The mental world in which the imagination lives is the world to which Blake invites us. In one of his first illuminated works, There is no Natural Religion, he teaches that the sense organs do not provide the totality of perception. The mind processes the input which the senses receive. Art and science which depend on presenting descriptions of the material world as perceived by the senses, without seeking the element of the Eternal which is revealed through Imagination, is to Blake bad art and science. The exterior world receives its meaning from the mind that perceives it - not the reverse. Thought for Blake is ever active: engaging in intellectual conflict which creates 'Mental forms" which build the 'Universe stupendous.'
There is No Natural Religion , Series b, Plate 2, (E 2)
"I . Mans perceptions are not bounded by organs of perception. he
percieves more than sense (tho' ever so acute) can discover."
A Vision of the Last Judgment , (E 565)
"The Last Judgment is an Overwhelming of Bad Art & Science.
Mental Things are alone Real what is Calld Corporeal Nobody Knows
of its Dwelling Place
Imposture Where is the Existence Out of Mind or Thought Where is
it but in the Mind of a Fool. Some People flatter themselves
that there will be No Last Judgment & that Bad Art will be
adopted & mixed with Good Art That Error or Experiment will make
a Part of Truth & they Boast that it is its Foundation these
People flatter themselves I will not Flatter them 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. What it
will be Questiond When the Sun rises do you not see a round
Disk of fire somewhat like a Guinea O no no I see an Innumerable
company of the Heavenly host crying Holy Holy Holy is the Lord
God Almighty I question not my Corporeal or Vegetative Eye any
more than I would Question a Window concerning a Sight I look
thro it & not with it.
Milton , Plate 1, (E 95)
"Rouze up O Young Men of the New Age! set your foreheads
against the ignorant Hirelings! For we have Hirelings in the
Camp, the Court, & the University: who would if they could, for
ever depress Mental & prolong Corporeal War. Painters! on you I
call! Sculptors! Architects! Suffer not the fash[i]onable Fools
to depress your powers by the prices they pretend to give for
contemptible works or the expensive advertizing boasts that they
make of such works; believe Christ & his Apostles that there is a
Class of Men whose whole delight is in Destroying. We do not
want either Greek or Roman Models if we are but just & true to
our own Imaginations, those Worlds of Eternity in which we shall
live for ever; in Jesus our Lord."
Milton , PLATE 30 , (E 129)
"Lo the Eternal Great Humanity
To whom be Glory & Dominion Evermore Amen
Walks among all his awful Family seen in every face
As the breath of the Almighty. such are the words of man to man
In the great Wars of Eternity, in fury of Poetic Inspiration,
To build the Universe stupendous: Mental forms Creating"