CONCAVE EARTH

Because man is created in the Image of God, his role is central.  Blake sees God as the 'intellectual fountain of Humanity.' The individual human lives within his own mind in spite of appearances to the contrary.  Around this Image of God in each individual, man creates his own reality.

In Milton: A Poem by William Blake by Kay Parkhurst Easson and Roger R. Easson we receive an explanation of the concave earth which results from the centrality of man.

Page 141
"Blake describes the earth as concave, as cavern of 'labyrinthine intricacy'; this earth is the human skull or body which, if observed from without, is convex but, if observed from within, is concave. Similarly Blake describes the sky as an 'immortal Tent' ; man 'standing on his own roof, or in his garden'  sees such concave space as his universe; he sees it from within to without. Because this is true, Blake insists that the astronomer's model of  the earth as 'a Globe rolling through Voidness' is a delusion, for such would be the model of an earth separated from its perceiver. In a concave model, however, all the earth, the sky, the universe are within man's immediate perception.

This view of the physical world attests that Blake has returned the physical body of the individual, and the soul within it, to the center of his cosmos as the medieval world view had done before him.  This is the Vitruvian man, the man in the center of a circle proscribed by the extensions of his limbs. Here, however, Blake's universe is proscribed not by a conceptual framework of geography and terrain, but only by the limits of and individual's perception... What Blake asserts, then, is that it is our interaction with perceived objects which is the essential element of reality. 

Just as the Vitruvian man stands in the center of his circle, we stand in a perceptual concavity which is much like a great sensory balloon. Blake calls this concavity the Mundane Egg."

Jerusalem, Plate 71, (E 225)
"What is Above is Within, for every-thing in Eternity is translucent:
The Circumference is Within: Without, is formed the Selfish Center
And the Circumference still expands going forward to Eternity.
And the Center has Eternal States! these States we now explore."

Jerusalem, Plate 71, (E 225)
"All were his Friends & their Sons & Daughters intermarry in Beulah
For all are Men in Eternity. Rivers Mountains Cities Villages,
All are Human & when you enter into their Bosoms you walk
In Heavens & Earths; as in your own Bosom you bear your Heaven
And Earth, & all you behold, tho it appears Without it is Within
In your Imagination of which this World of Mortality is but a Shadow."    

Jerusalem, Plate 72, (E 227)
"All the Nations Peoples & Tongues throughout all the Earth

And the Four Gates of Los surround the Universe Within and       
Without; & whatever is visible in the Vegetable Earth, the same
Is visible in the Mundane Shell; reversd in mountain & vale
And a Son of Eden was set over each Daughter of Beulah to guard
In Albions Tomb the wondrous Creation: & the Four-fold Gate
Towards Beulah is to the South[.] Fenelon, Guion, Teresa,    
Whitefield & Hervey, guard that Gate; with all the gentle Souls
Who guide the great Wine-press of Love; Four precious stones that Gate:"