The essential nature of the mind is like space. There is no such thing as a mind that truly exists or a mind that is inherently established even though we might find reasonings, scriptures, or experience to the contrary. Mind is empty. Our ordinary mind, however, becomes confused in thinking that things really exist. The nature of our mind is emptiness, but not a blankness, not the result of mere negation: emptiness is also radiant clarity, the basis for the appearances of both samsara and nirvana. The mind is like space and it also has a clear and knowing aspect, which allows us to say, “This is space.” Resting in mind’s empty, clear nature, we will be at ease as we move along the path of practice.
from the book “Music In The Sky: The Life, Art, And Teachings Of The 17Th Karmapa Ogyen Trinley Dorje”