If I were required to give a "quick and dirty" definition of meditation, it would be that meditation is the practice of escaping into life. It's escape in the sense that one does not feel limited by the mind/body process or the surrounding situation. But, the direction of escape is not from what's happening, but rather into it.
This is very challenging. It's challenging to understand, and it's challenging to do. The experience of escaping into something is totally different from merely being passionately involved in it. When we ingenuously try to describe this experience, it comes out sounding like we are playing with words, fabricating paradoxes to shock or impress people. Escaping into something simply means having a radically complete experience of it. A radically complete experience is rich and fulfilling, but it is also empty and transparent. I sometimes say that we Buddhists are our own worst public relations representatives because our vocabulary seems designed to turn people off. You know, we are always talking about emptiness, no self, void.
...But the nothingness of the mystic is a very special kind of nothingness. The nihil of Meister Eckhart is not the nihil of nihilism. The nada of St. John of the Cross is not "nada." Nothingness is a terminus technicus, a well-defined technical term in the vocabulary of world mysticism.
Hinduism, Buddhism, Judaism, Christianity, Islam, and Taoism differ radically in their beliefs and customs. Yet, the mystics who represent the core of these traditions often speak of the Spiritual Source as a special kind of nothing. Historically, this can only partially be explained as the result of mutual influences. Despite what some New Age books would have you believe, these formulations arose independently in India, China, and the West before there was significant contact. So, we are faced with some fascinating questions. Why should they agree on such a counter-intuitive (if not downright offensive) description of God when they disagree in so many other areas? And furthermore, why does the mystic's description of the awesome creative power of nothingness sound so similar to contemporary theories of cosmology and quantum physics? Is it coincidence or convergence?
As a person of Jewish ancestry, I find it deeply satisfying that the description of God's creative activity as it appears in the Kabbalah is remarkably parallel to that of my present teacher Joshu Sasaki Roshi, contemporary Japanese Zen Master. The goal of Jewish meditation is to experience Briah yesh me ayn. In Hebrew: Briah (the creation) yesh (of things) me (from) ayn (nothing). Ayn is synonymous with Ha Makom, the Source, i.e., God. Moreover, in Kabbalah, creation is conceived as happening continuously. God literally loves us into existence each moment through the oscillating interplay of hesed (expansion) and gevurah (contraction).
Physicists speak of the creative power of quantum fluctuations of the void. This seems remarkably similar to the descriptions of mystics, especially Buddhist mystics. At the very least, it provides us with some wonderful metaphors. The enlightened people of the world can now stand up and say, "I know that what I'm trying to describe to you sounds weird and paradoxical, but it's not any weirder than these widely accepted theories of science, and as a matter of fact, it's rather similar to them."
...the concept of wave-particle complementarity is extremely useful in explaining certain aspects of meditative experience. The basic idea behind complementarity is that objects can be looked upon either as waves or particles. "Particle" does not necessarily imply "small." Any chunk of matter is a particle-a bowling ball, or the earth itself. Associated with every particle is its wave function.
When you think about it, it's absolutely astonishing, because particles and waves seem to be so fundamentally different. Particles are rigid and separate-two billiard balls recoil if they collide. Waves are bending and interactive-two water waves immediately merge upon contact. Particles have established boundaries and fixed centers. Waves expand and contract. A particle retains scratches and is vulnerable to shattering force. If you attempt to scratch or shatter a wave, it simply digests the energy of the attack into itself.
The practical implication of complementarity lies in the fact that some applications work better from the wave perspective, while other applications work better from the particle perspective. The issue boils down to knowing which perspective is appropriate, and the fact that the engineer always has the freedom to choose either one.
Spiritual freedom is very much like this. For some life applications, we must congeal the mind and body into a separate particular person-for example, when you need to figure stuff out or negotiate a contract. The problem is that most people are limited to the particulate perspective only. They are unable to immediately switch to the undulatory paradigm when they encounter situations that work better with the wave self. What situations are those? Well, let me give you just a few representative examples: enjoying a morsel of food, experiencing bereavement, making love, being embarrassed in public, and praying.
Once again, the issue here is freedom - freedom to adopt the most appropriate perspective. If you cannot dissolve into a wave, you are missing out on a lot of life. Naturally, death is frightening. Indeed, there are human experiences for which the wave self is not only appropriate, but absolutely essential. To attempt to pass through these experiences while maintaining a separate particulate self causes unspeakable suffering. Acute physical or emotional pain, chronic pain, and, of course, death itself, are in this category.