Cut off, and, for the book of knowledge fair,
Presented with a universal blank
Of Nature's works, to me expunged and rased,
And wisdom at one entrance quite shut out. 50
So much the rather thou, Celestial Light,
Shine inward and the mind through all her powers
Irradiate; there plant eyes; all mist from thence
Purge and disperse, that I may see and tell
Of things invisible to mortal sight.' 55
—Paradise Lost, Book iii. 1-55.