GREATEST HITS 5

INTRODUCTION 

Marriage of Heaven & Hell, Plate 7, (E 35)
 "How do you know but ev'ry Bird that cuts the airy way,
   Is an immense world of delight, clos'd by your senses five?"

Wikimedia Commons 
Illustration to Poems of Thomas Gray
Ode to Spring

The phrase in context:
Marriage of Heaven & Hell, Plate 6 & 7, (E 35)
 "A Memorable Fancy.                        

   As I was walking among the fires of hell, delighted with the 
enjoyments of Genius; which to Angels look like torment and
insanity. I collected some of their Proverbs: thinking that as
the sayings used in a nation, mark its character, so the Proverbs
of Hell, shew the nature of Infernal wisdom better than any
description of buildings or garments.
   When I came home; on the abyss of the five senses, where a
flat  sided steep frowns over the present world. I saw a mighty
Devil folded in black clouds, hovering on the sides of the rock,
with corroding fires he wrote the following sentence now
percieved by the minds of men, & read by them on earth.   

   How do you know but ev'ry Bird that cuts the airy way,
   Is an immense world of delight, clos'd by your senses five?"

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