I came across the following from Thomas Merton. I’ve never read a better description.

Contemplation is the highest expression of man’s intellectual and spiritual life. Is that life itself, fully awake, fully active, fully aware that it is alive. It is a spiritual wonder. It is spontaneous awe at the sacredness of life, of being. It is gratitude for life, for awareness and for being. It is a vivid realization of the fact that life and being in us proceeds from an invisible, transcendent and infinitely abundant Source.

Contemplation is, above all, awareness of the reality of that Source. It knows the Source, obscurely, inexplicably, but with a certitude that goes both beyond reason and beyond simple faith. For contemplation is a kind of spiritual vision to which both reason and faith aspire, by their very nature, because without it they must always remain incomplete. Yet contemplation is not vision because it “sees without seeing” and knows “without knowing.”

It is a more profound depth of face, a knowledge too deep to be grasped in images, in the words or even in clear concepts. It can be suggested by words, by symbols, but in the very moment of trying to indicate what is knows the contemplative mind takes back what it has said, and denies what it has affirmed. For in contemplation we know by ‘unknowing.’ Or, better, we know beyond all knowing or “unknowing.

Thomas Merton, Trappist monk, theologian, mystic

Author, New Seeds of Contemplation