Primum Mobile

The Latin term Primum Mobile (PREE-mum moe-BEE-leh) may be unfamiliar to some of our readers, so this page has been established to explain its origin. It finds its source in the Medieval view of the universe, often called the Ptolemaic System, since it was advanced by 2nd century astronomer Ptolemy.

This vision of the universe puts Earth at the center with the heavenly bodies revolving around it. There are ten globes circling the Earth, starting with the moon, with Mercury, Venus, the Sun, Mars, Jupiter, and Saturn following that. Next is the Stellatum, which are the stars. Then comes the Primum Mobile, or the "First Moveable."

The movement of the Primum Mobile causes movement in the lower globes. As for what moves the Primum Mobile itself, Aristotle gives us an answer in Metaphysics. The Primum Mobile moves out of its own love for God. C.S. Lewis explains, saying that "an object of desire moves those who desire it" (The Discarded Image).

Obviously, this version of our universe has been discarded (thus the title of Lewis' book), but that is not to say that it is not worth our attention. We would make a mistake to think that subscribers to this vision were stupid simply because science had not evolved long enough to develop a theory of gravity or technology advanced enough to record accurate observations of the universe. After all, for most of us, we know that the Earth revolves around the sun only because someone told us that it did. Such a theory is remarkably difficult to prove on your own.

In fact, we may admire these scientists for getting as much right as they did. Ptolemy was perfectly aware of the vastness of the universe, and he was quite correct regarding the order of the planets, even though the outer planets had not been discovered. His only major fault was putting the Earth at the center. Considering the popular beliefs that people from that time were Neanderthals with no sense of science, his beliefs about astronomy are remarkable.

But most interesting about the Ptolemaic System is what it says about the people living before the Renaissance. When they looked to the sky, they did not see a cosmic accident or random spots of light. They saw order and hierarchy. They saw a definitive plan in something that modern man sees as chaos. They saw a place teeming with life. How ironic, since this is the time of space travel, that we see the sky as so dead. Lastly, they saw faith.

This is important: their model of the universe was perfectly scientific and perfectly religious at the same time.

That sort of faith, interconnected with science, is something we have forgotten, but there is no reason for that. Had the Medievals the technology to see that the Earth rotated around the Sun, they could have rearranged their map quite easily without destroying the magic and imagination of it. Compare that to our own cold and sterile vision of the way our universe moves and works. Why is it that we must discard the soul of universe simply because we have moved the Sun to the center?

We at Primum Mobile Magazine cannot agree with the general layout of Ptolemy's model. Science has progressed enough that we know differently. But though our model looks more like the universe actually is, Ptolemy's certainly feels more right. It is in his universe we would rather live.

Suggested reading: Lewis, C. S. The Discarded Image. 1964.

Written by Paul Lytle