of health care as a method of stress and pain reduction. For example, in an early study in 1972, transcendental meditation was shown to effect the human metabolism by lowering the biochemical byproducts of stress, such as lactate (lactic acid), and by decreasing heart rate and blood pressure and inducing favorable brain waves.
As a method of stress reduction, meditation is often used in hospitals in cases of chronic or terminal illness to reduce complications associated with increased stress including a depressed immune system. There is a growing consensus in the medical community that mental factors such as stress significantly contribute to a lack of physical health, and there is a growing movement in mainstream science to fund and do research in this area (e.g. the establishment by the NIH in the U.S. of 5 research centers to research the mind-body aspects of disease.)
Dr. James Austin, a neurophysiologist at the University of Colorado, reported that Zazen or Zen meditation rewires the circuitry of the brain in his landmark book Zen and the Brain. This has been confirmed using sophisticated imaging techniques which examine the electrical activity of the brain.
Dr. Herbert Benson of the Mind-Body Medical Institute, which is affiliated with Harvard and several Boston hospitals, reports that meditation induces a host of biochemical and physical changes in the body collectively referred to as the "relaxation response." The relaxation response includes changes in metabolism, heart rate, respiration, blood pressure, and brain chemistry.
The Urantia Book indicates that relaxation is similarly a result of dynamic-mind meditation, thus its health benefits should be the same. However this has not been confirmed by scientific investigations.
Specific traditions - specific classifications include:
Observation (e.g., exploring the mind and all its thoughts)
Focus (e.g., exploring one thought to the exclusion of all else)
Trance (experiencing emptiness)
Theravada Buddhist practice involves both Samadhi and Vipassana, as well as the developing of "loving kindness" (Metta).
Zen Buddhism practices Zazen, similar to Vipassana.
Most Abrahamic traditions practice forms of meditation that use their God, Saints and/or Prophets as concentration focus
Some people, including the controversial Guru Rajneesh (also known as "Osho"), taught forms of "Dynamic Meditation" that involve violent exercise and hyperventilation, akin to aerobic exercise or those like the Sufi whirling.
Meditation based on questioning "Who am I" draws from various traditions, especially Vipassana, Insight Meditation, Zazen, and with the express purpose of getting to know one's true nature, and/or experiencing Kensho, Satori, Enlightenment. This method teaches to be wary of trance-like states of relaxation, and advocates intense inquiry into the nature of thought, mind, ego, self, and desire.
Jesus-style, dynamic-mind, meditation engages the creative consciousness and full awareness. The mind and thinking processes are expanded rather than shut down or dulled. The only requirements are sincerity, persistence, and God-consciousness. The Urantia Book cautions against the use of "physical fatigue, fasting, psychic dissociation, profound aesthetic experiences, vivid sex impulses, anxiety, rage, and wild dancing" to initiate "mystic communion". It states that "the trancelike state of visionary consciousness should not be cultivated as a religious experience."