"Paradise Lost is a text which contains cosmic themes, and the historical evolution of the understanding of space as "a distance between two separate points" to space as "the firmament beyond the Earth's atmosphere"..... Milton is eager to define knowledge and the limits placed on the acquisition of knowledge in order to provide his reader with a means of understanding reality." from 'Mythic Qualities of Space and Time in John Milton's Paradise Lost' - https://macsphere.mcmaster.ca/bitstream/11375/12303/1/fulltext.pdf