For what is Mysticism? It is not the attempt to draw near to God, not by rites or ceremonies, but by inward disposition? Is it not merely a hard word for 'The Kingdom of Heaven is within'? Heaven is neither a place nor a time.
Florence Nightingale, Michael D. Calabria, Janet A. Macrae (1994). “Suggestions for Thought by Florence Nightingale: Selections and Commentaries”, p.13, University of Pennsylvania Press
