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.
But, more positively, it is at least possible that Lewis – despite not being an academic theologian himself – might have something to teach academic theologians about their own subject. Among other things, this may have to do with the way in which Lewis harnessed his imagination, reason, historical knowledge, wit, and considerable rhetorical gifts in a sustained effort to communicate the substance of his convictions to as wide an audience as possible. In its commendable quest for disciplinary purity and intellectual integrity, academic theology is actually in great danger of sealing itself within a very small, self-enclosed echo chamber in which experts talk to other experts while losing all contact with the outside world. Meanwhile, Lewis continues to sell millions of books a year and to shape the religious faith of thousands.
(2012-10-17). The Cambridge Companion to C. S. Lewis (Cambridge Companions to Religion) (p. 4). Cambridge University Press. Kindle Edition.