Feast of St Domnina the Martyr and her Daughters
THE ARCHITECTURE of the Ptolemaic universe is now so generally known that I will deal with it as briefly as possible. The central (and spherical) Earth is surrounded by a series of hollow and transparent globes, one above the other, and each of course larger than the one below. These are the “spheres”, “heavens”, or (sometimes) “elements”. Fixed in each of the first seven spheres is one luminous body. Starting from Earth, the order is the Moon, Mercury, Venus, the Sun, Mars, Jupiter and Saturn; the “seven planets”. Beyond the sphere of Saturn is the Stellatum, to which belong all those stars that we still call “fixed” because their positions relative to one another are, unlike those of the planets, invariable. Beyond the Stellatum there is a sphere called the First Movable or Primum Mobile. This, since it carries no luminous body, gives no evidence of itself to our senses; its existence was inferred to account for the motions of all the others.
And beyond the Primum Mobile what? The answer to this unavoidable question had been given, in its first form, by Aristotle. “Outside the heaven there is neither place nor void nor time. Hence whatever is there is of such a kind as not to occupy space, nor does time affect it.” The timidity, the hushed voice, is characteristic of the best Paganism. Adopted into Christianity, the doctrine speaks loud and jubilant. What is in one sense “outside the heaven” is now, in another sense, “the very Heaven”, caelum ipsum, and full of God, as Bernardus says. So when Dante passes that last frontier he is told, “We have got outside the largest corporeal thing (del maggior corpo) into that Heaven which is pure light, intellectual light, full of love” (Paradiso, XXX, 38). In other words, as we shall see more clearly later on, at this frontier the whole spatial way of thinking breaks down. There can be, in the ordinary spatial sense, no “end” to a three-dimensional space. The end of space is the end of spatiality. The light beyond the material universe is intellectual light.
The dimensions of the medieval universe are not, even now, so generally realized as its structure; within my own lifetime a distinguished scientist has helped to disseminate error. The reader of this book will already know that Earth was, by cosmic standards, a point – it had no appreciable magnitude. The stars, as the Somnium Scipionis had taught, were larger than it. Isidore in the sixth century knows that the Sun is larger, and the Moon smaller than the Earth (Etymologies, III, 47-8), Maimonides in the twelfth maintains that every star is ninety time as big, Roger Bacon in the thirteenth simply that the least star is “bigger” than she. […]
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 realizing how such a universe must have affected those who believed in it. The recipe for such realization 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 center, really the lowest place; movement to it from whatever direction is downward movement. As a modern, you locate 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 height; 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 their distance in the modern, will turn out not to have the kind of importance 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 really important difference is that the medieval universe, while unimaginably large, was also unambiguously finite. And one unexpected result of this is to make the smallness of Earth more vividly felt. In our universe she is small, no doubt; 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’s maggior corpo is, quite simply and finally, the largest object in existence. The word “small” as applied to Earth thus takes on a far more absolute significance. Again, because the medieval universe is finite, it has a shape, the perfect spherical shape, containing within itself an ordered variety. Hence to look out on the night sky with modern eyes is like looking out over a sea that fades away into mist, or looking about one in a trackless forest – trees forever and no horizon. To look up at the towering medieval universe is much more like looking at a great building. The “space” of modern astronomy may arouse terror, or bewilderment or vague reverie; the spheres of the old present us with an object in which the mind can rest, overwhelming in its greatness but satisfying in its harmony. That is the sense in which our universe is romantic, and theirs was classical.
~C. S. Lewis, The Discarded Image