In most people’s minds today, there is a common misunderstanding about the Middle Ages, based on two or three accepted ‘facts’ which are not actually true. Most people believe that mediaeval thinkers considered that the world was flat; most think that religion was vehemently opposed to scientific discovery; and many believe that ideas like other universes or life on other planets are strictly modern ideas which would never have appeared in mediaeval thought.
This, along with many other things, creates what Lewis called a ‘chronological snobbery’, the notion that because we have moved on from the Middle Ages and made various scientific discoveries which have changed our perceptions of the world, we are somehow ‘better’ and that the Middle Ages were ‘inferior’. But this conclusion, often unquestioned, is very uncertain in reality.
An example can be seen in Paris in the 13th-century. The Pope wrote to the university at the Sorbonne, where it was alleged that members of the arts faculty had come up with various radical ideas, mainly derived from Aristotle. At first, Bishop Tempier, whose job it was to look into this situation, made a list of many heretical propositions. What he was doing without realising it was undermining the authority of Aristotle as a source for mediaeval thought, and into that vacuum came a new way of looking at the universe which included contemplating the possibility of other planets and aliens.
In the 19th century, scientist and historian Pierre Duhem concluded that our common belief that the Renaissance had brought about a scientific revolution was incorrect: the notions of the later Middle Ages had in fact evolved over the years into later ideas - Bishop Tempier’s 1277 condemnations was one of the steps that had liberated Christian thinkers from the dogma Aristotle and had opened up the way to a more scientific view based on observation. One of these condemned ideas, for example, was the principle of Aristotelian thought that held that the ‘first cause’ (or God) could only have made one world.
The four elements of Earth, Air, Wind and Fire are well known enough as mediaeval ideas, but the principle of ‘kindly enclyning’, by which elements tended to gravitate towards one another, is less well known. According to this principle, a particle of Earth would naturally move towards another particle of Earth, and, philosophers concluded, as Earth was heavier than the other three elements, it would tend to ‘enclyne’ to the bottom or centre of the universe. Aristotle decided that other worlds or ‘collections of Earth’ couldn’t exist as they would be pulled towards our own, resulting in only one ‘Earth’.
Bishop Tempier disagreed: God was all-powerful. An elemental rule such as the notion that similar things gravitated towards similar things, was not senior to the creative power of God. It must be the case, therefore, that God may have made other worlds, other Earths.
Richard of Middleton wrote to Tempier, agreeing that it must be possible to have more than one universe: ‘God could have and could still now create another universe.’ According to Richard, this need not necessarily violate Aristotle’s principle if it could be accepted that the ‘Earth’ element of a second world would stay in an entirely separate universe. Then Aristotle would still be correct and these separate universes would have their own worlds.
William of Ware, a scholar of the early 14th century, forwarded the idea that these separate universes must have no way of interacting or they would violate the idea of Creation being a sole event, but if we accepted the idea that they could not in any way interact, they might still exist: in effect, there might be parallel universes.
Within the coming century, theologian and astronomer Nicholas of Cusa (1401 to 1464) believed that if people were able to leave the earth, they would find stars, planets, and moons similar to our own, even going so far as to imagine that these planets might have inhabitants: sun-dwellers would be bright and intellectual; moon-dwellers might be insane of ‘lunatics’.
All of this Lewis would have known about from his studies of the literature of the period, and, what’s more, it would have directly appealed not only to his imagination but to his imaginative need - he could use all of this to create wondrous other worlds of his own, but he could also use all this to forward the primary effect he sought to have upon readers: he could ‘snap them out of’ the dark world into which they had fallen, and place them in a parallel one, a world sufficiently recognisable to prompt an affinity but sufficiently different to urge transformation.
And that’s precisely what he did with Narnia.