“Things Invisible to Mortal Sight”: Light, Vision, and the Unity of Book 3 of Paradise Lost

Milton tightly structures book 3 of Paradise Lost around analogies and distinctions between divine and solar light, the invisible heaven beheld by the poet's blind faith in the book's first half and the visible universe and sun visited by Satan in its second, vision down and up the ladder of Creation. The vision of “things invisible to mortal sight” that the poet asks for in the opening invocation is analogized, in the divine council that the book goes on to depict, to the Son's faith in his triumph over death. False analogy leads the fools of the Limbo of Vanity to understand God in terms of his and their own works; equally vain philosophers falsely separate the sun from God as an independent power source. Milton criticizes both the Neoplatonic solar mysticism and the godless materialism that could be associated with the new heliocentric model of the cosmos. He stakes out a middle ground for poetry to occupy vis-à-vis the New Science, a poetry skeptical of its own inherited fictions based on the old cosmology, a poetry whose own formal patterns and unity intimate order against a more sweeping empirical doubt.