DEATH & LIFE

Northrup Frye, writing in Fearful Symmetry, clarifies our understanding of the development of the prophet through man's enhancing his ability to perceive. Frye finds that for Blake imagination, perception, art and prophecy are interrelated in the fully developed, visionary man:

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Illustrations to the poems of Thomas Gray

"Man has within himself the principle of life and the principle of death; one is the imagination, the other the natural man. In the natural world the natural principle will win out eventually and the man will die. As an individual ego reflecting on his sensations of an outer space-world while existing in time, the natural man is a dying man; and like most chronic invalids the ego is fretful, irascible, cruel, bothered by trifles, jealous and inordinately vain. Its only freedom is in domineering over or hindering others; its only happiness is in solitary possession; and in everything it seeks, like Cleopatra, for a painless from of suicide.
The only cure for the original sin of this Selfhood of the natural man is vision, the revelation that this world is fallen therefore not ultimate. 
...
The destruction of the appearance of this world must precede the vision of the same world purified, and, subject and object being inseparable, the Selfhood must be annihilated before the true self can appear.
Now all the kindly and honest people who act as though  they believed evil to be neither necessary or desirable are on the right side. But an honest man is not quite the  noblest work of God until the faith by which the just live develops in to full imaginative vision. The fully imaginative man is therefore a visionary whose imaginative activity is prophecy and whose perception produces art. These two are the same thing, perception being an act.
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The 'seer' has insight, not second sight: he is not a charlatan but the contrary of one, an honest man with a sharper perception and a clearer perspective than other honest men possess. The imagination in seeing a bird sees through it an 'immense world of delight';  the imagination in looking at society not only sees its hypocrisies but sees through them, and sees an infinitely better world. The prophet can see an infinite and eternal reality, but nobody sees an indefinite future, except conditionally:

 'Prophets in the modern sense of the word have never existed
Jonah was no prophet in the modern sense for his prophecy of
Nineveh failed   Every honest man is a Prophet he utters his
opinion both of private & public matters/Thus/If you go on So/the
result is So/He never says such a thing shall happen let you do
what you will. a Prophet is a Seer not an Arbitrary Dictator.' 
[Annotations to Watson, (E 617)]

It is the superior clarity and accuracy of the prophet's vision that makes him an artist, and that makes the great artist prophetic." (Page 58-59) 

Milton, Plate 24 [26], (E 121) 
"Los is by mortals nam'd Time Enitharmon is nam'd Space
But they depict him bald & aged who is in eternal youth
All powerful and his locks flourish like the brows of morning    
He is the Spirit of Prophecy the ever apparent Elias
Time is the mercy of Eternity; without Times swiftness
Which is the swiftest of all things: all were eternal torment:
All the Gods of the Kingdoms of Earth labour in Los's Halls.
Every one is a fallen Son of the Spirit of Prophecy             
He is the Fourth Zoa, that stood arou[n]d the Throne Divine."

Jerusalem, Plate 39 [44], (E 186)
"they with one accord delegated Los
Conjuring him by the Highest that he should Watch over them
Till Jesus shall appear: & they gave their power to Los       
Naming him the Spirit of Prophecy, calling him Elijah"