From Symbol and Image in William Blake by, George W. Digby (Page 10-11):
"Now Blake in his Prophetic Books used two ideas, or images, for measuring man's growth, his limitation to or freedom from the confined and crawling state typified by the caterpillar or worm. Both ideas are expressed in terms of a scale of degrees between two opposite states, or qualities. The first is a scale of Contraction-Expansion; the second is the scale of Opaqueness-Lucidity. In The Four Zoas, Milton, and Jerusalem Blake often uses and refers to these very significant ideas. In the scale of Contraction-Expansion, contraction is the lower limit of the scale; this is a physical, animal-like state which is regulated absolutely by the five senses. This he called the state of Adam. Adam is man, or human nature dominated exclusively by physical urges or impulses.
In the scale of Opaqueness-Lucidity, opaqueness stands at the lower limit. This a state in which all imagination and sensibility, all those promptings of the heart, all understanding which springs from human feeling and sympathy are absent. In this state man is utterly opaque and dark; he is bereft of every glimmer of intuitive insight. This state Blake called Satan.
The idea of Expansion is not so much the full development of man's nature, his facilities and talents, as it is the awareness that he is a part of a greater whole; that although he constitutes an individual center with marvelous capacities, man is not the lord of the earth, nor anything in himself alone.
For Lucidity refers to man's inner nature, his psychological state, his intuitive awareness of himself his motives and values. Just as expansion is not primarily concerned with the development of faculties and talents, but the relation with the whole, so lucidity is less concerned with a particular understanding or realization than with awareness of man's total psychosomatic being, with all its contradictions and conflicts."
Jerusalem, Plate 42 (Lines 25-40) Text Los speaking to Albion.
"Thou wast the Image of God surrounded by the Four Zoa's
Three thou hast slain! I am the Fourth: thou canst not destroy
Thou art in Error; trouble me not with thy righteousness.
I have innocence to defend and ignorance to instruct:
I have no time for seeming; and little arts of compliment,
In morality and virtue: in self-glorying and pride.
There is a limit of Opakeness, and a limit of Contraction;
In every Individual Man, and the limit of Opakeness,
Is named Satan: and the limit of Contraction is named Adam.
But when Man sleeps in Beulah, the Saviour in mercy takes
Contractions Limit, and of the Limit he forms Woman: That
Himself may in process of time be born Man to redeem
But there is no Limit of Expansion! there is no Limit of
In the bosom of Man for ever from eternity to eternity.
Therefore I break thy bonds of righteousness; I crush thy
That they may not crush me and mine: do thou be righteous,
And I will return it; otherwise I defy thy worst revenge:"