Turiya

literally, the "fourth," being the fourth state of consciousness, beyond waking, dreaming, and deep sleep. This state is so far removed from all normal states of consciousness, that it is utterly beyond words to describe it. Therefore, the writer of Mandukya Upanishad chose this simple numerical designation to avoid any misleading attempt at a descriptive name for the state, which would serve only to confuse the student. It is said of this fourth state that, "Those who know, do not say [cannot say]; and those who say, do not know [because if they did know, they could not express it in words]."