The Witness is that which is capable of observing the flow of what is—without interfering with it, commenting on it, or in any way manipulating it. The Witness simply observes the stream of events both inside and outside the mind-body in a creatively detached fashion, since, in fact, the Witness is not exclusively identified with either. In other words, when you realize that your mind and your body can be perceived objectively, you spontaneously realize that they cannot constitute a real subjective self. As Huang Po put it, "Let me remind you, the perceived cannot perceive."
We are part of the tremendous through
Forever surging in transcendent flight,
Perilous though the journey be long.
And all, it is ordained, will earn the right
To add our separate voices to the song
Rising triumphant from the chorus of the light.