If literary art is ‘imitation’ in the sense used by Aristotle, to understand literature, let alone to judge it, requires of its reader some prior knowledge of the world it imitates. Lewis was a pioneer in what later French historians would call l’histoire des mentalités – the shifting history of human mental structures. The ‘image’ that we have ‘discarded’ is precisely the pre-modern understanding of the structure of the universe with the Earth as its centre, and with human beings the central reality of an Earth created by an omnipotent and immanent God. It is this universe, and not ours of infinite galaxies randomly distributed in an infinite space, that is reflected in medieval and Renaissance literature.
(2012-10-17). The Cambridge Companion to C. S. Lewis (Cambridge Companions to Religion) (p. 22). Cambridge University Press. Kindle Edition.
Locusts and Wild Honey 