The pursuit of the contemplative life is something for which a great and sustained effort on the part of the powers of the soul is required, an effort to rise from earthly to heavenly things, an effort to keep one’s attention fixed on spiritual things, an effort to pass beyond and above the sphere of things visible to the eyes of flesh, an effort finally to hem oneself in, so to speak, in order to gain access to spaces that are broad and open. There are times indeed when one succeeds, overcoming the opposing obscurity of one’s blindness and catching at least a glimpse, be it ever so fleeting and superficial, of boundless light.
–Saint Gregory the Great (c. 540-604)