The Medieval Model
How do you pronounce it? Using the ecclesiastical pronunciation, it’s odd CHAI-lows (odd as in “odd,” chai as in the tea, and lows as opposed to “highs”). The second syllable is emphasized.
Where did the name come from? I studied Latin in high school and college, and when I was working on my master’s at HCU, we did a deep dive on the Middle Ages, focusing in particular on what is called the “medieval model” of the universe.
Ever the “systemizers,” medieval thinkers envisioned the created order with the earth at the center, and concentric, invisible spheres (“heavens”) as you moved outwards. Each of these spheres held a “planet” (which simply means “wanderer”), starting with the moon and moving outward and upward through Mercury, Venus, etc. Beyond the seventh planet, Saturn, was the firmament, into which all the stars were placed.
Seven spheres, seven planets: “The Seven Heavens.”*
What does it mean? In Latin, ad means “to” or “moving in a direction towards.” And caelos means “heavens” (accusative plural). Ad caelos —> “moving away from the earth, upwards toward the heavens,” which is what Jesus did in the Ascension (ascendit ad caelos).
More than you wanted to know. But there you have it.
*In his book The Discarded Image, C.S. Lewis holds that while we now know the Medieval cosmology to be untrue, it still holds great value as a “a supreme medieval work of art.” It was a beautiful way for our forbears to understand God’s created order and is not to be confused with our modern conception of “astrology.”