Chaucer wrote no poetical work having a cosmographical background as
completely set forth as is that in Dante's _Divine Comedy_ or that in
Milton's _Paradise Lost_. Although his cosmological references are often
incidental they are not introduced in a pedantic manner. Whenever they are
not parts of interpolations from other writers his use of them is due to
their intimate relation to the life his poetry portrays or to his
appreciation of their poetic value. When Chaucer says, for example, that
the sun has grown old and shines in Capricorn with a paler light than is
his wont, he is not using a merely conventional device for showing that
winter has come, but is expressing this fact in truly poetic manner and in
words quite comprehensible to the men of his day, who were accustomed to
think of time relations in terms of heavenly phenomena.
Popular and scientific views of the universe in Chaucer's century were by
no means the same. The untaught man doubtless still thought of the earth
as being flat, as it appears to be, as bounded by the waters of the ocean,
and as covered by a dome-like material firmament through which the waters
above sometimes came as rain; while, as we have seen, by the fourteenth
century among scholars the geocentric system of astronomy was firmly
established and the spheres and epicycles of Ptolemy were becoming more
widely known. It is the view held by the educated men of his century that
Chaucer's poetry chiefly reflects.