Originally Posted by http://science.jrank.org/pages/7857/Meditation-Eastern.html

Buddhist traditions analyze the results of meditation into eight stages of increasingly subtle states of consciousness called the "absorptions" or "trance" states of higher consciousness (in Pali, jhana; in Sanskrit, dhyana). These are, it is said, the states of mind the Buddha passed through in deep meditation on his way to enlightenment. The first is described as a mental state of detachment from sensual pleasures and craving, in which, however, the discursive intellect is still active. In the second state, the mind grows more still, concentration increases, discursive thought ends, and great joy and peace arise. The third stage is characterized by the transcendence of sensual joy itself and the attainment of equanimity, which brings about a higher form of bliss, and by the diminishing of the sense of self as the subject of this experience. The fourth trance state is where consciousness of all duality abates and one achieves the "utter purity of mindfulness," which lies beyond all words.

The second set of four even subtler states of mind are called the "formless" jhanas because they are based on contemplation of formless subjects: the infinity of space, the infinity of consciousness, nothingness, and "neither perception nor nonperception." The last of these is where subject and object are nearly indistinguishable and all pairs of opposites are totally transcended.