The scene of the poem is the spiritual world, of which we are
members even while still denizens mu the world of time. In the
spiritual world the results of sin or perverted love, and of
virtue or right love, in this life of probation, are manifest.
The life to come is but the fulfilment of the life that now is.
This is the truth that Dante sought to enforce. The allegory in
which he cloaked it is of a character that separates the Divine
Comedy from all other works of similar intent, In The Pilgrim's
Progress, for example, the personages introduced are mere
simulacra of men and women, the types of moral qualities or
religious dispositions. They are abstractions which the genius of
Bunyan fails to inform with vitality sufficient to kindle the
imagination of the reader with a sense of their actual, living
and breathing existence. But in the Divine Comedy the personages
are all from real life, they are men and women with their natural
passions and emotions, and they are undergoing an actual
experience. The allegory consists in making their characters and
their fates, what all human characters and fates really are, the
types and images of spiritual law. Virgil and Beatrice, whose
nature as depicted in the poem makes nearest approach to purely
abstract and typical existence, are always consistently presented
as living individuals, exalted indeed in wisdom and power, but
with hardly less definite and concrete humanity than that of
Dante himself.

The scheme of the created Universe held by the Christians of the
Middle Ages was comparatively simple, and so definite that Dante,
in accepting it in its main features without modification, was
provided with the limited stage that was requisite for his
design, and of which the general disposition was familiar to all