"These facts are in themselves curiosities of mediocre interest. They become valuable only in so far as they enable us to enter more fully into the consciousness of our ancestors by realising how such a universe must have affected those who believed in it. The recipe for such realisation is not the study of books. You must go out on a starry night and walk about for half an hour trying to see the sky in terms of the old cosmology. Remember that you now have an absolute Up and Down. The Earth is really the centre, really the lowest place; movement to it from whatever direction is downward movement. As a modern, you located the stars at a great distance. For distance you must now substitute that very special, and far less abstract, sort of distance which we call heightl height, which speaks immediately to our muscles and nerves. The Medieval Model is vertiginous. And the fact that the height of the stars in the medieval astronomy is very small compared with distance in the modern, will turn out not to have the kind of importace you anticipated. For thought and imagination, ten million miles and a thousand million are much the same. Both can be conceived (that is, we can do sums with both) and neither can be imagined; and the more imagination we have the better we shall know this. The reality important difference is that the medieval universe, while unimaginably large, was also unabiguously finite. And one unexpected result of this is to make the smallness of Earth more vividly felt. In our universe she is small, no dount; but so are the galaxies, so is everything - and so what? But in theirs there was an absolute standard of comparison. The furthest sphere, Dante'