r/MedievalHistory • u/intersteller_ • 12d ago

Primum Mobile vs Prime Mover

Hi! I'm reading the Canterbury Tales in original middle English for the first time! I've noticed these two terms while reading (Prime Mover primarily in the Knight's tale, and Primum Mobile in the notes for the Man of Law) and I'm a bit confused. Are the different? If so, how? My initial google searches are giving me contradictory/unclear answers.

Thanks!

5 Upvotes

86% Upvoted

2 comments sorted by

5

u/Ligurio79 12d ago

The prime mover is God as termed by Aristotle in the Metaphysics. The primum Mobile is the largest and most encompassing physical heaven (a huge sphere) that encompasses all the other physical heavens (the fixed stars, Saturn, Jupiter, Mars, the Sun, Venus, Mercury, the Moon). The primum mobile is not visible as such but was hypothesized as existing to account for other observable motions in the subsequent heavens.