I heard a conversation the other day between two Catholics about whether the earth is in the centre of the universe or not. The first one argued that it was reasonable to suppose that God would have placed the earth in such a special position, since mankind is uniquely valuable in this visible universe, and since earth was destined to be the venue for the Incarnation. He thought that the popular modern idea that earth is not in a spatially central position would have been very distressing for people at the start of our modern period, and must have led to a decline in Christianity.
The other speaker disagreed with this. He said that contrary to common belief, people in the middle ages had not thought that there was anything favourable about living at the centre of the universe. On the contrary, the centre was seen as a particularly unfavourable location: it was the sub-lunar sphere, the place of change and decay, so bad in fact that at the very centre of the centre was hell itself. This is the idea that C. S. Lewis develops in his book The Discarded Image, in which he explains that to the mediaeval mind, to live on earth was to be ‘outside the city walls’: an exile or a barbarian. St Thomas Aquinas says in his commentary on the De Caelo et Mundo (I wish I’d noted down the reference) that the centre of the universe is the least noble part because it is the least ‘formal’ part. The outermost sphere, he explains, contains everything else and so it is the most formal part – that is, it acts on the other parts, at least in the rarefied philosophical sense in which to contain is to exercise an act. The central spheres both contain and are contained. Only our sphere is contained and does not contain. Therefore because form is better than matter, the centre is the least noble location.
I don’t see why one shouldn’t hold both positions at the same time. That is, one could hold that philosophically speaking the centre is the least noble place, and thus suitable for a race under probation and for the punishment of sins, while also holding that given the way man spontaneously thinks, it would be a striking sign of God’s loving care for earth to be in the middle – a sign that we are the apple of His eye. Likewise we could contemplate the fittingness of the Incarnation from both perspectives: considering the earth as in the least noble place, we would see a new sign of the ‘condescension’ of the divine Word, who humbles Himself to live even here; considering our tendency to place a dramatic event in the midst of the crowd watching it, like a great wrestling match in a ring in the middle of the wrestling hall, it would be a sign of the unique greatness and drama of the Incarnation, that it should happen in the midst of the universe, while the angelic powers spread throughout the universe look on in wonder.
Of course, this all supposes that one is able to accept the statement of the Catechism of the Council of Trent that God placed the earth in the middle part of the universe, in media mundi parte…