BLAKE'S FURNACES II

New York Public Library
 Milton 
bottom of Plate 16

 The work of the furnaces is internal work: the work of altering the patterns of thought that allow the mind to accept the errors upon which systems of oppression are built. Do we manifest errors which deserve extreme measures to correct? We are willing to train our young people in acts of violence so that we can send them off to war in order to commit and witness murder against other human beings. We tolerate forcing the underprivileged to work for a pittance so that the privileged can enjoy the luxuries of material affluence. We over-exploit the resources of the planet risking the consequences of disastrous collapse of the environmental systems. The symptoms appear in the outer world but the mental errors which support them exist internally. Outer abuses disappear when the mind is cleared of error; this internal work is represented by Blake as the work of the furnaces.
 
Vision of Last Judgment, (E 565)

"Error is Created 
Truth is Eternal Error or Creation will be Burned Up &
then & not till then Truth or Eternity will appear It is Burnt up
the Moment Men cease to behold it I assert for My self that I do
not behold the Outward Creation & that to me it is hindrance &
not Action it is as the Dirt upon my feet No part of Me."

Milton voluntarily descended from Eternity for the sake of correcting his errors. Realizing that Satan was his own selfhood he undertook the journey within to explore the furnace of his self-made hell.

Milton, Plate 14 [15], (E 108)

[spoken by Milton]
"What do I here before the Judgment? without my Emanation?
With the daughters of memory, & not with the daughters of inspiration[?]
I in my Selfhood am that Satan: I am that Evil One!              
He is my Spectre! in my obedience to loose him from my Hells
To claim the Hells, my Furnaces, I go to Eternal Death.

And Milton said. I go to Eternal Death! Eternity shudder'd
For he took the outside course, among the graves of the dead
A mournful shade. Eternity shudderd at the image of eternal death

Then on the verge of Beulah he beheld his own Shadow;
A mournful form double; hermaphroditic: male & female
In one wonderful body. and he enterd into it
In direful pain for the dread shadow, twenty-seven-fold

Reachd to the depths of direst Hell, & thence to Albions land:  
Which is this earth of vegetation on which now I write,"

The mental struggle occupies Albion as the furnaces of Los are prepared for his battle.

Jerusalem, Plate 41 [46], (E 188)

[spoken by the merciful Son of Heaven]
"Thou art in Error Albion, the Land of Ulro:               
One Error not remov'd, will destroy a human Sould for his battle
Repose in Beulahs night, till the Error is remov'd
Reason not on both sides. Repose upon our bosoms
Till the Plow of Jehovah, and the Harrow of Shaddai
Have passed over the Dead, to awake the Dead to Judgment.     
But Albion turn'd away refusing comfort.

Oxford trembled while he spoke, then fainted in the arms
Of Norwich, Peterboro, Rochester, Chester awful, Worcester,
Litchfield, Saint Davids, Landaff, Asaph, Bangor, Sodor,
Bowing their heads devoted: and the Furnaces of Los         
Began to rage, thundering loud the storms began to roar
Upon the Furnaces, and loud the Furnaces rebellow beneath"