Meditation has nothing to do with contemplation of eternal questions, or of one's own folly, or even of one's navel, although a clearer view on all of these enigmas may result. It has nothing to do with thought of any kind — with anything at all, in fact, but intuiting the true nature of existence, which is why it has appeared, in one form or another, in almost every culture known to man.
The entranced Bushman staring into fire, the Eskimo using a sharp rock to draw an ever-deepening circle into the flat surface of a stone achieves the same obliteration of the ego (and the same power) as the dervish or the Pueblo sacred dancer.
Among Hindus and Buddhists, realization is attained through inner stillness, usually achieved through the samadhi state of sitting yoga.
In Tantric practice, the student may displace the ego by filling his whole being with the real or imagined object of his concentration; in Zen, one seeks to empty out the mind, to return it to the clear, pure stillness of a seashell or flower petal.
When body and mind are one, then the whole thing, scoured clean of intellect, emotions, and the senses, may be laid open to the experience that individual existence, ego, the "reality" of matter and phenomena are no more than fleeting and illusory arrangements of molecules.
The weary self of masks and screens, defenses, preconceptions, and opinions that are propped up by ideas and words, imagines itself to be some sort of an entity (in a society of like entities) may suddenly fall away, dissolve into formless faux where concepts such as "death" and "life", "time" and "space", "past" and "future" have no meaning.
There is only a pearly radiance of Emptiness, the Uncreated, without beginning, therefore without end. Like the round bottomed Bodhidharma doll, returning to its center, meditation represents the foundation of the universe to which all returns, as in the stillness of the dead of night, the stillness between tides and winds, the stillness of the instant before Creation.
In this "void", this dynamic state of rest, without impediments, lies ultimate reality, and here one's own true nature is reborn, in a return from what Buddhists speak of as "great death".
[Thanks, Whiskey River!]