There is a silence of the tongue, a silence of the whole body, the silence of the soul, the silence of the mind, and the silence of the spirit. The silence of the tongue is merely when it is not incited to speech; the silence of the entire body is when its senses are unoccupied; the silence of the soul is when no ugly thoughts burst forth within it; the silence of the mind is when it is not reflecting on anything harmful; the silence of the spirit is when the mind ceases even from stirrings caused by created spiritual beings and all its movements are stirred solely by Being, at the wondrous awe of the silence which surrounds Being.
~ from "John the Solitary, on Prayer" trans. by Sebastian Brock