These two different four-fold divisions indicate two different ways that Blake divides the Human faculties. The division into Zoas dominates Blake's psychological analysis in his earlier prophecies and The Four Zoas . The division into Humanity, Spectre, Emanation, and Shadow is given more prominence in Milton and Jerusalem . Los is the Eternal Prophet. His office is to preserve the vision of Eternity in the fallen world, to arrest the fall, and ultimately to awaken Albion .
Eternity is reality.
It is inhabited by the Eternals who build the worlds that they live and meet in. It is also the community of the Eternals. Its chief quality is its malleability to the creativity of the Eternals. Thus in Eternity incommensurable and conflicting universes may be created by different Eternals. At the same time, Eternity preserves all forms.