the.com/unmoved mover

The thing that starts everything but needed no one to start it.

means a first cause that sets all other things into motion or change while itself remaining unchanged and uncaused by anything prior

from Straight out of Aristotle's Physics and Metaphysics, where it translates his phrase for the source of all motion in the cosmos — something that causes change by being an object of desire or thought, not by being pushed itself, the way a beloved can move a lover without lifting a finger. Medieval theologians, especially Aquinas, later borrowed the idea wholesale as one of the classic philosophical arguments for God's existence, cementing the phrase in English as shorthand for any first cause that itself needs no cause.

origin
Aristotle's answer to what kicks off motion itself
key trait
causes change while undergoing none itself
later use
Aquinas borrowed it to argue for God
not
a first domino, more like the table it sits on
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