Satan, in Milton's Paradise Lost, declares that the mind "can make a heaven of hell, a hell of heaven." Meditation confronts the hell of worry, anxiety, anger, boredom, jealousy, depression and the general unsettledness that is such a large part of being human. Tortured by our own minds like no other animal, we dedicate a lot of mental energy to reliving past anguish and anticipating future distress. The promise of meditation is to free us from being hostage to this self-inflicted misery. Does it work?
The first challenge in answering this question is clarifying what we mean by "meditation"?
Multiple forms
There are so many forms of meditation that researchers at the University of Alberta concluded that "it is impossible to select components that might be considered universal." (They concede that the use of breathing and attention control is common, but there is no commonality among the techniques employed for either). According to the researchers, the wide spectrum of practices makes evaluating meditation very difficult from a scientific perspective.
While there is no standard definition of meditation, here is one that satisfies the main criterion of most forms of it: attention to immediate experience.
The catch is that there are many things happening in the present moment that one can attend to, and various ways of attending to them (hence the lack of a unified description). But meditative practices can be divided into four broad categories differentiated by their focus of attention (with the original Pali terms in parentheses):
Meditative Practice - Focus
Concentration (samatha) - Body (typically the breath)
Insight (vipassana) - Mind (thoughts and feelings)
Delight (piti) - World (sights, sounds, smells, textures, tastes)
Loving-kindness (metta) - Others (deserving of compassion)
Here is a brief description of each category:
1.Concentration (samatha): While the focus is usually the breath, attention can also be extended to sensations throughout the entire body (as in a "body scan," which takes a mental inventory of sensations from feet to head). Some techniques focus on a word or phrase (mantra). Concentrative meditation attempts to keep all extraneous activity out of its scope of attention, particularly mental and emotional churning. The intended result is a calm centeredness. (The ancient yogic tradition of breath/body focus was intended to unify the individual self with the cosmic Self that pervades the universe.)
2.Insight (vipassana): Here the focus is mental: attention is geared towards thoughts and feelings. The meditator investigates the constant flux of her arising and disappearing thoughts/feelings. She observes in a detached but curious way, without getting hooked by the content of the thoughts/feelings. The intended result is insight - a deeper understanding of what affects us and an awareness of how obsessive and pointless much of our rumination is. A form of this meditation morphed into what is now commonly known in the West as "mindfulness" - a translation of the Pali word sati by the scholar T.W. Rhys Davids. (The original Buddhist intent was to reveal the profound insight of the Four Noble Truths, which expose our suffering as self-induced and avoidable once we accept that our desires can never be satisfied by the impermanent flux of reality.)
3.Delight (piti): Attention is directed to the external world. The goal is neither to calm the mind (although that is a side benefit), nor to "catch and detach" by observing our spinning thoughts. The goal here is to immerse oneself in the present moment by focusing on the brilliant colours and intricate textures of what our eyes take in, or the fascinating and constantly changing cacophony that resonates within our ears, or the myriad tastes as we eat, or sensations as we walk. This meditation is a powerful way to imbue any situation at any time with meaning. (The Pali word piti has a range of meanings that all relate to joyful engagement; the simplest form of piti describes the delight of being engaged with a particular object. However, the Buddhist tradition would not use piti in the sense of engaging with the world for sheer pleasure because this activity is anathema to the Buddhist philosophy of detachment. Savouring the present moment for pure enjoyment arose from the combination of Western mindfulness and positive psychology movements.)
4.Loving-kindness (metta): Starting with loving thoughts about oneself, the meditator then extends these warm feelings to close relations, then other acquaintances, then enemies, and finally to all beings. The intent is to generate a serene feeling of connectedness to humankind and all living things. The expression "loving-kindness" was appropriated from Christianity, where it originated in a 16th century translation of the bible. Most Pali scholars argue that metta is more accurately translated as friendliness or goodwill. (While the Buddha advocated for a friendly disposition towards all creatures, many academics argue that some of the metta-focused sermons attributed to him were likely embellished after his death.)
So do any of these forms of meditation achieve their putative benefits? There are two ways to answer this question. The first is to examine the scientific evidence and the second is to consider subjective accounts from the many practitioners. Each perspective points in a slightly different direction; they are both explored in Part II: The Evidence.