Stillness is an undisturbed state of the intellect
Notes from Wikiquote
the tranquil unwavering stability of the heart in God | the contemplation of light | the knowledge of the mysteries of God | consciousness of wisdom by virtue of a pure mind | the abyss of divine intellections | the rapture of the intellect | intercourse with God | an unsleeping watchfulness | spiritual prayer | untroubled repose in the midst of great hardship and | finally, solidarity and union with God. | "On the Inner Nature of Things", #64, p.125