Primum Mobile (Primum Mobile) — The First Movable

The First Movable — carries no luminous body, inferred to explain all motion.

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. All power, movement, and efficacy descend from God to the Primum Mobile and cause it to rotate — and its rotation cascades downward through every sphere beneath it.

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.

LLM parallel: Training Algorithm (Backpropagation)

The first cause of all transformations in the model: itself invisible in the final artifact, inferred only from its effects. It sets every fixed weight in the descending chain, from the final layer down through the first — the model's own unmoved (but moving) mover.

Part of an interactive 3D tower of the Ptolemaic cosmos and its mirror in transformer architecture, built as a companion to the essay The Celestial Mirror: How Medieval Cosmology Reveals the Architecture of (Artificial) Intelligence.